CROSS-REFERENCE TO RELATED PATENT APPLICATION(S)
This patent application is a continuation-in-part patent application of prior United States
Patent Application No. 61/392,506 filed October 13, 201 0 and a continuation-in-part of prior
United States Patent Application No. 61/267,581 filed December 8, 2009. This patent
application also claims the benefit and priority dates of prior United States Patent Application
Nos. 61/392,506 filed October 13, 201 0 and Patent No. 61/267,581 filed December 8, 2009.
TECHNICAL FIELD
An aspect generally relates to (but is not limited to) mold-tools systems including (but not
limited to) a mold-tool system having a manifold body defining uninterrupted melt channels.
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' concept 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 amount of total clamp
force 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, more injection pressure may be needed 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 5536164 discloses a manifold assembly for supplying plastic
material from a plastic source to a mold assembly in an injection molding machine includes
a flexible manifold having an interior conduit connected between the plastic source and the
mold assembly. The flexible manifold is configured to define an input connector, a first
curved segment attached to the input connector, a second curved segment, an output
connector attaching the second curved segment to the mold assembly, and an intermediary
segment connecting the first and second curved segments. This provides the flexible
manifold with a generally S-shaped configuration that flexes with temperature changes to
maintain a substantially constant positioning between the input connector and the output
connector, preventing thermally induced movement of the mold assembly with respect to
the input connector as heated plastic is injected through the conduit.
United States Patent Number 5738149 discloses a manifold assembly for supplying plastic
material from a plastic source to a mold assembly in an injection molding machine includes
a flexible manifold having an interior conduit connected between the plastic source and the
mold assembly. The flexible manifold is configured to define an input connector, a first
curved segment attached to the input connector, a second curved segment, an output
connector attaching the second curved segment to the mold assembly, and an intermediary
segment connecting the first and second curved segments. This provides the flexible
manifold with a generally S-shaped configuration that flexes with temperature changes to
maintain a substantially constant positioning between the input connector and the output
connector, preventing thermally induced movement of the mold assembly with respect to
the input connector as heated plastic is injected through the conduit.
United States Patent Number 6149423 discloses the hot channel die is arranged within a
casing filled with oil. In the hollow space filled with oil, baffles are installed which effect a
current of the oil directed toward the two ends of the die. For this purpose, the heating
element is arranged on the underside of the casing. The discharge sleeve, which introduces
the liquid plastic from the feeding screw, discharges into the hollow body, which is mounted
in a recess in the hot runner plate of a hot channel injection molding die. The distribution
conduits, which are constructed as curved tubes, are installed on the discharge sleeve, and
lead to the side wall, against which the rear ends of the injection nozzles lie. The hollow
space is filled with a heat-conducting medium, for example oil, which is heated by a heater
and uniformly circulated within the hollow space by convention or motorized circulation.
Baffles optimize the circulation of the medium and its return guidance to the heater.
United States Patent Number 5683731 discloses a redistributing device for use with melt
flow exhibiting boundary layer flow and centralized flow comprises a body including a melt
flow inlet end and a plurality of melt flow outlets. A first flow diverter is included for
distributing at least the boundary layer flow among the plurality of the melt flow outlets. A
second flow diverter is included for distributing at least the centralized flow among the
plurality of melt flow outlets.
United States Patent Number 4965028 discloses a method and apparatus for thermoplastic
multigated single cavity or multicavity injection molding. A plasticated melt flows along a melt
distributing passageway, and enters through a plurality of gates associated with and enters
through a plurality of gates associated with one or more mold cavity. Melt temperature is
maintained by means of manifold heaters, bushing heater band and, most preferably, heated
probe. A unique melt conditioning element placed just upstream of gate forces the melt to
enter a plurality of inlet melt channels and flow through a region of constricted cross section
and/or angular change of flow direction formed by the geometric relationship of a bushing
wall to said element. The result is to provide, by design, various degrees of melt heating,
melt filtration, and melt homogenization.
