CA2182482C - Heating device, in particular for use in injection molds for the processing of thermoplastic materials - Google Patents
Heating device, in particular for use in injection molds for the processing of thermoplastic materials Download PDFInfo
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- CA2182482C CA2182482C CA002182482A CA2182482A CA2182482C CA 2182482 C CA2182482 C CA 2182482C CA 002182482 A CA002182482 A CA 002182482A CA 2182482 A CA2182482 A CA 2182482A CA 2182482 C CA2182482 C CA 2182482C
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- Prior art keywords
- heating
- insulating
- layer
- heating device
- housing
- Prior art date
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- 238000010438 heat treatment Methods 0.000 title claims abstract description 128
- 239000012815 thermoplastic material Substances 0.000 title claims abstract description 12
- 238000002347 injection Methods 0.000 title claims abstract description 10
- 239000007924 injection Substances 0.000 title claims abstract description 10
- 238000012545 processing Methods 0.000 title claims abstract description 10
- 229910001069 Ti alloy Inorganic materials 0.000 claims description 9
- 229910001369 Brass Inorganic materials 0.000 claims description 8
- 239000010951 brass Substances 0.000 claims description 8
- 239000010445 mica Substances 0.000 claims description 6
- 229910052618 mica group Inorganic materials 0.000 claims description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 238000010276 construction Methods 0.000 claims description 3
- 239000004020 conductor Substances 0.000 claims description 2
- 238000003780 insertion Methods 0.000 abstract 1
- 230000037431 insertion Effects 0.000 abstract 1
- 229940090045 cartridge Drugs 0.000 description 14
- 238000005266 casting Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- 239000000306 component Substances 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000013461 design Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- 229910000881 Cu alloy Inorganic materials 0.000 description 1
- 241001484259 Lacuna Species 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000012671 ceramic insulating material Substances 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000004512 die casting Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000009415 formwork Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000284 resting effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/26—Moulds
- B29C45/27—Sprue channels ; Runner channels or runner nozzles
- B29C45/2737—Heating or cooling means therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
- B29C45/17—Component parts, details or accessories; Auxiliary operations
- B29C45/26—Moulds
- B29C45/27—Sprue channels ; Runner channels or runner nozzles
- B29C45/2737—Heating or cooling means therefor
- B29C2045/2743—Electrical heating element constructions
- B29C2045/2748—Insulating layers covering the electrical heating element
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C33/00—Moulds or cores; Details thereof or accessories therefor
- B29C33/02—Moulds or cores; Details thereof or accessories therefor with incorporated heating or cooling means
- B29C33/06—Moulds or cores; Details thereof or accessories therefor with incorporated heating or cooling means using radiation, e.g. electro-magnetic waves, induction heating
Abstract
A heating device (11), especially for insertion into injection moulds for processing thermoplastic materials, with a substantially shaped hollow housing and a heating unit (12) to which a heating current can be applied, especially a heating coil, fitted in/on the housing, is characterised in that a layer-like insulating device (30) at least locally surrounds the heating unit on the inside or outside.
Description
2 1 82482 January 18, 1996 DESCRIPTION
Heating device, in particular for use in injection molds for the processing of thermoplastic materials TECHNICAL FIELD
The present invention relates to a heating device, in particular for use in injection molds for the processing of thermoplastic materials, having a housing substantially in the form of a hollow profile and a heating unit, in particular heating coil, which is in/on the housing and can be subjected to heating current.
Such heating devices are used as so-called tubular heating cartridges or heating bands in order, for example, to bring runners of gating devices (hot runner nozzles and manifolds) to a predeterminable temperature or to keep them at a predeterminable temperature, in order to ensure a constant throughflow of the thermo-plastic material thereby kept in the flow range.
In addition, such heating devices are used in the region of heat conducting pipes which serve for controlling the temperature of molding zones or hot runner nozzles and hot runner manifold blocks.
PRIOR ART
Heating devices in which the heating coil is covered with cast copper or brass are known. On the outside, these cast heating cartridges are surrounded by a casing of stainless steel. These heating cartridges have the disadvantage of relatively great outward heat dissipation. As a result, components which actually do not need any heating are heated, which has a detrimental effect when considering the overall energy balance.
A heating device of the type mentioned at the beginning is disclosed in EP-A-0468483. Described there is a heating device for a heating [sic] runner nozzle January 18, 1996 which is surrounded alternately by a plurality of layers of stainless steel and ceramic insulating material. The layers may be provided in different thicknesses here.
