[0007]
The invention can be realized in the following aspects
or application examples.
[0008]
According to an aspect of the invention, there is
provided a sheet manufacturing apparatus including: a
screening unit that has first openings for screening a
defibrated material that is defibrating-processed; a
refining unit that has second openings having sizes equal to
or greater than sizes of the first openings and refines the
defibrated material passing through the screening unit by
causing the defibrated material to pass through the second
openings; and a deposition unit on which the defibrated
material passing through the refining unit is deposited.
[0009]
In such a sheet manufacturing apparatus, the defibrated
material passes through the first openings of the screening
unit. In this case, the defibr~ted material passing through
the screening unit may be in a state of being not uniformly
deposited, for example, by reason of clogging in a part of
the first openings. Then, the defibrated material passing
through the screening unit further passes through the second
openings. Since the sizes of the second openings are equal
to or greater than the sizes of the first openings, the
defibrated material passes through the second openings
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without clogging. Thus, the defibrated material can be
uniformly deposited. In addition, when the defibrated
material passing through the screening unit is further
delivered to the refining unit, the defibrated material may
be aggregated into a lump shape, but the lump-shaped
defibrated material can be refined by passing through the
second openings. As a result, .the refining unit can deposit
the defibrated material having good uniformity on the
deposition unit and such a sheet manufacturing apparatus can
manufacture a sheet having strength and good texture.
[0010]
In the sheet manufacturing apparatus according to the
invention, the sizes of the second openings may be greater
than the sizes of the first openihgs.
[0011]
In such a sheet manufacturing apparatus, it is possible
to reduce a possibility that the defibrated material passing
through the first openings of the screening unit remains
within the refining unit. Thus, in such a sheet
manufacturing apparatus, it is possible to prevent the
refining unit from being clogged by the defibrated material
(for example, entangled defibrated material) that does not
pass through the second openings.
[0 012]
In the sheet manufacturing apparatus accordin~ to the
J _____________________________________________________________________________________ _
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invention, the refining unit may be provided with a
plurality of the second openings and the sizes of the
plurality of second openings may be equal to each other.
[0013]
In such a sheet manufacturing apparatus, since the
sizes of the plurality of second openings are equal to each
other, it is possible to uniformly deposit the defibrated
material on the deposition unit by causing the defibrated
material to pass through the second openings.
[0014]
In the sheet manufacturing apparatus according to the
invention, the screening unit may be provided with a
plurality of the first openings and the sizes of the
plurality of first openings may be equal to each other.
[0015]
In such a sheet manufacturing apparatus, since the
sizes of the plurality of first openings are equal to each
other, it is possible to cause the size of the defibrated
material passing through the first openings of the screening
unit to fall in a predetermined range.
[0016]
In the sheet manufacturing apparatus according to the
--------
invention, the screening unit may be movable, the refining
unit may be movable, and the screening unit may move faster
than the refining unit.
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[00l7]
In such a sheet manufacturing apparatus, the screening
unit is likely to be clogged more than the refining unit.
Thus, fibers having sizes enough to pass through the first
openings may not pass through the screening unit by being
caught in a clogged portion. However, a centrifugal force
is increased with a moving speed of the screening unit made
faster than that of the refining unit and the fibers can
pass through the first openings. Furthermore, it is
possible to suppress that an amount of the defibrated
material passing through the first openings per unit time is
decreased due to the clogging.
[OOlB]
In the sheet manufacturing apparatus according to the
invention, the screening unit may be movable and the
screening unit may move faster than the refining unit.
[00l9]
In such a sheet manufacturing apparatus, the screening
unit is likely to be clogged more than the refining unit.
Thus, fibers having sizes enough to pass through the first
openings may not pass through the screening unit·by being
caught in a clogged portion. However, the centrifugal force
------·--------------
is increased with the moving speed of the screening unit
made faster than that of the refining unit and the fibers
can pass through the first openings. Furthermore, the
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8
refining unit can cause the fibers to pass therethrough by
using airflow from insides of the second openings and the
like even if the refining. unit is not moved.
[0020]
The sheet manufacturing apparatus according to the
invention may further include a supplying unit that supplies
resin bonding the defibrated material between the screening
unit and the refining unit.
[0021]
If resin is supplied to a transport unit connected to
the screening unit on an upstream side in a transport
direction of the defibrated material, the resin may adhere,
to a non-screened material (residue that does not pass
through the first openings) that is not screened in the
screening unit. Then, the resin adhering to the nonscreened
material is no longer used in the manufacturing of
the sheet thereafter and an amount of the resin is wasted.
Furthermore, even if the resin is supplied to the defibrated
material after passing through the refining unit, the fibers
and the resin are not uniformly mixed. It is possible to
mix the fibers and the resin in the middle of transporting
to the refining unit or in the refining unit and the resin
is not wasted by supplying the resin between the screening
unit and the refining unit.
[0022]
--------·
9
The sheet manufacturing apparatus according to the
invention may further include a defibrating unit that
performs a defibrating process on a defibration object and a
returning flow path that returns the defibrated material not
passing through the screening unit to the defibrating unit.
[0023]
In such a sheet manufacturing apparatus, it is possible
to perform the defibrating process on the residue (for
example, the residue including undefibrated pieces and the
defibrated material having a size greater than those of the
openings of the screening unit) that does not pass through
the screening unit in the defibrating unit. That is, the
undefibrated pieces can be ·used in the manufacturing of the
sheet without being discarded.
[0024]
The sheet manufacturing apparatus according to the
invention may further include a screening unit that screens
a defibrated material that is defibrating-processed by
causing the defibrated material to pass through first
openings, a refining unit that refines the defibrated
material passing through the screening unit, and an
depositing unit on which the defibrated material passing
through the refining unit is deposited.
[0025]
In such a sheet manufacturing apparatus, the defibrated
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10
material passes through the first openings of the screening
unit. In this case, the defibrated material passing through
the screening unit is in.a state of being not uniformly
deposited, for example, by reason of clogging in a part of
the first openings and the like. Then, the defibrated
material can be in a state of being further uniformed by
providing the refining unit that refines the defibrated
material passing through the screening unit. As a result,
it is possible to manufacture the sheet having the strength
and good texture.
[0026]
According to another aspect of. the invention, there is
provided a sheet manufacturing method including: a step of
screening a defibrated material that is defibratingprocessed
by first openings; a step of causing the
defibrated material passing through the first openings to
pass through second openings having sizes equal to or
greater than sizes of the first openings; and a step of
depositing the defibrated material passing through the
second openings.
[0027]
In such a sheet manufacturing method, it is possible to
manufacture the sheet having good texture.
[0 028 J
In the sheet manufacturing method, a plurality of the
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first openings and the second openings may be respectively
provided, the sizes of the plurality of first openings may
be equal to each other, and the sizes of the plurality of
second openings may be equal to each other.
[0029]
In the sheet manufacturing method, a screening unit
having the first openings and a refining unit having the
second openings may be movable, and the screening unit may
move faster than the refining unit.
[0030]
The sheet manufacturing method may further include a.
step of supplying resin that bonds the defibrated material
between the step of screening the defibrated material that
is defibrating-proce~sed by the ~irst openings and the step
of causing the defibrated material passing through the first
openings to pass through 'the secorid openings.
[0031]
The sheet manufacturing method may further include a
step of returning the defibrated material not passing
through the first openings to a defibrating unit in which a
defibration object is defibrating-processed.
Brief Description of Drawings
[0032]
[Fig. 1] Fig. 1 is a view schematically illustrating a
sheet manufacturing apparatus according to an embodiment.
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[Fig. 2] Fig. 2 is a view schematically illustrating a
defibrated material.
[Fig. 3] Fig. 3 is a view schematically illustrating
the defibrated material.
[Fig. 4] Fig. 4 is a view schematically illustrating an
undefibrated piece.
