DESCRIPTION]
[Technical F i e l d ]
[ O O O l ]
The p r e s e n t invention r e l a t e s t o a sheet manufacturing
apparatus and a method of manufacturing s h e e t s .
[Background]
[0002]
Conventionalsheetmanufacturingapparatusesuseawetprocess
i n which f e e d s t o c k c o n t a i n i n g f i b e r is s o a k e d i n w a t e r , d e f i b r a t e d
by p r i m a r i l y mechanical means, and detangled ( s e e , f o r example,
PTL 1 ) . Such wet process sheet manufacturing apparatuses r e q u i r e
a l a r g e amount of water and the equipment i s l a r g e . Maintenance
ofawatertreatmentfacilityisalsotime-consuming, a n d s i g n i f i c a n t
energy i s r e q u i r e d f o r a d r y i n g p r o c e s s .
[0003]
Dry-process sheetmanufacturingapparatusesrequiringminimal
water have t h e r e f o r e been proposed t o reduce device s i z e and save
energy ( s e e , f o r example, PTL 2 ) . PTL 2 d e s c r i b e s d e f i b r a t l n g p a p e r
shredstofiberinadrydef~brator,p assingthedefibratedmaterial
( f i b e r ) through a f i n e screen on the s u r f a c e of a forming drum,
and laying t h e f i b e r on a mesh b e l t t o form paper.
[ C i t a t i o n L i s t ]
[Patent L i t e r a t u r e ]
[0004]
[PTL 11 JP-A-2013-87368
[PTL 21 JP-A-2012-144819
[Summary of Invention]
[Technical Problem]
[0005]
PTL 1 d e s c r i b e s stopping supplying new paper f e e d s t o c k t o t h e
head box i n t h e i d l e mode, and going t o the i d l e mode a f t e r forming
a l l paper feedstock remaining i n the head box i n t o paper. PTL 2
is s i l e n t about c o n t r o l f o r s t o p p i n g o p e r a t i o n , and if t h e method
of P T L l i s a p p l i e d t o t h e d r y - p r o c e s s sheetmanufacturingapparatus
d e s c r i b e d i n P T L 2 , operationstopsafterallmaterialinthe forming
drumhasbeendischarged.Thisrequirestimetodischargeal1material
i n t h e formingdrumwhenstoppingoperation, a n d r e q u i r e s t i m e u n t i l
m a t e r i a l accumulates i n the forming drum and can be s t a b l y discharged
when s t a r t i n g o p e r a t i o n .
[ S o l u t i o n t o Problem]
[0006]
The i n v e n t i o n is d i r e c t e d t o solving a t l e a s t p a r t of the
foregoingproblem,andcanbeembodiedbytheembodimentsandexamples
described below.
[0007]
Asheetmanufacturingapparatusinone aspect o f t h e invention
comprises a s i e v e u n i t having a t l e a s t p a r t of m a t e r i a l d e f i b r a t e d
i n a d e f i b r a t i o n p r o c e s s i n t r o d u c e d t h e r e t o , m o v i n g a t a f i r s t s p e e d ,
and passing t h e d e f i b r a t e d m a t e r i a l through m u l t i p l e openings
disposed i n the main s e c t i o n t h e r e o f ; and a forming u n i t forming
a sheet using p r e c i p i t a t e t h a t p a s t through t h e openings of t h e
s i e v e u n i t ; t h e s h e e t manufacturing apparatus stopping the s i e v e
u n i t with d e f i b r a t e d m a t e r i a l t h a t was introduced s t o r e d i n s i d e
t h e s i e v e u n i t .
[0008]
"Withdefibratedmaterialstoredinthe s i e v e u n i t W m e a n s t h a t
d e f i b r a t e d m a t e r i a l remains i n t h e s i e v e u n i t t o t h e e x t e n t t h a t
defibratedmaterialinsidethesieveunitpassesthroughtheopenings
when t h e s i e v e u n i t is then moved i n t h a t s t a t e .
[0009]
The time u n t i l the s h e e t manufacturing apparatus stops can
beshortenedbytheapparatus stoppingthesieveunitwithdefibrated
m a t e r i a l s t o r e d i n s i d e t h e s i e v e u n i t . Because the d e f i b r a t e d
m a t e r i a l s t o r e d i n the s i e v e u n i t passes through the openings i f
t h e apparatus is then s t a r t e d from t h i s s t a t e , t h e time u n t i l sheet
production s t a r t s can a l s o be shortened.
[OOlO]
I n t h e sheet manufacturing apparatus of the invention, t h e
defibrated material may be stored in the sieve unit by stopping
movement ofthe main section while the defibratedmaterial is being
introduced to the sieve unit.
[OOll]
Because defibrated material is introduced to the sieve unit
when movement of the main sectlon is stopped in this sheet
manufacturing apparatus, the sieve unit can be easily stopped with
defibrated material stored therein.
[0012]
In the sheet manufacturing apparatus of the invention, the
defibrated material may be stored in the sieve unit by moving the
main section at a lower speed than the first speedwhile the defibrated
material is being introduced to the sieve unit.
[0013]
By setting the speed of main section movement lower than the
first speed while defibrated material is being introduced to the
sieve unit in this sheet manufacturing apparatus, deflbrated
material can be stored inside the sieve unit because defibrated
material is introduced to the sieve unit while the amount of
defibrated material passing through the openings decreases.
[0014]
In the sheet manufacturing apparatus of the invention, the
main sectlon may move at a higher speed than the first speed while
the defibrated material is being introduced to the sieve unit,
movement ofthe main section stopping once the defibratedmaterial
is stored in the sieve unit.
[0015]
By setting the speed of main section movement above the first
speed while defibrated material is being introduced to the sieve
unit, the sheetmanufacturlngapparatusthus comprisedcanmalntain
the amount of defibrated material passing through the openings,
and the quality of the manufactured sheet can be maintained, even
if the amount of defibrated material introduced decreases before
the sieve unit stops. Furthermore, by stopping the sieve unit with
d e f i b r a t e d m a t e r i a l s t o r e d i n s i d e t h e s i e v e u n i t ( b e f o r e a l l
d e f i b r a t e d m a t e r i a l i n t h e sieveunitpassesthroughthe openings),
t h e time u n t i l t h e apparatus s t o p s can be shortened.
[0016]
A sheet manufacturing method according t o another aspect of
t h e invention comprises: a s t e p of introducing a t l e a s t p a r t of
materialdefibratedinadefibrationprocesstoa s i e v e u n i t , moving
a main s e c t i o n of the s i e v e u n i t a t a f i r s t speed, and passing t h e
defibratedmaterialthroughmultiple openings d i s p o s e d i n t h e main
s e c t i o n ; and a s t e p of forming a s h e e t using p r e c i p i t a t e t h a t p a s t
through the openings of t h e s i e v e u n i t ; t h e sheet manufacturing
method stopping t h e s i e v e u n i t with d e f i b r a t e d m a t e r i a l t h a t was
introduced s t o r e d i n s i d e t h e s i e v e u n i t .
[0017]
I n t h e s h e e t manufacturing method thus comprised, the t i m e
u n t i l t h e apparatus s t o p s can be shortened by stopping the s i e v e
u n i t with d e f i b r a t e d m a t e r i a l s t o r e d i n s i d e t h e s i e v e u n i t . The
time u n t i l s h e e t production s t a r t s can a l s o be shortened because
t h e d e f l b r a t e d m a t e r i a l s t o r e d i n t h e s i e v e u n i t passes through
t h e openings i f t h e apparatus is then s t a r t e d from t h i s s t a t e .
[Brief Description of Drawings]
[0018]
FIG. 1 schematically i l l u s t r a t e s a sheet manufacturing
apparatus according t o an embodiment of the invention
FIG. 2 is an oblique view i l l u s t r a t i n g a f i r s t s i e v e u n i t .
FIG. 3 is a f u n c t i o n block diagram of a sheet manufacturing
apparatus according t o an embodiment of the i n v e n t i o n .
FIG. 4 is a flow c h a r t of t h e process c o n t r o l l i n g stopping
o p e r a t i o n i n a f i r s t example.
FIG. 5 i s a flow c h a r t of t h e process c o n t r o l l i n g stopping
o p e r a t i o n i n a second example.
