MOLD-TOOL ASSEMBLY HAVING NOZZLE ASSEMBLIES TO PROVIDE
RESINS MOLDED ADJACENTLY
TECHNICAL FIELD
An aspect of the present invention generally relates to (but is not limited to) a
mold-tool assembly having nozzle assemblies configured to provide resins to
mold cavities, the resins provided adjacently to each other.
BACKGROUND
The first man-made plastic was invented in Britain in 1851 by Alexander
PARKES. He publicly demonstrated it at the 1862 International Exhibition in
London, calling the material Parkesine. Derived from cellulose, Parkesine could
be heated, molded, and retain its shape when cooled. It was, however,
expensive to produce, prone to cracking, and highly flammable. In 1868,
American inventor John Wesley HYATT developed a plastic material he named
Celluloid, improving on PARKES' invention so that it could be processed into
finished form. HYATT patented the first injection molding machine in 1872. It
worked like a large hypodermic needle, using a plunger to inject plastic through
a heated cylinder into a mold. The industry expanded rapidly in the 1940s
because World War I I created a huge demand for inexpensive, mass-produced
products. In 1946, American inventor James Watson HENDRY built the first
screw injection machine. This machine also allowed material to be mixed before
injection, so that colored or recycled plastic could be added to virgin material
and mixed thoroughly before being injected. In the 1970s, HENDRY went on to
develop the first gas-assisted injection molding process.
Injection molding machines consist of a material hopper, an injection ram or
screw-type plunger, and a heating unit. They are also known as presses, they
hold the molds in which the components are shaped. Presses are rated by
tonnage, which expresses the amount of clamping force that the machine can
exert. This force keeps the mold closed during the injection process. Tonnage
can vary from less than five tons to 6000 tons, with the higher figures used in
comparatively few manufacturing operations. The total clamp force needed is
determined by the projected area of the part being molded. This projected area
is multiplied by a clamp force of from two to eight tons for each square inch of
the projected areas. As a rule of thumb, four or five tons per square inch can be
used for most products. If the plastic material is very stiff, it will require more
injection pressure to fill the mold, thus more clamp tonnage to hold the mold
closed. The required force can also be determined by the material used and the
size of the part, larger parts require higher clamping force. With Injection
Molding, granular plastic is fed by gravity from a hopper into a heated barrel. As
the granules are slowly moved forward by a screw-type plunger, the plastic is
forced into a heated chamber, where it is melted. As the plunger advances, the
melted plastic is forced through a nozzle that rests against the mold, allowing it
to enter the mold cavity through a gate and runner system. The mold remains
cold so the plastic solidifies almost as soon as the mold is filled. Mold assembly
or die are terms used to describe the tooling used to produce plastic parts in
molding. The mold assembly is used in mass production where thousands of
parts are produced. Molds are typically constructed from hardened steel, etc.
Hot-runner systems are used in molding systems, along with mold assemblies,
for the manufacture of plastic articles. Usually, hot-runners systems and mold
assemblies are treated as tools that may be sold and supplied separately from
molding systems.
United States Patent Number 4521 179 discloses a moveable core ring gated
injection molding system. Pressurized melt from a molding machine flows
through the system and into a cavity. A gate leading to the cavity and a bore in
the movable mold platen are in alignment and of the same size to receive the
head portion of the valve pin which extends from a reduced neck portion.
Actuating mechanism drives the valve pin between a retracted closed position
to an open position in which the reduced neck portion extends into the cavity. In
the closed position, the head portion of the valve pin extends a considerable
distance into the bore in the mold platen to provide sufficient cooling to rapidly
cool the melt in the cavity adjacent the pin. In one embodiment, the valve pin
has a hollow portion adjacent the neck portion to provide the valve pin with
thermal separation between the hot melt and the cool mold platen. In another
embodiment, the valve pin has a copper portion between the hollow portion and
the tip end to promote cooling of the melt in the cavity.
