Note: Descriptions are shown in the official language in which they were submitted.
CA 02567134 2009-08-31
H-1046-0-CA
A MOLDYNG STRUCTURE AND A lETHOD OF M)LDING
'1'ECBNICAL FIELD i
The present invention generally relates to, but is not limited
to, molding systems, and more specifically the present invention
relates to, but is not limited to, a molding structure, and a
method of molding, amongst other things.
SACRGROM'ID OF THE INVENTION Injection molding systems that are configured to
produce molded
articles having multiple layers of varying thermoplastic
compositions typically have a high capital cost relative to
injection molding systems that are configured to produce molded
articles of a homogenous thermoplastic composition. A molded
article having multiple layers may be, for example, a multi-
preform, of the type that is blow molded into a bottle, A
layer
typical multi-layer preform includes three layers, the inner and
outer layer are made from a first thermoplastic composition, resin 'A', such
as polyethylene terephthalate (PET), while an
intermediate layer may be made from a second thermoplastic
composition, resin 'H', such as ethylene vinyl alcohol copolymer
resin (EVOH). The intermediate layer of 'B' resin is commonly
referred to as a barrier, as it funCtions to prevent oxygen and
other gases from permeating through the molded article which may
otherwise adversely affect the quality of a product, such as a
beverage, that is sealed in the bottle.
The hi.gh capital cost of multi-layer injection molding Systems
presents a capital burden for preform producers (converters),
for example, when purchasing a multi-layer molding system
without first securing firm contracts to supply the multi-layer
preforms. Today, the long lead time required to procure a multi-
material molding system make it difficult for converters to
react quickly to business multi-layer preform supply
opportunities from the relatively fast-paced preform consumer
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market without otherwise having idle multi-layer molding
equipment at the ready. A field upgrade of a purpose built mono-
layer molding system is not practical owing to the extent to
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which the molding structure of the system would need to be
altered, not the least of which is a required machining of the
stationary platen to incorporate a passageway to accommodate a
second injection unit. The net effect of the foregoing is that
preform converters have been reticent to go after multi-layer
preform business.
United States patent 6,517,337 (Inventor: HEHL, Karl, Published:
llth February, 2003) describes an injection molding machine
having a plurality of modular drive groups that provides
possibilities for the customer to optimize the injection molding
machine depending on the injection molded product.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is
provided a modular molding system having an initial-build
configuration for producing a molded article of a first molding
composition. The modular molding system further configured to be
field upgradable with a module to an upgraded configuration for
producing molded articles including a combination of the first
molding composition and a second molding composition.
According to a second aspect of the present invention, there is
provided a method for molding a molded article. The method
includes the steps of factory configuring a modular molding
system having an initial-build configuration for producing a
molded article of a first molding composition, and factory
configuring the modular molding system to be field upgradable
with a module to an upgraded configuration for producing the
molded article including a combination of the first molding
composition and a second molding composition.
A technical effect, amongst others, of the aspects of the
present invention is that the modular molding system provides
the molder, such as a preform converter, the ability to promote
production capacity for multi-layer molded articles, for
example, on a shorter notice and with a lower initial capital
equipment cost than heretofore possible. Upon securing a
contract for the multi-layer preforms the molder need only
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purchase and field install the required module to upgrade the
functionality of the molding system.
Preferable embodiments of the present invention are subject of
the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A better understanding of the exemplary embodiments of the
present invention (including alternatives and/or variations
thereof) may be obtained with reference to the detailed
description of the exemplary embodiments along with the
following drawings, in which:
FIG. 1 is a perspective view of a upgradable injection
molding system according to a first exemplary embodiment (which
is the preferred embodiment);
FIG. 2 is another perspective view of the upgradable
injection molding system of FIG. 1.
The drawings are not necessarily to scale and may be illustrated
having phantom lines, diagrammatic representations and
fragmentary views. In certain instances, details that are not
necessary for an understanding of the exemplary embodiments or
that render other details difficult to perceive may have been
omitted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
With reference to FIG. 1, molding structure is shown that has
been configured for molding multi-layer molded articles, such as
multi-layer preforms. The molding structure includes a modular
molding system 10 having an injection unit 12 and a clamp unit
14. More particularly, the modular molding system 10 includes an
initial-build configuration consistent with a purpose-built
mono-layer system with an upgrade module including the molding
structure of a purpose-built multi-layer molding system.
Alternatively, the molded article could be a simple multi-
material molded article not having discreet layers.