FIG. 6 i s a flow c h a r t of t h e process c o n t r o l l i n g stopping
o p e r a t i o n i n a t h i r d example.
FIG. 7 is a flow c h a r t of t h e process c o n t r o l l i n g stopping
operation in a fourth example.
FIG. 8 is a flow chart of the process controlling starting
operation in a fifth example.
FIG. 9 is a flow chart of the process controlling starting
operation in a sixth example.
FIG. 10 is a flow chart of the process controlling starting
operation in a seventh example.
FIG. 11 is a flow chart of the process controlling starting
operation in an eighth example.
[Description of Embodiments]
[0019]
Preferred embodiments of the invention are described below
described below do not unduly limit the scope of the invention
describedinthe accompanying claims. All configurations described
below are alsonotnecessarilyessentialelements ofthe invention.
[0020]
1. Configuration
FIG. 1 schematically illustrates a sheet manufacturing
apparatus 100 according to an embodiment ofthe invention. As shown
in FIG. 1, the sheet manufacturing apparatus 100 has a supply unit
10, defibrating unit 20, classifier 30, first sieve unit 40, resin
supply unit 50, second sieve unit 60, and forming unit 70.
[0021]
The supply unit 10 cuts feedstock such as pulp sheet and inserted
sheets (such as A4 size recovered paper) in air into small shreds
and supplies the shreds to the defibrating unit 20. The shape and
size ofthe shreds are not specifically limited, and ln this example
theshredsareafewcentimeterssquare. Intheexampleinthe figure,
the supply unit 10 has shredder blades 11, cuts the supplied feedstock
lnto shreds with the rotating shredder blades 11, and supplies the
shreds downstream. The supply unit 10 functions as a shredder that
cuts the feedstock (material containing fiber) Into shreds, and
functions as a supply unit that supplies feedstock downstream, but
may f u n c t i o n only a s a supply u n i t . Note t h a t s e p a r a t e shredder
and s u p p l y u n i t s m a y b e used. The supply u n i t may a l s o be configured
a s a s h e e t feeder t h a t s u p p l i e s t h e feedstock a s whole s h e e t s .
[0022]
The shreds t h a t a r e cut up by t h e supply u n i t 10 a r e received
by a hopper 15 and conveyed therefrom through a f i r s t conveyance
u n i t 81 t o t h e d e f i b r a t i n g u n i t 20. The f i r s t conveyance u n i t 81
c o m m u n i c a t e s w i t h t h e i n l e t 2 1 o f t h e d e f i b r a t i n g u n i t 2 0 . The f i r s t
conveyance u n i t 8 1 and the second t o s i x t h conveyance u n i t s 82 t o
86 described below a r e t u b u l a r i n t h i s example.
[0023]
The d e f i b r a t i n g u n i t 20 d e f i b r a t e s the s h r e d s ( u n d e f i b r a t e d
m a t e r i a l ) . The d e f i b r a t i n g u n i t 20 converts t h e shreds i n t o f i b e r
t h a t is detangled i n t o f i b e r s i n t h e d e f i b r a t i o n process.
[0024]
The d e f i b r a t l o n process is a process of converting shreds of
many bonded f i b e r s i n t o i n d i v i d u a l d e t a n g l e d f i b e r s . Material t h a t
h a s p a s t t h r o u g h t h e d e f i b r a t i n g u n i t 2 0 i s r e f e r r e d t o a s d e f i b r a t e d
m a t e r i a l . In a d d i t i o n t o untangled f i b e r s , t h e d e f i b r a t e d m a t e r i a l
may a l s o c o n t a i n r e s i n p a r t i c l e s (resinusedtobindmultiple f i b e r s
t o g e t h e r ) and ink p a r t i c l e s such as ink, t o n e r , and s i z i n g agents,
t h a t a r e s e p a r a t e d from t h e f i b e r s when t h e f i b e r s a r e detangled.
Below, d e f i b r a t e d m a t e r i a l r e f e r s t o a t l e a s t p a r t of t h e m a t e r i a l
t h a t p a s t t h e d e f i b r a t i n g u n i t 20, and may include m a t e r i a l t h a t
i s a d d e d a f t e r p a s s i n g t h r o u g h t h e d e f i b r a t i n g u n i t 2 0 . Undefibrated
materialmeansmaterialthat is t o be d e f i b r a t e d in t h e d e f i b r a t i n g
u n i t 20.
[0025]
T h e d e f i b r a t i n g u n i t 2 0 s e p a r a t e s r e s i n p a r t i c l e s , i n k , t o n e r ,
s i z i n g agents, and other and ink p a r t i c l e s adhering t o the shreds.
The r e s i n p a r t i c l e s and ink p a r t i c l e s a r e discharged with the
d e f i b r a t e d m a t e r i a l from t h e o u t l e t 22. The d e f i b r a t i n g u n i t 20
d e f i b r a t e s the s h r e d s i n t r o d u c e d from the i n l e t 21 by means of
r o t a t i n g b l a d e s . T h e d e f i b r a t i n g u n i t 2 0 d e f i b r a t e s i n a d r y p r o c e s s
i n a i r .
[0026]
Thedefibratingunit2Opreferablyhasamechanismforproducing
an a i r c u r r e n t . In t h i s c o n f i g u r a t i o n , t h e d e f i b r a t i n g u n i t 20
s u c t i o n s t h e s h r e d s t o g e t h e r with t h e a i r flow from the i n l e t 21,
d e f i b r a t e s t h e m a t e r i a l , and then conveys t h e d e f i b r a t e d m a t e r i a l
t o the o u t l e t 22 using t h e a i r flow produced by t h e d e f i b r a t i n g
through a second conveyance u n i t 82 t o t h e c l a s s i f i e r 30. I f a
d e f i b r a t i n g u n i t 20 without a mechanism f o r producing an a i r flow
is used, a mechanism f o r producing an a i r flow t h a t c a r r i e s the
shreds t o the i n l e t 21 may be disposed e x t e r n a l l y .
[0027]
The c l a s s i f i e r 30 s e p a r a t e s and removes r e s i n p a r t i c l e s and
ink p a r t i c l e s from t h e d e f i b r a t e d material. An a i r c l a s s i f i e r is
used a s the c l a s s i f i e r 30. An a i r c l a s s i f i e r produces a h e l i c a l
a i r flow, and s e p a r a t e s m a t e r i a l by c e n t r i f u g a l force and t h e s i z e
and d e n s i t y of t h e m a t e r i a l being c l a s s i f i e d , and t h e cut point
can be a d j u s t e d by a d j u s t i n g t h e speed of t h e a i r flow and the
c e n t r i f u g a l f o r c e . More s p e c i f i c a l l y , a cyclone, elbow-jet or eddy
c l a s s i f i e r , f o r example, may be used a s a c l a s s i f i e r 30. A cyclone
is p a r t i c u l a r l y well s u i t e d a s t h e c l a s s i f i e r 30 because of i t s
simple c o n s t r u c t i o n . A c o n f i g u r a t i o n u s i n g a cyclone a s the
c l a s s i f i e r 30 is described below.
[0028]
The c l a s s i f i e r 30 has a t l e a s t an i n l e t 31, a bottom discharge
p o r t 3 4 disposed a t thebottom, and a t o p discharge p o r t 35 disposed
a t the t o p . In t h e c l a s s i f i e r 30, t h e a i r flow c a r r y i n g d e f i b r a t e d
m a t e r i a l introduced from the i n l e t 31 changes t o a c i r c u l a r a i r
flow, c e n t r i f u g a l f o r c e is thereby a p p l i e d t o d e f i b r a t e d m a t e r i a l
t h a t is introduced, and the d e f i b r a t e d m a t e r i a l is separated i n t o
f i b e r ( d e t a n g l e d f i b e r s ) andwaste ( r e s i n p a r t i c l e s , i n k p a r t i c l e s )
t h a t a r e smaller and have lower d e n s i t y than the f i b e r . The f i b e r
i s t h e n d i s c h a r g e d f r o m t h e b o t t o m d i s c h a r g e p o r t 3 4 , p a s s e s t h r o u g h
the third conveyance unit 83, and is carried to the inlet 46 of
the first sieve unit 40. The waste passes from the top discharge
port 35 through a fourth conveyance unit 84, and is discharged to
the outside of the classifier 30.