[Fig. 5] Fig. 5 is a perspective view schematically
illustrating a screening unit of the sheet manufacturing
apparatus according to the embodiment.
[Fig. 6] Fig. 6 is a plan view developing a net unit of
the screening unit of the sheet manufacturing apparatus
according to the embodiment.
[Fig. 7] Fig. 7 is a perspective view schematically
illustrating a refining unit of the sheet manufacturing
apparatus according to the embodiment.
[Fig. 8] Fig. 8 is a view schematically illustrating
the sheet manufacturing apparatus according to the
embodiment.
Description of Embodiments
[0033]
Hereinafter, a preferred embodiment of the invention
will be described in detail with refer~nce to the drawings.
----------------------------------------------------------
Moreover, the embodiment described below does not unduly
limit contents of the invention described in the claims. In
addition, not all of the elements that are described are
13
essential requirements of the invention.
[0034]
1. Sheet Manufacturing Apparatus
A sheet manufacturing apparatus according to the
embodiment w'ill be described with reference to the drawings.
Fig. 1 is a view schematically illustrating a sheet
manufacturing apparatus 100 according to the embodiment.
Moreover, for the sake of convenience, in Fig. 1, a
screening unit 40 and a refining unit 60 are simplified.
[0035]
As illustrated in Fig. 1, the sheet manufacturing
apparatus 100 includes a crushing unit 10, a defibrating
unit 20, a classifying unit 30, the screening unit 40, a
resin supplying unit 50, the refining unit 60, and a sheet
forming unit 70.
[0036]
The crushing unit 10 cuts a raw material such as a pulp
sheet or a sheet (for example, waste paper of A4 size) to be
small pieces in the air. Shapes and sizes of the small
pieces are not particularly limited, but, for example, are
several em squares. In the illustrated example, the
crushing unit 10 has crushing blades 11 and it is possible
to cut the fed raw material by the crushing blades 11. The
crushing unit 10 may have an automatic fe~ding unit (not
illustrated) for continuously feeding the raw material.
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[0037]
The small pieces that are cut by the crushing unit 10
are transported to the defibrating unit 20 via a first
transport unit 81 after being received by a hopper 5. The
first transport unit 81 communicates with an inlet 21 of the
defibrating unit 20. Shapes of the first transport unit 81
and second to sixth transport units 82 to 86 described below
are, for example, a tubular.
[0038]
The defibrating unit 20 performs a defibrating process
on the small pieces (defibration object). The defibrating
unit 20 generates fibers 2 that are untangled in fibrous by
performing the defibrating process on the small pieces.
Here, Figs. 2 and 3 are views schematically illustrating the
fibers 2 that are untangled.
[0039]
Here, the "defibrating process" refers that the small
pieces formed by binding a plurality of fibers are untangled
to the fibers one by one. The "defibrated material" is
referred to as one passing through the defibrating unit 20.
The "defibrated material" may include resin (resin for
bonding a plurality of fibers to each other) particles, ink
particles such as ink, tonet, and blur-preventing agent
which are separated from the fibers when the fibers are
untangled in addition to the untangled fibers 2. In the
15
following description, the 11 defibrated materialn is at least
a part ~f the defibrated material passing through the
defibrating unit 20 and may be one to which other matters
are mixed after passing through the defibrating unit 20.
One of the defibrated material that is defibrating-processed
by the defibrating unit 20, which is supplied to the
screening unit 40 described below, is referred to as
ndefibrated material that is defibrating-processedn. _ The
shape of the fiber 2 that is untangled is a string shape or
a ribbon shape. However, as illustrated in Fig. 2, the
untangled fiber 2 is present in a state (independent stat)
of not being entangled in other untangled fibers, but as
illustrated in Fig. 3, may be present in a state (state of
forming a so-called 11 lumpn) of being lump-shaped by being
entangled in other untangled fibers 2. A length (length of
the untangled fiber 2 in a longitudinal direction,
hereinafter, also referred to as nfiber lengthn) of the
untangled fiber 2 is, for example, 50 ~m or more and lO~m or
less. In addition, the nfiber lengthn is a distance between
both ends when pulling both ends of independent one fiber
and then placing the fiber substantially linearly so as not
to be cut if necessary. A shape of cross section of the
1------- ----
untangled fiber 2 is not particularly limited, may be a
polygonal, or may be circular or elliptical. In the
following description, the 11 fiber" mainly indicates the
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untangled fiber.
[0040]
Furthermore, the ndefibrated materialn may include an
"undefibrated piecen. As illustra,ted in Fig. 4, the
"undefibrated piecen is debris that is obtained by tearing
the small pieces fed into the defibrating unit 20 without
defibrating the small pieces in fibrous. That is, an
undefibrated piece 4 is the small pieces that are not
defibrated even if the small pieces are defibratingprocessed
in the defibrating unit 20. A shape of the
undefibrated piece 4 is not specifically limited, but a size
of the undefibrated piece 4 is, for example, 1 mm or more
and 10 mm or less when representing in a mesh sieve for
measurement test by a sieving method. Moreover, the
"defibrating processn means to be fed and discharged the
defibration object (small piece) into and from the
defibrating unit 20 that is driven and as described above,
may include a case where the undefibrated piece 4 that is
not defibrated is generated.
[0041]
The defibrating unit 20 separates the resin particles,
the ink particles such as ink, 'toner, and blur-preventing
agent, and the like which are adhered to the small pieces
from the fibers. The resin particles and the ink particles
are discharged from an outlet 22 together with the
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defibrated material.
[0042]
The defibrating unit 20 performs defibrating process on
the small pieces fed from the inlet 21 by a rotary blade.
The defibrating unit 20 performs defibrating in the dry-type
in the air.
[0043]
A rotational speed of the defibrating unit 20 is 3000
rpm or greater and 10000 rpm or less. If the rotational
speed is less than 3000 rpm, a ratio of the undefibrated
piece 4 may be increased. If the rotational speed is
greater than 10000 rpm, a ratio of the fiber having a
relatively short length may be increased and it causes
lowering of the strength of the sheet that is manufactured.
[0044]
It is preferable that the defibratirig unit 20 has a
mechanism for generating the airflow. In this case, the
defibrating unit 20 suctions the small pieces from the inlet
21 by the airflow generated by the defibrating unit 20
together ~ith the airflow, perfor~s defibrating process, and
can transport the small pieces to the outlet 22. As
illustrated in Fig. 1, the defibrated material discharged
from the outlet 22 is fed into the classifying unit 30 via
the second transport unit 82. Moreover, when using the
defi~rating unit 20 that does not have the airflow
J:----------------------------------------------------------------------------------~
18
generating mechanism, a mechanism for generating the airflow
that guides the small pieces to the inlet 21 may be provided
on an outside.
[0045]
The classifying unit 30 separates and removes the resin
particles and the ink particles from the defibrated material.
As the classifying unit 30, an airflow classifier is used.
The airflow classifier is provided to generate a whirling
airflow, separate the resin particles and the ink particles
by the centrifugal force, the size, and the density thereof,
and can adjust classification points by adjusting the speed
of the airflow and the centrifugal force. Specifically, as
the classifying unit 30, cyclone, elbow jet, eddy classifier,
and the like are used. Particularly, since the cyclone is
simple in structure, it is possible to appropriately use as
the classifying unit 30. Hereinafter, a case where as the
classifying unit 30, the cyclone is used is described.
[0046]
The classifying unit 30 has an inlet 31, a cylindrical
unit 32 that is connected to the inlet 31, an inverse cone
unit 33 that is positioned below the cylindrical unit 32 and
is connected to the cylindrical unit 32, a lower outlet 34
that is provided a lower center of the inverse cone unit 33,
and an upper outlet 35 that is provided in an upper center
of the cylindrical unit 32.