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The initial-build of the injection unit 12 includes an 'A'
injection unit. The 'A' injection unit 30 is arranged on a base
20. More particularly, the base 20 includes a pair of rails 22
upon which a carriage 31 of the 'A' injection unit 30 is
slidably arranged. The carriage 31 is connected to a stationary
platen 100 of the clamp unit 14 by at least one carriage
actuator 24.
The 'A' injection unit 30 includes an extruder 32. Preferably,
but not exclusively, the 'A' injection unit 30 also preferably
includes a shooting pot 36. As shown, the shooting pot 36 is
connected to the extruder 32 by a distributor 34. Each of the
extruder 32, the distributor 34 and the shooting pot 36 are
connected to the carriage 31. Also shown is a screw drive 38 for
operation of a screw (not shown), preferably by means of
rotating and reciprocating of the screw in a barrel (not shown)
of the 'A' extruder 32. The configuration and the operation of
the 'A' injection unit 30 is in keeping with known two-stage
injection units, the structure and the operation of which is
well-known to those skilled in the art, and need not be
described in any detail hereafter. The 'A' injection unit 30 is
also shown as including an 'A' hopper valve 39 for controllably
connecting the extruder 32 with a supply of 'A' resin.
The injection unit 12 is configured, at initial-build, to
receive a 'B' injection unit 50. For example, the base 20 of the
injection unit 12 is configured to include a pair of mounts 64
upon which a 'B' unit support 60 is connectable. The 'B' unit
support 60 comprises a base 61 and a pair of rails 62.
The 'B' injection unit 50 is slideably arranged on the rails 62
of the 'B' unit support 60. The 'B' injection unit 50 includes
an extruder 52 and a screw drive 58 for rotation and
reciprocation of a screw (not shown) in a barrel (not shown) of
the extruder 52. The drive 58 preferably includes an electrical
motor for screw rotation and a hydraulic actuator for screw
reciprocation. Alternatively, the drive 58 may be fully
electric, fully hydraulic, or any combination thereof. The 'B'
injection unit 50 further includes at least one carriage
actuator 52 connecting the carriage 56 to the platen 100 of the
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clamp unit 14. The nozzle 54 is preferably configured to
cooperate with a nozzle shut-off actuator 108 for controllably
connecting the mold (not shown) with the extruder 52. As will be
described hereinafter, the nozzle shut-off actuator 108 is
connected to the stationary platen 100. The 'B' injection unit
50 further includes a nozzle 54 for connection of the extruder
52 to a mold (not shown) . The 'B' injection unit 50 is also
shown as including a 'B' hopper valve 59 for controlling a flow
of molding resin from a reservoir (not shown) to the extruder
52.
The base 20 of the injection unit 12 includes a hydraulic power
pack (not shown) on the non-operator side of the injection unit.
The power pack is accessible behind power pack covers 26, the
power pack cover 26 shown in FIG. 1 being in an open position
for accessing the power pack. A walkway 16 is shown on the non-
operator side of the injection unit 12. Not shown is a removable
power pack cover adjacent to the ladder of the walkway 16. At
the rear of the injection unit 12, just behind the walkway 16,
is a rack 17 for accommodating a plurality of hydraulic
accumulators. The rack 17 shown in FIG. 1 is configured for
accommodating five cylinder-type hydraulic accumulators. The
hydraulic accumulators, as is generally known, are connected to
the power pack (not shown) and with a power manifold 80 shown at
the rear of the injection unit 12. The power manifold 80 is in
turn controllably connected with the actuation devices of the
molding system 10. For example, a set of hydraulic hoses 82 are
shown connecting the power manifold 80 with the 'A' carriage
actuators 24 and the screw drive 38. Also shown are a second set
of hydraulic hoses 84 connecting the power manifold 80 with the
'B' screw drive 58 and the 'B' carriage actuators 24. As shown,
the 'B' unit hydraulic hoses 84 are routed along the base 20 in
a service tray 19.
Along the operator side of the injection unit 12 are the main
control modules 70. The main control modules include a machine
controller 74, shown in hidden lines behind the doors of the
module 70 as well as a control device 76 also show in hidden
lines within the module 70. The controller 74 and the control
device 76 are interconnected by means of a data bus 78. Likewise
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the actuators and feedback devices of the molding system, such
as hydraulic actuators, servo motors, position sensors, pressure
sensors, and the like are interconnected to the control device
76 by the data bus 78 or alternatively or in combination with
dedicated wiring. The main control module 70 further includes a
control interface 79 for interconnection of an auxiliary control
module 72, shown as a free-standing unit. The auxiliary control
module 72 may include control hardware such as servo drives,
injection control cards, and servo amplifiers for controlling of
the drive 56. The auxiliary control module 72 may also include a
controller for the barrel heaters of the 'B' unit extruder 52.
