WO2012162021A1

WO2012162021A1 - Delivering radiative heat to mold tool system

Info

Publication number: WO2012162021A1
Application number: PCT/US2012/037891
Authority: WO
Inventors: Paul R. Blais; Angelo Mier; Brian Esser
Original assignee: Husky Injection Molding Systems Ltd; Husky Injection Molding Systems SA
Current assignee: Husky Injection Molding Systems Ltd; Husky Injection Molding Systems SA
Priority date: 2011-05-20
Filing date: 2012-05-15
Publication date: 2012-11-29
Anticipated expiration: 2013-11-20

Abstract

A mold-tool system (100), comprising: a heating assembly (102) being configured to deliver heat to a heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat.

Description

DELIVERING RADIATIVE HEAT TO MOLD-TOOL SYSTEM

TECHNICAL FIELD

An aspect generally relates to (but is not limited to) a mold-tool system and/or a molding system having the mold-tool system.

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 the public does not know this understanding.

The current problem is that electrical resistive heater assemblies supply a fixed wattage per linear length of the heater assembly. Known installation method depends on installing the heater assembly to have good thermal conductance to a component of a runner assembly. This arrangement may improve heat transfer. However, heat transfer is a two way street, not only does the above arrangement improve heat going out to the manifold from the heater assembly, but the above arrangement may also improve cooling of the heater assembly at the location of heat losses. For an ideal cased, the temperature of the electric heater is independent of the temperature of the component. However, the next best case may be to limit the effect of the component's temperature on the temperature of the heater assembly. Instead of transferring a majority of the heat by conductance, the solution may reduce, at least in part, heat transfer by conduction and/or may improve heat transfer by radiation.

To resolve the above, at least in part, according to a first aspect, there is provided a mold- tool system (100), comprising: a heating assembly (102) being configured to deliver heat to a heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat. Radiative heat transfer is a function of the fourth power of temperature difference between two bodies (using an absolute scale), and thus is much higher for larger differences in temperature. This then acts as a partially self regulating heat transfer mode, as the amount of heat transferred increases dramatically as the temperature differential increases, and correspondingly decreases as the temperature differential decreases. This is in contrast to conductive and convective heat transfer modes, where the heat transfer typically has a linear relationship as a function of the temperature differential. The ideal resistive heater design combines conductive, convective and radiative heat transfer modes with the contribution of each dependent upon numerous parameters, including but not limited to, materials, desired temperature profiles, environmental conditions, etc.

To resolve the above, at least in part, according to a second aspect, there is provided a mold-tool system (100), comprising: a heatable component (101 ); and a heating assembly (102) being configured to deliver heat to the heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat.

To resolve the above, at least in part, according to a third aspect, there is provided a molding system having any one of the mold-tool system (100) as described above.

To resolve the above, at least in part, according to a fourth aspect, there is provided a runner assembly (916) having the mold-tool system (100) as described above.

To resolve the above, at least in part, according to a fifth aspect, there is provided a method of operating the mold-tool system (100) as described above, the method comprising: delivering heat to a heatable component (101 ) of the mold-tool system (100), the heat being delivered to the heatable component (101 ) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) is a combination of conductive heat and convective heat.