Such a heating device is relatively complex to produce and is not optimal with regard to its insulating effect.
DESCRIPTION OF THE INVENTION
The present invention is based on the object or the technical problem of specifying an improved heating device of the type mentioned at the beginning which ensures optimum heating properties at the points at which the thermal energy or heating energy is required, has a simple structure and consequently ensures efficient fabrication and, in addition, can be used reliably in continuous operation.
It is furthermore an object of the present invention to specify a heating device which has a compact structure and is consequently of a small design.
A further object is to specify a reliably operat-ing gating device or nozzle device which is of a small design and dissipates as little heat as possible to its surroundings.
The heating device according to the invention is provided by the features of claim 1. Advantageous refine-ments and developments are the subject of the subclaims.
Accordingly, the heating device according to the invention is distinguished in that the insulating device 60; 70 has the following ways of viewing [sic]: wear resistant layer, with relatively low coefficient of thermal conductivity, of titanium or a titanium alloy, insulating layer of mica, it being possible for the wear resistant layer to be arranged on the inside and/or outside. Whether the wear resistant layer is arranged on the outside or inside or outside and inside depends on the respective field of application. By the use of the materials titanium/titanium alloy and mica, a heating device of a very compact construction which has very good ~DME-008PCT - 3 - 2 ~ 82482 January 18, 1996 insulation values and, on account of its high wear resistance, a long service life can be produced.
It is ensured by the heating element according to the invention that the heat is supplied to a greater extent to where it is needed. If the insulating device is arranged on the outside, the heating device is preferably suitable for use for the encasing of a valve pin of a gating device, since in this case the heat is supplied predom;n~ntly inwards to the nozzle runner in order to keep the thermoplastic material flowing therein at a predeterminable temperature.
In addition, the heating devices according to the invention can in the same advantageous way be pushed onto heat conducting pipes.
15In the case of an inner arrangement of the - insulating device, the heating device according to the invention is preferably used as a heating band for outer heating. Conversely, in the case of an arrangement of the insulating layer on the outside, the heating device may be used as a heating band for inner heating.
By the use of the said insulating materials, a very good thermal insulation can be accomplished.
For the purpose of simple, low-cost production of the complete heating device it has proved to be favor-able, depending on the application, to form the insulat-ing device such that, when producing the heating device, it can either be pushed onto the housing on the outside or can be pushed into the housing on the inside. In a further variant, the housing itself forms the insulating device. It is also possible for the insulating unit to be deposited [sic] as formwork for the casting of the heating coil with thermally conducting material, which allows particularly low-cost fabrication.
With regard to a good heat transfer from the heating coil to the component to be heated, it is advan-tageous to cast the heating coil, at least in certain regions, with a material which conducts heat very well (for example copper, copper alloy, brass, etc).
A preferred refinement is distinguished in that the heating unit (heating coil) is cast in certain regions in such a way that the heating coil itself still protrudes in certain regions out of the cast region and that, with the insulating device resting on the protru-sion, there is additionally an insulating layer of air between the casting compound and the insulating device.
An injection mold with hot runner for the pro-cessing of thermoplastic materials according to the invention is characterized in that there is arranged at least one heating device according to the invention.
A gating device (hot runner) according to the invention for an injection mold for the processing of thermoplastic material is distinguished in that the gating device has at least one heating device according to the invention in intergrated [sic] construction.
With the heating device according to the inven-tion, energy savings of up to 50 % and more in comparison with the previous known heating devices can be accom-plished. Furthermore, it is possible to achieve compact ~;mensions~ since the ~im~nsions for the heating unit itself can be kept smaller because of the improved supply of heat to the points at which the heat is required. The temperature of the mold itself is reduced.
Further embodiments and advantages of the inven-tion are obtained from the features further presented in the claims and from the exemplary embodiments specified below. The features of the claims can be combined with one another in any desired way, provided that they are not obviously mutually exclusive.
