# US 10,766,182 B2 · Extrusion parison head for discontinuous foaming > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,766,182 B2 - Document ID: US10766182B2 - Status: Granted - Kind: B2 - Application number: 14/895,058 - Filed: 2014-06-04 - Published: 2016-04-14 - Granted: 2020-09-08 - Earliest claimed: 2013-06-04 - Assignees: W. Müller GmbH - Applicants: W. MüLler GmbH - Inventors: Guido Knipp - Web page: https://patentgrep.com/patent/US10766182B2 ## CPC - B29B 7/7414: {with rotatable stirrer, e.g. using an intermeshing rotor-stator system (B29B7/7423 takes precedence)} - B29C 44/3446: {Feeding the blowing agent} - B29C 48/0012: {combined with shaping by internal pressure generated in the material, e.g. foaming} - B29C 48/0017: {combined with blow-moulding or thermoforming} - B29C 48/09: Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels - B29C 48/30: Extrusion nozzles or dies (extrusion characterised by the shape or cross-section of the extruded article B29C48/03) - B29C 48/338: {using a die with concentric parts, e.g. rings, cylinders} - B29C 48/705: {in the die zone, e.g. to create flow homogeneity} - B29C 49/041: {using an accumulator head} - B29C 49/04104: {extruding the material discontinuously} - B29C 49/04108: {extruding several parisons parallel to each other at the same time} - B29K 2101/12: Thermoplastic materials - B29K 2105/04: cellular or porous - B29L 2023/00: Tubular articles (B29L2024/00 takes precedence {; catheters B29L2031/7542}) - B29B: PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS - 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 (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) - B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS - B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES ## Abstract Extrusion head 1 for manufacturing hose-like parisons from an extruded plastic material, which are made up from at least one first layer and a second layer, wherein the extrusion head 1 comprises the following: a first manifold 15 with a connection 2 for a first extruder, a second manifold 19 with a connection 8 for a second extruder 3, a first flow channel 17 with an annular first outlet opening 18 for producing a first layer, wherein the first flow channel 17 is fed by the first manifold 15, a second flow channel 21 with an annular second outlet opening 22 for producing a second layer, wherein the second flow channel 21 is fed by the second manifold 19, and a mixer 27 within the second flow channel 21 with a connection 54 for introducing a foaming agent. ## Claims ### Claim 1 Extrusion head for producing tubular parisons from extrudable plastic, which are made up from at least a first layer and a second layer, wherein the extrusion head comprises: a first manifold with a connection for a first extruder, a second manifold with a connection for a second extruder, a first flow channel with an annular first outlet opening for producing the first layer, wherein the first flow channel is fed by the first manifold, a second flow channel with an annular second outlet opening for producing the second layer, wherein the second flow channel is fed by the second manifold, a dynamic mixer arranged within the second flow channel with a connection for introducing a foaming agent, wherein the dynamic mixer comprises a mixer housing with a bore, a mixing element rotatingly drivable arranged within said bore, and a first annular channel portion between the bore of the mixer housing and the mixing element, wherein the first annular channel portion is part of the second flow channel, a bore shaped channel portion of the second flow channel downstream of the mixer, wherein the material flows out of the first annular channel portion of the mixer is joined in the bore shaped channel portion, and a second annular channel portion of the second flow channel is downstream of said bore shaped channel portion, wherein the material flows out of the bore shaped channel portion to the second annular channel portion. ### Claim 2 (depends on 1) Extrusion head according to claim 1, wherein a first set of mixing blades are arranged on an outer circumferential face of the mixing element. ### Claim 3 (depends on 2) Extrusion head according to claim 2, wherein a second set of mixing blades, which interact with the first set of mixing blades of the mixing element, are provided on an inner circumferential face of the mixer housing. ### Claim 4 (depends on 1) Extrusion head according to claim 1, wherein the connection for introducing a foaming agents is provided on the mixer housing, wherein a foaming agent feed line leads to the first annular channel portion. ### Claim 5 (depends on 1) Extrusion head according to claim 1, wherein a servomotor is provided for driving the mixing element of the mixer with a variable rotational speed. ### Claim 6 (depends on 1) Extrusion head according to claim 1, wherein upstream of the mixer, a shut-off valve is provided. ### Claim 7 (depends on 1) Extrusion head according to claim 1, wherein the first outlet opening and/or the second outlet opening can be closed. ### Claim 8 (depends on 1) Extrusion head according to claim 1, wherein the second outlet opening is arranged such, that the second layer is arranged within the first layer. ### Claim 9 (depends on 1) Extrusion head according to claim 1, wherein a third manifold with a connection is provided for a third extruder and wherein a third flow channel is provided with an annular third outlet opening for producing a third layer, wherein the third flow channel is fed by the third manifold. ### Claim 10 (depends on 9) Extrusion head according to claim 9, wherein the third outlet opening is arranged such, that the third layer is arranged within the second layer. ### Claim 11 (depends on 9) Extrusion head according to claim 9, wherein the second outlet opening is arranged downstream from the third outlet opening or wherein the first outlet opening is arranged downstream of the second outlet opening and the third outlet opening. ### Claim 12 (depends on 1) Extrusion machine with an extrusion head according to claim 1, wherein in front of each manifold a temporary storage is provided for the extruded material. ### Claim 13 (depends on 1) Method for operating an extrusion head according to claim 1, in which the pressure within the second flow channel is held at a defined value. ### Claim 14 (depends on 13) Method according to claim 13, wherein, when falling below the pressure within the second flow channel, the pressure is regulated by means of adapting the expelling velocity of a second temporary storage for the extruded material arranged in front of the extrusion head. ### Claim 15 (depends on 13) Method according to claim 13, wherein the temperature within the second flow channel is adjusted to a different value than within the other flow channels.