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[0047]
In the classifying unit 30, the airflow carrying the
defibrated material introduced from the inlet 31 is changed
into a circumferential movement by the cylindrical unit 32
having an outer diameter of substantially 100 mm or greater
and 300 mm or less. Thus, the centrifugal force is applied
to the introduced defibrated material and the classifying
unit 30 separates the defibrated material into a first
classified material (fiber 2 and the undefibrated piece 4)
and a second classified material (resin particles and the
ink particles) of which the size and density are lower than
the first classified material. The first classified
material is discharged from the lpwer outlet 34 and is
introduced into an inlet 46 of the screening unit 40 via the
third transport unit 83. On the other hand, the second
classified material is discharged from the upper outlet 35
to the outside of the classifying unit 30 via the fourth
transport unit 84. As described above, since the resin
particles are discharged to the outside by the classifying
unit 30, even if the resin is supplied by the resin
supplying unit 50 described below, it is possible to prevent
the resin from excessively being supplied with respect to
·--------------------------------
the defibrated material.
[0048]
Moreover, it is described that the first classified
20
material and the second classified material are separated by
the classifying unit 30, it is not translated to be
completely sep~rated. The defibrated material having a
relatively small size in the second classified material or
low density in the first classified material may be
discharged to the outside together with the second
classified ~aterial. The defibrated material having a
relatively high density or entangled in the first classified
material may be introduced into the screening unit 40
together with the first classified material. In addition,
if the raw material is a pulp sheet rather than a waste
paper, since the defibrated material qorresponding to the
second classified material is not included, the sheet
manufacturing apparatus may have no classifying unit 30.
Thus, materials that are intr.oduced into the screening unit
40 is not only the defib~~ted'mat~rial classified by the
classifying unit 30. Thus, in thS ~resent application, the
defibrated material, which passes through the defibrating
unit 20 and is introduced into the screening unit 40, is
referred to as "defibrated material that is defibratingprocessed"
and there is a case where the resin particles or
the ink particles of small amount enter the defibrated
---·--------------~-----~-- ·---------------
material in addition to the untangled fiber 2 or the
undefibrated piece 4.
[0049]
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The screening unit 40 screens the defibrated material
that is defibrating-processed into a "passed material" that
passes through first openings 42 of the screening unit 40
and a ''remaining material" that does not pass through the
first openings 42 in the air. Hereinafter, the screening
unit 40 will be described in detail.
[0050]
As the screening unit 40, a sieve (screen) is used.
Here, Fig. 5 is a perspective view schematically
illustrating the screening unit 40. Fig. 6 is a plan view
(development view) developing a net unit 41 of the screening
unit 40. As illustrated in Fig. 5, the screening unit 40
has the net unit 41, disk units 44 and 45, an inlet 46, and
an outlet 47. The screening unit 40 is a rotary sieve in
which the net unit 41 is rotated around a rotational axis Q
by a motor (not illustrated) . The net unit 41 is rotated
and thereby the defibrated material having a size in the
defibrated material within the net unit 41, which is capable
of passing through the first openings 42, passes through the
first openings 42 and the defibrated material having a size,
which is not capable of passing through the first openings
42, does not pass through the first openings 42.
[0051]
The net unit 41 of the screening unit 40 has a
plurality of first openings 42. The net unit 41 is
22
configured of a plain weave wire mesh, a welded wire mesh,
or the like. The net unit 41 has the wire mesh to be in a
cylindrical shape and an inside of the cylinder is hollow.
Moreover, since the cylindrical shape is difficult to be a
perfect circle, the cylindrical shape includes an elliptical
shape rather than the exact circle and also includes a
polygonal shape.
[0052]
Moreover, as the screening unit 40, expanded metal that
is formed by extending a metal plate in which cut lines are
run, and a perforated metal in which holes are formed in a
metal plate by a press machine may be used instead of the
net unit 41 configured of the wire mesh. If the expanded
metal is used, the first openings 42 are holes that are
formed by extending the cut lines in the metal plate. If
the perforated metal is used, 'the first openings 42 are
holes that are formed in.the metal plate by the press
machine. In addition, a member having the first openings 42
may be made of a material other than metal.
[0053]
The first openings 42 provided in the net unit 41 of
the screening unit 40 are eyes of the net unit 41. As
illustrated in Fig. 6, the net unit 41 has a plurality of
line portions 43 having a linear shape made of metal and the
first opening 42 is a portion surrounded by the line
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portions 43. A shape of the fir~t opening 42 is not
specifically limited as long as the screening unit 40
functions as the sieve and may be a circular shape, an.
elliptical shape, and the like, but in the example
illustrated in Fig. 6, the shape is square. It is
preferable that shapes or sizes of a plurality of first
openings 42 are equal to each other. It is preferable that
the plurality of first openings 42 are uniformly disposed
with good uniformity.
[0054]
Moreover, the "shape of first opening" is a planar
shape of the first opening 42 when developing the
cylindrical net unit 41 if the net unit 41 is the
cylindrical shape. The description about the abovedescribed
first opening is similar to a "second opening"
described below.
[0055]
It is preferable that a mesh of the net unit 41 of the
screening unit 40 'is 300 ~m or greater and 2000 ~m or less.
If the mesh is less than 300 ~m, since the length of the
fiber is short, cross portions of the fiber and the fiber
increase. Since the number of pieces of resin bonding the
-------·
fiber and the fiber is hot limit~d, portions in which the
fibers are not bonded to each other are present and the
strength of the manufactured sheet may be lowered. If the
I
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mesh is equal to or greater than 2000 ~m, a possibility that
the undefibrated piece 4 that is not defibrated passes
through the first openings 42 increases and texture of the
manufactured sheet may be deteriorated.
[0056]
Moreover, as illustrated in Fig. 6, the "mesh" has a
size A between adjacent line portions 43 when developing the
net unit 41. If the shape of the first opening 42 is the
square, the mesh is a length of one side of the square.
[0057]
The disk units 44 and 45 of the screening unit 40 ar~
disposed in two openings formed in end portions by making
the net unit 41 be the cylindrical shape. The inlet 46 into
which the defibrated material that is defibrating-processed
is introduced is provided in the disk unit 44 and the outlet
47 from which the remaining material is discharged is
provided in the disk unit 45. When the screening unit 40 is
rotated, the net unit 41 is roiated and the disk units 44
and 45, the inlet 46, and the outlet 47 are not rotated.
The disk units 44 and 45 come into contact with the end
portions of the net unit 41 so that the net unit 41 can be
rotated. The disk units 44 and 45, and the net unit 41 come
into contact with each other without a gap, and thereby the
defibrated material within the net unit 41 is prevented from
being leaked to the outside. Positions of the inlet 46 and
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the outlet 47 are not specifically limitedr but in the
example illustrated in Fig. 5 1 are positioned in positions
shifted from the rotational axis Q of the screening unit 40.
Specifically/ in the example illustrated in Fig. 5r the
inlet 46 is provided vertically above the rotational axis Q
and below the uppermost portion of the net unit 41 in a
vertical direction. The outlet 47 is provided vertically
below the rotational axis Q and above the lowermost portion
of the net unit 41 in the vertical direction. The
defibrated material that does not pass through the first
openings 42 remains on an inside of the net unit 41. It is
possible to supply the defibrated material to a space in
which the defibrated material does not remain by positioning
the inlet 46 above the rotational axis Q in the vertical
direction. Thus 1 the defibrated material does not remain in
the position of the inlet 46. In addition/ since the
defibrated material that does not pass through the first
openings 42 remains below the rotational axis Q in the
vertical direction/ the defibrated material is likely to be
discharged by providing the outlet 47 below the rotational
axis Q in the vertical direction. In addition/ diameters of
the inlet 46 and the outlet 47 are smaller tha·n a radius of
the cylinder of the net unit 41. Thusr even if the
defibrated material supplied from the inlet 46 is
excessively increased/ the inside of the net unit 41 is not
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filled with the defibrated material. In addition, the
defibrated material is suppressed to be discharged from the
outlet 47 without being sufficiently screened.
