This invention concerns the use of improved heating and or cooling arrangement incorporating a thermal coupling layer that enhances thermal performance, product economics and productivity of an injection moulding tool or CFRP Layup tool that more specifically delivers improved temperature uniformity across entire surface of tool in reduced time improving process economics and or quality.

Background to the Invention

Injection moulding tools are used in industry to form thermoplastic polymers into a variety of complex shapes. The process involves the injection of a pre-prepared pliable thermoplastic into a tool, which may have been preheated, whereupon it acquires the shape of the mould cavity within the tool. The thermoplastic is then cooled so that it sets while retaining the shape of the cavity. Other common terms for the tool are mould or die, made up of in simplest form a Cavity and Core. It is a well-established method known as RHCM or Variotherm to mould parts that have superior surface reproduction and are free of surface defects like weld lines or gloss variation caused by premature cooling of the melt. Herein the tool is heated to a substantially high temperature, typically near to vicat softening temperature of the moulding Material prior to injection of material followed by cooling the tool and part there-in. In a good design of the tool, the heating and or cooling conduits are so configured that the surface of tool achieves target temperature uniformly over entire surface in a very short time. The uniformity of temperature is important from quality requirements and getting there quickly is economic requirement that allows for fast cycling of tool to produce more parts of acceptable quality in fastest possible time.

Lack of temperature uniformity in a commercially acceptable time frame affects quality of parts produced that have defects like gloss variation, "Imprinting" of cooling or heating channel layout on the moulded article, "Tiger Stripes".

It will be advantageous to bring heat exchange conduits close to the surface and preferably conformal to surface allowing rapid heat exchange with Surface and place them very close to each other in a tight pitch configuration, ideally touching each other ensuring uniformity of temperature on tool Surface. However there are practical limitations as to how close two adjacent heat exchange conduits can be placed. For example if induction heating means are built in tool surface and brought very close to each other laterally, then it leaves no room to place cooling channels close to surface which will affect time required to cool the moulded part affecting cycle time. That limitation is cause of temperature variation between a point on tool surface that is directly in front and closest to a given heat exchange conduit or portion of it and at a point on the tool surface that is farthest removed from closest heat exchange conduit, typically in between two adjacent heat exchange conduits.

Another major area where thermodynamic performance affects process economics significantly is in manufacture of CFRP panels e.g. Carbon fiber reinforced aerospace

1

Substitute Sheet

(Rule26)RO/AU components where entire tool is heated in an autoclave or an aeroclave and significant time is lost in trying to raise temperature of tool itself due to significant mass and associated thermal inertia.

Various efforts are made in prior art to overcome some of the challenges.

PCT/AU2014/001184

Conformal Cooling Tool With Rapid Heat Cycle Performance shows variety of means to provide heat exchange conduit close to surface. This disclosure fails to control temperature variation when heating and cooling means are discrete as it leads to increased spacing among them.

US 8770968 B2

Injection molding tool with embedded induction heater

Main disadvantage here is that heating will take place in top face of tool causing that area to get extremely hot while the Zone adjacent to the heated zone may have lot less temperature. If the induction heater is placed extremely close to each other the heating uniformity may improve but leaves no room for laying cooling channels and heat removal aspect of tool may be very badly compromised affecting productivity out of such a tool.

US 20020100858 A1

A double-shell nickel mold produced by nickel vapor deposition. This method suffers from high temperature variation across its Surface, that leads to gloss and texture variation and "imprinting" of the heating or cooling lines is typically visible on the moulded part. And there is no way to control chilling of moulded article in immediate vicinity of the cooling channel and appearance and or property variation is a real quality issue. Furthermore Ni shells do not chemically etch well and traditional methods of texture production are ineffective.

Permanent mould for metal-, plastic- and glass casting

EP 0711615 B1 (Priority date Nov 9, 1994)

Discloses a method of manufacturing a mould out of high conductivity Material like Copper having diffusion bonded layer of steel such that high conductivity tool having wear resistance of steel is produced. This method suffers from high cost and size limitations associated with diffusion bonding process and issues related to differential thermal expansion during diffusion bonding process that has high likelihood of failed bond and or distorted tool. This method cannot be applied in free form shapes in large tools as matching precisely complex shapes without any gaps is not practically achievable. This is essentially a copper tool with hard wearing skin and this method fails to deliver thermal performance when the tool has to be made of special metals e.g. Invar.

