WO2015157151A1

WO2015157151A1 - Molding material distributor

Info

Publication number: WO2015157151A1
Application number: PCT/US2015/024466
Authority: WO
Inventors: Darrin Albert Macleod; Dietmar Tiemo BRAND; Stephen Daniel Ferenc; William Steven Keir; Manon Danielle Belzile
Original assignee: Husky Injection Molding Systems Ltd.
Priority date: 2014-04-07
Filing date: 2015-04-06
Publication date: 2015-10-15

Abstract

A molding material distributor (100) including a split manifold assembly (110). The split manifold assembly (110) defines a flow channel (112) configured to convey, in use, a molding material. The split manifold assembly (110) includes a selectively operable flow-control device (140) contacting, in use, the molding material. The selectively operable flow-control device (140) is configured to be selectively controllable for controlling a flow of the molding material through the flow channel (112).

Description

MOLDING MATERIAL DISTRIBUTOR TECHNICAL FIELD

Non-limiting embodiments disclosed herein generally relate to molding material distributors for use in molding systems.

BACKGROUND

Molding is a process by virtue of which a molded article can be formed from a molding material by using a molding system. Various molded articles can be formed by using a molding process, such as an injection molding process. An example of a molded article that can be formed, for example, from polyethylene terephthalate (PET) is a preform suitable for subsequent blow molding into a final shaped container.

A typical molding system includes (among other things): (i) an injection unit, (ii) a clamp assembly, (iii) a mold assembly, and (iv) a molding material distributor, e.g. a hot runner.

In the operation of a typical molding system, the injection unit forces a desired amount of the molding material into a molding cavity defined by the mold assembly. The molding material may enter the mold cavity through a gate via the molding material distributor. Usually, the molding material distributor and the mold assembly are treated as tools that may be sold separately (or together) from molding systems.

SUMMARY

In accordance with an aspect disclosed herein, there is provided a molding material distributor including a split manifold assembly. The split manifold assembly defines a flow channel configured to convey, in use, a molding material. The split manifold assembly includes a selectively operable flow-control device contacting, in use, the molding material. The selectively operable flow-control device is configured to control a flow of the molding material through the flow channel.

These and other aspects and features of non-limiting embodiments will now become apparent to those skilled in the art upon review of the following description of specific non-limiting embodiments in conjunction with the accompanying drawings. DESCRIPTION OF THE DRAWINGS

The non-limiting embodiments will be more fully appreciated by reference to the accompanying drawings, in which:

FIG. 1 depicts a schematic representation of a molding system according to a first non-limiting embodiment.

FIG. 2 depicts a transparent, exploded view of a perspective schematic representation of a split manifold assembly according to a first non-limiting embodiment.

FIG. 3A depicts a perspective schematic representation of a part of the split manifold assembly shown in FIG. 2.

FIG. 3B depicts a perspective schematic representation of a part of the split manifold assembly shown in FIG. 2.

FIG. 4 depicts a perspective schematic representation of a part of the split manifold assembly shown in FIG. 2.

FIG. 5 depicts a perspective schematic representation of a part of the split manifold assembly shown in FIG. 2.

The drawings are not necessarily to scale and may be illustrated by phantom lines, schematic representations and fragmentary views. In certain instances, details that are not necessary for an understanding of the embodiments or that render other details difficult to perceive may have been omitted.

DETAILED DESCRIPTION OF THE NON-LIMITING EMBODIMENT(S)

Reference will now be made in detail to various non-limiting embodiment(s) of a molding system and a molding material distributor for use in a molding system. It should be understood that other non- limiting embodiment(s), modifications and equivalents will be evident to one of ordinary skill in the art in view of the non-limiting embodiment(s) disclosed herein and that these variants should be considered to be within scope of the appended claims. Furthermore, it will be recognized by one of ordinary skill in the art that certain structural and operational details of the non-limiting embodiment(s) discussed hereafter may be modified or omitted (i.e. non-essential) altogether. In other instances, well known methods, procedures, and components have not been described in detail.