[0029]
Note that the classifier 30 is described as separating the
fiber and waste, but this does not mean complete separation.
Relatively smallandlowdensityfibermaybe dischargedexternally
with the waste. Relatively high density waste and waste that is
interlocked with fiber may also be introduced with the fiber to
the first sieve unit40. Material that is discharged fromthebottom
discharge port 34 (material with a higher percentage of long fibers
than the waste) is referred to herein as fiber or fiber material,
and material that is discharged from the top discharge port 35
(material with a lower percentage of long fibers than the fiber)
is referred to as waste. Note that when the feedstock is pulp sheet
instead of recovered paper, there is nomaterial equivalent tothis
' waste, and the classifier 30 may be omitted from the configuration
of the sheet manufacturing apparatus 100.
[0030]
The first sieve unit 40 (an example of a sieve unit) separates
the fiber that was separated by the classifier 30 (the defibrated
material output from the defibrating unit 20 if the classifier 30
is omitted) into precipitate that past the first sieve unit 40,
and remnants that did not pass.
[0031]
FIG. 2 is an oblique view illustrating the first sieve unit
40. As shown in FIG. 2, the main section 48 of the first sieve unit
40 includes a screen 41, round caps 44, 45, an inlet 46, and an
outlet 47. The main section 48 is a rotary sieve configured so that
the cylindrical screen 41 rotates (an example of movement) on an
axis of rotation Q when driven by a motor (not shown in the figure) .
The screen 41 has many openings 42, and there is a hollow space
inside the screen 41. When the screen 41 turns, fibers of a size
t h a t can pass through the openings 42 a n d a r e c o n t a i n e d i n t h e f i b e r
introduced t o t h e screen 4 1 pass through, and f i b e r s t o o l a r g e t o
p a s s t h r o u g h t h e o p e n i n g s 42 d o n o t p a s s through. More s p e c i f i c a l l y ,
t h e f i r s t s i e v e u n i t 40 can s e l e c t fromthe f i b e r t h a t is introduced
f i b e r s ( p r e c i p i t a t e ) t h a t a r e s h o r t e r t h a n a s p e c i f i c length. The
screen 4 1 is a m e t a l s c r e e n such a s p l a i n weave wire mesh or welded
metalmesh. Notethatexpandedmetalmadebyexpandingametalsheet
with s l i t s formed t h e r e i n may be used, o r punched metal having
openings formed by a p r e s s i n a metal sheet may be used, i n t h e
f i r s t s i e v e u n i t 40 i n s t e a d of a s c r e e n 4 1 c o n f i g u r e d w i t h metal
mesh. I f e x p a n d e d m e t a l i s u s e d , theopeningsaretheopenings formed
by s t r e t c h i n g t h e s l i t s f o r m e d i n t h e m e t a l s h e e t . I f punchedmetal
is used, t h e openings a r e the openings formed i n t h e metal sheet
by a p r e s s , f o r example. A forarninous member made of a m a t e r i a l
o t h e r than metal may a l s o be used. The main s e c t i o n of the f i r s t
s i e v e u n i t 40 may a l s o be configured from a foraminous f l a t sheet
s i e v e ( f l a t s i e v e ) ( s c r e e n p o r t i o n ) i n s t e a d o f a c y l i n d r i c a l s i e v e .
In t h i s c o n f i g u r a t i o n , t h e main s e c t i o n of t h e f i r s t s i e v e u n i t
40 moves i n a r e c i p r o c a t i n g a c t i o n (another example of movement)
causing f i b e r s t o pass through t h e openings.
[0032]
The round caps 4 4 , 45 of t h e f i r s t s i e v e u n i t 40 a r e disposed
t o the two openings formed a t t h e ends of the screen 4 1 when t h e
screen 4 1 forms a c y l i n d e r . The i n l e t 46 through which f i b e r is
introduced i s disposed t o one cap 4 4 , and the o u t l e t 47 through
which waste is discharged is disposed t o t h e o t h e r cap 45. When
t h e f i r s t s i e v e u n i t 40 t u r n s , t h e screen 4 1 t u r n s , but the round
caps 4 4 , 45, i n l e t 46, and o u t l e t 47 i o not t u r n . The round caps
4 4 , 45 c o n t a c t the ends of the screen 4 1 so t h a t the screen 4 1 can
r o t a t e . Because t h e round caps 4 4 , 45 and screen 41 touch with no
gap therebetween, f i b e r i n s i d e t h e screen 4 1 is preventedfromleaking
t o the o u t s i d e .
[0033]
Waste t h a t does not pass through t h e openings 42 i n the f i r s t
sieve unit 40 is discharged from the outlet 47, conveyed to the
hopper 15through a fifth conveyance unit 85 configured as a return
channel, and returnedtothe defibrating unit 20. Precipitate that
past the openings 42 in the first sieve unit 40 is received in a
hopper 16 and conveyed therefrom through a sixth conveyance unit
86 to the inlet 66 of the second sieve unit 60. A supply port 51
for supplying resin to bind fibers (defibrated material) together
is disposed to the sixth conveyance unit 86.
[0034]
The resin supply unit 50 supplies resin in air from the supply
port 51 to the sixth conveyance unit 86. More specifically, the
resin supply unit 50 supplies resin to the path of the precipitate
that past the mesh in the first sieve unit 40 from the first sieve
unit 40 to the second sieve unit 60 (the path between the first
sieve unit 40 and the second sieve unit 60). The configuration of
the resin supply unit 50 is not specifically limited insofar as
it can supply resin to the sixth conveyance unit 86, and may use
a screw feeder or circle feeder, for example. Resin supplied from
the resin supply unit 50 is resin for bonding fibers together. The
fibers have not been bonded at the time the resin is supplied to
the sixth conveyance unit 86. The resin melts and bonds fibers when
passing the forming unit 70 described below. The resin may be a
thermoplastic resin or thermoset resin, and may be in a fiber form
or powder form. The amount of resin that is supplied from the resin
supply unit 50 is set appropriately according to the type of sheet
to bemanufactured. Note that in addition to resin forblnding fibers,
a coloring agent for adding color tothe fiber, or ananti-blocking
agent for preventing agglomeration of fiber, may also be supplied
according to the type of sheet to be manufactured. Note that the
resin supply unit 50 may also be omitted in the configuration of
the sheet manufacturing apparatus 100.
[0035]
Resin supplied from the resin supply unit 50 is mixed with
the precipitate that past the openings in the first sieve unit 40
by a mixing unit (not shown in the figure) disposed in the sixth
conveyance unit 86. The mixing unit produces an air current for
conveying the second sieve unit 60 while mixing the precipitate
and resin.
[0036]
The second sieve unit 60 (an example of a sifter) detangles
tangled material. If the resin supplied from the resin supply unit
50 is in a fiber form, the second sieve unit 60 also detangles
interlocked resin fibers. The second sieve unit 60 lays the
precipitate a n d r e s i n u n i f o r r n l y o n t h e d e p o s i t i o n u n i t 7 2 described
below. In other words, "detangle" includes the action of breaking
apartandtheactionofuniformlylayinginterlockedfibrousmaterial.
Note that if there are no interlocked fibers, detangling acts to
deposit the fiber uniformly. The second sieve unit 60 is a rotary
sieve configured so that a cylindrical screen rotates when driven
by a motor (not shown in the figure). Note that the sieve of the
second sleve unit 60 may be configured without functionality for
selecting specific material. More specifically, the sieve of the
second sieve unit 60 means a device having a foraminous screen portion,
and the second sieve unit 60 may cause all of the fiber and resin
introduced to the second sieve unit to be discharged through the
openings to the outside. In this configuration, the size of the
screen openings in the second sieve unit is greater than or equal
to the size of the screen openings in the first sieve unit 40. A
difference in the configurations of the second sieve unit 60 and
the first sieve unit 40 is that the second sieve unit 60 does not
have a discharge port (a part equivalent to the outlet 47 of the
first sieve unit 40). Like the first sieve unit 40, themain section
of the second sieve unit 60 may be configured from a foraminous
flat sheet sieve (flat sieve) andmove reciprocally. Note also that
either one of the first sieve unit 40 and second sieve unit 60 may
be omitted from the configuration of the sheet manufacturing
apparatus 100.