Mould With Conformal Cooling

CA 2713824 A1, Zaffino, Pascal, CA

Discloses provision of conformal cooling channels by milling from top Surface and welding the opening leaving a cooling channel underneath the welding. This method also suffers from high temperature variation across its surface.

Technical Problem

2

Substitute Sheet

(Rule26)RO/AU In some aspects all of prior art suffer from high temperature variation on tool face and or limitation forced by the physical restriction about how close or how conformal to tool face various means of heating or cooling can be provided, major restriction on a core side coming from the fact that various mechanisms like ejectors, side cores and lifters have to be provided on a tool and that forces apart, at least partially, the placement of heating and cooling means leading to high temperature variation on tool face for a given time of heating or high variation of rate of cooling for a given cooling time.

If heating and cooling means are separate than alternating laterally or axially the means of heating or cooling makes either one of the functions compromised affecting cycle time or quality or both.

Advantageous Effects of Invention

It would be desirable improvement in tools, and is intent of the present invention, that very high rate of heat addition or heat removal at improved temperature uniformity is achieved within shortest possible time applicable to any moulding tool without size limitation.

Summary of the Invention

A component of a moulding tool a first tool body at least partially having laminated construction arranged in at least three zones Zone 1 , Zone 2 and Zone 3 sequentially arranged:

The Zone 3 base made of third material having interface 3 having provision of at least one means of heating and or means of cooling advantageously conformal and in close proximity of the interface 3, advantageously the third material is a metal having high mechanical strength and low cost by way of example including but not limited to structural steel,

The Zone 2 thermal coupling layer made of second material advantageously in permanent connection with the base applied on top of and covering substantially entirety of the interface 3 having two opposing surfaces interface 2 and interface 22 generally parallel to each other and to the interface 3, interface 2 in intimate contact with the interface 3 and interface 22 farthest removed from the interface 2, advantageously the second material is metal having high thermal conductivity by way of example including but not limited to Copper or Aluminium,

The Zone 1 functional layer made of first material applied on top of the thermal coupling layer having two opposing surfaces interfacel and first top face generally parallel to each other, the interface 1 in intimate contact and permanent connection covering substantially entirety of the interface 22 and the first top face removed from the interface 1 forming at least part of moulding surface, advantageously the first material is metal having high mechanical strength, wear resistance, permeability to electromagnetic field including but not limited to tool steels H13, Invar, Titanium, Nickel, AISI 1 .2344,

P20/AISI 1 .2312 or AISI 420, ferromagnetic material, non-ferromagnetic material, so characterised that thermal conduction to the first top face from the means of heating and or thermal conduction from the first top face to the means of cooling when activated and or thermal conduction from regions of high temperature to regions of lower temperature that may be present on the first top face thermal energy accelerates

3

Substitute Sheet

(Rule26)RO/AU laterally through the thermal coupling layer improving temperature uniformity on the first top face in reduced time improving process economics and or quality.

The functional layer as previously defined is optionally at least partially made of fourth material strategically applied having different thermal conductivity or the functional layer is having varying thickness improving temperature uniformity on the first top face enabling controlled rate of heat transfer selectively between means of heating and or means of cooling and the functional layer.

In a preferred embodiment at least some of the means of heating and or the means of cooling as previously defined in simplest form are made up of heat transfer conduit provided for by drilling passages through the base however advantageously but not limited to by laying pipes in channels milled in the base from the interface 3 optionally incorporating process monitoring sensors and electronics followed by covering the pipes with application of fifth material generally level with opening of the channel to the interface 3, followed by application of the thermal coupling layer followed by application of the functional layer and advantageously shape of the channels and choice of the fifth material is based on requirements of structural strength and or rate of heat transfer to and from the pipes, optionally the fifth material is same as the second material and the pipes are in a non-limiting case are made of copper and connected making up a closed loop circuit in communication to heating fluid and or cooling fluid supply and at least through some of the pipes advantageously flow of the heating fluid and the cooling fluid is alternated.

At least some of the heat transfer conduit as previously defined is provided for by sacrificial core material in a non-limiting case water soluble salts or wax based material or hollow polymeric tube inlaid in bottom of channels milled in the base preferably from the interface 3, preparing top surface of so laid material to predetermined finish, texture, geometry and dimensions followed by application of the thermal coupling layer followed by application of the functional layer and the sacrificial core material is removed at some stage of manufacture and the conduit is connected in closed loop circuit in

communication to heating fluid and or cooling fluid supply.