SUMMARY
The inventors have researched a problem associated with known molding systems that
inadvertently manufacture bad-quality molded articles or parts. After much study, the
inventors believe they have arrived at an understanding of the problem and its solution,
which are stated below, and the inventors believe this understanding is not known to the
public.
The inventors believe that known melt channel layouts used in known hot runner system
create a mass imbalance. Every hot runner with multiple drops tries to divide the melt such
that each drop gets an equal amount of resin. The problem is believed to be that most all
intersections are designed to perfectly geometrically divide the melt flow, but are dividing a
non homogeneous melt flow front. In addition, each melt channel splits the melt flow front
and becomes more and more non homogeneous, therefore the more splits there are the
more imbalance exists in the hot runner. Melt channel intersections or splits are typically the
highest stress areas in the known manifold. As the inventors see more challenging
applications, the inventors see the requirement for higher injection pressures. Therefore the
manifold material strength needs to increase to support these larger stresses. The higher
strength material costs more money, and is counter to our goal of reducing our
manufacturing cost of a hot runner.
FIG. 1A depicts a schematic representation of a known mold-tool system (1). The mold-tool
system (1) includes a melt-distribution assembly (2), which includes a manifold body. The
manifold body is of the type known as a gun drilled manifold body. An inlet assembly (3)
includes an inlet (4) defined by the manifold body of the manifold assembly (2). The
manifold body also defines outlets (6A, 6B, 6C, 6D). A melt channel (7) is defined by the
manifold body. The melt channel (7) extends from the inlet (4) along two separate
directions toward split (9A, 9B). The melt channel (7) splits at each split
(9A, 9B) into four separate directions. For example, the melt channel (7) divides from the
split (9A) into four directions in which two of the directions meet up with additional splits
(10A, 10B). A split is an interruption or an intersection in the melt channel (7). The melt
channel (7) further divides out from the splits toward four outlets (depicted but not
identified). A heater (12) is attached to the manifold assembly (2).
FIG. 1B depicts a schematic representation of thermal profiles (14A, 14B, 14C, 14D) of
outputs (6A, 6B, 6C, 6D), respectively, of the known mold-tool system (1) of FIG. 1A. It
appears that different outlets of the manifold body depicted in FIG. 1A each have different
temperature profiles in which some outlets are hotter than other outlets. It will be
appreciated that a colder outlet may result in a light weight molded part, whereas hotter
outlets may results in relatively heavier molded parts because more of the melt may enter
into the mold cavity of a mold assembly that fluidly communicates with the outlet. This is
known as unbalanced filling of the mold assembly, and the inventors believes that the
reason for this is as result of the splits (9A, 9B, 10A, 10B); that is, splitting and re-splitting of
the melt flowing along the melt channel (7). It is believes that another issue that is created
is that the splits create dead zones which are low flow or no flow portions of the melt in the
melt channel 97), which may result in degradation of color changes, etc as a result of a melt
that hangs and fails to move quickly enough from the melt channel (7) fast enough.
According to one aspect, there is provided a mold-tool system comprising: a manifold
assembly, including: a manifold body defining: an inlet assembly; outlets being set apart
from the inlet assembly; and uninterrupted melt channels extending between the inlet
assembly and the outlets.
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:
FIG. 1A depicts a schematic representation of a known mold-tool system (1);
FIG. 1B depicts a schematic representation of thermal profiles of outputs of the known
mold-tool system (1) of FIG. 1A;
FIG. 2A depicts a schematic representation of a mold-tool system (100);
FIG. 2B depicts a schematic representation of thermal profiles of outputs of the mold-tool
system (100) of FIG. 2A;
FIG. 2C depicts a close up view of the mold-tool system (100) of FIG. 2A; and
FIGS. 3A, 3B, 3C, 3D, 3E depict additional aspects of the mold-tool system (100) of FIG.
2A.
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)
FIG. 2A depicts the schematic representation of the mold-tool system (100). The mold-tool
system (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-
446-1 7733-7) 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.