[0058]
The net unit 41 of the screening unit 40 is movable. In
Fig. 5, the net unit 41 can be rotated around the rotational
axis Q. When the net unit 41 is rotated, the first openings
42 also are rotated. A rotational speed of the net unit 41
is, for example, 50 rpm or greater and 800 rpm or less. It
is preferable that a moving speed of the net unit 41 of the
screening unit 40 is greater than a moving speed of a net.
unit 61 of the refining unit 60. That is, the net unit 41
of the screening unit 40 is rotated faster than the net unit
61 of the refining unit 60. Here, the "moving speed" can be
replaced to the rotational speed of the net units 41 and 61
if the net units 41 and 61 are rotated. That is, the
rotational speed of the net unit 41 of the screening unit 40
is faster than the rotational speed of the net unit 61 of
the refining unit 60. Moreover, the net unit 41 may be
moved in a horizontal direction or the vertical direction in
addition to the rotation. Thus, the "movement" includes
rotation, linear movement, pendulum-like reciprocation, and
the like, the "moving speed" includes the moving speed, a
frequency, and a vibration frequency, in respective
direction. The description about the "movement" is similar
27
to the 0 Second opening 0 described below.
[0059]
In a state where the screening unit 40 is rotated
around the rotational axis Q, the defibrated material that
is defibrating-processed is introduced from the inlet 46
into the screening unit 40. Then, the net unit 41 is
rotated and thereby the defibrated material passing through
the first openings 42 is discharged to the outside of the
screening unit as the passed material (screened material) .
The passed material is mainly formed of fibers shorter than
the size of the mesh of the first opening 42. Furthermore,
the defibrated material that does not pass through the first
opening 42 is discharged from the outlet 47 without passing
through the first opening 42. The remaining material is the
" fiber, the undefibrated piece 4, or the lump having a length
which does not pass through the first opening 42. As
described above, the screening unit 40 can screen the fiber
(passed material) having a length shorter than a
predetermined length from the defibrated material that is
defibrating-processed by the net unit 41 having the first
openings 42.
[0060]
i----·
As illustrated in Fig. 1, the remaining material not
passing through the first openings 42 of the screening unit
40 is discharged from the outlet 47, is transported to the
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hopper 5 via the fifth transport unit 85, and is returned to
the defibrating unit 20 gain.
[0061]
The passed material passing through the first openings
42 of the screening unit 40 is transported from the hopper 5
to an inlet 66 of the refining unit 60 via the sixth
transport unit 86. A supply port 51 for supplying the resin
bonding the fibers to each other (bonding defibrated
materials to each other) is provided in the sixth transport
unit 86.
[0062]
The resin supplying unit 50 supplies the resin from the
supply port 51 to the sixth transport unit 86 in the air.
That is, the resin supplying unit 50 supplies the resin to a
path (between the screening unit 40 and the refining unit
60) in which the passed material passing through the first
openings 42 is directed from the screening unit 40 to the
refining unit 60. The resin supplying unit 50 is not
specifically limited as long as the resin is supplied to the
sixth transport unit 86 and a screw feeder, a circle feeder,
and the like are used.
[0063]
Moreover, a mechanism for mixing the defibrated
material and the resin is not limited to a turbo blower and
may be that stirs the defibrated material such as a juicer
-~ I
I
I
_,______________ _________ ~!
29
mixer and the resin by a blade rotating at a high speed or
may be one that uses rotation of a container such as a vshaped
mixer.
[0064]
The resin supplied to the resin supplying unit 50 is
resin for bonding a plurality of fibers. The plurality of
fibers are not bonded at the time point that the resin is
supplied to the sixth transport unit 86. The resin is cured
and bonds the plurality of fibers when passing through the
sheet forming unit 70 described below.
[0065]
The resin supplied from the resin supplying unit 50 is
thermoplastic resin or thermosetting resin, and may include
AS resin, ABS resin, polypropylene, polyethylene, polyvinyl
chloride, polystyrene, acrylic resin, polyester resin,
polyethylene terephthalate, polyphenylene ether,
polybutylene terephthalate, nylon, polyamide, polycarbonate,
polyacetal, polyphenylene sulfide, polyether ether ketone,
and the like. Those resins may be used singly or may be
used by being appropriately mixed.
[0066]
The resin supplied from the resin supplying unit 50 may
be fibrous or may be powder. If the resin is fibrous, it is
preferable that a length of the fiber of the resin is equal
to or less than the fiber length of the fiber 2.
30
Specifically, the fiber length of the resin is preferably
equal to or less than 3 mm and is further preferably equal
to or less than 2 mm. If the fiber length of the resin is
greater than 3 mm, the resin may not pass through second
openings 62 of the refining unit 60 and is unlikely to be
uniformly mixed to the fiber 2. If the resin is powder, a
particle diameter of the resin is preferably 1 ~m or greater
and 50 ~m or less, and is further preferably 2 ~m or greater
and 20 ~m or less. If the particle diameter of the resin is
less than 1 ~m, a bonding force bonding the fibers 2 to each
other may be lowered. If the particle diameter of the re~in
is greater than 20 ~m, the fiber 2 and the resin are
unlikely to be mixed without uniformity, an adhesion force
to the fiber 2 is lowered, and then the resin may be
separated from the fiber 2.
[0067]
An amount of the resin supplied from the resin
supplying unit 50 is appropriately set in compliance with a
type of the sheet that is manufactured. A coloring agent
for coloring the fiber 2 or an aggregation preventing agent
for preventing aggregation of the fibers 2 may be supplied
in compliance with the type to sheet that is manufactured in
addition to the resin bonding the fibers 2. The resin that
is supplied is mixed to the passed material passing through
the first openings 42 by a mixing unit (not illustrated)
31
provided within the sixth transport unit 86. The mixi.ng
unit generates the airflow for transporting the passed
material and the resin to the refining unit 60 while mixing
the passed material and ~he resin. As illustrated in Fig. 3,
the passed materials may be entangled in each other when
passing through the sixth transport unit 86.
[0068]
The refining unit 60 refines the engaged passed
material. Furthermore, the refining unit 60 refines the
engaged resin if the resin supplied from the resin supplying
unit 50 is fibrous. In addition, the refining unit 60
uniformly deposits the passed material or the resin on a
deposition unit 72 described below. That is, the term
0 refiningo includes an operation of separating entangled
fibers one by one or an operation of uniformly depositing
the fibers. Moreover, the fibers are uniformly deposited if
the fiber~ are not entangled.
[0069]
As the refining unit 60, the sieve is used. Here, Fig.
7 is a perspective view schematically illustrating the
refining unit 60. As illustrated in Fig. 7, the refining
unit 60 is a rotary-type sieve that can be rotated by a
motor (not illustrated) . Here, the o sieve o used as the
refining unit 60 may not have a function of screening a
specific object. That is, the 0 Sieve 0 that is used as the
i
I
I
i
I
J~-------------------------------------------------1
32
refining unit 60 means a sieve that includes the net unit 61
having a plurality of second openings 62. The refining unit
60 may discharge all the defibrated material and the resin
introduced into the refining unit 60 from the second
openings 62 to the outside.
[0070]
The refining unit 60 has the net unit 61, disk units 64
and 65, and the inlet 66. The refining unit 60 is different
from the screening unit 40 in that an outlet (portion
corresponding to the outlet 47 of the screening unit 40) is
not provided. Hereinafter, in the description of the
refining unit 60, description of portions having the same
shapes as the screening unit 40 will be omitted.
[0071]
The net unit 61 of the refining unit 60 has the
plurality of second openings 62. A size of the second
opening 62 is equal to or greater than the size of the first
opening 42. That is, the size of the second opening 62 is
equal to the size of the first opening 42 or is greater thari
the size of the first opening 42. However, the upper limit
of the size of the second opening 62 is 5 mm. It is
possible to cause the entangled· fibers to pass through the
second opening 62 without causing the lump to pass through
the second opening 62 by making the size of the second
opening 62 be equal to or less than 5 mm.