[00371
While t h e second s i e v e u n i t 60 r o t a t e s , t h e mixture of
p r e c i p i t a t e ( f i b e r ) t h a t p a s t t h e f i r s t s i e v e u n i t 40 and r e s i n
i s i n t r o d u c e d f r o m t h e i n l e t 6 6 t o t h e secondsieveunit60comprising
a t u b u l a r screen. The mixture introduced t o the second s i e v e u n i t
60 moves by c e n t r i f u g a l force t o the s c r e e n . As described above,
t h e mixture introduced t o the second s i e v e u n i t 60 may c o n t a i n tangled
f i b e r and r e s i n , and t h e i n t e r l o c k e d f i b e r and r e s i n is detangled
i n a i r by the r o t a t i n g screen. The detangled r e s i n and f i b e r then
passes through t h e openings. The f i b e r and r e s i n t h a t p a s t through
t h e openings t r a v e l s through a i r and i s l a i d uniformly on the
d e p o s i t i o n u n i t 72 described below.
[0038]
The f i b e r a n d r e s i n t h a t p a s t t h r o u g h t h e o p e n i n g s i n t h e second
s i e v e u n i t 60 IS d e p o s i t e d on t h e d e p o s i t i o n u n i t 72 of t h e forming
u n i t 7 0 . The f o r m i n g u n i t 7 0 i n c l u d e s t h e d e p o s i t i o n u n i t 7 2 , t e n s i o n
r o l l e r s 74, heat r o l l e r s 76, t e n s i o n r o l l e r 77, and take-up r o l l e r
78. The f o r m ~ n gu n i t 70 forms a s h e e t from t h e p r e c i p i t a t e ( f i b e r
and r e s i n ) t h a t p a s t t h e second s i e v e u n i t 60.
[0039]
The f i b e r and r e s i n t h a t p a s t t h e openings o f t h e second s i e v e
u n i t 60 is received by and accumulates on t h e deposition u n i t 72
of the forming u n i t 70 a s d e p o s i t e d m a t e r i a l . The deposition u n i t
72 is l o c a t e d below t h e second s i e v e u n i t 60. The d e p o s i t i o n u n i t
72 i s , f o r example, a mesh b e l t . Mesh t h a t is tensioned by t e n s i o n
r o l l e r s 74 is formedin t h e m e s h b e l t . The d e p o s i t i o n u n i t 72 moves
when t h e t e n s i o n r o l l e r s 74 r o t a t e . A web of a uniform thickness
is formed on t h e d e p o s i t i o n u n i t 72 by the d e f i b r a t e d m a t e r i a l and
r e s i n p r e c i p i t a t i n g continuously from the second s i e v e u n i t 60
accumulating continuously while the d e p o s i t i o n u n i t 72 moves
continuously.
[0040]
A s u c t i o n d e v i c e ( n o t shown i n t h e f i g u r e ) t h a t s u c t i o n s t h e
deposited m a t e r i a l down i s disposed below the d e p o s i t i o n u n i t 72.
The s u c t i o n device is l o c a t e d below t h e second s i e v e u n i t with t h e
deposition u n i t 72 therebetween, and produces a downward flow of
a i r ( a i r flow d i r e c t e d from t h e second s i e v e u n i t 60 t o t h e d e p o s i t i o n
u n i t 72) . The d e f i b r a t e d m a t e r i a l and r e s i n d i s t r i b u t e d i n a i r can
t h e r e f o r e be s u c t i o n e d , and t h e discharge speed from the second
s i e v e u n i t 60 can be i n c r e a s e d . As a r e s u l t , t h e p r o d u c t i v i t y of
t h e sheetmanufacturing apparatus 100 c a n b e i n c r e a s e d . The s u c t i o n
device a l s o c r e a t e s a downward flow i n t h e p r e c i p i t a t i o n path of
t h e d e f i b r a t e d m a t e r i a l a n d r e s i n , and t h e d e f i b r a t e d m a t e r i a l a n d
r e s i n can be prevented from becoming tangled while p r e c i p i t a t i n g .
[0041]
Heat and p r e s s u r e a r e a p p l i e d by the heat r o l l e r s 76 t o t h e
d e f i b r a t e d m a t e r i a l and r e s i n l a i d on the d e p o s i t i o n u n i t 72 of
t h e forming u n i t 70 while moving with t h e d e p o s i t i o n u n i t 72. Heat
causes t h e r e s i n t o function a s a bonding agent t h a t binds f i b e r s
t o g e t h e r , p r e s s u r e r e d u c e s t h i c k n e s s , the s u r f a c e is smoothedwhile
passing betweencalender r o l l e r s notshown, a n d a s h e e t P i s formed.
In the example shown i n t h e f i g u r e s , t h e sheet P is wound onto a
take-up r o l l e r 78. A sheet P can t h e r e f o r e be manufactured.
[0042]
FIG. 3 is a f u n c t i o n block diagram of t h e s h e e t manufacturing
apparatus 1 0 0 . The sheet manufacturing apparatus 100 has a c o n t r o l
u n i t 110 i n c l u d i n g a CPU anda s t o r a g e u n i t (ROM, RAM), andan operating
u n i t 120 f o r i n p u t t i n g o p e r a t i n g information.
[0043]
The c o n t r o l u n i t 1 1 0 o u t p u t s c o n t r o l s i g n a l s t o f i r s t t o f o u r t h
d r i v e r s (motor d r i v e r s ) 111 - 1 1 4 . The f i r s t d r i v e r 111 c o n t r o l s
t h e motor of t h e supply u n i t 1 0 and d r i v e s the supply u n i t 10 based
on c o n t r o l s i g n a l s . The second d r i v e r 1 1 2 c o n t r o l s the motor of
t h e d e f i b r a t i n g u n i t 20 and d r i v e s t h e d e f i b r a t i n g u n i t 20 based
on c o n t r o l s i g n a l s . The t h i r d d r i v e r 113 c o n t r o l s the motor of t h e
f i r s t s i e v e u n i t 40 and d r i v e s t h e f i r s t s i e v e u n i t 40 based on
c o n t r o l s i g n a l s . The f o u r t h d r i v e r 1 1 4 c o n t r o l s the motor of t h e
second s i e v e u n i t 60 and d r i v e s t h e second s i e v e u n i t 60 based on
c o n t r o l s i g n a l s .
[0044]
Whenoperatinginformationinstructing startingtheapparatus
(starting production) is received from the operating unit 120, the
control unit 110 outputs control signals to the first to fourth
drivers 111 - 114 and starts driving the motors; and when operating
information instructing stopping the apparatus is received from
the operating unit 120, outputs control signals to the first to
fourth drivers 111 - 114 and stops driving the motors. The control
unit 110 also outputs control signals to the third driver 113 to
control the operating speed of the first sieve unit 40 (the rotat~onal
speed of the screen 41), and outputs control signals to the fourth
driver 114 to control the operating speed of the second sieve unit
60 (the rotational speed of the screen portion).
[0045]
2. Controlling stopping
The process of controlling stopping the sheet manufacturing
apparatus 100 according to this embodiment is described next.
[0046]
When operation of the sheet manufacturing apparatus 100
according to this embodiment stops (when sheet production stops),
the first sieveunit40 andsecondsieveunit60 stopwithdefibrated
material remaining in the main sections of the first sieve unit
40 and second sieve unit 60.
[0047]
2-1. Example 1
FIG. 4 is a flow chart of the process controlling stopping
operation in a first example.
[0048]
The control unit 110 first outputs a control signal to the
first driver 111 to stop the supply unit 10 (step S10). Next, the
control unit 110 outputs control signals to the third driver 113
and fourth driver 114 to stop rotation (an example of movement)
of the first sieve unit 40 and second sieve unit 60 (step 512).
Next, the control unit 110 outputs a control signal to the second
d r i v e r 1 1 2 t o s t o p t h e d e f i b r a t i n g u n i t 20 ( s t e p S14).