FIG. 1 is a schematic representation of a molding system 900 in accordance with a first non-limiting embodiment. Generally, the molding system 900 includes (among other things): (i) an injection unit 902, (ii) a clamp assembly 904, (iii) a mold assembly 906, and (iv) a molding material distributor 100. The injection unit 902 includes (among other things): (i) a barrel 912, (ii) a hopper 914, (iii) a heater 916, and (iv) a screw 918. The mold assembly 906 includes (among other things): (i) a movable mold portion 910, and (ii) a stationary mold portion 908. The movable mold portion 910 and the stationary mold portion 908 may cooperate to define a mold cavity 920.

The molding material distributor 100 includes a split manifold assembly 110. The split manifold assembly 110 is configured to convey, in use, a molding material from the injection unit 902 to the mold assembly 906. The split manifold assembly 110 defines a flow channel 112 in fluid communication with the injection unit 902 and the mold assembly 906. The split manifold assembly 110 includes a first manifold sub-assembly 120. The split manifold assembly 110 further includes a second manifold sub-assembly 130. As depicted in FIG. 1, the first manifold sub-assembly 120 and the second manifold sub-assembly 130 are attached. The molding material distributor 100 may also include a sprue (not depicted) to receive molding material from the injection unit 902 and a nozzle (not depicted) to transfer the molding material from the flow channel 112 to the mold cavity 920.

At least one of the first manifold sub-assembly 120 and the second manifold sub-assembly 130 defines a groove. The groove partially defines the flow channel 112.

The first manifold sub-assembly 120 and the second manifold sub-assembly 130 may be attached by any suitable means. For example, the first manifold sub-assembly 120 and the second manifold subassembly 130 may be attached via a fastener (e.g. screw, bolt, rivet, etc.). Welding, brazing, transient liquid phase bonding, and diffusion bonding may also attach the first manifold sub-assembly 120 and the second manifold sub-assembly 130. Any combination of any suitable means may also attach the first manifold sub-assembly 120 and the second manifold sub-assembly 130 (e.g. a combination of welding and fastening, etc.). In operation, the clamp assembly 904 closes the mold assembly 906 such that the mold cavity 920 is defined. The clamp assembly 904 is configured to apply a clamping force that squeezes the mold assembly 906 together as the mold cavity 920 is injected with the molding material from the injection unit 902. As depicted in FIG. 1, the injection unit 902 injects the molding material into the mold cavity 920 via the molding material distributor 100, which then conveys the molding material to the mold assembly 906.

FIG. 2 is schematic representation of the split manifold assembly 110 of FIG. 1, in accordance with a non-limiting embodiment. The first manifold sub-assembly 120 defines a first groove 122. The second manifold sub-assembly 130 defines a second groove 132. The first groove 122 and the second groove 132 cooperate to define the flow channel 112 when the first manifold sub-assembly 120 and the second manifold sub-assembly 130 are attached.

The first manifold sub-assembly 120 and the second manifold sub-assembly 130 may be manufactured by any suitable means. For example, a machine may be used to form, integrally, the first groove 122 and the second groove 132 with the first manifold sub-assembly 120 and the second manifold sub-assembly 130, respectively. One example of a suitable machine is a milling machine.

Another example of a manufacturing method for forming the first groove 122 and the second groove 132 is a solid freeform fabrication process (SFF). SFF is an additive manufacturing fabrication process. SFF is a collection of techniques for manufacturing solid objects by the sequential delivery of energy and/or material to specified points in space to produce that solid. SFF is sometimes referred to as rapid prototyping, rapid manufacturing, layered manufacturing, additive fabrication, and free form manufacturing.

Yet another example of a manufacturing method for making the first manifold sub-assembly 120 and the second manifold sub-assembly 130 is to use a non-solid freeform fabrication, such as casting. Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various cold setting materials that cure after mixing two or more components together. Examples of casting materials include epoxy, concrete, plaster, clay, etc.

The split manifold assembly 110, as depicted in FIGS. 1-4, further includes a selectively operable flow-control device 140 contacting, in use, the molding material. The selectively operable flow- control device 140 is configured to control a flow of the molding material through the flow channel 112. The selectively operable flow-control device 140 may be at least partially located in at least one of the first groove 122 and the second groove 132. The selectively operable flow-control device 140 may be any selectively operable flow-control device 140 known to a person skilled in the art. Examples of suitable selectively operable flow-control devices include suitable selectively operable heaters, selectively operable pumps, selectively operable valves, selectively operable mixers, selectively operable heated pumps, selectively operable heated valves, selectively operable heated mixers, etc.