United States Patent Number 5071 335 discloses an injection molding tool for
production of a magnetic tape cassette casing constructed, in part, in two
layers. The apparatus has a fixed core provided, on the rim, with a projection
which provides a sealing strip relative to the moving core. After the injection
molding process into the first mould cavity, the moving core is moved axially
downwards by about half the wall thickness, whereupon the second mould
cavity is filled by injection through a second needle shut-off nozzle.
United States Patent Number 5084223 discloses a mold for forming a magnetic
tape cassette and a method for multi-color molding a magnetic tape cassette or
the like. Sprue-runners connected to submarine gates used in making at least
portions of the cassette are formed with notches near the submarine gates to
reduce the cross-sectional area of the sprue-runners. As result, the spruerunners
can be easily cut off from the body of the cassette by breaking the
notched portions.
United States Patent Number 6074593 discloses an arrangement and method
for mounting a core pin for an injection molding a part, includes mounting a core
pin in a cavity plate to extend upwardly through the cavity and into an opening
in one end of a valve sleeve operated to control melt injection through a gate in
a heated injection nozzle. The core pin moves away from the injection nozzle
when the cavity plate is separated to remove the part.
United States Patent Number 6328920 discloses a plastic part having a
complex structure as a first layer and a simple structure as a second layer, is
formed using a method for molding. Initially, a single mold is provided, the mold
having an interior cavity and a runner reaching from an exterior of the mold to
the cavity. The mold is kept closed while a quantity of a first plastic material is
injected via the runner into the interior cavity to form a first layer of the plastic
part. The mold is then partially opened, creating an increased interior cavity
section, into which a quantity of a second plastic material is injected, via the
runner, to form a second layer of the plastic part. The solidified plastic part can
then be ejected from the mold.
United States Patent Publication Number 20050266254 discloses a plastic
injection molded part having a molded metal reinforcement located therein.
SUMMARY
According to one aspect, there is provided a mold-tool assembly (100),
comprising: a first nozzle assembly (1 10) being configured to provide a first
resin (1 12) to a first mold cavity (1 14); and a second nozzle assembly (1 16)
being configured to provide a second resin (1 18) to a second mold cavity (120),
the second resin (118) being provided adjacent to the first resin (1 12).
Other aspects and features of the non-limiting embodiments will now become
apparent to those skilled in the art upon review of the following detailed
description of the non-limiting embodiments with the accompanying drawings.
DETAILED DESCRIPTION OF THE DRAWINGS
The non-limiting embodiments will be more fully appreciated by reference to the
following detailed description of the non-limiting embodiments when taken in
conjunction with the accompanying drawings, in which:
FIGS. 1 - 3 depict schematic representations of a mold-tool assembly (100).
The drawings are not necessarily to scale and may be illustrated by phantom
lines, diagrammatic representations and fragmentary views. In certain
instances, details not necessary for an understanding of the embodiments
(and/or details that render other details difficult to perceive) may have been
omitted.
DETAILED DESCRIPTION OF THE NON-LIMITING EMBODIMENT(S)
FIGS. 1 - 3 depict schematic representations of a mold-tool assembly (100). The
mold-tool assembly (100) may include components that are known to persons
skilled in the art, and these known components will not be described here; these
known components are described, at least in part, in the following reference
books (for example): (i) "Injection Molding Handbook ' authored by
OSSWALD/TURNG/GRAMANN (ISBN: 3-446-21 669-2), (ii) "Injection Molding
Handbook' authored by ROSATO AND ROSATO (ISBN: 0-41 2-99381 -3), (iii)
"Injection Molding Systems" 3rd Edition authored by JOHANNABER (ISBN 3-446-
17733-7) and/or (iv) "Runner and Gating Design Handbook ' authored by
BEAUMONT (ISBN 1-446-22672-9). It will be appreciated that for the purposes
of this document, the phrase "includes (but is not limited to)" is equivalent to the
word "comprising". The word "comprising" is a transitional phrase or word that
links the preamble of a patent claim to the specific elements set forth in the claim
which define what the invention itself actually is. The transitional phrase acts as a
limitation on the claim, indicating whether a similar device, method, or
composition infringes the patent if the accused device (etc) contains more or
fewer elements than the claim in the patent. The word "comprising" is to be
treated as an open transition, which is the broadest form of transition, as it does
not limit the preamble to whatever elements are identified in the claim.