At least some of the heat transfer conduit as previously defined is provided for by covering opening of channels milled in the base preferably from the interface 3 with a material in sheet form thus defining cross section of the conduit by way of example but not limited to application of ultrasonic compacting or temporarily securing with capacitive discharge spot welding followed by application of the thermal coupling layer followed by application of the functional layer, advantageously material of the sheet is same as that of thermal coupling layer and in a non limiting case at least one layer is applied over substantially entirety of the interface 3 advantageously in permanent connection and application of the thermal coupling layer is omitted.

At least one of the means of heating as previously defined is an induction heater and the functional layer is at least partially made of ferromagnetic material advantageously strategically placed in close proximity of the induction heater so arranged that when current is passed through the induction heater it produces heat in the ferromagnetic

4

Substitute Sheet

(Rule26)RO/AU material raising temperature on the first top face and thermal energy accelerates laterally through the thermal coupling layer and back into the functional layer in regions of lower temperature improving temperature uniformity among hot and cold regions that may be present on the first top face in reduced time improving process economics and or quality. This improved thermal coupling among hot and cold regions on the first top face improves temperature uniformity on the first top face faster than otherwise possible reducing time needed to achieve desired temperature and temperature uniformity thus helps with improving process quality and or economics.

The base as previously defined is provided with at least one induction heater and the functional layer is at least partially made of non-ferromagnetic material strategically placed in close proximity of the induction heater having minimal coupling to magnetic field generated by the induction heater when current is passed through it allowing it to pass through and engage with second top face of second tool body made of

ferromagnetic material substantially in close proximity to the first top face having high coupling to the magnetic field producing eddy currents in the second top face generating heat therein.

Induction heater as previously defined optionally combining resistive heating preferably in the form of tubular element through which cooling fluid may be circulated and is advantageously provided with magnetic flux concentrator in the direction away from the first top face including but not limited to placing magnetic flux concentrator inlay, Gas Dynamic Cold Spray (GDCS) deposition of magnetic flux concentrator advantageously in permanent connection prior to laying the induction heater and advantageously the third material is a non-ferromagnetic material including but not limited to Aluminium.

The base as previously defined is advantageously provided with a thermal barrier on the interface 3 and optionally sides and bottom of milled channels including but not limited to placing honeycomb structure, refractory inlay, a refractory sprayed deposit advantageously in permanent connection prior to laying the means of heating or means of cooling reducing heat loss from means of heating to the base and reducing heat load into means of cooling from the base.

The functional layer as previously defined is provided structural support by providing direct permanent connection between the base and the functional layer by way of example only strategically designed and left standing at least one protrusion or rib integral to base from the interface 3 prior to deposition of thermal coupling layer or any intermediate deposits and the functional layer deposit bonds permanently to the protrusion or the rib, alternatively at least partially extending the functional layer deposit in permanent bond with the base at the interface 3 by building the functional layer deposit through clearance provided through the thermal coupling layer or any intermediate deposits or layers.

As previously defined process of the application is preferably but not limited to Gas Dynamic Cold Spray (GDCS) which optionally may involve intermediate machining operations and surface preparation and may involve additional intermediate materials

5

Substitute Sheet

(Rule26)RO/AU and or coatings to provide specific function including but not limited to provide increased bond strength, provide electrical isolation and or provide specific heat transfer rate and may involve heat treatment at some stage of manufacturing process and the thickness of each deposit is typically of the order of fraction of a mm. to few mm., including but not limited to 0.01 mm. to 10 mm, it should be appreciated that other

configurations/depths/thicknesses may be similarly used depending on the particular application.

In a preferred embodiment the functional layer as previously defined may be made up of at least two layers, advantageously in permanent connection, inner layer made up by application of sixth material applied first on the interface 22 and outer layer made up by application of first material sequentially applied later which may optionally involve intermediate machining operation and surface preparation so characterised that in finished condition the outer layer has lower porosity than that of the inner layer and the process of application of the inner layer is preferably including but not limited to Gas Dynamic Cold Spray (GDCS) and the process of application of the outer layer is preferably including but not limited to Coaxially Laser Assisted Cold Spray (COLA) or blown powder Laser Direct Metal Deposition (Laser-DMD), HVAF or HVOF wherein both the sixth material and the first material may be essentially same and optionally during deposition process cooling medium is passed through means of heating and or means of cooling.