The mold-tool system (100) may be implemented as a hot runner system or may be
implemented as a cold runner system. The mold-tool system (100) is a system that is
supported by a platen assembly (known but not depicted) of a molding system (known and
not depicted), such as an injection molding system.
The mold-tool system (100) may include (and is not limited to): a melt-distribution assembly
(102). The melt-distribution assembly (102) may include (but is not limited to): a manifold
body (104). The manifold body (104) may define: (i) an inlet assembly (106), outlets (108)
that are set apart from the inlet assembly (106), and (iii) uninterrupted melt channels (110)
extending between the inlet assembly (106) and the outlets (108).
The definition of the uninterrupted melt channels (110) is as follows: there are no meltchannel
intersections between the uninterrupted melt channels (110) so that there is no
mixing or flow of a melt (resin) between the uninterrupted melt channels (110); that is, there
is no inter-channel mixing between the uninterrupted melt channels (110). The
uninterrupted melt channels (1 10) are channels that have no breaks in the uninterrupted
melt channels (1 10) so as to avoid causing a split (or a branching) in the flow of a melt
flowing along the uninterrupted melt channels (110). A technical effect of the foregoing is
that each of the outlets (108) may have similar heat profiles. The manifold body (104) may
be manufactured using 3D manufacturing methods or by gun drills, etc. In sharp contrast to
FIG 1A, there are no melt channel splits in the manifold body (4) of the mold-tool system
(100) of FIG. 2A. Each of the uninterrupted melt channels (110) is a single contiguous melt
channel from inlet to outlet for each drop leading into a mold cavity of a mold assembly
(known and not depicted). By removing the splits from the manifold body, high stress
intersections may be removed or reduced, and the imbalance caused by multiple melt
channel splits may also be removed or reduced. Another benefit of not having any split in
the manifold body is that the size of the melt channel may be kept relatively smaller if so
desired (so that a single large melt channel may not be required to carry the melt to the
outlets), and each of the uninterrupted melt channels (110) may need to be large enough to
carry the melt to a single outlet. By reducing the size of the uninterrupted melt channels
(110), the stress may be reduced, and may be able to use weaker, cheaper, and thinner
manifold material for the manifold body (104). The manifold body (104) is depicted having
sixteen outlets (108). The known mold-tool system (1) has relatively poorer thermal
homogeneity while the mold-tool system (100) has relatively improved uniform thermal
uniformity for the outputs. It is preferred that each of the uninterrupted melt channels (110)
is if identical length for balanced melt flow so that the temperature profile for each outlet is
similar. Each of the uninterrupted melt channels (110) continues uninterrupted from a
dedicated inlet and a dedicated outlet the inlet assembly (106) is configured to divide a
flow of melt from to the outlets (108) into geometrically symmetrical portions equivalent to a
number of outlets (108).
FIG. 2B depicts the schematic representation of thermal profiles (114A, 114B, 114C, 114D)
of four of the outlets (108), respectively, of the mold-tool system (100) of FIG. 2A. The
inventors have determined that by using the mold-tool system (100), each of the outlets
(108) of the manifold body (104) each have a similar temperature profile thus avoiding a
situation where some outlets are hotter or cooler than other outlets. This arrangement
advantageously permits improved balanced filling of the mold assembly by avoiding the use
of splits in the uninterrupted melt channels (110).
According to one example of the mold-tool system (100), the inlet assembly (106) includes
a single inlet, and the uninterrupted melt channels (1 10) connect each of outlets (108) to
the single inlet. A heating element (212) may be attached or connected to the manifold
body (104). According to another example of the mold-tool system (100), the inlet assembly
(106) includes inlets (107), the uninterrupted melt channels (110) extend between the inlets
(107) and the outlets (108), and each of the uninterrupted melt channels (110) has a
exclusive pair of inlet and outlet being selected from the inlets (107) and the outlets (108),
and the exclusive pair of inlet and outlet are unassociated with any other uninterrupted melt
channel.
FIG. 2C depicts a close up view of the mold-tool system (100) of FIG. 2A.