BRIEF DESCRIPTION OF THE DRAWING
The invention and advantageous embodiments and developments of the same are described in more detail and explained below with reference to the examples represented in the drawing. The features disclosed by the description and the drawing can be used according to the invention individually on their own or together in any desired combination. In the drawing:
Fig. 1 shows a diagrammatic sectional representation of a heating device with insulating device for a heat conducting pipe, Fig. 2 shows a diagrammatic sectional representation of a heating device with an insulating device for a nozzle device, Fig. 3 shows a diagrammatic section through a heating ~ band with an insulating device for outer heating,0 Fig. 4 shows a diagrammatic section through a heating band with an insulating device for inner heating, Fig. 5 shows a diagrammatic section through a heating cartridge with a layered insulating device according to a first exemplary embodiment,5 Fig. 6 shows an end view of the heating cartridge according to Figure 5, Fig. 7 shows a detail from the walling of a heating cartridge with a layered insulating device according to a second exemplary embodiment,0 Fig. 8 shows a diagrammatic longitudinal section through a heating cartridge with a layered insulating device according to a third exemplary embodiment, Fig. 9 shows an end view according to [sic] the heating cartridge according to Figure 8,5 Fig. 10 shows a detail from the walling of a heating cartridge with a layered insulating device according to a fourth exemplary embodiment, Fig. 11 shows an arrangement of a heating device inside a gating device and0 Fig. 12 shows a diagrammatic section through a nozzle device with a heating device.
WAYS OF IMPLEMENTING THE INVENTION
According to Figure 1, there is arranged in an outer circumferential form on a heat conducting pipe 26, which serves in particular for controlling the tempera-ture of molding zones (not shown), a heating device 10, which rests on the outer circumference of the heat conducting pipe 26. The heating device 10 itself has,from inside to outside, first of all a first cast layer 24 of brass, inside which there is cast a heating unit or heating coil 12. On the outside, an insulating device 20 surrounds the cast unit 24. Since an increased heating capacity is required in the marginal region, the axial spacing of the turns of the heating coil 12 is reduced in this region.
The heating device 11 diagrammatically represent-ed in Figure 2 is applied to the outer circumference of the nozzle runner 34 of a nozzle device 32. It has a structure similar to the heating device 10 according to Figure 1, but in addition to a first insulating layer 30.1 there is on the outside a second insulating layer 1530.2. The first insulating layer 30.1 may [lacuna] from ceramic or mica. The the [sic] second insulating layer 30.2 is at the same time formed as a wear resistant layer and consists of a titanium alloy with a low coefficient of thermal conductivity.
20Represented diagrammatically in Figure 3 is a heating band 13, which is used for outer heating. In this case, the heating unit 12 is arranged with its cast layer 24 on the outside. Adjoining on the inside there is an insulating device 40 formed in the manner of an insu-lating layer.
The heating band 15 represented in Figure 4 is suitable for so-called inner heating, ie. on the outside of this inner heating means there is an insulating device 50, which in this exemplary embodiment has a first 30insulating layer 50.1 and a second insulating layer 50.2.
In Figures 1 to 4, the power supply to the heating unit 12 is not shown.
The specific exemplary embodiment of the walling of a heating device 25 which is represented as a detail in Figure 7 and takes the form of a cylindrical heating cartridge 25 comprises the following layered structure.
On the inside there is a cast unit formed as a cast layer 24, cast inside which there is the heating coil 12.
However, the individual heating coil cross sections 12 21 824~2 are not completely surrounded by casting compound, so that they protrude outwards.
The partially cast heating coil 12 is surrounded on the outside by an insulating layer 70, which has the following structure. Adjoining the protruding heating coil elements 12 there is first of all a first wear resistant layer 18, which consists of a titanium alloy with a low coefficient of thermal conductivity. On the first wear resistant layer 18 there is an insulating layer 22, on which in turn there is a second wear resis-tant layer 16, which surrounds the heating cartridge 25 on the outside and consists of a titanium alloy with a low coefficient of thermal conductivity. The heating coil cross sections are flattened in the region of the cast layer 24 surrounding them.
Consequently, between the heating unit 12 and the insulating device 70 there is a layer of air 18, which additionally increases the insulating effect.
In the following description, identical compo-nents bear the same designations and are not explained again.
The heating cartridge 21, diagrammatically represented in Figure 5, is formed in a way similar to the representation as a detail of the heating car-25tridge 25 according to Figure 7, with a layer of air 14 between the heating device 12 and an outer insulating device 60, but the insulating device 60 comprises only an outer wear resistant layer 16, and an inner insulating layer 22, the heating coil 12 having a square profiling.
30At the ends, the heating cartridge 21 according to Figure 5 is sealed off by annular profiles 44, the thickness of which corresponds to the thickness of the cast layer 24, the layer of air 14 and the inner insulat-ing layer 22. Likewise represented diagrammatically in Figure 5 is a power connection unit 36 to the heating unit 12.