Suitable selectively operable heaters include (and are not limited to) heaters applied by thermal spraying techniques (e.g. plasma spraying, etc.), thin film heaters, and thick film heaters, etc. Suitable selectively operable pumps include (and are not limited to): positive displacement pumps (e.g. gear pumps, screw pumps, peristaltic pump, plunger pumps, etc.), etc. Suitable selectively operable valves include (and are not limited to): piezoelectric valves, etc.

With reference to FIGS. 1-3, at least one of the first groove 122 and the second groove 132 define a chamber 150. The selectively operable flow-control device 140 may be disposed in the chamber 150. The chamber 150 is configured to contain, at least partially, the selectively operable flow-control device 140. When the first manifold sub-assembly 120 and the second manifold sub-assembly 130 are attached, the chamber 150 is in fluid communication with the flow channel 112. When located in chamber 150, the selectively operable flow-control device 140 partially defines the flow channel 112. As depicted, a volume of the chamber 150 defined by the first groove 122 is equal to a volume of the chamber 150 defined by the second groove 132. However, according to a non- limiting embodiment (not depicted), a volume of the chamber 150 defined by the first groove 122 is not equal to a volume of the chamber 150 defined by the second groove 132. According to another non-limiting embodiment (not depicted), at least one of the first manifold sub-assembly 120 and the second manifold sub-assembly 130 further defines an access channel configured to permit access to the selectively operable flow-control device 140 when first manifold sub-assembly (120) and the second manifold sub-assembly (130) are attached. According to another non- limiting embodiment (not depicted), at least a portion of the selectively operable flow-control device 140 may be located in the access channel. As depicted in FIG. 3 A, the selectively operable flow-control device 140 located in chamber 150 is a valve configured as an orifice insert 142. The orifice insert 142 defines a continuous portion (i.e. uninterrupted portion) of the flow channel 112.

As depicted in FIG. 3B, the selectively operable flow-control device 140 located in chamber 150 is a valve configured as an intersection insert 144. The intersection insert 144 defines a channel intersection of the flow channel 112. As depicted in FIG. 4, the selectively operable flow-control device 140 is a thermally sprayed heater 146. The thermally sprayed heater 146 is deposited as a layer in the second groove 132. As depicted in FIGS. 2 and 5, the split manifold assembly 110 further includes a sensor 160. Generally, the sensor 160 is configured to sense, in use, a parameter associated with a flow of the molding material through the flow channel 112. The sensor 160 may also provide an output signal expressing the sensed parameter associated with the flow of the molding material through the flow channel 112.

The parameter associated with the flow of the molding material may be any suitable parameter known to a person skilled in the in the art. For example, parameters such as temperature, pressure, flow rate, viscosity, etc., may be used to understand properties of the molding material at a first location of the flow channel 112, and then compared with properties of the molding material at a second location of the flow channel 112. The difference may be analyzed to determine how to control the selectively operable flow-control device 140 to control, for example, fill rates of a plurality of identical mold cavities.

As depicted in FIGS. 1 and 5, the molding material distributor 100 further includes a controller 170 associated with the selectively operable flow-control device 140 and the sensor 160. Generally, the controller 170 is configured to control an operating parameter of the selectively operable flow-control device 140. According to a non- limiting embodiment, the controller 170 may be configured as an open- loop controller. According to another non- limiting embodiment, the controller 170 may be configured as a closed- loop controller, whereby the controller 170 receives and monitors the output signal and determine a fault condition based on a comparison made between the output signal and a predetermined threshold. The predetermined threshold may be a threshold value stored by the controller 170.

In operation, when the controller 170 is configured as a closed- loop controller, when the molding system 900 is activated, with the injection unit 902 operating, the molding material is conveyed from the hopper 914 by the screw 918. The screw 918 will inject the molding material into the mold cavity 920 via the molding material distributor 100.

The controller 170 may start monitoring the output signal provided by the sensor 160, for example, at the time at which injection unit 902 begins operating. The controller 170, depending on what the desired outcome is, may determine a fault condition based on a comparing the monitored output signal and a selected threshold. If the fault condition is determined, the controller 170 may take corrective action and/or signal the fault condition to an operator.

