GB757664A - Improvements in methods of extruding polytetrafluoroethylene - Google Patents

Improvements in methods of extruding polytetrafluoroethylene

Info

Publication number
GB757664A
GB757664A GB24342/54A GB2434254A GB757664A GB 757664 A GB757664 A GB 757664A GB 24342/54 A GB24342/54 A GB 24342/54A GB 2434254 A GB2434254 A GB 2434254A GB 757664 A GB757664 A GB 757664A
Authority
GB
United Kingdom
Prior art keywords
die
unbaked
heated
temperature
extruder
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
GB24342/54A
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 GB757664A publication Critical patent/GB757664A/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
    • B29C48/022—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the choice of material
    • 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
    • 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
    • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
    • B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
    • B29K2027/18—PTFE, i.e. polytetrafluorethene, e.g. ePTFE, i.e. expanded polytetrafluorethene

Landscapes

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

Abstract

Pure, unbaked polytetrafluorethylene is heated in an extruder to a temperature higher than its normal melting point, while sufficient pressure is applied to prevent it from melting, and is forced through the die at that temperature, the pressure decreasing as the material passes through the die, causing the extrudate to melt. For a temperature range of 350 DEG -375 DEG C. the required pressure range is 7,500-10,000 lb./sq. in. The unbaked polytetrafluoroethylene may be in the grannular or agglommerated colloidal form, or it may be introduced into the extruder cylinder as an unbaked preform. Small proportions of stabilizer or coloured pigments may be added to the material. Multiple ram extruders may be used. The process may be continuous or intermittent, the die in the latter case being blocked while the material is heated in the cylinder. An example is given of coating wire by the process.
GB24342/54A 1953-08-21 1954-08-20 Improvements in methods of extruding polytetrafluoroethylene Expired GB757664A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US757664XA 1953-08-21 1953-08-21

Publications (1)

Publication Number Publication Date
GB757664A true GB757664A (en) 1956-09-19

Family

ID=22127843

Family Applications (1)

Application Number Title Priority Date Filing Date
GB24342/54A Expired GB757664A (en) 1953-08-21 1954-08-20 Improvements in methods of extruding polytetrafluoroethylene

Country Status (1)

Country Link
GB (1) GB757664A (en)

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