The heating cartridge 23 represented in Figure 8 differs from the heating cartridge according to Figure 5 in that here the provision of an additionally insulating layer of air 14 has been dispensed with and the cast layer 24 goes right up to the insulating layer 22, ie.
the heating coil 12 is cast virtually completely with brass.
The diagrammatic detail of the walling of a heating cartridge 27 represented in Figure lO has the same layered insulating device 70 as the heating car-tridge 25 according to Figure 7. The heating device 12 has a heating coil with a circular profile, the indivi-dual turns being completely surrounded by a cast unit 24 and the insulating device 70 directly adjoining the cast layer 24 on the outside.
The casting compound may consist of brass, copper or other alloys which conduct heat well. The insulating wear resistant layers preferably consist of titanium or titanium alloys, the underside of which has a polished finish. Considered with preference as the material for the insulating layer is ceramic or mica. In addition, the insulating layer may also take the form of a layer of air or a vacuum layer.
The heating cartridges 21, 23, 25, 27 have an inside diameter which iB constant throughout, so that they can be pushed without any problem onto, for example, a nozzle device of an injection mold for the processing of thermoplastic materials.
In Figure 11 it is diagrammatically represented how the heating device 90 according to the invention with the insulating device can be used in a simple way in an encasing manner on a gating device 110 in the region of a nozzle runner 102.
Diagrammatically represented in cross section in Figure 12 is a nozzle device 190, in which the heating device 99 is present in an integrated form between a nozzle head 100, consisting of special steel, and a nozzle insert 101, consisting of special steel. The nozzle device 190 is designed as a disposable nozzle. The heating device 99 has the following layered structure from inside to outside: brass cast layer 92 with heating coils 94 cast therein, titanium alloy layer 95, mica 2 1 ~24~2 g fill 93 and, finishing off on the outside around the circumference, a titanium alloy layer 91.
Used with preference for producing heating devices is the gravity die casting process, in which brass is preferably used as the casting material for encapsulating the heating coils.
The nozzle device 101 according to Figure 12 is preferably formed as a "micronozzle", which has length dimensions of about 6 cm and diameter dimensions of about 1 cm.
According to the invention, the heating device is formed as a cylindrical hollow element, the individual layers forming sleeves which are adjacent to one another, at least in certain regions.
Heating device, in particular for use in injection molds for the processing of thermoplastic materials TECHNICAL FIELD
The present invention relates to a heating device, in particular for use in injection molds for the processing of thermoplastic materials, having a housing substantially in the form of a hollow profile and a heating unit, in particular heating coil, which is in/on the housing and can be subjected to heating current.
Such heating devices are used as so-called tubular heating cartridges or heating bands in order, for example, to bring runners of gating devices (hot runner nozzles and manifolds) to a predeterminable temperature or to keep them at a predeterminable temperature, in order to ensure a constant throughflow of the thermo-plastic material thereby kept in the flow range.
In addition, such heating devices are used in the region of heat conducting pipes which serve for controlling the temperature of molding zones or hot runner nozzles and hot runner manifold blocks.
PRIOR ART
Heating devices in which the heating coil is covered with cast copper or brass are known. On the outside, these cast heating cartridges are surrounded by a casing of stainless steel. These heating cartridges have the disadvantage of relatively great outward heat dissipation. As a result, components which actually do not need any heating are heated, which has a detrimental effect when considering the overall energy balance.
A heating device of the type mentioned at the beginning is disclosed in EP-A-0468483. Described there is a heating device for a heating [sic] runner nozzle January 18, 1996 which is surrounded alternately by a plurality of layers of stainless steel and ceramic insulating material. The layers may be provided in different thicknesses here.
Such a heating device is relatively complex to produce and is not optimal with regard to its insulating effect.
DESCRIPTION OF THE INVENTION
The present invention is based on the object or the technical problem of specifying an improved heating device of the type mentioned at the beginning which ensures optimum heating properties at the points at which the thermal energy or heating energy is required, has a simple structure and consequently ensures efficient fabrication and, in addition, can be used reliably in continuous operation.
It is furthermore an object of the present invention to specify a heating device which has a compact structure and is consequently of a small design.
A further object is to specify a reliably operat-ing gating device or nozzle device which is of a small design and dissipates as little heat as possible to its surroundings.
The heating device according to the invention is provided by the features of claim 1. Advantageous refine-ments and developments are the subject of the subclaims.
