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
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
• • 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
  • B29C33/00—Moulds or cores; Details thereof or accessories therefor
  • B29C33/56—Coatings, e.g. enameled or galvanised; Releasing, lubricating or separating agents
• • 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
  • B29C51/00—Shaping 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
  • B29C51/26—Component parts, details or accessories; Auxiliary operations
  • B29C51/28—Component parts, details or accessories; Auxiliary operations for applying pressure through the wall of an inflated bag or diaphragm
• • 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
  • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
  • B29C43/02—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles
  • B29C43/10—Isostatic pressing, i.e. using non-rigid pressure-exerting members against rigid parts or dies
  • B29C43/12—Isostatic pressing, i.e. using non-rigid pressure-exerting members against rigid parts or dies using bags surrounding the moulding material or using membranes contacting the moulding material

Definitions

• the present invention relates to a method of forming products, especially prototype pieces, of thermoplastic materials.
• Thermoplastic material such as reinforced plastics material sheets, can be formed into products by heating it first to a softening temperature and transferring it thereafter to a mould in which it is pressed and allowed to set.
• the moulds are usually machined or cast metal moulds. The manufacture of prototype pieces in particular has therefore been difficult, expensive and time-consuming.
• the object of this invention is to provide a method by which the manufacture of products formed of a thermoplastic material, and in particular the production of prototype pieces, is faster and less expensive than before.
• a sheet of thermoplastic material is heated and transferred to a mould against which it is formed by pressing; and it is a characteristic feature of the invention that the mould is a model backed against a planar mould table by a backing material.
• a model of the desired shape can be used as the mould.
• the lower surface of the model i.e. the surface facing the mould table, need not be planar.
• the model can, for example, have the shape of a dish turned upside down and it can be made of sheet metal. According to the invention it is, prior to placing on the mould table, filled with for example polyurethane foam which gives a planar lower surface.
• a material the surface of which is easy to form to a plane is suitable to be used as the backing material.
• Materials of this kind are for example foamy settable substances, such as polyurethane, or casting materials, such as gypsum.
• foamy settable substances such as polyurethane
• casting materials such as gypsum.
• the method of the present invention it is possible to produce fast and with low costs a prototype piece with the corresponding properties, for example appearance, insulation ability, ridigity, etc., as the products manufactured with known methods.
• the methods allows the use of models of a large variety of shapes. It does not cause high tool costs as the same planar mould table can be used for various shapes of models.
• the model can be made of different materials such as for example wood, plywood, sheet metal or a sheet of polyester. It is a prereguisite of the material of the model that it will not be deformed by the hot thermoplastic sheet.
• a model 2 is supported by a backing material 1 and placed on a mould table 6 having a planar top surface.
• a thoroughly soft and pliable sheet 3 of a thermoplastic material heated in an oven is transferred to the mould (1 and 2).
• An elastic diaphragm 4 of a pressure bell 5 is applied and presses the thermoplastic material tightly againts the mould by means of the pressure prevailing in the pressure bell.
• air is exhausted from the region of the sheet to be formed via passages 7.
• a pressure of less than 0.1 MPa is in most cases adeguate for the pressing. However, higher pressures can be used, particularly if the density of the backing material is increased.
• the present method is very well applicable in forming prototype pieces of porous sheet-like fiber-reinforced non- compressed particle-form plastics material, the fiber and plastics components of which are bound together.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
• Moulding By Coating Moulds (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8530732

Family Applications (1)

Country Status (7)

Families Citing this family (5)

Family Cites Families (8)

• 1990
  • 1990-07-02 FI FI903324A patent/FI903324A7/fi not_active Application Discontinuation
• 1991
  • 1991-06-20 CA CA002085478A patent/CA2085478A1/en not_active Abandoned
  • 1991-06-20 KR KR1019920703402A patent/KR930701278A/ko not_active Ceased
  • 1991-06-20 EP EP91911007A patent/EP0537192A1/de not_active Ceased
  • 1991-06-20 WO PCT/FI1991/000193 patent/WO1992000176A1/en not_active Ceased
  • 1991-06-20 JP JP3511651A patent/JPH0741663B2/ja not_active Expired - Lifetime
  • 1991-08-15 TW TW080106468A patent/TW200428B/zh active

Non-Patent Citations (1)

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