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 to 7 depict schematic representations of a mold-tool system (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 to 7 depict the schematic representations 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: 3-446-21669-2), (ii) "Injection Molding Handbook' authored by ROSATO AND ROSATO (ISBN: 0-412- 99381 -3), (iii) "Injection Molding Systems" 3^rd 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 (and 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 that 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 a schematic representation of a molding system (900) having the mold-tool system (100). The molding system (900) may also be called an injection-molding system for example. According to the example depicted in FIG. 1 , the molding system (900) includes (and is not limited to): (i) an extruder assembly (902), (ii) a clamp assembly (904), (iii) a runner assembly (916), and (iv) a mold assembly (918). By way of example, the extruder assembly (902) is configured, to prepare, in use, a heated, flowable resin, and is also configured to inject or to move the resin from the extruder assembly (902) toward the runner assembly (916). Other names for the extruder assembly (902) may include injection unit, melt-preparation assembly, etc. By way of example, the clamp assembly (904) includes (and is not limited to): (i) a stationary platen (906), (ii) a movable platen (908), (iii) a rod assembly (910), (iv) a clamping assembly (912), and (v) a lock assembly (914). The stationary platen (906) does not move. The stationary platen (906) may be fixedly positioned relative to the ground or floor. The movable platen (908) is configured to be movable relative to the stationary platen (906). A platen-moving mechanism (not depicted but known) is connected to the movable platen (908); the platen-moving mechanism is configured to move, in use, the movable platen (908). The rod assembly (910) extends between the movable platen (908) and the stationary platen (906). The rod assembly (910) is configured to guide movement of the movable platen (908) relative to the stationary platen (906). A clamping assembly (912) is connected to the rod assembly (910). The stationary platen (906) supports the clamping assembly (912). The lock assembly (914) is connected to the rod assembly (910). The movable platen (908) supports the lock assembly (914). By way of example, the runner assembly (916) is attached to or supported by the stationary platen (906). The runner assembly (916) includes (and is not limited to) a mold- tool system (100). The definition of the mold-tool system (100) is as follows: a system that may be positioned and/or may be used in an envelope defined by the stationary platen (906) and the movable platen (908) of the molding system (900). The molding system (900) may include (and is not limited to) the mold-tool system (100). The runner assembly (916) is configured to receive the resin from the extruder assembly (902). By way of example, the mold assembly (918) includes (and is not limited to): (i) a stationary-mold assembly (920), and (ii) a movable-mold assembly (922) that is movable relative to the stationary-mold assembly (920). The movable-mold assembly (922) is attached to or supported by the movable platen (908). The stationary-mold assembly (920) is attached to or supported by the runner assembly (916), so that the movable-mold assembly (922) faces the stationary- mold assembly (920). The runner assembly (916) is configured to distribute the resin from the extruder assembly (902) to the mold assembly (918).

In operation, the movable platen (908) is moved toward the stationary platen (906) so that the stationary-mold assembly (920) is closed against the movable-mold assembly (922), so that the mold assembly (918) may define a mold cavity structure that is configured to receive the resin from the runner assembly (916). The lock assembly (914) is engaged so as to lock the position of the movable platen (908) so that the movable platen (908) no longer moves relative to the stationary platen (906). The clamping assembly (912) is then engaged to apply a camping pressure, in use, to the rod assembly (910), so that the clamping pressure then may be transferred to the mold assembly (918). The extruder assembly (902) pushes or injects, in use, the resin to the runner assembly (916), which then the runner assembly (916) distributes the resin to the mold cavity structure defined by the mold assembly (918). Once the resin in the mold assembly (918) is solidified, the clamping assembly (912) is deactivated so as to remove the clamping force from the mold assembly (918), and then the lock assembly (914) is deactivated to permit movement of the movable platen (908) away from the stationary platen (906), and then a molded article may be removed from the mold assembly (918).

It will be appreciated that: (i) all of the above components, assemblies, etc, may: (i) all be sold separately or provided by a combination of multiple vendors, (ii) some vendors may provide a combination of a limited selection of the above components, assemblies, etc, or, (iii) a single vendor may provide all of the above of the above components, assemblies, etc.

In general terms, referring to FIGS. 2 to 7, there is depicted a first example of the mold-tool system (100), in which the mold-tool system (100) includes (and s not limited to) a heating assembly (102). The heating assembly (102) is configured to deliver heat to a heatable component (101 ). The heat delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat.

In general terms, referring to FIGS. 2 to 7, there is depicted a second example of the mold- tool system (100), in which the mold-tool system (100) includes (and is not limited to): (i) the heatable component (101 ), and (ii) the heating assembly (102). The heating assembly (102) is configured to deliver heat to the heatable component (101 ). The heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat. In general terms, referring to FIGS. 2 to 7, there is depicted a third example of the mold-tool system (100), in which the molding system (900) has or includes the mold-tool system (100).