Accordingly, the heating device according to the invention is distinguished in that the insulating device 60; 70 has the following ways of viewing [sic]: wear resistant layer, with relatively low coefficient of thermal conductivity, of titanium or a titanium alloy, insulating layer of mica, it being possible for the wear resistant layer to be arranged on the inside and/or outside. Whether the wear resistant layer is arranged on the outside or inside or outside and inside depends on the respective field of application. By the use of the materials titanium/titanium alloy and mica, a heating device of a very compact construction which has very good ~DME-008PCT - 3 - 2 ~ 82482 January 18, 1996 insulation values and, on account of its high wear resistance, a long service life can be produced.
It is ensured by the heating element according to the invention that the heat is supplied to a greater extent to where it is needed. If the insulating device is arranged on the outside, the heating device is preferably suitable for use for the encasing of a valve pin of a gating device, since in this case the heat is supplied predom;n~ntly inwards to the nozzle runner in order to keep the thermoplastic material flowing therein at a predeterminable temperature.
In addition, the heating devices according to the invention can in the same advantageous way be pushed onto heat conducting pipes.
15In the case of an inner arrangement of the - insulating device, the heating device according to the invention is preferably used as a heating band for outer heating. Conversely, in the case of an arrangement of the insulating layer on the outside, the heating device may be used as a heating band for inner heating.
By the use of the said insulating materials, a very good thermal insulation can be accomplished.
For the purpose of simple, low-cost production of the complete heating device it has proved to be favor-able, depending on the application, to form the insulat-ing device such that, when producing the heating device, it can either be pushed onto the housing on the outside or can be pushed into the housing on the inside. In a further variant, the housing itself forms the insulating device. It is also possible for the insulating unit to be deposited [sic] as formwork for the casting of the heating coil with thermally conducting material, which allows particularly low-cost fabrication.
With regard to a good heat transfer from the heating coil to the component to be heated, it is advan-tageous to cast the heating coil, at least in certain regions, with a material which conducts heat very well (for example copper, copper alloy, brass, etc).
A preferred refinement is distinguished in that the heating unit (heating coil) is cast in certain regions in such a way that the heating coil itself still protrudes in certain regions out of the cast region and that, with the insulating device resting on the protru-sion, there is additionally an insulating layer of air between the casting compound and the insulating device.
An injection mold with hot runner for the pro-cessing of thermoplastic materials according to the invention is characterized in that there is arranged at least one heating device according to the invention.
A gating device (hot runner) according to the invention for an injection mold for the processing of thermoplastic material is distinguished in that the gating device has at least one heating device according to the invention in intergrated [sic] construction.
With the heating device according to the inven-tion, energy savings of up to 50 % and more in comparison with the previous known heating devices can be accom-plished. Furthermore, it is possible to achieve compact ~;mensions~ since the ~im~nsions for the heating unit itself can be kept smaller because of the improved supply of heat to the points at which the heat is required. The temperature of the mold itself is reduced.
Further embodiments and advantages of the inven-tion are obtained from the features further presented in the claims and from the exemplary embodiments specified below. The features of the claims can be combined with one another in any desired way, provided that they are not obviously mutually exclusive.
BRIEF DESCRIPTION OF THE DRAWING
The invention and advantageous embodiments and developments of the same are described in more detail and explained below with reference to the examples represented in the drawing. The features disclosed by the description and the drawing can be used according to the invention individually on their own or together in any desired combination. In the drawing:
Fig. 1 shows a diagrammatic sectional representation of a heating device with insulating device for a heat conducting pipe, Fig. 2 shows a diagrammatic sectional representation of a heating device with an insulating device for a nozzle device, Fig. 3 shows a diagrammatic section through a heating ~ band with an insulating device for outer heating,0 Fig. 4 shows a diagrammatic section through a heating band with an insulating device for inner heating, Fig. 5 shows a diagrammatic section through a heating cartridge with a layered insulating device according to a first exemplary embodiment,5 Fig. 6 shows an end view of the heating cartridge according to Figure 5, Fig. 7 shows a detail from the walling of a heating cartridge with a layered insulating device according to a second exemplary embodiment,0 Fig. 8 shows a diagrammatic longitudinal section through a heating cartridge with a layered insulating device according to a third exemplary embodiment, Fig. 9 shows an end view according to [sic] the heating cartridge according to Figure 8,5 Fig. 10 shows a detail from the walling of a heating cartridge with a layered insulating device according to a fourth exemplary embodiment, Fig. 11 shows an arrangement of a heating device inside a gating device and0 Fig. 12 shows a diagrammatic section through a nozzle device with a heating device.
