EP0180571A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Extrusion die arrangement and automatic centering extrusion method
Assignee: Individual
•
Filing: 1985-09-06
•
Granted: —
•
Expires: 2005-09-06
Abstract
Abstract This invention relates to extruder arrangements of the type used in extruding elements such as tube-shaped pipes of circular or profiled cross sectional configuration or other profile products from an extrudable melt such as, for example, polymeric material, e.g. unplasticised polyvinylchloride. According to the invention an extruder arrangement comprising [a] an annular die having a bore which constitutes a forming surface, [b] a mandrel disposed in the die and presenting a forming surface facing the forming surface of the die and spaced therefrom such that an extrusion passage is defined between the two forming surfaces, and [c] a heating arrangement in heat conductive relationship with one of the forming surfacen is characterised in that it includes temperature differential means in heat conductive relationship with at least one of the forming surfaces, which temperature differential means is adapted in use to allow the temperature of selected circumferential zones of an extrusion piece disposed in the extrusion passage to be individually controlled.
Inventors
- 👤 Erwin Hartl
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 15:07
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/78; B29C48/86; B29C48/872; B29C48/865; B29C48/87; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92114; B29C2948/92152; B29C2948/92323; B29C2948/92428; B29C2948/92504; B29C2948/9258; B29C2948/926; B29C2948/92609; B29C2948/92647; B29C2948/92704; B29C2948/92819; B29C2948/92857; B29C2948/92904; B29C2948/92971; B29C48/03; B29C48/06; B29C48/09; B29C48/10; B29L; B29L2023/00; B29L2023/22
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
114 words
An extruder arrangement comprising [a] an annular die having a bore which constitutes a forming surface, [b] a mandrel disposed in the die and presenting a forming surface facing the forming surface at the die and spaced therefrom such that an extrusion passage is defined between the two forming surfaces, and [c] a heating arrangement in heat conductive relationship with one of the forming surfaces, characterised in that it includes temperature differential means in heat conductive relationship with at least one of the forming surfaces, which temperature differential means is adapted in use to allow the temperature of selected circumferential zones of an extrusion piece disposed in the extrusion passage to be individually controlled.
Claim 2
Dependent Claim
114 words
An extruder arrangement comprising [a] an annular die having a bore which constitutes a forming surface, [b] a mandrel disposed in the die and presenting a forming surface facing the forming surface at the die and spaced therefrom such that an extrusion passage is defined between the two forming surfaces, and [c] a heating arrangement in heat conductive relationship with one of the forming surfaces, characterised in that it includes temperature differential means in heat conductive relationship with at least one of the forming surfaces, which temperature differential means is adapted in use to allow the temperature of selected circumferential zones of an extrusion piece disposed in the extrusion passage to be individually controlled.
Claim 3
Dependent Claim
23 words
The extruder arrangement of claim 1 wherein the temperature differential means is in heat conductive relationship with the forming surface of the mandrel.
Claim 4
Dependent Claim
23 words
The extruder arrangement of claim 1 wherein the temperature differential means is in heat conductive relationship with the forming surface of the die.
Claim 5
Dependent Claim
80 words
The extruder arrangement of claim 3 wherein the temperature differential means includes an annular heating sleeve which is adapted in use to be received in heat conductive relationship about the annular die and which includes a plurality of heating segments at least some of which segments are adapted to be individually energised to be heated to different temperatures, thereby to allow a heat differential to be created between the die zones in heat contact with the individually controllable heating segments.
Claim 6
Dependent Claim
35 words
The extruder arrangement of claim 4 wherein the annular heating sleeve comprises eight heating segments in side by side relationship collectively to define a continuous sleeve, each heating segment being adapted to be individually energised.
Claim 7
Dependent Claim
111 words
The extruder arrangement of claim 4 wherein the sleeve is in the form of a heat conductive metallic member defining an annular contact surface and adapted to be clamped in heat transferring contact about the exterior surface of the die, the member being provided with a plurality of heating zones each including at least one receiving formation, the receiving formations being located about the contact surface and spaced from the contact surface and each containing a heating element arranged in use to impart heat to its associated heating zone of the member and thereby to heat the zone of the die in the vicinity of that heating zone upon being energised.