In general terms, referring to FIGS. 2 to 7, there is depicted a fourth example of the mold-tool system (100), in which a method is associated with operating the mold-tool system (100). The method includes (and is not limited to): delivering heat to the heatable component (101 ) of the mold-tool system (100), in which the heat being delivered to the heatable component

(101 ) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) is a combination of conductive heat and convective heat. Referring now to FIG. 3, which depicts an option of the mold-tool system (100), wherein the heating assembly (102) includes (and is not limited to): an infrared assembly (104) configured to provide infrared-radiative heat to the heatable component (101 ). The heating assembly (102), such as an infrared heaters (by way of example), are non-contact heaters that provide heat to an object receiving the heat primarily through radiative-heat transfer across a gap; the gap exists between the heating assembly (102) and the heatable component (101 ) this is to receive the heat from the heating assembly (102). Aside from a heater support mechanism (configured to support and position the heating assembly (102), no contact of the heating assembly (102) to either the heatable component (101 ) or to the component supporting the heating assembly (102) is required (these may be, in fact, the same component). The support components may transfer some amount of heat (heat conduction) as a consequence of the mechanical coupling with the heating assembly (102), but the coupling mechanism is not intended to be a primary source of heat transfer between the heating assembly (102) and the heatable component (101 ) but rather heat transfer through the mechanical coupling is simply a result of the mechanical coupling, and may be minimized as much as possible.

Referring now to FIG. 4, which depicts an option of the mold-tool system (100), wherein the heating assembly (102) is partially connected to and partially decoupled from the heatable component (101 ). This partial coupling is a consequence of supporting the heating assembly (102) and not intended to be a primary source of heat transfer from the heating assembly

(102) to the item receiving the heat. The primary source of heat transfer from the heating assembly (102) that is to be received by the object or item is radiatve heat.

Referring now to FIG. 5, which depicts an option of the mold-tool system (100), wherein the heating assembly (102) is positioned, at least in part, in a void (106) being defined by the heatable component (101 ). By supporting the heating assembly (102), such as an infrared heater, within the void (106) formed in the heatable component (101 ), all (or at least most) of the radiation emitted from the heating assembly (102) is directed, via the void (106), towards the heatable component (101 ). It will be appreciated that the support structure configured to maintain the heating assembly (102) in position in the void (106) may be minimized so as to reduce heat transfer along the support structure to the heatable component (101 ). This arrangement provides the advantage of improved heating efficiency. However, it will be appreciated that the support structure may provide a degree of mechanical coupling, and so heat transfer along the support structure may be minimized as much as possible.

Referring now to FIG. 6, which depicts an option of the mold-tool system (100), wherein the heating assembly (102) is connected to another component (110) that is located adjacent to the heatable component (101 ). This configuration reduces an amount of mechanical coupling between the heating assembly (102) and the heatable component (101 ), and any associated localized heat transfer to the heatable component (101 ) through the mechanical coupling, and then this arrangement provides for improved consistency of temperature associated with the heatable component (101 ). There may also be advantages from a usability,

manufacturability, and serviceability point of view. Referring now to FIG. 7, which depicts an option of the mold-tool system (100), in which the mold-tool system (100) further includes (and is not limited to) a reflector assembly (112) . The reflector assembly (112) is for reflecting an amount of heat imparted from the heating assembly (102) to the heatable component (101 ). The reflector assembly (112) may be set apart from the heating assembly (102). The reflector assembly (112) improves heating efficiency by increasing amount of heat to be transfered from the heating assembly (102) to the heatable component (101 ). It is noted that the reflector assembly (112) may be used in the arrangements depicted in the other FIGS, such as FIGS. 4 and 6. Additionally, the reflector assembly (112) may also include a mechanism (not depicted) that is configured to support position of the heating assembly (102) relative to the heatable component (101 ).

