EP0183905A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Head for the circular coextrusion of a plurality of thermoplastic material layers
Assignee: Officina Meccanica G Prandi and C SpA
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Filing: 1985-06-20
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Granted: —
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Expires: 2005-06-20
Abstract
Abstract Head for the coextrusion of N thermoplastic materials consisting of N + 1 plates which are substantially modular and are assembled by form coupling constraint, each plate comprising a longitudinal conduit to feed one of said materials; at least an annular semi-collector-distributor; at least a semi-channel; a projection and a specular recess. The intermediate plates between the first and the last plate show a second semi-collector and a second semi- channel which by coupling with a precedent or successive semi-collector respectively semi-channel form a collector respectively a channel which extend annularly over the whole plate, the distributor section area and the channel length showing gradients over the 360°.
Inventors
- 👤 Claudio Gini
- 👤 Giuseppe Vanetti
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 13:51
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/32; B29C48/34; B29C48/03; B29C48/09; B29C48/10; B29C48/14; B29C48/147; B29C48/1472; B29C48/16; B29C48/18; B29C48/21; B29C48/335; B29C48/336; B29C48/3363; B29C2791/00; B29C2791/004; B29C2791/007
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
Head for the coe-extrusion of N thermoplastic resins in the form of N superposed tubes, said head consisting of a male inner body whose cylindrical surface is at a short distance from a concentric inner cylindrical surface with which it creates the narrow annular space or air gap where the primary composite tube is formed, characterized in that said inner air gap forming surface is made of a plurality of N+l plates which are modular and fit with their form; and that each plate shows a longitudinal conduit for feeding one of the N thermoplastic resins to be extruded, at least a semi-collector acting as distributor of the resin coming from said conduit, at least a semi-channel which extends radially from said collector to the inner generatrix formed by the cylindrical plate assembly, a projection and a recess.
Claim 2
Dependent Claim
138 words
Head for the coe-extrusion of N thermoplastic resins in the form of N superposed tubes, said head consisting of a male inner body whose cylindrical surface is at a short distance from a concentric inner cylindrical surface with which it creates the narrow annular space or air gap where the primary composite tube is formed, characterized in that said inner air gap forming surface is made of a plurality of N+l plates which are modular and fit with their form; and that each plate shows a longitudinal conduit for feeding one of the N thermoplastic resins to be extruded, at least a semi-collector acting as distributor of the resin coming from said conduit, at least a semi-channel which extends radially from said collector to the inner generatrix formed by the cylindrical plate assembly, a projection and a recess.
Claim 3
Dependent Claim
61 words
Head according to claim 1, characterized in that the plates included between the first and the last plate i.e. plates from 2 to N, have a second semi-collector distributor and a second radial semi-channel, one of the two semi-collectors and semi-channels being on the upper transversal face and the other one being on the lower transversal face of each intermediate plate.
Claim 4
Dependent Claim
135 words
Head according to claims 1 and 2, characterized in that the semi-distributor respectively the semi-channellon one face, f.i. the lower face of a plate forms with the semi-collector respectively the semi-channel on the-other face f.i. the upper face of the successive plate a collector respectively a channel, each of which extends on the whole inner circumference of the plate, the initial cross-section area of the distributor at the bottom of the feeding conduit as well as the width and the radial extension of the channel starting from said initial collector crosssection varying along the whole circumference , so as to have on a plate pressure gradients of the material under extrusion substantially equal along the locuses of the centers of all transversal sections of the distributor and of the channel terminals facing the male body.
Claim 5
Dependent Claim
26 words
Head according to claim 3, characterized in that the circumference of said locuses on one couple of plates is eccentric (off-set) over the male longitudinal axis.
Claim 6
Dependent Claim
29 words
Head according to the preceding claims, characterized in that the circumference of a couple of plates is in off-set over the circumference of all the other couples of plates.
Claim 7
Dependent Claim
8 words
Head substantially according to what described and shown.
Claim 8
Dependent Claim
8 words
Head substantially according to what described and shown.
References Cited (Backward Citations)
No citation records indexed.
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