FIGS. 3A, 3B, 3C, 3D, 3E depict additional aspects of the mold-tool system (100) of FIG.
2A.
FIG. 3A depicts the perspective view of the mold-tool system (100), in which the mold-tool
system (100) is adapted so that the melt-distribution assembly (102) includes (and is not
limited to the following components: (i) an upper melt-distribution assembly (102A) that has
uninterrupted melt channels (110A) , (ii) a plurality of lower melt-distribution assemblies
(102B) each of which has uninterrupted melt channels (11OB), (iii) a melt distributor
assembly (120) that has (a) an upper melt distributor assembly (120A) , and (b) a plurality of
lower melt distributor assemblies (120B) . the upper melt distributor assembly (120A) is
attached to the upper melt-distribution assembly (102A) . The plurality of lower melt
distributor assemblies (120B) connects the upper melt-distribution assembly (102A) to the
plurality of lower melt-distribution assemblies (1 02B). It will be appreciated that FIG . 2A
depicts an example of a mold-tool system (1 00) that is structured for a single manifold
arrangement for 16 outputs, while FIG . 3A depicts an example of a mold-tool system (100)
that is structured for a multiple manifold arrangement (that is, a cross manifold to sub
manifold arrangement) . Each of the examples uses the uninterrupted melt channels (110).
FIG . 3B depicts a close up perspective view of a lower melt distributor assembly (120B) .
FIG. 3C depicts a close up perspective view of the upper melt distributor assembly (120A) .
FIG . 3D depicts a top view of the lower melt-distribution assembly (1 02B).
FIG . 3E depicts a top view of the upper melt-distribution assembly (102A) .
It is understood that the scope of the present invention is limited to the scope provided by
the independent claim(s), 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 (and is
not limited to)" is equivalent to the word "comprising". It is noted that the foregoing has
outlined the non-limiting embodiments (examples) . The description is made for particular
non-limiting embodiments (examples). It is understood that the non-limiting embodiments
are merely illustrative as examples.

CLAIMS
WHAT IS CLAIMED IS:
1. A mold-tool system (100) [such as a hot runner system], comprising:
a melt-distribution assembly (102), including:
a manifold body (104) defining:
an inlet assembly (106);
outlets (108) being set apart from the inlet assembly (106); and
uninterrupted melt channels (110) extending between the inlet
assembly (106) and the outlets (108).
2. The mold-tool system (100) of claim 1, wherein:
the inlet assembly (106) includes a single inlet; and
the uninterrupted melt channels (1 10) connect each of outlets (108) to the
single inlet.
3. The mold-tool system (100) of claim 1, wherein:
the inlet assembly (106) includes inlets (107); and
the uninterrupted melt channels (110) extend between the inlets (107) and the
outlets (108);
each of the uninterrupted melt channels (110) has a exclusive pair of inlet and
outlet being selected from the inlets (107) and the outlets (108), and the exclusive pair
of inlet and outlet are unassociated with any other uninterrupted melt channel.
4. The mold-tool system (100) of claim 1, wherein:
each of the uninterrupted melt channels (110) continues uninterrupted from a
dedicated inlet and a dedicated outlet.
5. The mold-tool system (100) of claim 1, wherein:
the inlet assembly (106) is configured to divide a flow of melt from to the
outlets (108) into geometrically symmetrical portions equivalent to a number of
outlets (108).
6. The mold-tool system (100) of claim 1, wherein:
the melt-distribution assembly (102) includes:
an upper melt-distribution assembly (102A) having the uninterrupted
melt channels (110A);
a plurality of lower melt-distribution assemblies (102B) each having the
uninterrupted melt channels (110B);
a melt distributor assembly (120) having an upper melt distributor
assembly (120A), and also having a plurality of lower melt distributor
assemblies (120B);
the upper melt distributor assembly (120A) is attached to the upper
melt-distribution assembly (102A); and
the plurality of lower melt distributor assemblies (120B) connects the
upper melt-distribution assembly (102A) to the plurality of lower meltdistribution
assemblies (102B).