WAYS OF IMPLEMENTING THE INVENTION
According to Figure 1, there is arranged in an outer circumferential form on a heat conducting pipe 26, which serves in particular for controlling the tempera-ture of molding zones (not shown), a heating device 10, which rests on the outer circumference of the heat conducting pipe 26. The heating device 10 itself has,from inside to outside, first of all a first cast layer 24 of brass, inside which there is cast a heating unit or heating coil 12. On the outside, an insulating device 20 surrounds the cast unit 24. Since an increased heating capacity is required in the marginal region, the axial spacing of the turns of the heating coil 12 is reduced in this region.
The heating device 11 diagrammatically represent-ed in Figure 2 is applied to the outer circumference of the nozzle runner 34 of a nozzle device 32. It has a structure similar to the heating device 10 according to Figure 1, but in addition to a first insulating layer 30.1 there is on the outside a second insulating layer 1530.2. The first insulating layer 30.1 may [lacuna] from ceramic or mica. The the [sic] second insulating layer 30.2 is at the same time formed as a wear resistant layer and consists of a titanium alloy with a low coefficient of thermal conductivity.
20Represented diagrammatically in Figure 3 is a heating band 13, which is used for outer heating. In this case, the heating unit 12 is arranged with its cast layer 24 on the outside. Adjoining on the inside there is an insulating device 40 formed in the manner of an insu-lating layer.
The heating band 15 represented in Figure 4 is suitable for so-called inner heating, ie. on the outside of this inner heating means there is an insulating device 50, which in this exemplary embodiment has a first 30insulating layer 50.1 and a second insulating layer 50.2.
In Figures 1 to 4, the power supply to the heating unit 12 is not shown.
The specific exemplary embodiment of the walling of a heating device 25 which is represented as a detail in Figure 7 and takes the form of a cylindrical heating cartridge 25 comprises the following layered structure.
On the inside there is a cast unit formed as a cast layer 24, cast inside which there is the heating coil 12.
However, the individual heating coil cross sections 12 21 824~2 are not completely surrounded by casting compound, so that they protrude outwards.
The partially cast heating coil 12 is surrounded on the outside by an insulating layer 70, which has the following structure. Adjoining the protruding heating coil elements 12 there is first of all a first wear resistant layer 18, which consists of a titanium alloy with a low coefficient of thermal conductivity. On the first wear resistant layer 18 there is an insulating layer 22, on which in turn there is a second wear resis-tant layer 16, which surrounds the heating cartridge 25 on the outside and consists of a titanium alloy with a low coefficient of thermal conductivity. The heating coil cross sections are flattened in the region of the cast layer 24 surrounding them.
Consequently, between the heating unit 12 and the insulating device 70 there is a layer of air 18, which additionally increases the insulating effect.
In the following description, identical compo-nents bear the same designations and are not explained again.
The heating cartridge 21, diagrammatically represented in Figure 5, is formed in a way similar to the representation as a detail of the heating car-25tridge 25 according to Figure 7, with a layer of air 14 between the heating device 12 and an outer insulating device 60, but the insulating device 60 comprises only an outer wear resistant layer 16, and an inner insulating layer 22, the heating coil 12 having a square profiling.
30At the ends, the heating cartridge 21 according to Figure 5 is sealed off by annular profiles 44, the thickness of which corresponds to the thickness of the cast layer 24, the layer of air 14 and the inner insulat-ing layer 22. Likewise represented diagrammatically in Figure 5 is a power connection unit 36 to the heating unit 12.
The heating cartridge 23 represented in Figure 8 differs from the heating cartridge according to Figure 5 in that here the provision of an additionally insulating layer of air 14 has been dispensed with and the cast layer 24 goes right up to the insulating layer 22, ie.
the heating coil 12 is cast virtually completely with brass.
The diagrammatic detail of the walling of a heating cartridge 27 represented in Figure lO has the same layered insulating device 70 as the heating car-tridge 25 according to Figure 7. The heating device 12 has a heating coil with a circular profile, the indivi-dual turns being completely surrounded by a cast unit 24 and the insulating device 70 directly adjoining the cast layer 24 on the outside.
The casting compound may consist of brass, copper or other alloys which conduct heat well. The insulating wear resistant layers preferably consist of titanium or titanium alloys, the underside of which has a polished finish. Considered with preference as the material for the insulating layer is ceramic or mica. In addition, the insulating layer may also take the form of a layer of air or a vacuum layer.