[0049]
Because t h e d e f i b r a t i n g u n i t 20 is s t i l l being driven a f t e r
thesupplyunitlOisstoppedinstepS10,defibratedmaterial(fiber)
is introduced t o the f i r s t s i e v e u n i t 40 from t h e d e f i b r a t i n g u n i t
20 a n d t h e conveyance path f r o m t h e d e f i b r a t i n g u n i t 2 0 . By stopping
r o t a t i o n of the f i r s t s i e v e u n i t 40 In s t e p 512, discharge of
d e f i b r a t e d m a t e r i a l f r o m t h e f i r s t s i e v e u n i t 40 s t o p s ( d e f i b r a t e d
m a t e r i a l s t o p s passing through t h e o p e n i n g s i n t h e f i r s t s i e v e u n i t
4 0 ) . Defibrated m a t e r i a l can t h e r e f o r e be s t o r e d i n s i d e t h e f i r s t
s i e v e u n i t 40 by stopping r o t a t i o n of t h e f i r s t s i e v e u n i t 40 while
d e f i b r a t e d m a t e r i a l is being introduced t o the f i r s t s i e v e u n i t
4 0 .
[OOSO]
Likewise, because t h e d e f i b r a t i n g u n i t 2 0 a n d f l r s t s l e v e u n i t
40 a r e s t i l l being drlven even though t h e supply u n i t 1 0 stops i n
s t e p S10, d e f i b r a t e d m a t e r i a l ( f i b e r and r e s i n ) i s introduced t o
t h e s e c o n d s i e v e u n i t 60 fromthe f i r s t s i e v e u n i t 40 andthe conveyance
path from t h e f i r s t s l e v e u n i t 4 0 . By then stopping r o t a t i o n of
thesecondsieveunlt6OinstepS12,dischargeofdefibratedmaterial
f r o m t h e s e c o n d s i e v e u n i t 6 O s t o p s (defibratedmaterialstopspassing
through the openings i n t h e second s i e v e u n i t 60) . D e f i b r a t e d m a t e r i a l
c a n t h e r e f o r e be s t o r e d i n s i d e t h e second s i e v e u n i t 60 by stopping
r o t a t i o n of the second s i e v e u n i t 60 while d e f i b r a t e d m a t e r i a l i s
being introduced t o t h e second s i e v e u n i t 6 0 .
[0051]
The time r e q u i r e d f o r the apparatus t o stop can t h e r e f o r e be
shortenedby stopping t h e f i r s t s i e v e u n i t 40 and second s i e v e u n i t
60 while d e f i b r a t e d m a t e r i a l remains i n s i d e t h e f i r s t s i e v e u n i t
40 and second s i e v e u n i t 60. Because d e f i b r a t e d m a t e r i a l i s a l r e a d y
s t o r e d i n s i d e t h e f i r s t s i e v e u n i t 40 and second s i e v e u n i t 60 t h e
next time the apparatus s t a r t s o p e r a t i n g , a s u f f i c i e n t amount of
d e f i b r a t e d m a t e r i a l can be supplied t o t h e downstream s i d e of t h e
f i r s t s l e v e u n i t 4 0 a n d s e c o n d s i e v e u n i t 6 0 a s soonas the apparatus
starts operating, the time required for the apparatus to start up
can be shortened, and sheet quality is stable from the start of
operation.
[0052]
Note that in step S12 the first sieve unit 40 and second sieve
unit 60 may be stopped simultaneously, the second sieve unit 60
may be stopped after stopping the first sieve unit 40, or the first
sieve unit 40 may be stopped after stopping the second sieve unit
60. These can be changed as long as defibrated material is stored
inside the first sieve unit 40 and second sieve unit 60.
[0053]
The defibrating unit 20 is also preferably stopped in step
S14 after all defibrated materlal inside the defibrating unit 20
has been discharged. This is because if the defibrating unit 20
is driven with material already in the defibrating unit 20 when
operation starts, the load increases, starting torque may be
insufficient, and the defibrating unit 20 may not be able to start.
As a result, stopping the supply unit 10 in step S10 and stopping
the defibrating unit 20 in step 514 are delayed a time sufficient
to discharge any defibrated mater~al inside the defibrating unit
20. The first sieve unit 40 and second sieve unit 60 may be stopped
during this delay with material stored inside.
[0054]
2-2. Example 2
FIG. 5 is a flow chart of the process controlling stopplng
operation in a second example
[0055]
The control unit 110 first outputs a control signal to the
first driver 111 to stop the supply unit 10 (step 520). Next, the
control unit 110 outputs a control signal to the third driver 113
to change the rotationalspeedofthe first sieve unit40 to a slower
speed than the normal operating speed (flrst speed) (step S22),
and outputs a control signal to the fourth driver 114 to change
the rotat-ional speed of the second sieve unit 60 to a slower speed
than t h e normal o p e r a t i n g speed ( s t e p S24). Next, t h e c o n t r o l u n i t
1 1 0 outputs c o n t r o l s i g n a l s t o t h e t h i r d d r i v e r 1 1 3 a n d f o u r t h d r i v e r
1 1 4 t o s t o p t h e f i r s t s i e v e u n i t 40 and second s i e v e u n i t 60 ( s t e p
S26). Next, t h e c o n t r o l u n i t 110 o u t p u t s a c o n t r o l s i g n a l t o the
second d r i v e r 112 t o stop t h e d e f i b r a t i n g u n i t 20 ( s t e p 52%).
[0056]
Because t h e d e f i b r a t i n g u n i t 20 is s t i l l being driven a f t e r
t h e s u p p l y u n i t l O i s s t o p p e d i n s t e p S 2 0 , d e f i b r a t e d m a t e r i a l ( f i b e r )
is introduced t o t h e f i r s t s i e v e u n i t 40 from t h e d e f i b r a t i n g u n i t
20 and t h e conveyance path from t h e d e f i b r a t i n g u n l t 20. I f t h e
f i r s t s i e v e u n i t 40 s t o p s t u r n i n g , d e f i b r a t e d m a t e r i a l f e d t o the
f i r s t s i e v e u n i t 40 a f t e r d e f i b r a t e d m a t e r i a l i s s t o r e d i n t h e f i r s t
s i e v e u n i t 40 may clog the upstream s i d e of the f i r s t s i e v e u n i t
40 or t h e i n s i d e of the f i r s t s i e v e u n i t 40 and p o s s i b l y cause
conveyance problems.
[GO571
As a r e s u l t , by t u r n i n g t h e f i r s t s i e v e u n i t 40 a t a lower
speed than normal i n s t e p S22 i n t h e second example, d e f i b r a t e d
materialisintroducedtothe f i r s t s i e v e u n i t 4 0 i n s t e a d o f c l o g g i n g
the upstream s i d e , t h e amount discharged from the f i r s t s i e v e u n i t
40 is reduced, and d e f i b r a t e d m a t e r i a l can be s t o r e d i n the f i r s t
s l e v e u n i t 40. Likewise, by t u r n i n g the second s l e v e u n i t 60 a t
a lower speed than normal i n s t e p S24, d e f i b r a t e d m a t e r i a l is
introduced t o t h e second s i e v e u n i t 60 i n s t e a d of clogging the
upstream s i d e , t h e amount discharged from the second s i e v e u n i t
60 is reduced, and d e f i b r a t e d m a t e r i a l can be s t o r e d i n t h e second
s i e v e u n i t 60.
[OOSS]
By t h e n s t o p p i n g the f i r s t s i e v e u n l t 40 and second s i e v e u n i t
60 i n s t e p S26, discharge of d e f i b r a t e d m a t e r i a l from t h e f i r s t
sieve u n i t 4 0 a n d s e c o n d s i e v e u n i t 60 s t o p s , a n d d e f i b r a t e d m a t e r i a l
can be s t o r e d i n t h e f i r s t sieve u n i t 40 and second s i e v e u n l t 60.
[GO591
Asinthefirstexample,theconfigurationofthesecondexample
can also shorten the time required for the apparatus to stop by
stopping the first sieve unit 40 and second sieve unit 60 while
d e f i b r a t e d m a t e r i a l r e m a i n s i n s i d e t h e f i r s t s i e v e u n i t 4 0 andsecond
sieve unit 60. In addition, the configuration ofthe secondexample
can store defibrated material inside the flrst sieve unit 40 and
secondsieve unit 60 while suppressing the occurrence of conveyance
problems.