For example, where the molding system 900 includes a plurality of identical mold cavities, and the output signal expresses a flow rate of the molding material through the flow channel 112, the controller 170 may monitor whether the fill rates of the plurality of identical mold cavities are balanced. On determining imbalance, the controller 170 could control one or more selectively operable flow-control devices 140, thereby be selectively controllable for controlling the flow of the molding material through the flow channel 112 to correct the imbalance.

It is noted that the foregoing has outlined some of the more pertinent non-limiting embodiments. It will be clear to those skilled in the art that modifications to the disclosed non-embodiment(s) can be effected without departing from the spirit and scope thereof. As such, the described non-limiting embodiment(s) ought to be considered to be merely illustrative of some of the more prominent features and applications. Other beneficial results can be realized by applying the non-limiting embodiments in a different manner or modifying them in ways known to those familiar with the art. This includes the mixing and matching of features, elements and/or functions between various non- limiting embodiment(s) expressly contemplated herein. Thus, one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless described otherwise, above. Although the description is made for particular arrangements and methods, the intent and concept thereof may be suitable and applicable to other arrangements and applications.

Claims

WHAT IS CLAIMED IS:

A molding material distributor (100) comprising:

a split manifold assembly (110) defining a flow channel (112) configured to convey, in use, a molding material, the split manifold assembly (110) including:

a selectively operable flow-control device (140) contacting, in use, the molding material, the selectively operable flow-control device (140) configured to control a flow of the molding material through the flow channel (112).

The molding material distributor (100) of claim 1, wherein the split manifold assembly (110) further includes:

a first manifold sub-assembly (120); and

a second manifold sub-assembly (130), wherein at least one of the first manifold subassembly (120) and the second manifold sub-assembly (130) define a groove, the groove partially defining the flow channel (112).

The molding material distributor (100) of claim 2, wherein:

the first manifold sub-assembly (120) defines a first groove (122); and

the second manifold sub-assembly (130) defines a second groove (132), wherein the first manifold sub-assembly (120) and the second manifold sub-assembly (130) are attached such that the first groove (122) and the second groove (132) cooperate to at least partially define the flow channel (112).

The molding material distributor (100) of claim 3, wherein:

the selectively operable flow-control device (140) is at least partially located in at least one of the first groove (122) and the second groove (132).

The molding material distributor (100) of claim 3, wherein:

the selectively operable flow-control device (140) is integrally formed with at least one of the first manifold sub-assembly (120) and the second manifold sub-assembly (130).

The molding material distributor (100) of claim 3, wherein:

the selectively operable flow-control device (140) is deposited as a layer in at least one of the first groove (122) and the second groove (132).

The molding material distributor (100) of claim 3, wherein: at least one of the first groove (122) and the second groove (132) define a chamber (150) in fluid communication with the flow channel (112), the chamber (150) being configured to at least partially contain the selectively operable flow-control device (140).

8. The molding material distributor (100) of claim 7, wherein:

the selectively operable flow-control device (140) at least partially defines the flow channel (112).

9. The molding material distributor (100) of claim 1, wherein:

the selectively operable flow-control device (140) is configured as an orifice insert (142) defining a continuous portion of the flow channel (112).

10. The molding material distributor (100) of claim 1, wherein:

the selectively operable flow-control device (140) is configured as an intersection insert (144) defining a channel intersection of the flow channel (112).

11. The molding material distributor (100) of claim 1, wherein:

the selectively operable flow-control device (140) is configured as a thermally sprayed heater (146) deposited as a layer in the flow channel (112).

12. The molding material distributor (100) of claim 1, further comprising:

a controller (170) associated with the selectively operable flow-control device (140), the controller configured to control the selectively operable flow-control device (140).

13. The molding material distributor (100) of claim 12, wherein the split manifold assembly (110) further includes:

a sensor (160) configured to sense, in use, a parameter associated with the flow of the molding material through the flow channel (112) and provide an output signal, wherein the controller (170) is configured to receive and monitor the output signal and control the selectively operable flow-control device (140) based on a comparison made between the output signal and a predetermined threshold.

14. The molding material distributor (100) of claim 13, wherein:

the controller (170) is configured to cooperate with the sensor (160) and the selectively operable flow-control device (140) for balancing the flow of the molding material through the flow channel (112).