The heating cartridges 21, 23, 25, 27 have an inside diameter which iB constant throughout, so that they can be pushed without any problem onto, for example, a nozzle device of an injection mold for the processing of thermoplastic materials.
In Figure 11 it is diagrammatically represented how the heating device 90 according to the invention with the insulating device can be used in a simple way in an encasing manner on a gating device 110 in the region of a nozzle runner 102.
Diagrammatically represented in cross section in Figure 12 is a nozzle device 190, in which the heating device 99 is present in an integrated form between a nozzle head 100, consisting of special steel, and a nozzle insert 101, consisting of special steel. The nozzle device 190 is designed as a disposable nozzle. The heating device 99 has the following layered structure from inside to outside: brass cast layer 92 with heating coils 94 cast therein, titanium alloy layer 95, mica 2 1 ~24~2 g fill 93 and, finishing off on the outside around the circumference, a titanium alloy layer 91.
Used with preference for producing heating devices is the gravity die casting process, in which brass is preferably used as the casting material for encapsulating the heating coils.
The nozzle device 101 according to Figure 12 is preferably formed as a "micronozzle", which has length dimensions of about 6 cm and diameter dimensions of about 1 cm.
According to the invention, the heating device is formed as a cylindrical hollow element, the individual layers forming sleeves which are adjacent to one another, at least in certain regions.
Claims
01) A heating device (10; 11; 13; 15; 21; 23; 25; 27;
90), in particular for use in injection molds for the processing of thermoplastic materials, having - a housing substantially in the form of a hollow pro-file, - a heating unit (12), in particular heating coil, which is in/on the housing and can be subjected to heating current, where - there is, at least in certain regions, a layer-like insulating device (20; 30; 40; 50; 60; 70) surrounding the heating unit on the inside or on the outside and - the insulating device (20; 30; 40; 50; 60; 70) is formed in a sandwich construction having at least one insulating layer, wherein the insulating device (60; 70) has the following layered structure:
- wear resistant layer (16), with relatively low coeffi-cient of thermal conductivity, of titanium or a titanium alloy, - insulating layer (22) of mica, it being possible for the wear resistant layer to be arranged on the inside and/or outside.
02) The heating device as claimed in claim 1, wherein between the insulating device (60; 70) and the heating unit (12) there is additional [sic] a layer of air (14) (Fig. 5, Fig. 7).
03) The heating device as claimed in one or more of the preceding claims, wherein, for producing the heating device, the insulating device is formed such that it can be pushed onto the housing on the outside/can be pushed into the housing on the inside, or the insulating device forms the outer walling/the inner walling of the heating element to be cast.
04) The heating device as claimed in one or more of the preceding claims, wherein the heating unit (14) is cast, at least in certain regions, with a conducting material (24), preferably brass.
05) The heating device as claimed in one or more of the preceding claims, wherein the insulating device forms the housing of the heating device.
06) An injection mold with hot runner or heated nozzle for the processing of thermoplastic materials, wherein there is arranged at least one heating device as claimed in one or more of the preceding claims.
07) A gating device or a nozzle device for an injection mold for the processing of thermoplastic materials, wherein the gating device (110) or nozzle device (190) has a heating device (90) as claimed in one or more of the preceding claims 1 to 5 in an integrated instruction.
90), in particular for use in injection molds for the processing of thermoplastic materials, having - a housing substantially in the form of a hollow pro-file, - a heating unit (12), in particular heating coil, which is in/on the housing and can be subjected to heating current, where - there is, at least in certain regions, a layer-like insulating device (20; 30; 40; 50; 60; 70) surrounding the heating unit on the inside or on the outside and - the insulating device (20; 30; 40; 50; 60; 70) is formed in a sandwich construction having at least one insulating layer, wherein the insulating device (60; 70) has the following layered structure:
- wear resistant layer (16), with relatively low coeffi-cient of thermal conductivity, of titanium or a titanium alloy, - insulating layer (22) of mica, it being possible for the wear resistant layer to be arranged on the inside and/or outside.
02) The heating device as claimed in claim 1, wherein between the insulating device (60; 70) and the heating unit (12) there is additional [sic] a layer of air (14) (Fig. 5, Fig. 7).
03) The heating device as claimed in one or more of the preceding claims, wherein, for producing the heating device, the insulating device is formed such that it can be pushed onto the housing on the outside/can be pushed into the housing on the inside, or the insulating device forms the outer walling/the inner walling of the heating element to be cast.