FIG. 1 depicts the mold-tool assembly (100) in the case before the manufacture
of any molded articles. The mold-tool assembly (100) includes (but is not limited
to): (i) a first nozzle assembly (1 10), (ii) a second nozzle assembly (1 16). The
first nozzle assembly (1 10) is configured, as depicted in FIG. 2, to provide a first
resin (1 12) to a first mold cavity (1 14). FIGS. 1 and 3 depict the first nozzle
assembly (1 10) in a no-flow state (that is, no resin flows), and FIG. 2 depicts the
first nozzle assembly (1 10) in a flow state (that is, resin flows). The second
nozzle assembly (1 16) is configured, as depicted in FIG. 3 , to provide a second
resin (1 18) to a second mold cavity (120), and the second resin (1 18) will be
provided adjacent to the first resin (1 12). FIGS. 1 and 2 depict the second
nozzle assembly (1 16) in a no-flow state (that is, no resin flows), and FIG. 3
depicts the second nozzle assembly (1 16) in a flow state (that is, resin flows).
The mold-tool assembly (100) further includes (but is not limited to): (i) a mold
assembly (122), (ii) a mold pin (124), and (iii) a mold core (126). The mold
assembly (122) has (or defines) the first mold cavity (114) that is in fluid
communication with the first nozzle assembly (1 10), so that the first resin (1 12)
may flow from the first nozzle assembly (1 10) into the first mold cavity (1 14)
when actuated to do so. By way of example, and not limited thereto, the mold
assembly (122) includes a stationary-mold portion and a movable-mold portion
that is movable (and separable) relative to the stationary mold portion. The mold
assembly (122) is supported in platen structure of a molding system (not
depicted but known). The mold pin (124) is in communication with the second
nozzle assembly (1 16) through the first mold cavity (1 14). That is, the mold pin
(124) extends and is movable through the first mold cavity (1 14) when actuated
to do so. The mold core (126) is movable (when actuated to do so) within the first
mold cavity (1 14) between a first position and a second position. The first
position is depicted in FIGS. 1 and 2, and the second position is depicted in Fig.
3 .
In the first position, as depicted in FIG. 1, the mold core (126) defines, at least in
part, the first mold cavity (1 14). More specifically, the mold pin (124) extends
through the first mold cavity (1 14) so as to be in contact with an exit (128) of the
second nozzle assembly (1 16).
In the first position, as depicted in FIG. 2, the first nozzle assembly (1 10)
operates in the flow condition so as to provide the first resin (112) to the first
mold cavity (1 14), and the first mold cavity (1 14) may form a first molded article
(130). In addition, the mold pin (124) extends through the first molded article
(130) so as to form a passageway (132) through the first molded article (130)
toward the second nozzle assembly (1 16).
In the second position, as depicted in FIG. 3 , the mold core (126) is offset (that
is, moved or retracted) from the first molded article (130) formed in the first mold
cavity (1 14) so that the second mold cavity (120) is formed between the first
molded article (130) and the mold core (126). In addition, the mold pin (124) is
moved away from the second nozzle assembly (1 16), and the mold pin (124)
leaves behind the passageway (132) in the first molded article (130) formed in
the first mold cavity (1 14), and the passageway (132) leads from the second
nozzle assembly (1 16) to the second mold cavity (120). In addition, the second
nozzle assembly (1 16) operates in the flow condition to provide the second resin
(1 18) to flow through the passageway (132) past the first molded article (130) to
the second mold cavity (120) so as to form a second molded article (134) in the
second mold cavity (120). Once the second mold cavity (120) is filled then the
second resin (1 18) stops flowing from the second nozzle assembly (1 16). The
first resin (1 12) and the second resin (1 18) solidify, and then the first molded
article (130) and the second molded article (134) may then be removed from the
first mold cavity (1 14) and the second mold cavity (120).