The auxiliary control module 72 may also include a third-party
heat controller for a hot runner of the mold (not shown) or an
interface for connection therewith. The auxiliary control module
72 may also include a dual-voltage control outlet for peripheral
devices such as mixers or blenders. A data bus 78, power cable
77, and device cable 79 are shown linking the main control
module 70 with the auxiliary control module 72
Alternatively, the main control module 70 may otherwise house
the control devices of the auxiliary control module 72.
With reference to FIG. 2, the structure of the 'B' unit support
60 is shown in more detail as including angle brackets 66
supporting the base 61 of the 'B' unit support 60. The brackets
66 connectable to the mounts 64 that are preferably integrated
with the machine base 20. Also shown in FIG. 2 is a purge guard
90 for the 'A' injection unit 30. The 'A' injection unit guard
90 preferably includes an access door through which the operator
can remove drool from the extruder 32. The door (not shown) is
preferably re-located on the non-operator side of the machine
for ease of access. Not shown is a'B' injection unit purge
guard that would otherwise mount to a purge guard mount 109
provided on the rear of the stationary platen 100.
The clamp unit 14 includes a base 102 upon which is slideably
arranged the stationary platen 100. Also shown is a moving
platen 110 that is slideably arranged on the base 102. A series
of tie bars 18 interconnect the moving platen and a clamp (not
shown). The stationary platen 100 includes a platen ear 101 as a
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projection extending from the operator side of the platen 100.
Alternatively the platen ear 101, and hence the 'B' injection
unit 50, could be located on the non-operator side of the platen
100. The platen ear 101 defining a 'B' passageway 106 which
extends between the front and back of the stationary platen 100
for passage of the machine nozzle 54 of the 'B' injection unit
50. Likewise, as shown in FIG. 2, there is provided an 'A'
passageway 104 for passage of a machine nozzle 35 of the 'A'
injection unit 30 for connection with the mold (not shown).
The front face of the stationary platen includes the mold
mounting pattern 103. The mold mounting pattern may include
standard mounting configurations such as Euromap and SPI and may
further include proprietary mounting patterns for such mold
makers as KORTEC (a trademark of Kortec Incorporated,
Massachusetts, USA) for their multi-layer preform molds.
As indicated previously, the stationary platen 100 may include a
nozzle shut-off actuator 108 connected to the platen ear 101
that is configured for operation of the valve of the nozzle 54
of the 'B' injection unit 50.
The modular molding system 10 described hereinbefore is
preferably factory configured to have an initial-build
configuration for producing a molded article of a first molding
composition. The modular molding system 10 configured to be
field upgradable with a module to an upgraded configuration for
producing the molded article including a combination of the
first molding composition and a second molding composition. The
initial-build configuration of the modular molding system 10
preferably includes a molding structure of a purpose-built mono-
layer molding system, and a first subset of a molding structure
of a purpose-built multi-layer molding system. The module having
a remainder subset of the molding structure of the purpose-built
multi-layer molding system.
A technical effect of the exemplary embodiment of the present
invention is that the molder can defer capital expenditure for a
multi-layer molding system until a contract for the molded
article is made knowing that the upgrade of the preconfigured
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monolayer molding system to multi-layer can be purchased,
assembled, and tested at the customer's facility in a short
amount of time.
Accordingly, what follows are examples of differentiating
technical features between a purpose-built mono-layer molding
system and a purpose-built multi-layer molding system.
For example, the injection unit walkway 16 is preferably moved
from the operator side to the non-operator side as shown, but
that there is space on the operator side to accommodate the
injection unit 50.
Alternatively, the accumulator rack 17 may include an extra
mount for an additional accumulator as required to increase the
capacity of the hydraulic system for operation of the injection
unit 50.
Alternatively, the 'B' unit hydraulic hoses 84 and electrical
control cables 85 for the 'B' injection unit may be pre-
configured in service trays 19 on the injection unit base or at
the very least, the service trays 19 are provided and the
hydraulic hoses and electrical cables 84 and 85 would be
supplied at the time of upgrade.
Alternatively, the injection unit base 20 would be pre-
configured to include the mount 64 for the 'B' unit support 60.
