GB644429A - Improvements in or relating to the treatment of polythene - Google Patents

Improvements in or relating to the treatment of polythene

Info

Publication number
GB644429A
GB644429A GB23841/47A GB2384147A GB644429A GB 644429 A GB644429 A GB 644429A GB 23841/47 A GB23841/47 A GB 23841/47A GB 2384147 A GB2384147 A GB 2384147A GB 644429 A GB644429 A GB 644429A
Authority
GB
United Kingdom
Prior art keywords
polythene
smearhead
wire
coating
extrusion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB23841/47A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EIDP Inc
Original Assignee
EI Du Pont de Nemours and Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by EI Du Pont de Nemours and Co filed Critical EI Du Pont de Nemours and Co
Publication of GB644429A publication Critical patent/GB644429A/en
Expired legal-status Critical Current

Links

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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
    • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/05—Filamentary, e.g. strands
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/06—Rod-shaped

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Extrusion Moulding Of Plastics Or The Like (AREA)

Abstract

644,429. Extruding polythene. DU PONT DE NEMOURS & CO., E. I. Aug. 28, 1947, No. 23841. Convention date, Aug. 28, 1946. [Class 87 (ii)] [Also in Group II] A process for improving the extrusion properties of polythene, especially with a view to its use in coating wires, comprises forcing polythene at a temperature above 100‹ C. through a confined space between concentric surfaces, one of which is rotating with respect to the other at a peripheral speed of at least 90 feet per minute, so that the polythene is subjected to a shearing force at right angles to the direction of flow, the confined space having a clearance factor of at least 40. The concentric surfaces are formed by a cylinder 4, known as a smearhead, rotating in a cylindrical tube, and the clearance factor is defined as the length 20 of the smearhead multiplied by the reciprocal of the clearance between the smearhead and the tube. The polythene is introduced .at 1, preferably in powdered form, and is forced towards the smearhead by an Archimedean screw 2. To produce the maximum working effect on the polythene the temperature should be as low as practicable and a cooling chamber 7 is provided round the smearhead. A jacket 5 is used to heat or cool the polythene, as required, in its advance along the Archimedean screw. The treated polythene is discharged through an opening 21 or it may be passed directly through a die to shape it according to the ordinary method of extrusion. The Archimedean screw may have a diminishing pitch, as shown. To give greater flexibility of operation the smearhead 4 and screw 2 may be separately driven at different speeds and in different directions. The Specification describes a method of testing the suitability of a polythene for coating wires according to which it is extruded through a standard type of wire coating machine under stated conditions of die dimension, temperature, extrusion pressure, and wire diameter and the wire is drawn through at increasing speeds. As the speed of the wire rises the surface of the polythene coating it becomes wavy and the point at which the waviness is unsatisfactory is the measure of the suitability of the polythene for wire coating. The Specification also mentions making sheets from polythene treated according to the invention.
GB23841/47A 1946-08-28 1947-08-28 Improvements in or relating to the treatment of polythene Expired GB644429A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US644429XA 1946-08-28 1946-08-28

Publications (1)

Publication Number Publication Date
GB644429A true GB644429A (en) 1950-10-11

Family

ID=22056009

Family Applications (1)

Application Number Title Priority Date Filing Date
GB23841/47A Expired GB644429A (en) 1946-08-28 1947-08-28 Improvements in or relating to the treatment of polythene

Country Status (1)

Country Link
GB (1) GB644429A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2776274A (en) * 1957-01-01 Polyethylene refining
US3165505A (en) * 1953-04-04 1965-01-12 Basf Ag Process for improving the properties of polyethylene
EP0186861A2 (en) * 1984-12-19 1986-07-09 Idemitsu Petrochemical Co. Ltd. Method of and apparatus for extruding thermoplastic resin
GB2218034A (en) * 1988-05-04 1989-11-08 Atomic Energy Authority Uk An extrusion process and apparatus therefor

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2776274A (en) * 1957-01-01 Polyethylene refining
US3165505A (en) * 1953-04-04 1965-01-12 Basf Ag Process for improving the properties of polyethylene
EP0186861A2 (en) * 1984-12-19 1986-07-09 Idemitsu Petrochemical Co. Ltd. Method of and apparatus for extruding thermoplastic resin
EP0186861A3 (en) * 1984-12-19 1988-03-02 Idemitsu Petrochemical Company Limited Method of and apparatus for extruding thermoplastic resin
GB2218034A (en) * 1988-05-04 1989-11-08 Atomic Energy Authority Uk An extrusion process and apparatus therefor
GB2218034B (en) * 1988-05-04 1992-08-19 Atomic Energy Authority Uk An extrusion process

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