[0060]
Note that a configuration that drives only one of the first
s i e v e u n i t 4 0 a n d s e c o n d s i e v e u n i t 6 0 atalowspeed (aconfiguration
that omits either step 522 or 524) is also conceivable. The same
concept described in the first example also applies to stopping
the supply unit 10 and defibrating unit 20.
[0061]
2-3. Example 3
FIG. 6 is a flow chart of the process controlling stopping
operation in a third example.
[0062]
The control unit 110 first outputs a control signal to the
first driver 111 to stop the supply unit 10 (step 530). Next, the
control unit 110 outputs a control signal to the third driver 113
to change the rotationalspeedofthe first sieve unit40toa slower
speed than the normal operating speed (step S32), and outputs a
control signal to the fourth driver 114 to change the rotational
speed of the second sieve unit 60 to a higher speed than the normal
operating speed (step 534) . Next, the control unit 110 outputs control
signals to the third drlver 113 and fourth driver 114 to stop the
first sieve unit 40 and second sieve unit 60 (step S36). Next, the
control unit 110 outputs a control signal to the second driver 112
to stop the defibrating unit 20 (step 538).
[0063]
The third example differs from the second example in that the
second sieve unit 60 is driven at a higher speed than normal after
introduced to the second sieve unit 60 decreases when the first
sieve unit 40 is driven at a slow speed after the supply unit 10
stops, the amountofdefibratedmaterialdischargedfromthe second
sieve unit 60 also decreases and the amount of material deposited
discharged from the second sieve unit 60 increases as the amount
of defibrated material in the second sieve unit 60 increases, and
increases as the rotational speed of the second sieve unit 60
increases.
[0064]
Therefore, by driving the second sieve unit 60 at a higher
than normal speed in step S34 in the third example, the amount of
defibrated material discharged from the second sieve unit 60 does
not change even if the amount of defibrated material introduced
to the second sieve unit 60 decreases. As a result, the quality
(thickness) of the sheet that is made can be maintained while
controlling stopping the apparatus.
[0065]
Note that rotation of the second sieve unit 60 is stopped in
step 536 before all defibrated material in the second sieve unit
60 is discharged. As a result, as in the first example, the time
until the apparatus stops can be shortened, and the time required
for the apparatus to start next can also be shortened. For example,
stopping rotation of the second sieve unit 60 is timed to when the
amount of defibrated material introduced to the second sieve unit
60 decreases to the point that the amount of defibrated material
discharged from the second sieve unlt 60 cannot be maintained even
if the second sieve unit 60 turns at high speed.
[0066]
2-4. Example 4
FIG. 7 is a flow chart of the process controlling stopping
operation in a fourth example.
[0067]
The control unit 110 first outputs a control signal to the
f i r s t d r i v e r 111 t o s t o p t h e supply u n i t 10 ( s t e p S40). Next, the
c o n t r o l u n i t 110 o u t p u t s a c o n t r o l s i g n a l t o the t h i r d d r i v e r 113
t o change the r o t a t i o n a l s p e e d o f t h e f i r s t s i e v e u n i t 4 0 t o a h i g h e r
speed than t h e normal o p e r a t i n g speed ( s t e p S42). Next, t h e c o n t r o l
u n i t 1 1 0 o u t p u t s a c o n t r o l s i g n a l t o t h e f o u r t h d r i v e r 1 1 4 t o change
t h e r o t a t i o n a l speed o f the second s i e v e u n i t 60 t o a h i g h e r speed
than t h e normal o p e r a t i n g speed ( s t e p S44). Next, the c o n t r o l u n i t
110 o u t p u t s controlsignalstothethirddriver 113 a n d f o u r t h d r i v e r
1 1 4 t o s t o p t h e f i r s t s i e v e u n i t 40 and second s i e v e u n i t 60 ( s t e p
546). Next, t h e c o n t r o l u n i t 110 o u t p u t s a c o n t r o l s i g n a l t o the
second d r l v e r 112 t o stop t h e d e f i b r a t i n g u n i t 20 ( s t e p 5 4 8 ) .
[GO681
The fourthexample d i f f e r s fromthe thirdexample i n t h a t a f t e r
stopplng the supply u n i t 1 0 , t h e f i r s t s i e v e u n i t 40 is driven a t
a h i g h e r speed than normal, and then t h e second s l e v e u n i t 60 is
driven a t a h i g h e r speed than normal. Because t h e amount of def i b r a t e d
m a t e r i a l introduced t o the f i r s t s i e v e u n i t 40 decreases a f t e r t h e
supply u n i t 1 0 s t o p s , the amount of defibratedmaterialdischarged
from t h e f i r s t s i e v e u n i t 40 a l s o d e c r e a s e s .
[0069]
The f l r s t s i e v e u n i t 40 is driven a t a hlgher thannormal speed
i n s t e p S42 i n t h e f o u r t h example so t h a t t h e amount of d e f i b r a t e d
m a t e r i a l discharged from the f i r s t s i e v e u n i t 40 does not change.
The amount of d e f i b r a t e d m a t e r i a l introduced t o the second s i e v e
u n i t 60 i s i n i t i a l l y maintained by the f i r s t s i e v e u n i t 40 t u r n i n g
a t high speed, b u t t h e n g r a d u a l l y d e c r e a s e s because the supply u n i t
10 has stopped. The second s i e v e u n i t 60 is t h e r e f o r e driven a t
a higher than normal speed i n s t e p 544 i n t h e f o u r t h example so
t h a t t h e amount of d e f i b r a t e d m a t e r i a l discharged f r o m t h e second
s i e v e u n i t 6 0 does not change when t h e arnountofdefibratedmaterial
introduced t o the second s i e v e u n i t 60 d e c r e a s e s . As a r e s u l t , t h e
q u a l i t y ( t h i c k n e s s ) of the sheet t h a t is made can be maintained
while c o n t r o l l i n g stopping the apparatus
[0070]
Note t h a t r o t a t i o n o f t h e f i r s t s i e v e u n i t 40 and second s i e v e
u n i t 60 s t o p s i n s t e p S46 before a l l d e f i b r a t e d m a t e r i a l i n s i d e
t h e f i r s t s i e v e u n i t 40 andsecond s i e v e u n i t 60 h a s b e e n d i s c h a r g e d
(while d e f i b r a t e d m a t e r i a l remains i n the f i r s t s i e v e u n i t 40 and
second s i e v e u n i t 6 0 ) . As a r e s u l t , a s i n the f i r s t example, t h e
time u n t i l t h e apparatus stops can be shortened, and t h e time required
f o r the apparatus t o s t a r t next can a l s o be shortened.
[ 0 0 7 1 ]
3. C o n t r o l l i n g s t a r t i n g
The process of c o n t r o l l i n g s t a r t i n g the s h e e t manufacturing
apparatus 1 0 0 according t o t h i s embodiment is described next.
[0072]
3-1. Example 5
FIG. 8 is a flow c h a r t of t h e process c o n t r o l l i n g s t a r t i n g
o p e r a t i o n i n a f i f t h example.
[0073]
The c o n t r o l u n i t 1 1 0 f i r s t o u t p u t s a c o n t r o l s i g n a l t o t h e
s e c o n d d r i v e r 1 1 2 t o s t a r t t h e d e f i b r a t i n g u n i t 2 0 ( s t e p 550). Next,
t h e c o n t r o l u n i t 1 1 0 o u t p u t s a c o n t r o l s i g n a l t o t h e t h i r d d r i v e r
1 1 3 t o s t a r t a n d d r i v e t h e f i r s t s i e v e u n i t 4 0 a t t h e n o r m a l o p e r a t i n g
speed (stepS52).Next,thecontrolunit110 o u t p u t s a c o n t r o l s i g n a l
t o the f i r s t d r i v e r 111 t o s t a r t t h e supply u n i t 10 ( s t e p S54).
Next, the c o n t r o l u n i t 1 1 0 o u t p u t s a c o n t r o l s i g n a l t o the f o u r t h
d r i v e r 1 1 4 t o s t a r t and d r i v e t h e second s i e v e u n i t 60 a t the normal
o p e r a t i n g speed ( s t e p 5 5 6 ) .