ADDITIONAL DESCRIPTION

The following clauses are offered as further description of the examples of the mold-tool system (100): Clause (1 ): a mold-tool system (100), comprising: a heating assembly (102) being configured to deliver heat to a heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat. Clause (2): a mold-tool system (100), comprising: a heatable component (101 ); and a heating assembly (102) being configured to deliver heat to the heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat. Clause (3): the mold-tool system (100) of any clause described in this paragraph, wherein: the heating assembly (102) includes: an infrared assembly (104) configured to provide infrared-radiative heat to the heatable component (101 ). Clause (4): the mold-tool system (100) of any clause described in this paragraph, wherein: the heating assembly (102) is partially connected to and partially decoupled from the heatable component (101 ). Clause (5): the mold-tool system (100) of any clause described in this paragraph, wherein: the heating assembly (102) is positioned, at least in part, in a void (106) being defined by the heatable component (101 ). Clause (6): the mold-tool system (100) of any clause described in this paragraph, wherein: the heating assembly (102) is connected to another component (110) that is located adjacent to the heatable component (101 ). Clause (7): the mold-tool system (100) of any clause described in this paragraph, further comprising: a reflector assembly (112) for reflecting an amount of heat imparted from the heating assembly (102) to the heatable component (101 ). Clause (8): the mold-tool system (100) of any clause described in this paragraph, wherein: the reflector assembly (112) is set apart from the heating assembly (102). Clause (9): a molding system (900) having the mold-tool system (100) of any clause described in this paragraph. Clause (10: a runner assembly (916) having the mold-tool system (100) of any clause described in this paragraph. Clause (11 ): a method of operating the mold-tool system (100) of any clause described in this paragraph, comprising: delivering heat to a heatable component (101 ) of the mold-tool system (100), the heat being delivered to the heatable component (101 ) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) is a combination of conductive heat and convective heat.

FIGS. 1 to 7 depict examples of the mold-tool system (100). It will be appreciated that the examples depicted in FIGS. 1 to 7 may be combined in any suitable permutation and combination well within the skill of persons of skill in the art. It will be appreciated that the assemblies and modules described above may be connected with each other as may be required to perform desired functions and tasks that are within the scope of persons of skill in the art to make such combinations and permutations without having to describe each and every one of them in explicit terms. There is no particular assembly, components, or software code that is superior to any of the equivalents available to the art. There is no particular mode of practicing the inventions and/or examples of the invention that is superior to others, so long as the functions may be performed. It is believed that all the crucial aspects of the invention have been provided in this document. 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), comprising:

a heating assembly (102) being configured to deliver heat to a heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat.

2. A mold-tool system (100), comprising:

a heatable component (101 ); and

a heating assembly (102) being configured to deliver heat to the heatable component (101 ), the heat being delivered to the heatable component (101 ) by the heating assembly (102) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) by the heating assembly (102) is a combination of conductive heat and convective heat.

3. The mold-tool system (100) of any preceding claim, wherein:

the heating assembly (102) includes:

an infrared assembly (104) configured to provide infrared-radiative heat to the heatable component (101 ).

4. The mold-tool system (100) of any preceding claim, wherein:

the heating assembly (102) is partially connected to and partially decoupled from the heatable component (101 ).

5. The mold-tool system (100) of any preceding claim, wherein:

the heating assembly (102) is positioned, at least in part, in a void (106) being defined by the heatable component (101 ).

6. The mold-tool system (100) of any preceding claim, wherein:

the heating assembly (102) is connected to another component (110) that is located adjacent to the heatable component (101 ).

7. The mold-tool system (100) any preceding claim, further comprising:

a reflector assembly (112) for reflecting an amount of heat imparted from the heating assembly (102) to the heatable component (101 ).

8. The mold-tool system (100) any preceding claim, wherein:

the reflector assembly (112) is set apart from the heating assembly (102).

9. A molding system (900) having the mold-tool system (100) of any preceding claim.

10. A runner assembly (916) having the mold-tool system (100) of any preceding claim.

11. A method of operating a mold-tool system (100), comprising:

delivering heat to a heatable component (101 ) of the mold-tool system (100), the heat being delivered to the heatable component (101 ) is substantially radiative heat, and the balance of the heat being delivered to the heatable component (101 ) is a combination of conductive heat and convective heat.