04) The heating device as claimed in one or more of the preceding claims, wherein the heating unit (14) is cast, at least in certain regions, with a conducting material (24), preferably brass.
05) The heating device as claimed in one or more of the preceding claims, wherein the insulating device forms the housing of the heating device.
06) An injection mold with hot runner or heated nozzle for the processing of thermoplastic materials, wherein there is arranged at least one heating device as claimed in one or more of the preceding claims.
07) A gating device or a nozzle device for an injection mold for the processing of thermoplastic materials, wherein the gating device (110) or nozzle device (190) has a heating device (90) as claimed in one or more of the preceding claims 1 to 5 in an integrated instruction.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE9403416U DE9403416U1 (en) | 1994-03-01 | 1994-03-01 | Heating device, in particular for use in injection molds for processing thermoplastic materials |
| DEG9403416.8U | 1994-03-01 | ||
| EP94108494.9 | 1994-06-02 | ||
| EP94108494A EP0670209B1 (en) | 1994-03-01 | 1994-06-02 | Heating device, in particular for use in injection moulds for processing thermoplastic materials |
| PCT/DE1995/000226 WO1995023680A1 (en) | 1994-03-01 | 1995-02-23 | Heating device, especially for insertion into injection moulds for processing thermoplastic materials |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2182482C true CA2182482C (en) | 2000-12-05 |
Family
ID=25961804
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002182482A Expired - Fee Related CA2182482C (en) | 1994-03-01 | 1995-02-23 | Heating device, in particular for use in injection molds for the processing of thermoplastic materials |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPH09509625A (en) |
| AU (1) | AU690222B2 (en) |
| CA (1) | CA2182482C (en) |
| WO (1) | WO1995023680A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5820900A (en) * | 1996-08-21 | 1998-10-13 | Mcgrevy; Alan N. | Heating device for an injection mold apparatus |
| AU2003203086A1 (en) * | 2002-02-05 | 2003-09-02 | Mold-Masters Limited | An injection nozzle having a heated head portion |
| ITTO20070447A1 (en) * | 2007-06-21 | 2008-12-22 | Vincenzo Commisso | PROCEDURE AND MEANS FOR THE MOLDING OF PLASTIC MATERIALS, ELASTOMERS, THERMO-HARDENERS, METALS AND THEIR ALLOYS BY INJECTION AND DIE CASTING. |
| US20210323072A1 (en) * | 2020-04-16 | 2021-10-21 | Ut-Battelle, Llc | Alignment system for magnetic particulate material used for additive manufacturing |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2821736C2 (en) * | 1978-05-18 | 1986-03-20 | Leo Pont-Saint-Martin Aosta Enrietti | Spray nozzle for the intermittent injection of plastic into molds |
| DE3001017A1 (en) * | 1980-01-12 | 1981-07-16 | Heinz 7203 Fridingen Stegmeier | Injection moulding nozzle - in which bore has double heater winding inside metal tube in ceramic sand consolidated before use |
| JPS5762848A (en) * | 1980-10-01 | 1982-04-16 | Toshiba Mach Co Ltd | Electric heating nozzle device |
| JPS60132724A (en) * | 1983-12-22 | 1985-07-15 | Fanuc Ltd | Vacuum heat insulating type heating cylinder in injection molding machine |
| DE3568525D1 (en) * | 1984-05-31 | 1989-04-06 | Toyota Motor Co Ltd | Device for tightening a coil on a cylindrical body |
| US4922082A (en) * | 1989-03-17 | 1990-05-01 | Axiomatics Corporation | Thermal valve gate for plastic molding apparatus |
| CA2022124A1 (en) * | 1990-07-27 | 1992-01-28 | Jobst Ulrich Gellert | Insulated injection molding nozzle |
-
1995
- 1995-02-23 WO PCT/DE1995/000226 patent/WO1995023680A1/en active Application Filing
- 1995-02-23 CA CA002182482A patent/CA2182482C/en not_active Expired - Fee Related
- 1995-02-23 JP JP7522618A patent/JPH09509625A/en active Pending
- 1995-02-23 AU AU17537/95A patent/AU690222B2/en not_active Ceased
Also Published As
| Publication number | Publication date |
|---|---|
| AU1753795A (en) | 1995-09-18 |
| WO1995023680A1 (en) | 1995-09-08 |
| JPH09509625A (en) | 1997-09-30 |
| AU690222B2 (en) | 1998-04-23 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |