IT1089304B - Solid-state heat-moulding polypropylene sheets - involves passing sheet intermittently across a continuous heating zone, to raise the temp. or the sheet to near its m.pt. - Google Patents

Solid-state heat-moulding polypropylene sheets - involves passing sheet intermittently across a continuous heating zone, to raise the temp. or the sheet to near its m.pt.

Info

Publication number
IT1089304B
IT1089304B IT2963677A IT2963677A IT1089304B IT 1089304 B IT1089304 B IT 1089304B IT 2963677 A IT2963677 A IT 2963677A IT 2963677 A IT2963677 A IT 2963677A IT 1089304 B IT1089304 B IT 1089304B
Authority
IT
Italy
Prior art keywords
sheet
temp
moulding
point
heating zone
Prior art date
Application number
IT2963677A
Other languages
Italian (it)
Original Assignee
Plastiform Srl
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 Plastiform Srl filed Critical Plastiform Srl
Priority to IT2963677A priority Critical patent/IT1089304B/en
Priority to BE0/195681A priority patent/BE876903A/en
Application granted granted Critical
Publication of IT1089304B publication Critical patent/IT1089304B/en

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/04Combined thermoforming and prestretching, e.g. biaxial stretching
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/002Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor characterised by the choice of material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/26Component parts, details or accessories; Auxiliary operations
    • B29C51/42Heating or cooling
    • B29C51/426Producing specific thermal regimes during thermoforming to obtain particular properties
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C51/00Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
    • B29C51/10Forming by pressure difference, e.g. vacuum

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)
  • Laminated Bodies (AREA)

Abstract

An improved method of heat-moulding polypropylene sheets in the solid state consists in passing the sheet intermittently across a continuous re-heating zone, the length of which is at least three times the useful length of any specific moulding zone. The sheet is gradually heated to a temp. below, but near to, its melting point. In the moulding zone a controlled pressure is applied to the peripheral zones of the sheet to set it. Pre-moulding is effected between a point in at least partial contact with the sheet and a hollow mould which can move relative to one another the point being heated, at least where it contacts the sheet, to a temp. 16-34 degrees C below the temp. of the sheet. A final moulding stage is effected by spraying, practically instantaneously a jet of fluid under pressure on to the surface of the sheet opposite the point of contact. This makes the sheet adhere to the walls of the mould surrounding the cavity; these walls are kept at a temp. below 10 degrees C. The method enables polypropylene heat-moulded prods. to be obtd. with considerably higher productivity and of considerably better quality than hitherto.
IT2963677A 1977-11-14 1977-11-14 Solid-state heat-moulding polypropylene sheets - involves passing sheet intermittently across a continuous heating zone, to raise the temp. or the sheet to near its m.pt. IT1089304B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
IT2963677A IT1089304B (en) 1977-11-14 1977-11-14 Solid-state heat-moulding polypropylene sheets - involves passing sheet intermittently across a continuous heating zone, to raise the temp. or the sheet to near its m.pt.
BE0/195681A BE876903A (en) 1977-11-14 1979-06-11 PERFECTED PROCESS FOR THERMOFORMING POLYPROPYLENE IN SHEETS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT2963677A IT1089304B (en) 1977-11-14 1977-11-14 Solid-state heat-moulding polypropylene sheets - involves passing sheet intermittently across a continuous heating zone, to raise the temp. or the sheet to near its m.pt.

Publications (1)

Publication Number Publication Date
IT1089304B true IT1089304B (en) 1985-06-18

Family

ID=11228154

Family Applications (1)

Application Number Title Priority Date Filing Date
IT2963677A IT1089304B (en) 1977-11-14 1977-11-14 Solid-state heat-moulding polypropylene sheets - involves passing sheet intermittently across a continuous heating zone, to raise the temp. or the sheet to near its m.pt.

Country Status (2)

Country Link
BE (1) BE876903A (en)
IT (1) IT1089304B (en)

Also Published As

Publication number Publication date
BE876903A (en) 1979-10-01

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