It is understood that the scope of the present invention is limited to the scope
provided by the independent claims, and it is also understood that the scope of
the present invention is not limited to: (i) the dependent claims, (ii) the detailed
description of the non-limiting embodiments, (iii) the summary, (iv) the abstract,
and/or (v) description provided outside of this document (that is, outside of the
instant application as filed, as prosecuted, and/or as granted). It is understood,
for the purposes of this document, the phrase "includes (but is not limited to)" is
equivalent to the word "comprising". The word "comprising" is a transitional
phrase or word that links the preamble of a patent claim to the specific elements
set forth in the claim which define what the invention itself actually is. The
transitional phrase acts as a limitation on the claim, indicating whether a similar
device, method, or composition infringes the patent if the accused device (etc)
contains more or fewer elements than the claim in the patent. The word
"comprising" is to be treated as an open transition, which is the broadest form of
transition, as it does not limit the preamble to whatever elements are identified
in the claim. It is noted that the foregoing has outlined the non-limiting
embodiments. Thus, although the description is made for particular non-limiting
embodiments, the scope of the present invention is suitable and applicable to
other arrangements and applications. Modifications to the non-limiting
embodiments can be effected without departing from the scope of the
independent claims. It is understood that the non-limiting embodiments are
merely illustrative.

WHAT IS CLAIMED IS:
1. A mold-tool assembly (100), comprising:
a first nozzle assembly (1 10) being configured to provide a first
resin (1 12) to a first mold cavity (1 14); and
a second nozzle assembly (1 16) being configured to provide a
second resin (1 18) to a second mold cavity (1 20), the second resin (1 18)
being provided adjacent to the first resin (1 12).
2. The mold-tool assembly (100) of claim 1, further comprising:
a mold assembly (122) having the first mold cavity (1 14) being in
fluid communication with the first nozzle assembly (1 10);
a mold pin (124) being in communication with the second nozzle
assembly (1 16) through the first mold cavity (1 14); and
a mold core (126) being movable within the first mold cavity (1 14)
between a first position and a second position.
3 . The mold-tool assembly (100) of claim 2, wherein in the first position,
the mold core (126) defines, at least in part, the first mold cavity
(1 14), and
the mold pin (124) extends through the first mold cavity (1 14) so as
to be in contact with an exit (128) of the second nozzle assembly (1 16).
4 . The mold-tool assembly (100) of claim 3 , wherein in the first position,
the first nozzle assembly (1 10) provides the first resin (1 12) to the
first mold cavity (1 14), which forms a first molded article (130), and
the mold pin (124) extends through the first molded article (130) so
as to form a passageway (132) through the first molded article (130).
5 . The mold-tool assembly (100) of claim 4 , wherein in the second position,
the mold core (126) is offset from the first molded article (130)
formed in the first mold cavity (1 14) so that the second mold cavity (120) is
formed between the first molded article (130) and the mold core (126).
6. The mold-tool assembly (100) of claim 5 , wherein in the second position,
the mold pin (124) is moved away from the second nozzle
assembly (1 16) and leaves behind the passageway (132) in the first
molded article (130) formed in the first mold cavity (1 14), the passageway
(132) leading from the second nozzle assembly (1 16) to the second mold
cavity (120).
7 . The mold-tool assembly (100) of claim 6, wherein in the second position,
the second nozzle assembly (1 16) provides the second resin (118)
to flow through the passageway (132) past the first molded article (130) to
the second mold cavity (120) so as to form a second molded article (134)
in the second mold cavity (120).
8 . A molding system having the mold-tool assembly (100) of any one of claims 1
to 7 .