Claim 8
Dependent Claim
77 words
The extruder arrangement of claim 3 wherein there is provided a die having a die wall defining the bore into which the mandrel is received in spaced relationship when in use, the die wall defining a plurality of heating zones each including at least one receiving formation, the receiving formations being spaced from and about the bore and each containing a heating element arranged in use to heat a die zone in its vicinity upon being energised.
Claim 9
Dependent Claim
35 words
The extruder arrangement of claim 6 and claim 7 wherein the receiving formations containing the heating elements are in the form of passages which extend parallel to the axis of the bore of the die.
Claim 10
Dependent Claim
19 words
The extruder arrangement of claim 8 wherein the receiving formations are spaced symmetrically about the bore of the die.
Claim 11
Dependent Claim
28 words
The extruder arrangement of any one of claims 6 to 9 wherein the heating elements are in the form of heating cartridges received snugly in the receiving formations.
Claim 12
Dependent Claim
21 words
The extruder arrangement of any one of claims 6 to 9 wherein each heating zone includes a plurality of receiving formations.
Claim 13
Dependent Claim
32 words
The extruder arrangement of any one of claims 3 to 11 wherein the heating elements forming part of the temperature differential means is the sole source of heat for heating the die.
Claim 14
Dependent Claim
53 words
The extruder arrangement of any one of claims 3 to 11 wherein the temperature differential means is used in conjunction with an additional die heating arrangement which is designed to heat the die to a uniform temperature along its entire circumference and wherein the temperature differential means primarily serve a temperature boosting function.
Claim 15
Dependent Claim
23 words
The extruder arrangement of claim 3 wherein the temperature differential means includes a cooling system arranged to cool selected zones of the die.
Claim 16
Dependent Claim
77 words
The extruder arrangement of claim 14 wherein the temperature differential means includes an annular cooling sleeve which is adapted in use to be received in heat conductive relationship about the annular die and which includes a plurality of cooling segments at least some of which segments are adapted to be individually supplied with a coolant thereby to allow a heat differential to be created between the die zones in heat contact with the individually controllable cooling segments.
Claim 17
Dependent Claim
53 words
The extruder arrangement of claim 15 wherein there is provided an annular cooling sleeve comprising eight cooling segments in side by side relationship collectively to define a continuous sleeve, each segment including a conduit and the arrangement being such that each conduit is adapted to be individually supplied with a coolant passing therethrough.
Claim 18
Dependent Claim
123 words
The extruder arrangement of claim 15 wherein the sleeve is in the form of a heat conductive metallic member defining an annular contact surface and adapted to be clamped in heat transferring contact about the exterior surface of the die, the member being provided with a plurality of cooling zones each including at least one receiving formation, the receiving formations being located about the contact surface and spaced from the contact surface and each receiving formation being adapted in use to serve as a conduit to receive a coolant therethrough to cool its associated cooling zone of the member and thereby in use to cool the zone of the die in the vicinity of that cooling zone upon a coolant being passed therethrough.
Claim 19
Dependent Claim
89 words
The extruder arrangement of claim 15 wherein there is provided a die having a die wall defining the bore into which the mandrel is received in spaced relationship when in use, the die wall defining a plurality of cooling zones each including at least one receiving formation, the receiving formations being spaced from and about the bore and each being adapted in use to serve as a conduit for a coolant in use to cool a die zone in its vicinity upon being supplied with a coolant passing therethrough.
Claim 20
Dependent Claim
33 words
The extruder arrangement of claim 17 or 18 wherein the receiving formations defining the conduits are in the form of passages which extend parallel to the axis of the bore of the die.
Claim 21
Dependent Claim
19 words
The extruder arrangement of claim 19 wherein the receiving formations are spaced symmetrically about the bore of the die.
Claim 22
Dependent Claim
24 words
The extruder arrangement of claim 20 wherein the receiving formations include valve means adapted in use to control the flow of the coolant therethrough.
Claim 23
Dependent Claim
60 words
The extruder arrangement of any one of claims 15 to 21 wherein at least some of the coolant receiving passages are adapted also to receive a heating element, each passage being formed'such as to allow a coolant to flow through the passage and about a heating element which is disposed in heat conductive contact with the wall of the passage.
Claim 24
Dependent Claim
18 words
The extruder arrangement of claim 22 wherein the passages have side walls in which helical by-passes are provided.