[0074]
Because t h e r e is no m a t e r i a l s t o r e d i n t h e d e f i b r a t i n g u n i t
20, t h e d e f i b r a t i n g u n i t 20 s t a r t s f i r s t . The f i r s t s i e v e u n i t 40
s t a r t s next i n p r e p a r a t i o n f o r t h e i n t r o d u c t i o n of d e f i b r a t e d
m a t e r i a l f r o m t h e d e f i b r a t i n g u n i t 2 0 t o t h e c l a s s i f i e r 30 and f i r s t
s i e v e u n i t 40. The supply u n i t 1 0 then s t a r t s and t h e second s i e v e
u n i t 60 s t a r t s . Some time is r e q u i r e d a f t e r the supply u n i t 10 f o r
s u f f i c i e n t d e f i b r a t e d m a t e r i a l t o be supplied downstream from the
d e f i b r a t i n g u n i t 20. However, a s described above, the f i r s t s i e v e
u n i t 4 0 a n d s e c o n d s i e v e u n i t 6 0 a r e stoppedwithdefibratedmaterial
l e f t i n s i d e . As a r e s u l t , t h e f i r s t s i e v e u n i t 40 and second s i e v e
u n i t 60 s t a r t o p e r a t i n g with d e f i b r a t e d m a t e r i a l i n s i d e . There is
t h e r e f o r e no need f o r t h e f i r s t s i e v e u n i t 40 and second s i e v e u n i t
60 t o remain stoppeduntildefibratedmaterialaccumulates i n s i d e .
Defibrated m a t e r i a l can t h e r e f o r e be supplied downstream f r o m t h e
f i r s t s i e v e u n i t 40 and second s i e v e u n i t 60 fromthe time operation
s t a r t s , t h e time r e q u i r e d f o r t h e apparatus t o s t a r t up can be
shortened, and sheet q u a l i t y i s s t a b l e fromthe s t a r t of o p e r a t i o n .
Note t h a t because t h e f i r s t s i e v e u n i t 40 s t a r t s before t h e supply
u n i t 10 s t a r t s , t h e f i r s t s i e v e u n i t 40 s t a r t s before d e f i b r a t e d
mater~alisintroducedtothefirstsieveunit40.Likewise, s t a r t i n g
t h e second s i e v e u n i t 60 may s t a r t before d e f i b r a t e d m a t e r i a l is
introduced from the f i r s t s i e v e u n i t 40.
[0075]
3-2. Example 6
FIG. 9 is a flow c h a r t of t h e process c o n t r o l l i n g s t a r t i n g
o p e r a t i o n i n a s i x t h example.
[ 0 0 7 6 ]
The c o n t r o l u n i t 110 f i r s t outputs a c o n t r o l s i g n a l t o the
second d r i v e r 1 1 2 t o s t a r t the d e f i b r a t i n g u n i t 2 0 ( s t e p S60). Next,
t h e c o n t r o l u n i t 1 1 0 outputs a c o n t r o l s i g n a l t o t h e t h i r d d r i v e r
113 t o s t a r t and d r i v e t h e f i r s t s i e v e u n i t 40 a t the speed of low
speed o p e r a t i o n ( a speed lower than the normal o p e r a t ~ n g speed)
( s t e p 562). Next, t h e c o n t r o l u n i t 110 outputs a c o n t r o l s l g n a l
t o the f ~ r sdtr i v e r 111 t o s t a r t t h e supply u n i t 1 0 s t e p S64). Next,
t h e c o n t r o l u n i t 110 o u t p u t s a c o n t r o l s i g n a l t o the f o u r t h d r i v e r
1 1 4 t o s t a r t and d r i v e t h e second s l e v e u n i t 60 a t the speed of
high speed o p e r a t i o n ( a higher speed than the normal o p e r a t i n g speed)
( s t e p 5 6 6 ) . Next, t h e supply u n i t 1 0 outputs c o n t r o l s i g n a l s t o
t h e t h i r d d r i v e r 113 and f o u r t h d r i v e r 1 1 4 t o change the r o t a t i o n a l
speed of t h e f i r s t s i e v e u n l t 40 and second s i e v e u n i t 60 t o the
normal o p e r a t i n g speed ( s t e p 568).
LO0771
Example 6 differs from example 5 in starting the first sieve
unit 40 at the speedof low speed operation and startingthe second
sieve unit 60 at the speed of high speed operation. Because the
amount of defibrated material introduced to the second sieve unit
6Oislowuntilsufficientdefibratedmaterialissupplieddownstream
from the defibrating unit 20, the second sieve unit 60 is started
atahigh speedsothat the amountofdefibratedmaterialdischarged
fromthe second sieve unit 60 does not change. Furthermore, because
the amount of defibrated material in the second sieve unit 60
decreases suddenly due to high speed operation, the first sieve
unit 40 starts at low speed, defibrated material from the upstream
sideaccumulatesinthe first sieveunit 40, anddefibratedmaterial
can be supplied from the first sieve unit 40 to the second sieve
unit 60 about the time the supply of defibrated material in the
second sieve unit 60 is depleted. The first sieve unit 40 and second
sieve unit 60 then change to normal operation when sufficient
defibrated material is supplied downstream from the defibrating
unit 20. Defibrated material cantherefore be supplied downstream
from the second sieve unit 60 from the time operation starts, the
time required for the apparatus to start up can be shortened, and
sheet quality is stable from the start of operation.
[0078]
3 - 3 . Example 7
FIG. 10 is a flow chart of the process controlling starting
operation in a seventh example.
[0079]
The control unit 110 first outputs a control signal to the
seconddriver 112to s t a r t t h e d e f i b r a t i n g u n i t 2 0 (step 570). Next,
the control unit 110 outputs a control signal to the third driver
113 to start and drive the first sieve unit 40 at the speed of high
speed operation (a speed higher than the normal operating speed)
(step 572). Next, the control unit 110 outputs a control signal
to the first driver 111 to start the supply unit 10 (step 574).
Next, the control unit 110 outputs a control signal to the fourth
d r i v e r 1 1 4 t o s t a r t and d r i v e t h e second s i e v e u n i t 60 a t t h e normal
speed of o p e r a t i o n ( s t e p S76). Next, t h e supply u n i t 10 outputs
a c o n t r o l s i g n a l t o t h e t h i r d d r i v e r 113 t o change t h e r o t a t i o n a l
speed o f t h e f i r s t s i e v e u n i t 4 0 t o t h e normal o p e r a t i n g speed ( s t e p
S78).
[0080]
Example 7 d i f f e r s from example 5 i n s t a r t i n g t h e f i r s t sieve
u n i t 40 a t t h e speed of high speed o p e r a t i o n . Because t h e amount
of d e f i b r a t e d m a t e r i a l introduced t o the f i r s t s i e v e u n i t 40 i s
low u n t i l s u f f i c i e n t d e f i b r a t e d m a t e r i a l is s u p p l i e d downstream
from t h e d e f i b r a t i n g u n i t 20, t h e f i r s t s i e v e u n i t 40 is s t a r t e d
a t a high speed so t h a t t h e amount of defibratedmaterialdischarged
from t h e f i r s t s i e v e u n i t 40 does not change. The f i r s t s i e v e u n i t
40 is then changed t o normal o p e r a t i o n when a s u f f i c i e n t amount
of d e f i b r a t e d m a t e r i a l i s supplied downstream fromthe d e f i b r a t i n g
u n i t 2 0 . A ~a r e s u l t , d e f i b r a t e d m a t e r i a l c a n b e supplieddownstream
from t h e f i r s t s i e v e u n i t 40 and second s i e v e u n i t 60 from the time
o p e r a t i o n s t a r t s , t h e time r e q u i r e d f o r the apparatus t o s t a r t up
can be shortened, and sheet q u a l i t y is s t a b l e from the s t a r t of
o p e r a t i o n .
[0081]
3-4. Example 8
FIG. 11 is a flow c h a r t of t h e process c o n t r o l l i n g s t a r t i n g
o p e r a t i o n i n an e i g h t h example.