33
[0072]
Since the passed material passing through the first
opening 42 can pass through the second opening 62, the
second opening 62 is not clogged. In addition, even if the
fibers and the resin entangled.within the sixth transport
unit 86 are present after passing through the first opening
42, the fibers and the resin are untangled when passing
through the second opening 62. Thus, the fibers and the
resin passing through the second opening 62 are deposited on
the deposition unit 72 described below with a uniform
thickness and density. Moreover, if the first opening 42
and the second opening 62 have the same size, the net unit
41 and the net unit 61 can use the same net unit. If the
second opening 62 is greater than the first opening 42, it
is possible to lower a possibility that the second opening
62 is clogged. In addition, since all or almost all of the
passed material introduced into the refining unit 60 passes
through the second opening 62, the ~emaining material
remaining in the refining unit 60 without passing through
the second opening 62 is little. Thus, the portion
corresponding to the outlet 47 of the screening unit 40 is
not present in the refining unit 60 and a flow path for
returning the defibrated material, which does not pass
through the refining unit 60 to the defibrating unit 20, is
not present. That is, a flow path communicating between the
34
refining unit 60 and the defibrating unit 20 is not provided.
[0073]
Moreover, the ~size of the opening~ is an area of the
opening in a state where the net units 41 and 61 are
developed, as illustrated in Figs. 5 and 7, if the net units
41 and 61 are the cylindrical shape. Specifically, if the
net unit 41 is made of the wire mesh (further specifically,
the shape of the openings 42 and 62 is square), the ~size of
the opening~ is may be the mesh of the net units 41 and 61.
Furthermore, if the shape'of the openings 42 and 62 is a
circular shape, the ~size of the opening~ is may be a
diameter of the openings 42 and 62. If the shape is one
other than the square or the circular shape, the size may be
a dimension of a portion that has the greatest dimension.
Moreover, ~equal to or greater than the size of the opening~
refers that the size of the opening is equal to or greater
than the size thereof.
[0074]
The net unit 61 of the refining unit 60 is movable.
Specifically, as illustrated in F~g. 7, the net unit 61 is a
cylindrical shape and is ~otated around the rotational axis
Q. When the net unit 61 is rotated, the second openings 62
are also rotated. A rotational speed of the net unit 61 is,
for example, 30 rpm or greater and 600 rpm or less. That is,
the rotational speed of the net unit 41 is faster than the
35
rotational speed of the net unit 61. Since the defibrated
material having a size greater than that of the mesh are
also included in the net unit 41, the defibrated material
having a size smaller than the size of the mesh may be
inhibited to pass through the mesh .. Thus, the defibrated
material is likely to pass through the first openings 42 as
the rotational speed of the net unit 41 is increased. On
the other hand, since the size of the opening of the net
unit 61 is equal to or greater than the size of the opening
of the net unit 41, the defibrated material is likely to
pass through the second openings 62 even if the rotational
speed thereof is slower than the net unit 41.
[0075]
In a state where the refining unit 60 is rotated around
the rotational axis Q, a mixture of the passed material
(fiber) and the resin passing through the screening unit 40
is introduced from the inlet 66 into the refining unit 60.
The mixture introduced into the refining unit 60 is moved on
the net unit 61 side by the centrifugal force. As described
above, the mixture introduced into the refining unit 60 may
include the engaged resin or the resin and the entangled
fibers or the resin is refined by the net unit 61 that is
rotated in the air. Then, ~rttangled fiber or the resin
passes through the second openings 62. The fiber and the
resin passing through the second openings 62 pass through
'
~ I
I
i
36
the air and are uniformly deposited in the deposition unit
72 described below.
[0076]
Moreover, "entangled fibers being untangled" includes a
case where the entangled fibers are completely untangled
(case of a state where all fibers are untangled) and a case
where a part of the entangled fibers is untangled to an
extent that the entangled fibers pass through the second
openings 62. The means that "the engaged resin being
untangled" are similar to the above description. Moreover,
if the defibrated material has a size equal to the mesh of
the second opening 62, even if the defibrated material
passing through the second opening 62 is entangled, there is
no problem in the texture of the defibrated material. In
addition, "uniformly deposited" refers that the deposited
defibrated materials are deposited in the same thickness and
the same density. However, since all the deposited
materials are not manufactured as the sheet, a portion to be
the sheet may be uniform. Terms "not uniformly deposited"
refers that the deposited material is not uniformly
deposited.
[0077]
The defibrated material and the resin passing through
the second openings 62 of the refining unit 60 are deposited
in the deposition unit 72 of the sheet forming unit 70. As
37
illustrated in Fig. 1, the sheet forming unit 70 has the
deposition unit 72, tension rollers 74, a heater roller 76,
tension rollers 77, and a winding roller 78. The sheet
forming unit 70 forms the sheet by using the defibrated
material and the resin passing through the refining unit 60.
Hereinafter, the sheet forming unit 70 will be described in
detail.
[0078]
The deposition unit 72 of the sheet forming unit 70
·deposits the defibrated material and the resin by receiving
the defibrated material and the resin passing through the
second openings 62 of the refining unit 60. The deposition
unit 72 is positioned below "the refining unit 60. The
deposition unit 72 is provided to receive the defibrated
material and the resin passing through the second openings
62 and, for example, is a mesh belt. A mesh that is
tensioned by the tension rollers 74 is formed in the mesh
belt. The deposition unit 72 is moved by rotating the
tension rollers 74. The defibrated material and the resin
are continuously fall from the refining unit 60 and a web
having a uniform thickness is formed on the deposition unit
72 while the deposition unit 72 is continuously moved.
------------------------
[0079]
Moreover, even not illustrated, a suction device, which
is positioned below the refining unit 60 via the deposition
~-
·--------------------------------------------------~~
38
unit 72 and generates the airflow (airflow from the refining
unit 60 to the deposition unit 72) downward, may be provided.
Thus, it is possible to suction the defibrated material and
the resin dispersed in the air and to increase a discharge
speed from the refining unit 60. As a result, it is
possible to increase productivity of the sheet manufacturing
apparatus 100. In addition, it is possible to form a
downflow in a falling path of the defibrated material and
the resin and to prevent the defibrated material or the
resin from being entangled during falling by the suction
device.
[0080]
A material of the mesh belt used as the deposition unit
72 of the sheet forming unit 70 is metal, resin, nonwoven,
and the like. A hole diameter (diameter) of the mesh belt
is, for example, 60 ~m or greater and 250 ~m or less. If the
hole diameter of the mesh belt is less than 60 ~m, it may be
difficult to form stable airflow by the suction device
described above. If the hole diameter of the mesh belt is
greater than 250 ~m, since the fibers enter between the
meshes, unevenness of a surface of the sheet that is
manufactured may increase.
[0081]
The defibrated material and the resin deposited on the
deposition unit 72 of the sheet forming unit 70 are heated
39
and pressed by passing through the heater roller 76 along
with the movement of the deposition unit 72. The resin
functions as a bonding agent and bonds the fibers to each
other by heating/ the fibers are thinned by pressing 1 the
surface thereof is smoothed by passing through a calendar
roller (not illustrated) 1 and then a sheet P is formed. In
the illustrated example 1 the sheet P is wound around the
winding roller 78.
[0082]
As described above/ it is possible to manufacture the
sheet P.
[0083]
The sheet manufacturing apparatus 100 has the following
effects.
[0084]
The defibrated material passes through the first
openings 42 of the screening unit 40 and then the defibrated
material that does not pass through the first openings 42 is
screened. Then1 the defibrated material having the size
passing through the first openings 42 is aligned. However/
since the first openings 42 may be portions through which
the defibrated material does. not pass due to clogging/ the
-------------------1
passed defibrated material is deposited with non-uniform
density. Thus/ the defibrated material passes through the
second openings 62 of the refining unit 60. Since the size
I
I
I
I
40
of the opening of the second opening 62 is equal to or
greater than the size of the opening of the first opening 42,
the defibrated material passing through the first opening 42
is not clogged in the second opening 62. Thus, the
defibrated material passing through the second openings 62
can be deposited on the deposition unit 72 with uniform
thickness and density. In addition, the defibrated material
that is gathered in the process of transporting from the
screening unit 40 to the refining unit 60 can also be
untangled by passing through the second openings 62. As a
result, the sheet manufacturing apparatus 100 can
manufacture the sheet with high strength and good texture.
Moreover, the effects of th~ present application are
particularly good in a paper described below. In the paper
manufacturing apparatus of the related art, since it is not
possible to deposit the defibrated material with uniform
thickness and density, it is not possible to manufacture a
forming material with thin thickness and high strength
required to the paper. In the present application, in a
case of the paper, it is possible to manufacture the paper
with thin thickness, high strength, and good texture, and to
solve the problem in the dry-type paper manufacturing
apparatus. The effects exert in the paper, but also in
nonwoven fabric, an external shape is good without being
immediately pulled out.
41
[0085]
Here, in PTL 1, only one of the screening unit 40 and
the refining unit 60 of the present application is present.
If only one is present, the defibrated material is in a
state of passing through the screening unit 40 of the
present application and the defibrated material is deposited
non-uniformly due to the clogging. Thus, it is possible to
manufacture the sheet favorably in the present application.
Moreover, in PTL 1, two forming drums are provided, but the
defibrated material that passes through one opening is not
transported to the other side and respectively do not have
functions of the screening unit and the refining unit.
[0086]
Furthermore, two screening units 40 are used and the
opening of the screening unit on a downstream side is
smaller than the opening of an upstream side in the
transport direction of the defibrated material. In this
case, clogging of the opening also occurs in the screening
unit on the downstream side and the defibrated material is
deposited non-uniformly. Thus, there is no effect even
though two screening units are provided and the refining
unit having the effect to untangle the defibrated material
or the effect to deposit uniformly the defibrated material
is required on the downstream side.
[0087]
42
Moreover, "texture" is a quality of the sheet and,
specifically, as illustrated in the following Experimental
Examples, the texture refers a degree (extent) of a
difference in density that is viewed when irradiating the
sheet with light from a back surface of the sheet. That is,
the "sheet having good texture" refers a sheet having small
difference in the density.
[0088]
Here, it is also conceivable to reduce the ratio of the
undefibrated piece 4 by increasing the rotational speed of
the defibrating unit. However, if the rotational speed of
the defibrating unit is increased, energy (defibrating
energy) consumed in the defibrating unit is increased and it
is not preferable in the viewpoint of energy saving. In
addition, if the rotational speed of the defibrating unit is
increased, the ratio of the short fiber is increased,
bonding strength of the defibrated material is weakened, and
thereby the strength of the sheet may be lowered. In the
sheet manufacturing apparatus 100, it is possible to prevent
the strength of the sheet from lowering due to the short
fiber while suppressing defibrating energy.
[0089]
Moreover, the "strength of the sheet" refers a tensile
structure of the sheet and specifically, as illustrated in
the following Experimental Examples, is strength that is
43
evaluated by using a tensile strength tester.
[0090]
In the sheet manufacturing apparatus 100, since the
size of the second opening 62 is greater than the size of
the first opening 42, it is possible to reduce a possibility
of remaining of the defibrated material within the refining
unit 60. Thus, it is possible to prevent the refining unit
60 from being clogged and to deposit the defibrated material
with uniform thickness and density.
[0091]
In the sheet manufacturing apparatus 100, the sizes of
the plurality of first openings 42 are equal to each other
and the sizes of the plurality of second openings 62 are
equal to each other. If the sizes of the plurality of first
openings 42 are equal to each other, since the passed
material passing through the first openings 42 is screened
under the same conditions, variation of the size of the
passed material is reduced. It is preferable that the
shapes of the plurality of first openings 42 are equal to
each other, but ~he plurality of first openings 42 may have
the same size even if the shapes are different from each
other. It is possible to uniformly deposit the fiber or the
·----··---------------------------------------·---
resin passing through the second openings 62 on the
deposition unit 72 by making the sizes of the plurality of
second openings 62 be equal to each other. Moreover, if the
I
---·----1 I
44
plurality of second openings 62 are arranged at equal
intervals, it is possible to uniformly deposit the fiber and
the resin.
[0092]
In the sheet manufacturing apparatus 100, the moving
speed of the screening unit 40 is greater than the moving
speed of the refining unit 60. It is preferable that a
processing performance of the screening unit 40 is improved
by increasing the moving speed of the screening unit 40 so
that a discharging amount per unit time of the defibrated
material that is discharged by passing through the first
openings 42 of the screening unit 40 is equal (approximate)
to a discharging amount per unit time of the defibrated
material that is discharged by passing through the second
openings 62 of the refining unit 60. Particularly, if the
size of the second opening 62 is greater than the size of
the first opening 42, it is further preferable that the
moving speed of the screening unit 40 is greater than the
moving speed of the refining unit 60. Moreover, the
screening unit 40 can easily screen the defibrated material
by being moved. On the other hand, ~ince the refining unit
60 is intended to untangle the fibers or uniformly deposit
---~- ~-----~-------- -----------~-------~--- --~-~---------------~-----
the fibers by causing the fibers to pass therethrough, the
refining unit 60 may not be moved. In this case, for
example, the fibers pass through the second openings 62 by
-i
I
I
45
using, for example, the airflow.
[0093]
The sheet manufacturing apparatus 100 includes the
resin supplying unit 50 supplying the resin to the sixth
transport unit 86 connecting the screening unit 40 and the
refining unit 60. Thus, even if the defibrated material and
the resin are entangled within the sixth transport unit 86,
it is possible to untangle the defibrated material and the
resin that are entangled by the refining unit 60 and to
deposit the defibrated material and the resin on the
deposition unit 72 with good uniformity. In addition, if
the resin is supplied to the third transport unit 83 on the
upstream side of the screening unit 40, the resin adhered to
the defibrated material not passing through the first
openings 42 in the screening unit 40 is not used in the
manufacturing of the sheet. Thus, the resin is waste, the
amount of the resin used in the manufacturing of the sheet
is reduced, and the strength of the sheet is insufficient.
[0094]
The sheet manufacturing apparatus 100 includes the
defibrating unit 20 that performs defibrating process on the
defibrated material and the fifth transport unit (returning
flow path) 85 for returning the remaining material not
passing through the scre~ning unit ~0 to the defibrating
unit 20. Thus, the defibrated material not passing through
46
the first openings 42 in the screening unit 40 can be
defibrating-processed in the defibrating unit 20. That is,
the remaining material can be used for the manufacturing of
the sheet without being discarded.
[0095]
Moreover, the sheet manufacturing apparatus 100 may not
have the flow path 85 for returning the defibrated material
that does not pass through the refining unit 60 to the
defibrating unit 20. In such a sheet manufacturing
apparatus 100, since the defibrated material that does not
pass through the refining unit 60 is little, it is possible
to omit the flow path for returning the defibrated material
to the defibrating unit 20 and to reduce the sheet
manufacturing apparatus 100 in size.
[0096]
2. Experimental Examples
Hereinafter, Experimental Examples are illustrated and
the invention is described in detail. Moreover, the
invention is not limited to any of the following
Experimental Examples.
[0097]
2. Creating Samples
2. Example 1
As the raw material, a paper for a Plain Paper Copier
(PPC) of an A4 size was used. As the sheet manufacturing
47
apparatus, as illustrated in Fig. 1, the sheet manufacturing
apparatus 100 was used.
[0098]
The PPC sheet was cut into paper pieces of 6 mmx14 mm
in the crushing unit (shedder) 10 before feeding the PPC
sheet into the defibrating unit 20. As the defibrating unit
20, an Impeller Mill 250 (manufactured by Seishin Co., Ltd.)
was used. A rotational speed of the Impeller Mill 250 was
5000 rpm and the defibrated material was generated by
defibrating the cut paper pieces. The defibrated material
was transported to the screening unit 40 via the classifying
unit (cyclone) 30.
[0099]
As the screening unit 40, a rotary-type sieve was used.
As the net unit 41 of the screening unit 40, the mesh is 970
~Lm, a diameter of the line was 3 00 ~m, an outer diameter was
220 mm, and the rotational speed was 220 rpm.
[0100]
The fibers were added io the material passing through
the first openings 42 of the screening unit 40.
Specifically, powder resin (polyester) having an average
particle diameter D50 = 8.2 ~m was added by 15 parts by
----------------------
weight with respect to the material of 100 parts by weight
passing through the first openings 42. Mixing of the
material and the resin passing through the first openings 42
48
was performed by a turbo fan blower provided within the
sixth transport unit 86.
[0101]
As the refining unit 60, the rotary-type sieve having
the same shape and the size as those of the sieve used as
the screening unit 40 except that the outlet 47 is not
provided was used. That is, as the net unit 61 of the
refining unit 60, the mesh was 970 ~m, the line diameter was
3 0 0 ~tm, and the outer diameter was 22 0 mm. The rotational
speed was 150 rpm.
[0102]
The defibrated material and the resin deposited on the
deposition unit 72, which pass through the refining unit 60,
became a thin-layered sheet (paper) by being heated and
pressed by the heater roller 76. A temperature of the paper
after passing through the heater roller 76 was 140°C and a
pressure applied by the heater roller 76 was approximately
30 kgf/cm2
. A thickness of the formed paper was
approximately 90 ~m.
[0103]
2.1.2. Example 2
As a raw material, a paper was manufactured in the same
steps as in Example 1 (in the same sheet manufacturing
apparatus) except that the paper manufactured in Example 1
was used.·
49
[0104]
2.1.3 Comparison Example 1
A paper was manufactured by using a sheet manufacturing
apparatus that does not have the screening unit 40. Other
portions (except that the screening unit 40 is not provided)
are the same as the sheet manufacturing apparatus used in
Example 1.
[0105]
2. Comparison Example 2
A paper was manufactured· in the same steps as in
Comparison Example 1 (in the same sheet manufacturing
apparatus) except that the rotational speed of the
defibrating unit 20 was 12000 rpm.
[0106]
2.2 Evaluation Result
Texture and the tensile strength of the paper of
Examples 1 and 2, and Comparison Examples 1 and 2 were
evaluated. The texture was evaluated by a difference in the
density by observing viewed when irradiating the paper with
light from the back surface of the paper. The tensile
strength was measured by using the tensile strength tester
such that a test piece (paper piece) having a length of 150
mm and a width of 15 mm becomes a span length of 100 mm.
Evaluation results of the texture and the tensile strength
are illustrated in Table 1. Furthermore, energy
50
(defibrating energy) consumed in defibrating process in the
defibrating unit 20 is illustrated in Table 1.
[0107]
Table 1
Tensile
Clogging Defibrating
of
Strength
Refining
Texture Energy
(MPa)
Unit
[kWh/m2
]
Example 1 45 No Good 0.026
Example 2 51 No Good 0.023
Comparison
Initial: Good
45 Yes After Clogging: 0.026
Example 1 Density Unevenness
Comparison
Initial: Good
11 Yes After Clogging: 0.046
Example 2 Density Unevenness
[0108]
As illustrated in Table 1; in the texture evaluation,
the papers of Examples 1 and 2 were found to have good
texture. In addition, the tensil~ strength of the papers of
Examples 1 and 2 was equal to or greater than 45 MPa and the
papers were found to have high strength. In addition, In
Examples 1 and 2, clogging of the net unit 61 of the
refining unit 60 did not occur. From the results of Example
2, the paper that is created by the paper as the raw
material created by the sheet manufacturing apparatus also
meets the--performarice-asfnepaper.-Thus--, -rt--rs--pcS-sslbYe ___ t_o _______________ i
I
repeatedly use the paper that is created by the apparatus
without using a commercially available paper.
51
[0109]
In Comparison Example 1, the undefibrated piece that is
not defibrated in the defibrating unit or the defibrated
material that is entangled gradually remained within the
refining unit, and the clogging occurred during continuously
operating the apparatus. As a result, the paper could not
continuously manufacture for a long period of time. It was
found that paper manufactured in operation easily had the
texture substantially the same as that of Example 1, but the
texture of a paper that was manufactured after the clogging
occurred was deteriorated.
[0110]
Also in Comparison Example 2, the clogging occurred in
the refining unit during continuously operating the
apparatus. However, a degree of the clogging was lighter
than Comparison Example 1. Similar to Comparison Example 1,
it was found that the paper manufactured after the clogging
occurred was deteriorated. Howev~r, a degree of density
unevenness was better than that of Comparison Example 1.
[0111]
The tensile strength of Comparison Example 2 was as low
as 11 MPa. It is conceivable that this is because the
I
---------·-·---1
rotational speed of the defibrated material is high and a
ratio of the defibrated material having the fibers of short
lengths is increased in Comparison Example 2. Here, Table 2
52
illustrates a distribution of the fiber ·length of the
defibrated material after passing through the defibrating
unit and before being introduced into the refining unit.
Specifically, Table 2 illustrates the distribution of the
fiber lengths of 20000 defibrated materials having the fiber
length equal to or greater than 50 ~m measured by a Fiber
Tester (L&W Co) . It was found that the fiber length of the
defibrated material in Comparison Example 2 is shorter than
that of Example 1 by Table 2.
[0112]
Table 2
than
200 ~m or Less 200 Greater than
greater and 800
~m BOO
~m or less ~m
Example 1 23.5% 65.9% 10.6%
Comparison 38.2% 55.1% 6.7%
Example 2
[0113]
The invention includes the substantially same
configuration (same configuration in the function, the
method, and the result or the same configuration in the
object and the effect) as the configuration described in the
I
I
embodiment. In addition, the invention includes
I configurations that replace non-essential portions of the
1--------------~ ~ ~ ~------~--~----
1 configuration described in the embodiment. In addition, the
invention includes configurations that can achieve the same
I
r-
~-------------------------------------------1
I
I
53
operational effect or the same object as the configuration
described in the embodiment. In addition, the invention
includes configurations that are obtained by adding known
technique to the configuration described in the embodiment.
[0114]
Moreover, the sheet manufactured by the sheet
manufacturing apparatus 100 mainly refers to those in a
sheet shape. However, the sheet is not limited to the sheet
shape and may be a board shape or a web shape. In the
present specification, the sheet is divided into paper and
non-woven fabric. Paper includes aspects formed in a thin
sheet shape and includes recording paper for writing or
printing, wallpaper, wrapping paper, colored paper, drawing
paper, Kent paper, and the like: Since non-woven fabric has
a thickness thicker than that of paper or has strength lower
than that of paper, the non-woven fabric includes general
non-woven fabric, fiber board, tissue paper, kitchen paper,
cleaner, filter, liquid absorption material, sound-absorbing
material, cushioning material, mat, and the like.
Furthermore, as the raw material, plant fibers such as
cellulose, chemical fibers such as polyethylene
terephthalate (PET) and polyester, and animal fibers such as
,----------------------
wool and silk may be included.
[0115]
The net unit 41 of the screening unit 40 or the net
-i-
1
54
unit 61 of the refining unit 60 is the cylindrical shape,
but may be a planar shape. A plurality of openings may be
opened in a plate or planar meshes may be provided.