Claim 25
Dependent Claim
21 words
The extruder arrangement of any one of claims 15 to 23 which is adapted to receive compressed air as a coolant
Claim 26
Dependent Claim
36 words
The extruder arrangement of claim 1 including a primary heating arrangement and a heat differential means including both a booster heating arrangement and a cooling arrangement as claimed in any one of claims 3 to 24.
Claim 27
Independent Claim
72 words
A method of forming a tube-shaped member including the steps of extruding a thermoplastic polymeric material through an extruder arrangement as claimed in any one of claims 1 to 25, monitoring the extrusion at predetermined intervals for uniformity of wall thickness and, if necessary, adjusting the temperature differential between one or more segmental zones of the die to improve unacceptable disuniformity in the monitored wall thickness by activating the heat differential means.
Claim 28
Dependent Claim
23 words
The method of claim 26 in which the wall thickness of the pipe is monitored by means of sonar wall thickness measuring equipment.
Claim 29
Dependent Claim
136 words
The method of claim 27 in which the sonar measuring system includes a transducer/receiver mounted on a suitable circular frame through which the extruded tube-shaped member is taken off and the transducer/receiver is arranged to move about the pipe circumference and to take a plurality of measurements about the circumference of the pipe, the system being controlled by a control system including a microprocessor arranged to compare the measurements taken with a set standard and allowable tolerances and to activate the heat differential means associated with the extruder arrangement in the event of detecting wall zones of a thickness falling outside of the set tolerances, said control system being arranged to adjust the temperature in the zone of the die through which the errant pipe zone was extruded to bring it to within the set tolerances.
Claim 30
Dependent Claim
40 words
The method of claim 28 in which the control system of the measuring system is programmed to take a number of measurements about the circumference equal to the number of heating or cooling segments present in the temperature differential means.
Claim 31
Dependent Claim
103 words
. 30. The method of claim 27 in which the wall thickness measuring equipment includes a plurality of ultrasonic transducer/receiver heads mounted in circular fashion about the take-off path of an extruded element, the number of heads being equal to the number of heating or cooling zones of the temperature differential means associated with the die from which the extruded article emerges, and the arrangement being such that each head is arranged to monitor the thickness of a wall section emerging from a particular segment of the extrusion passage disposed immediately adjacent a particular heating or cooling zone of the temperature differential means.
Claim 32
Dependent Claim
31 words
The method of claim 30 in which the heads are disposed in a water jacket to ensure a film of water between the head and the pipe wall to be monitored.
Claim 33
Dependent Claim
18 words
An extruder arrangement substantially as herein described with reference to the accompanying Figures 1 a and 1 b.
Claim 34
Dependent Claim
18 words
An extruder arrangement substantially as herein described with reference to the accompanying Figures 1 a and 1 b.
Claim 35
Dependent Claim
16 words
An extruder arrangement substantially as herein described with reference to the accompanying Figures 2a and 2b.
Claim 36
Dependent Claim
16 words
An extruder arrangement substantially as herein described with reference to the accompanying Figures 2a and 2b.
Claim 37
Dependent Claim
19 words
3 4 . An extruder arrangement substantially as herein described with reference to the accompanying Figures 3a and 3b.
Claim 38
Dependent Claim
19 words
3 4 . An extruder arrangement substantially as herein described with reference to the accompanying Figures 3a and 3b.
Claim 39
Dependent Claim
16 words
An extruder arrangement substantially as herein described with reference to the accompanying Figures 4a and 4b.
Claim 40
Dependent Claim
16 words
An extruder arrangement substantially as herein described with reference to the accompanying Figures 4a and 4b.
Claim 41
Independent Claim
19 words
A method of extruding a tube shaped member substantially as herein described with reference to the accompanying Figure 5.
Claim 42
Independent Claim
19 words
A method of extruding a tube shaped member substantially as herein described with reference to the accompanying Figure 5.
Claim 43
Independent Claim
19 words
A method of extruding a tube shaped member substantially as herein described with reference to the accompanying Figure 6.
Claim 44
Independent Claim
19 words
A method of extruding a tube shaped member substantially as herein described with reference to the accompanying Figure 6.
References Cited (Backward Citations)
No citation records indexed.
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