As per any of preceding claims in a non limiting aspect of invention the first tool body is core side and the second tool body is cavity side making up subsystems of an injection moulding tool or matched die composites layup and curing tool and the means of heating are activated to raise temperature of the first top face and optionally of the second top face and advantageously after predetermined time of heating the means of cooling are activated to remove heat from an article produced therein and the article is ejected after predetermined cooling time when it has reached requisite strength and dimensional stability improving temperature uniformity on the first top face and or second top face in reduced time improving process economics and or quality.

As previously defined in a non limiting aspect of invention the first tool body is part of composites layup and or curing tool including but not limited to CFRP layup tool used in an autoclave or out of autoclave setup wherein heat is applied either exclusively by activating the means of heating or combined with external means of heating within the autoclave or out of autoclave setup and the means of heating are activated to raise temperature of the first top face and optionally of the second top face and

advantageously after predetermined time of heating the means of cooling are activated to remove heat from an article produced therein and the article is ejected after predetermined cooling time when it has reached requisite strength and dimensional stability improving temperature uniformity on the first top face and or second top face in reduced time improving process economics and or quality

As previously defined the means of heating and or the means of cooling are arranged side by side in preferably alternating pattern and the thermal coupling layer substantially spans across all of them advantageously incorporating heat pipes having close thermal

6

Substitute Sheet

(Rule26)RO/AU coupling with the thermal coupling layer further improving acceleration of heat through the thermal coupling layer particularly to areas of tool that are far removed from means of application of heat or cooling.

As previously defined thickness and property of any of deposits applied is varied and optionally repeated in total or partially in any desired combination such that it results in required heat flux capabilities desired at a given zone and location and or improving temperature uniformity on the first top face.

As previously defined length of channels and subsequently laid the means of heating and or the means of cooling are segmented and in non-limiting aspect segmented elements in functional continuity are interconnected via passages provided underneath land in between any two adjacent segments reducing differential expansion during tool heat treatment or moulding process and optionally direct permanent connection between the base and the functional layer is provided at the land.

Method of deposits described may include but not limited to Gas dynamic Cold Spray (GDCS), Coaxially Laser Assisted Cold Spray (COLA), Vacuum Cold Spray, Direct Metal Deposition (Laser-DMD), Vacuum Plasma Spray (VPS), capacitive discharge spot welding, Ultrasonic Additive Manufacturing (UAM), 3D Printing, Laser Cusing, closed- loop direct metal deposition, electron beam sputtering, Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM) or any other additive manufacturing process known in the art.

Any of the deposition methods deployed may involve post-deposition heat treatment at some stage of manufacturing process to improve microstructure or performance of deposited material.

Whilst the above description refers generally to moulding tool, it should be understood to apply to variations including but not limited to Injection Moulding, carbon fibre reinforced polymer composite panel manufacturing tooling for in the autoclave and out of autoclave processing, matched die press tooling for composites manufacturing, die casting, glass moulding, liquid silicone rubber injection moulding, rubber curing, compression mold "Class A" car parts from glass-mat thermoplastic (GMT) composite sheet, twin sheet press vacuum forming, blow moulding, long-fiber thermoplastic injection molding, chemical and analytics work platform requiring precise uniform temperature and controlled heat flux, domestic cooking appliances, electric hot plates, sandwich press, cooking grill, aerospace components requiring improved thermal management where thermal barrier layers may advantageously be combined with or replaced with thermal coupling layer to name a few and are included by reference and form part of the invention. While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not as limiting.

7

Substitute Sheet

(Rule26)RO/AU It will be also understood that where the word "comprise", and variations such as "comprises" and "comprising", are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge.

Brief Description of the Drawings

In order that the invention may be more fully understood there will now be described, by way of example only, preferred embodiments and other elements of the invention with reference to the accompanying drawings where:

Figure 1 Isometric and top view of a tool configured for alternative embodiments.

Figure 2 Section views.

Figure 3 Enlarged detail views.

Figure 4 Isometric and top view of a tool configured for induction heating.

Figure 5 Sectional view showing electromagnetic flux lines.

Figure 6 Detail views showing thermal coupling during cooling mode and heating mode.

Description of the Preferred Embodiment and Other Examples of the Invention

Referring to Figure 1 we are shown an isometric view of a tool body CORE insert configured with variety of embodiments of invention. Heating or cooling elements (1 ), top face (2) and tool body (3). For simplification various other typical tool construction elements like mounting plates, bolster, ejector system etc. are not shown. Also shown is top view of the same assembly and section plane A-A, B-B and C-C.

Referring to Figure 2 we are section drawings A-A as transverse section, section B-B as transverse section through another location showing local detail of structural connection between the zone 3 and zone 1 , and Section C-C as longitudinal section.

Referring to Figure 2, Section A-A shows us details through various alternate embodiments of invention which will be discussed more in detail with detail views (D-J and J2), Figure 3. For purpose of simplification various alternate embodiments are shown as discrete arrangements however it should be understood that either one of them or any combination of them may be repeated and deployed throughout a tool configuration and not necessarily incorporate them all in the discrete fashion shown here.

Referring to Figure 2, Section B-B shows detail construction of the type shown at "H" in section A-A, but at a different location. It shows us one structural support (4) integral

8

Substitute Sheet

(Rule26)RO/AU to body (3), insulation layer (5) and thermal coupling layer (6) and top layer (8), the structural support transfers any structural load when applied to top layer (8) transferring it to body (3). By way of simplification only one support is shown, however a typical tool construction multitude of supports could be provided.

Referring to Figure 2, Section C-C shows us longitudinal section through tool construction of the alternate embodiment of the tool shown at "H" in section A-A. It highlights one of the heating or cooling elements in the form of a pipe (7) passes through a hole (9) underneath the structural support (4). A typical configuration involves milling a slot from the working face of tool in simplest form in two parts separated by a wall, providing an opening through the wall, a means of heating or cooling in form of a pipe (7) is passed through the hole, a structural support (4) is preferably integrally placed on top of the wall. The pipe and substantially entire top surface of tool is preferably covered with thermally conductive material (6) for example Copper. This is finally covered up by top layer (8) is made of material chosen by its functional mechanical chemical properties imparting high durability to top functional surface, typically tool steel. This top layer may be subsequently processed by traditional tool making practices providing forming at least part of moulding surface of the tool. The means of deposition of any of the layers described anywhere in this specification include but not limited to Gas Dynamic Cold Spray (GDCS), Coaxially Laser Assisted Cold Spray (COLA), deposition method or blown powder Direct Metal Deposition (Laser-DMD). The means of heating or cooling in simplest form will be a pipe through which heat transfer fluid is passed.

Referring to Figure 3, Detail D, we are shown a basic configuration of tool having slot (10), inlaid pipe (7), deposit of thermal coupling layer (6) followed by deposit of top layer (8). After each layer deposition the layer may be machined to required size and surface finish and prepared for subsequent layer. The thermal coupling layer (6) accelerates heat sideways improving thermal coupling across numerous other heating or cooling elements that may be present in such a tool as well as high to low temperatures on top layer (8). A typical arrangement may include alternating heating and cooling conduits and the thermal coupling layer (6) improves thermal coupling across them improving uniformity of temperature on top layer (8) forming at least part of moulding surface. This will be described more in detail later with reference to figure 6.

Referring to Figure 3, Detail E, we are shown a deposit of (1 1 ) covering the zone immediately in front of the inlaid pipe up to opening of the channel. This material has specific function in providing structural strength to the zone immediately in front of the slot thus minimizing deflection of the top layer under process conditions. This material may be optionally same as the material of the body in which the slot is milled and advantageously the material bonds permanently to the body. In yet another configuration the slot is provided wedge shape (not shown) allowing for stronger bond of material (1 1 ) and improving structural strength. This is followed by application of substantially uniform deposit of thermal coupling layer (6) and top layer as the case may be.

Referring to Figure 3, Detail F, we are shown thermal coupling layer (6) covered with two more layers (13) and (12) sequentially applied. It is generally expected that Cold

9

Substitute Sheet

(Rule26)RO/AU Flow deposition method chosen for very high deposition rates that may be employed for deposition of thermal coupling layer (6) and layer (13) may suffer from some porosity and may not be acceptable on functional surface, particularly for moulding of clear components or class A surface on cavity side of a tool. Here the layer (12) may be of same material as that for layer (13) or could be different having unique property profile and is advantageously of small thickness typically say 1 to 2 mm. and deposited by way of example Laser-DMD method where metal powder is blown on to surface where it is melted by laser forming homogenous and dense layer free of porosity. This way we can advantageously use by way of example Kinetic Spray Cold Flow deposition for larger deposition rates making up larger thickness of deposits thermal coupling layer (6) and (13) typically of the magnitude of 3 to 10 mm. in thickness while use lower deposition rate but superior surface and near net shape and size method for lesser thickness layer (12) deposition by way of example Laser-DMD.

Referring to Figure 3, Detail G, we are shown top layer deposit having varying thicknesses (14) and (15). As previously described thermal coupling layer (6) is by way of example made of Copper and layer (15) is made of tool steel which has far lower thermal conductivity than that of Copper. By increased thickness (14) of lower thermal conductivity material directly in front of the heating or cooling elements (7) we reduce thermal flux directly in front of the heating or cooling elements (7) improving temperature uniformity on top of (14) which makes up working face of tool. We are also shown insulation layer (5) that helps reduce heat loss to body (3) during heating phase as well as reduce cooling requirement during cooling phase.

Referring to Figure 3, Detail H, we are shown an induction heater (16), a magnetic flux concentrator (18), and top layer deposit (17) which may make part of functional surface of tool. The top layer is made of ferromagnetic material having high coupling to the induction heater and the said magnetic field produces eddy currents in the top layer generating heat therein when specific frequency current is passed through the induction heater. Thermal coupling layer (6) shown partially in front of induction heater is preferably made of Copper and helps with temperature equalization on top of functional surface (17). Also shown here are two structural supports (19) as extension from top layer (17) whilst (20) is integral to body (3). The supports advantageously make permanent connection between the top layer (17) and body (3) and protecting inlaid magnetic flux concentrator (18) from crushing under operational loads. This magnetic flux concentrator is advantageously deposited in-situ by Gas Dynamic Cold Spray (GDCS) or alternatively prefabricated from proprietary materials for example commercially available "Fluxtrol" and fitted in the space below the induction heater as shown.

Referring to Figure 3, Detail I, we are shown an induction heater (16), covered by top layer (21 ) that is having property of allowing electromagnetic flux to pass through and out of top surface. When current is passed through the induction heater electromagnetic flux engages with working surface (25) of cavity (24) (Figure 4, 5) substantially in close proximity to the top layer (21 ) and surface (25) is made of ferromagnetic material having high coupling to the induction heater and the said magnetic field produces eddy currents in the working surface 25 (Figure 5) generating heat there in.

10

Substitute Sheet

(Rule26)RO/AU Referring to Figure 3, Detail J, we are shown a means of heating or cooling in form of a conduit (40) initially configured by deposition of a sacrificial core material (22), and finishing it to size of finally required conduit (40), followed by deposition of thermal coupling layer (6) and optionally top layer (8). This conduit is given final shape by flowably removing the deposited material (22). Typically these are water-soluble salts or sacrificial core material as used by lost core method casting industry that flows out on application of heat.

Referring to Figure 3, Detail J2, in yet another embodiment of Detail J wherein the sacrificial core material is omitted and planar opening of the slot is covered by closing it with a material in sheet form (38) by way of example ultrasonic compacting also known as ultrasonic additive manufacturing (UAM) or temporarily securing with capacitive discharge spot welding thus defining cross section of the conduit (39) followed by deposition of thermal coupling layer (6) and optionally top layer (8). The applied material in sheet form (38) may be made of thermally conductive material, for example Copper and may involve multiple layers of material being applied substantially covering entire surface of tool that accelerates heat sideways improving thermal coupling across numerous other heating or cooling elements that may be present in such a tool and optionally separate thermal coupling layer (6) may be omitted.

Referring to Figure 4, we are shown an isometric view of tool inserts configured as CORE (23) and CAVITY (24). Also shown is top view of the same assembly and section plane D-D.

Referring to Figure 5, Section D, we are shown Induction heaters (16) covered immediately in front by top layer (21 ) that is made of non-ferromagnetic material allowing electromagnetic flux to pass through and out of top surface. When electric current is passed through the induction heater electromagnetic flux engages with working surface (25) of cavity (24), substantially in close proximity to the top layer (21 ) and made of ferromagnetic material having high coupling to the induction heater and the said magnetic field produces eddy currents in the working surface (25) generating heat therein. Magnetic field shown symbolically by lines (28) is provided a path of less resistance by provision of magnetic flux concentrator material (26) and (27) thus improving strength of eddy currents and heating in working surface (25). In this instance the thermal coupling layer (6) and the layer (21 ) are made of same material serving different function at different location as described above. There are many commercially available induction generators and some application may require electrical insulation at appropriate place in magnetic and induction heater arrangement and is assumed to be incorporated here by reference.