[0116]
In addition, although not illustrated, a water sprayer
to add spraying water to the deposited material deposited on
the deposition unit 72 may be provided. Thus, it is
possible to increase strength of hydrogen bonds when forming
the sheet P. Spray for adding water is performed with
respect to the deposited material before passing through the
heater roller 76. Starch, polyvinyl alcohol (PVA), and the
like may be added to the water sprayed by the water sprayer.
Thus, it is possible to further increase the strength of the
sheet P.
[0117]
In addition, in the examples described above, the
description is given for·an aspect that the sheet P is wound
around the winding roller 78, but the sheet P is cut into a
desired size by a cutting machine (not illustrated) or may
be stacked on a stacker and the like.
[0118]
I
In the sheet manufacturing apparatus 100, as I
~----------------------------- --~- ---------------~---_!
illustrated in Fig. 8, the crushing unit 10 may be omitted. _ i
For example, if the defibrated material that is crushed by a
known shredder is used as the raw material, the crushing
J
I
!
I
~
55
unit 10 is not necessary.
[0119]
In the sheet manufacturing apparatus 100, as
illustrated in Fig. 8, the crushing unit 10 and the
defibrating unit 20 may be omitted. If the defibrated
material that is defibrating-processed by a defibrating
machine separated from the sheet manufacturing apparatus 100
is used as the raw material, the crushing unit 10 and the
defibrating unit 20 are not necessary. Thus, the
"defibrated material that is defibrating-processed" also
includes a defibrated material that is processed in the
defibrating unit that is not mounted on the sheet
manufacturing apparatus 100.
[0120]
The fifth transport unit 85 as the returning flow path
may be omitted. The remaining material may be recovered and
discarded without returni~g to the defibrating unit 20. In
addition, if the defibrating unit 20 having performance by
which the remaining material does not appear, the fifth
transport unit 85 may be omitted.
[0121]
In the present application, "uniform", "same", "equal
intervals", and the like are used as means that the density,
the distance, the dimensions, and the like are equal. These
are desirably equal but since completely equal is difficult,
56
one that a value that is obtained by accumulation of errors,
variations, and the like is also included.
[0122]
Here, the waste paper is used as the material, the
invention is a waste paper recycling apparatus including a
defibrating unit that performs a defibrating process on a
waste paper, a screening unit that has first openings
screening a defibrated material that is defibratingprocessed
in the defibrating unit, a refining unit that has
second openings having sizes equal to or greater than sizes
of the first openings and refines the defibrated material
passing through the screening unit by causing the defibrated
material to pass through the second openings, and a
deposition unit on which the defibrated material passing
through the refining unit is deposited. Moreover, the waste
paper mainly indicates printed paper, but may include paper,
on which print is not performed, passing through a printing
apparatus.
Reference Signs List
[ 012 3]
2 FIBER
4 UNDEFIBRATED PIECE
,-~------------~-----~--- ----~---~----------~---~------------~--------------~~-----~~---------
5, 6 HOPPER
10 CRUSHING UNIT
11 CRUSHING BLADE
20 DEFIBRATING UNIT
21 INLET
22 OUTLET
30 CLASSIFYING UNIT
3l INLET
32 CYLINDRICAL UNIT
33 INVERSE CONE UNIT
34 LOWER OUTLET
35 UPPER OUTLET
40 SCREENING UNIT
41 NET UNIT
42 FIRST OPENING
43 LINE PORTION
44, 45 DISK UNIT
46 INLET
47 OUTLET
50 RESIN SUPPLYING UNIT
51 SUPPLY PORT
60 REFINING UNIT
61 NET UNIT
62 SECOND OPENING
64, 65 DISK UNITS
57
,---- ---------66--IN:LET---------------------------
70 SHEET FORMING UNIT
72 DEPOSITION UNIT
58
74 TENSION ROLLER
76 HEATER ROLLER
77 TENSION ROLLER
78 WINDING ROLLER
81 FIRST TRANSPORT UNIT
82 SECOND TRANSPORT UNIT
83 THIRD TRANSPORT UNIT
84 FOURTH TRANSPORT UNIT
85 FIFTH TRANSPORT UNIT
86 SIXTH TRANSPORT UNIT
100 SHEET MANUFACTURING APPARATUS

We Claim:-
[Claim 1]
A sheet manufacturing apparatus comprising:
a screening unit that has first openings for screening
a defibrated material that is defibrating-processed;
a refining unit that has second openings having sizes
equal to or greater than sizes of the first openings and
refines the defibrated material passing through the
screening unit by causing the defibrated material to pass
through the second openings; and
a deposition unit on which the defibrated material
passing through the refining unit is deposited.
[Claim 2]
The sheet manufacturing apparatus according to Claim 1,
wherein the sizes of the second openings are greater
' than the sizes of the first openings.
[Claim 3]
The sheet manufacturing apparatus according to Claim 1
or 2,
wherein the refining unit is provided with a plurality
of the second openings, and
wherein the sizes of the plurality of second openings
---------·I
are equal to each other.
[Claim 4]
The sheet manufacturing apparatus according to any one
60
of Claims 1 to 3,
wherein the screening unit is provided with a plurality
of the first openings, and
wherein the sizes of the plurality of first openings
are equal to each other.
[Claim 5]
The sheet manufacturing apparatus according to any one
of Claims 1 to 4,
wherein the screening unit is movable,
wherein the refining unit is movable, and
wherein the screening unit moves faster than the
refining unit.
[Claim 6]
The sheet manufacturing apparatus according to any one
of Claims 1 to 4,
wherein the screening unit is movable, and
wherein the screening unit moves faster than the
refining unit.
[Claim 7]
The sheet manufacturing apparatus according to any one
of Claims 1 to 6, further comprising:
a supplying unit that supplies resin bonding the
------ ~-----------~-- defibrated material b-etween thescreenfng- uriit andthe ______ _
refining unit.
[Claim 8]
61
The sheet manufacturing apparatus according to any one
of Claims 1 to 7, further comprising:
a defibrating unit that performs a defibrating process
on a defibration object; and
a returning flow path that returns the defibrated
material not passing through the screening unit to the
defibrating unit.
[Claim 9]
A sheet manufacturing apparatus comprising:
a screening unit that screens a defibrated material
that is defibrating-processed by causing the defibrated
material to pass through first openings;
a refining unit that refines the defibrated material
passing through the screening unit; and
a deposition unit on which the defibrated material
passing through·the refining unit is deposited.
[Claim 10]
A sheet manufacturing method comprising:
a step of screening a defibrated material that is
defibrating-processed by first openings;
a step of causing the defibrated material passing
through the first openings to pass through second openings
having sizes equal to or greater than sizes of the first
openings; and
a step of depositing the defibrated material passing
through the second openings.
[Claim 11]
62
The sheet manufacturing method according to claim 10,
wherein a plurality of the first openings and the
second openings are respectively provided,
wherein the sizes of the plurality of first openings
are equal to each other, and
wherein the sizes of the plurality of second openings
are equal to each other.
[Claim 12]
The sheet manufacturing method according to claim 10 or
11,
wherein a screening unit having the first openings and
a refining unit having the second openings are movable, and
wherein the screening unit moves faster than the
refining unit.
[Claim 13]
The sheet manufacturing .method according to any one of
claims 10 to 12, further comprising:
a step of supplying resin that bonds the defibrated
material between the step of screening the defibrated
material that is defibrating-processed by the first openings
------and-the -8-tepo:f-causiilg--the-d.e-fibrated:-ffiater:Lai--:P-ass:Cng----------------------
through the first openings to pass through the second
openings.
. .
63
[Claim 14]
The sheet manufacturing method according to any one of
claims 10 to 13, further comprising:
a step of returning the defibrated material not passing
through the first openings to a defibrating unit in which a
defibration object is defibrating-processed.