LO0821
The c o n t r o l u n i t 1 1 0 f i r s t o u t p u t s a c o n t r o l s i g n a l t o the
s e c o n d d r i v e r 1 1 2 t o s t a r t the d e f i b r a t i n g u n i t 2 0 ( s t e p S80). Next,
t h e c o n t r o l u n i t 1 1 0 outputs a c o n t r o l s i g n a l t o t h e t h i r d d r i v e r
113 t o s t a r t and d r i v e t h e f i r s t s i e v e u n i t 40 a t the speed of low
speed operation ( a speed lower than t h e normal o p e r a t i n g speed)
( s t e p 5 8 2 ) . Next, t h e c o n t r o l u n i t 1 1 0 outputs a c o n t r o l s i g n a l
t o the f i r s t d r i v e r 111 t o s t a r t t h e supply u n i t 10 ( s t e p S84).
Next, t h e c o n t r o l u n i t 110 o u t p u t s a c o n t r o l s i g n a l t o t h e f o u r t h
d r i v e r 1 1 4 t o s t a r t and d r i v e t h e second s i e v e u n i t 60 a t the speed
of low speed operation (step S86). Next, the supply unit10 outputs
control signals to the third driver 113 and fourth driver 114 to
change the rotational speed of the first sieve unit 40 and second
sieve unit 60 to the normal operating speed (step S88).
[0083]
Example 8 differs from example 5 in starting the first sieve
unit40 andsecondsieveunit 60 at the speedof low speedoperation.
Because some time is required until sufficient defibratedmaterial
is supplied downstream from the defibrating unit 20, starting the
first sieve unit 40 and second sieve unit 60 at a low speed allows
defibrated material from the upstream side to accumulate in the
first sieve unit 40 and second sieve unit 60, and when a sufficient
amount of defibratedmaterialis supplied fromthe defibrating unit
20, the flrst sieve unit 40 and second sieve unit 60 are changed
to normal operation. As a result, a sufficient amount of deflbrated
material can be discharged from the second sieve unit 60 and the
quallty of the sheet is stable immediately after the second sieve
unit 60 changes to normal operation.
[0084]
Note that at least one of the first sieve unit 40 and second
sieveunit 60mayremainstoppedin stepS82, 586insteadofstarting
the first sleve unit 40 and second sieve unit 60 at low speed (at
least one of step 582 and 586 may be omitted).
[0085]
4. Variations
The invention includes configurations that are effectively
the same as the configurations described above (configurations of
the same function, method, and result, or configurations of the
same objective and effect). The invention also includes
configurations that replace parts that are not essential to the
configuration described in the foregoing embodiment. Furthermore,
the invention includes configurations having the same operating
effect, or configurations that can achieve the same objective, as
configurations describedinthe foregoing embodiment. Furthermore,
t h e invention i n c l u d e s c o n f i g u r a t i o n s t h a t add technology known
from t h e l i t e r a t u r e t o c o n f i g u r a t i o n s described i n t h e foregoing
embodiment.
[0086]
Sheets m a n u f a c t u r e d b y t h i s s h e e t manufacturing apparatus 100
p o i n t p r i m a r i l y t o products i n t h e form of a s h e e t . The invention
is not l i m i t e d t o making s h e e t s , however, and may make paperboard
andweb forms. Sheets as r e f e r r e d t o h e r e i n a r e s e p a r a t e d i n t o paper
andnonwoven c l o t h . Paper i n c l u d e s products formedinto t h i n s h e e t s
frompulporrecoveredpaperasthe feedstock, a n d i n c l u d e s r e c o r d i n g
paper f o r handwriting and p r i n t i n g , wall paper, packaging paper,
c o l o r p a p e r , drawingpaper, a n d b r i s t o l p a p e r , forexample. Nonwoven
c l o t h i n c l u d e s products t h a t a r e t h i c k e r or have lower s t r e n g t h
than paper, and i n c l u d e s common nonwoven c l o t h , f i b e r b o a r d , t i s s u e
paper, kitchen paper, cleaning paper, f i l t e r paper, l i q u i d
absorption m a t e r i a l s , sound a b s o r b e r s , cushioning m a t e r i a l s , and
mats, f o r example. The feedstock may a l s o be c e l l u l o s e or o t h e r
type of p l a n t f i b e r , s y n t h e t i c f i b e r such as PET (polyethylene
t e r e p h t h a l a t e ) a n d p o l y e s t e r , orwool, s i l k , or o t h e r animal f i b e r .
[0087]
A water m i s t e r f o r adding moisture t o the m a t e r i a l deposited
on t h e d e p o s i t i o n u n i t 72 may a l s o be provided. This enables
i n c r e a s i n g t h e s t r e n g t h of hydrogen bonds when forming a s h e e t P.
Moisture is added t o the d e p o s i t e d r n a t e r i a l by misting b e f o r e p a s s i n g
through the heat r o l l e r s 7 6 . Starch or PVA (polyvinyl a l c o h o l ) ,
f o r example, may be added t o t h e moisture t h a t is misted by t h e
water m i s t e r . This can f u r t h e r i n c r e a s e t h e s t r e n g t h of the sheet
P.
[0088]
The sheet P is wound o n t o a take-up r o l l e r 78 i n t h e example
describedabove, b u t t h e s h e e t Pmaybecutintosheetsofadesirable
s i z e by a c u t t e r not shown and then stacked i n a s t a c k e r .
[0089]
The function of a shredder may a l s o be omitted fromthe supply
unit 10 in the sheet manufacturing apparatus 100. For example, the
shredder function is not needed if material that has shredded by
an existing shredder is used as the feedstock.
[00901
The fifth conveyance unit 85 used as a return path may also
be omitted. Remnants may be recovered and disposed of instead of
being returned to the defibrating unit 20. The fifth conveyance
unit 85 is also not needed if the performance of the defibrating
unit 20 produces no remnants
[Reference Signs List]
[00911
10 supply unit
11 shredder blades
15 hopper
16 hopper
20 defibrating unit
21 inlet
22 outlet
30 classifier
31 inlet
34 bottom discharge port
35 top discharge port
40 first sieve unit
screen
openings
c ap
cap
inlet
outlet
main section
resin supply unit
supply port
second sieve unit
inlet
forming unit
deposition unit
tension rollers
heat rollers
tension roller
take-up roller
first conveyance unit
second conveyance unit
third conveyance unit
fourth conveyance unit
fifth conveyance unit
sixth conveyance unit
sheet manufacturing apparatus
control unit
first drlver
second drlver
third driver
fourth driver
operating unlt
WE CLAIM:
[Claim 11
A sheet manufacturing apparatus comprising:
a sieve unit having at least part of material defibrated in
a defibration process introducedthereto, moving ata first speed,
and passing the defibrated material through multiple openings
disposed in the main section thereof; and
a forming unit forming a sheet using precipitate that past
through the openings of the sieve unit;
the sheetmanufacturing apparatus stopping the sieveunitwlth
defibrated material that was introduced stored inside the sieve
unit.
[Claim 21
Thesheetmanufacturingapparatusdescribedinclaim1, wherein
the defibrated material is stored in the sieve unit by stopping
movement ofthemain section while the defibratedmaterialis being
introduced to the sieve unit.
[Claim 31
T h e s h e e t m a n u f a c t u r i n g a p p a r a t u s d e s c r i b e d i n c l a i m 1 , wherein
the defibrated material is stored in the sieve uni-t by moving the
main section at a lower speed than the first speedwhile the defibrated
material is being introduced to the sieve unit.
[Clalm 41
Thesheetmanufacturingapparatusdescribedinclaim2,wherei~1
the main section moves at a higher speed than the first speed while
the defibrated material is being introduced to the sieve unit, and
movement of the main section stops once the deflbrated material
is stored in the sieve unlt.
[Claim 51
A sheet manufacturing method comprising:
a step of introducing at least part of material defibrated
in a defibration process to a sieve unit, moving a main section
of the sieve unit at a first speed, andpassing the defibratedmaterial
through multiple openings disposed in the main section; and
a step of forming a sheet using precipitate that past through
the openings of the sieve unit;
the sheet manufacturing method stopping the sieve unit with
defibrated material that was introduced stored inside the sieve
unit.