Alternatively, the power pack cover (not shown) that is arranged
behind the walkway 16 would need to be removable because the
walkway 16 would prevent the power pack cover 26 from being
opened.
Alternatively, the main control module would be configured to
include the control interface 79 for interconnection of the
auxiliary control module 72. The power manifold 80 would be pre-
configured to include connections for supplying hydraulic fluid
to the 'B' injection unit. The port for the 'B' injection unit
on the power manifold 80 would be plugged at the factory, the
power pack 80 otherwise configured preferably for a continuous
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supply of high pressure oil to the 'B' injection unit once
connected.
The base 20 of the injection unit encompasses a hydraulic tank.
Alternatively, the tank may need to have a capacity that's in
excess of a typical mono-layer to accommodate the 'B' injection
unit 50.
Alternatively, the 'A' purge guard 90 would require that the
door be moved to a non-operator side because the door, which
would normally be on the operator side, is obstructed by the
inclusion of the 'B' injection unit 50 and that also the 'A'
purge guard preferably includes an operator side extension.
Alternatively, the stationary platen 100 would be provided with
covers for the 'B' passageway 106 preferably on the front end
and backs of the platen, although possibly only in the front of
the platen.
Alternatively, the gates of the molding system which are not
shown would need to accommodate the platen ear 101.
Alternatively, other subtleties of the factory assembly of the
modular molding system (10) may include the orientation of the
barrel heaters (not shown) of the 'A' injection unit 30 such
that the clamps (not shown) of the heaters are accessible from
the non-operator side for ease of system maintenance.
Alternatively, a computer-readable product is provided, the
product embodying one or more instructions executable by the
controller 74 for controlling the control device 76' for the 'B'
injection unit 50, and interface screens on the human machine
interface (not shown).
Alternatively, a spacer (not shown) is provided for a molded
article handling device to align the molded article with the
mold.
The first subset of the purpose-built multi-layer molding system
configured with the initial-build configuration from the factory
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preferably includes the stationary platen 100 having the 'A'
passageway 104, the stationary platen 100 having the 'B'
passageway 106, the mount 64, the main control module 70
including the controller 74, the control device 76, and the
control interface 79, the power manifold 80, and a cover plate
for the 'B' passageway 106.
The first subset may also include the expandable accumulator
rack 17, the 'A' purge guard 90, the 'B' service tray 19, the
walkway 16, and the gate.
The remainder subset of the purpose-built multi-layer molding
system configured with the module for field upgrading of the
modular molding system preferably includes the 'B' injection
unit 50, the 'B' unit support 60, the control device 76' for the
'B' injection unit.
The remainder subset may also include the auxiliary control
module 72 including the control device 76' of the ' B' injection
unit, the auxiliary control module 72 configured for connection
with the main control module 70 through a control interface 79.
The remainder subset may also include the computer-readable
product.
Other molding structure that may accompany the module with the
remainder subset includes the 'B' nozzle shut-off actuator 108,
the 'B' purge guard, the 'B' hopper valve 59, the hydraulic hose
84, the cable 85, and the spacer for the molded article handling
device. Likewise, the module may include auxiliary equipment for
the molding system such as a barrier drier for the 'B' molding
composition, and auxiliary equipment such as a shuttle table for
use with the clamp unit 14.
An exemplary method of the present invention includes the steps
of factory configuring a modular molding system 10 having an
initial-build configuration for producing a molded article of a
first molding composition, and factory configuring the modular
molding system 10 to be field upgradable with a module to an
upgraded configuration for producing the molded article
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including a combination of the first molding composition and a
second molding composition. The method also preferably includes
the steps of factory configuring the initial-build configuration
of the modular molding system 10 to include a molding structure
of a purpose-built mono-layer molding system, and the first
subset of a molding structure of a purpose-built multi-layer
molding system. The method further including the step of field
configuring the modular molding system 10 to include the module
having the remainder subset of the molding structure of the
1o purpose-built multi-layer molding system.
The description of the exemplary embodiments provides examples
of the present invention, and these examples do not limit the
scope of the present invention. It is understood that the scope
of the present invention is limited by the claims. The concepts
described above may be adapted for specific conditions and/or
functions, and may be further extended to a variety of other
applications that are within the scope of the present invention.
Having thus described the exemplary embodiments, it will be
apparent that modifications and enhancements are possible
without departing from the concepts as described. Therefore,
what is to be protected by way of letters patent are limited
only by the scope of the following claims:
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