Referring to Figure 6, Detail K, we are shown thermal coupling effect of the thermal coupling layer (6) preferably made of Copper. As a moulding is produced by injection of liquefied polymer in space (33), heat is conducted from liquefied polymer into working surface (8) where from heat has to be conducted to cooling channels (7) where from flow of cooling medium transports the heat away. However due to poor thermal conductivity of tool steel typically H13/ P20 out of which most tool surfaces are constructed having regard to its mechanical properties like corrosion resistance,

11

Substitute Sheet

(Rule26)RO/AU strength, wear resistance and mechanical strength, heat accumulates in zone between the top layer (8) and the cooling channels (7). This accumulation is affected by square of distance between a given point on the top layer (8) and closest cooling channels (7). Thus at tool stabilisation the temperature at location (29) is higher than that at (30) which is directly in front of cooling channel and rate of heat removal from the liquefied polymer in front of (29) is slower than that at (30). This has detrimental effect with overall cooling time required affecting process economics and also can affect quality of part produced including defects like locked in stress, warpage, surface finish variation etc. Deposit of thermal coupling layer (6) makes up a high thermal coupling zone interconnecting the zone containing cooling channels (7) and the top layer (8). Here heat accelerates through the thermal coupling layer (6) symbolically shown as arrows (31 ) transporting heat from hot part (29) of the top layer to colder part (30) on same top layer thus reducing temperature difference across the top layer (8) and heat accelerates through the thermal coupling layer (6) symbolically shown as arrows (32) taking heat from hot part (29) of the top layer to cooling channels (7). This is analogues to driving from a suburban street to another in a large city and making trip fast by using a freeway or autobahn reducing total travel time.

Finally Referring to Figure 6, Detail L, we are shown induction heater (16), magnetic flux concentrator (18). Magnetic field shown symbolically by lines (36) is provided a path of less resistance by provision of magnetic flux concentrator material (18) improving strength of magnetic field affecting strength of eddy current induced and consequently heating in working surface (8) made of ferromagnetic material having high coupling to the induction heater. When electric current is passed through the induction

heater electromagnetic flux engages with top layer (8) substantially in close proximity to the induction heater and the said magnetic field produces eddy currents in the working surface (8) generating heat therein. Since magnetic field strength and rate of heating by induction is affected by distance of induction heater from the surface, consequently top layer (8) will have maximum temperature at (34) and will have lower temperature at a point (35) that is farthest away from closest induction heater. This temperature difference is undesirable and has detrimental effect with overall heating time required to produce uniform temperature as time is lost waiting for the temperature to equalise over entire working surface. If that time was not allowed, the surface will have a high temperature variation across the surface affecting quality of part produced including defects like surface finish variation, "imprinting" of heater pattern where in the heater pattern is visible as texture and gloss variation on final product. Deposit of thermal coupling layer (6) makes up a high thermal coupling zone interconnecting the zone containing induction heaters (16) and the working surface (8). Here heat accelerates through the thermal coupling layer (6) symbolically shown as arrows (37) thus

transporting heat from hot part (34) of the top layer to colder part (35) thus reducing temperature difference across the top surface (8) sooner. The same effect of

temperature equalisation is to be understood when heat is delivered by alternative means of heating for example passing heating oil or high pressure heated water through conduits placed in place of induction heaters or electrical resistance bendable or cartridge ceramic heaters. In alternative embodiment (not shown) a layer 7 of

ferromagnetic material having high coupling to the induction heater (16) is interposed between the induction heater (16) and the thermal coupling layer (6), and in this

12

Substitute Sheet

(Rule26)RO/AU instance top functional surface (8) is made of non-ferromagnetic material such that when specific frequency current is passed through the induction heater produces magnetic field which produces eddy currents in the layer 7 generating heat therein and heat generated in the layer 7 accelerates through thermal coupling layer 6 sideways and then to the top functional surface (8) improving temperature uniformity there upon.

The heating or cooling elements may cover an area of the tool face and may be specifically arranged in a manner known in the art of induction heating, conformal cooling or conformal heating in a coiled arrangement, looped arrangement or in one or more straight line sections, and more specifically in a manner to accommodate the requirements of the tool shape, design, and/or size and without limitation, the heating elements may optionally be disposed about sharp corners or thin flats to ensure proper fluidic resin flow into the full part cavity.

13

Substitute Sheet

(Rule26)RO/AU