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
  • 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
  • B29C43/18—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor of articles of definite length, i.e. discrete articles incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles
• • 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
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/04—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts comprising reinforcements only, e.g. self-reinforcing plastics
  • B29C70/28—Shaping operations therefor
  • B29C70/40—Shaping or impregnating by compression not applied
  • B29C70/42—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles
  • B29C70/46—Shaping or impregnating by compression not applied for producing articles of definite length, i.e. discrete articles using matched moulds, e.g. for deforming sheet moulding compounds [SMC] or prepregs
• • 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
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
  • B29C70/86—Incorporated in coherent impregnated reinforcing layers, e.g. by winding
  • B29C70/865—Incorporated in coherent impregnated reinforcing layers, e.g. by winding completely encapsulated
• • 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
  • B29C70/00—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts
  • B29C70/68—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks
  • B29C70/685—Shaping composites, i.e. plastics material comprising reinforcements, fillers or preformed parts, e.g. inserts by incorporating or moulding on preformed parts, e.g. inserts or layers, e.g. foam blocks by laminating inserts between two plastic films or plates
• • 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
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/25—Solid
  • B29K2105/253—Preform
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2009/00—Layered products

Definitions

• the present invention relates to a method for the manufacture of composite products More particularly the invention relates to a method for the manufacture of composite products comprising an outer cover layer comprising a thermoplastic mate ⁇ al and a fibrous reinforcement, and a core of extruded, foamed polymer, wherein the core mate ⁇ al is still soft and not completely cures when the product is given its final shape in a press shape mould.
• the invention further relates to a press shape mould (tool) for conducting the method.
• Composite products are used in an increasing va ⁇ ety of applications due to their combination of high strength and low weight. With a suitable choice of materials, such products also represent environmentally friendly alternatives, where a high degree of recycling is possible. The products are competitive also in other respects, e.g. with respect to resistance against degradation inflicted by chemicals, temperature etc.
• Composite products typically comprise several layers of reinforcement in a polymer matrix, envelops a foamed core with a very low weight.
• the reinforcement layers provide strength to the product, and may additionally provide a desired surface finish.
• Particular surface layers may e g consist of felt or PMMA foil
• the invention is characterized by the features discloses by the characterizing part of claim 1.
• the press shape mould (tool) for conducting the method is characterized by the features disclosed by claim 7.
• Figure la is a highly simplified, schematic view of an embodiment of a press shape mould tool according to the invention, in a state of a first work phase of the method,
• Figure lb shows the embodiment of figure la in a second work phase of the method.
• Figure lc shows the embodiment of figure la and lb in a third work phase of the method
• Figure Id shows the embodiment of figure la - lc in a fourth work phase of the method
• Figure 2a-2d shows the work phases of figures la- Id with a slightly modified press shape mould.
• the press shape mould tool 1 (for simplification hereinafter usually referred to as press tool 1 ), which is illustrated highly simplified, generally comprises two tool halves 2 and 3.
• a piston shaped member 4 which is arranged moveably back and forth (or up and down dependent on the orientation of the press tool) by means of any suitable mechanism 5 that may be influenced by an external force from an attachment not shown.
• the press tool 1 has internal surfaces 6a, 6b mainly located to the piston member 4 and to the tool half 3, forming the cavity of the tool, i.e. the shape is substantially complementary to the desired shape of the product, as these parts of the tool will bear directly against the product blanks during the press and shape procedure.
• the internal shape of a horizontal section of the press tool 1 in and of the piston member 4 is decided by the shape of the products. Thus, this shape may be of any regular or irregular kind.
• a material 1 1 with a significantly lower heat conductance than that of the piston member itself.
• product blank 7 is shown, which product blank comprises one or more enveloping materials 8a, 8b and at least one core material 9.
• Figure 1 a shows a situation where enveloping material 8a, 8b and freshly extruded core material 9 have been introduced into or preferably through the openings betwween the press tool halves 2, 3 that eventually decides the outer dimensions of the finished product.
• the assembly is shown with a horizontal input of material, but the invention works independently of this orientation. It may preferably have a vertical orientation as described in Applicant's Norwegian patent application No. 19993471. It is, however, essential that both the enveloping materials 8a, 8b and the core 9 are introduced in a heated but not yet consolidated state.
• Figure lb shows the next phase or step of the process.
• the press tool halves 2, 3 have been moved together and close the void in which the product is formed, defined mainly by the surfaces 6a, 6b.
• the piston member 4 of the press tool 1 has been moved forward to a position h,, where it bear against the outer surface of the product blank 7 that still is in a plastic non-consolidated state.
• Figure lc shows the next step of the method according to the invention, which is the step constituting the most significant feature.
• the piston member 4 has been moved further forward against the product blank to a level h 2 where the product blank 7 is compressed to a state far more than corresponding to its desired final shape.
• the locked up air or gas in the freshly extruded core 9, which is still not consolidated, is highly compressed. It cannot, however, escape and will therefore remain in the structure of the product.
• the position shown in fig. lc is maintained for a little while, the length of which depends a.o. of the size of the product, so that consolidation is initiated in this state.
• the material resting against the press tool i.e.
• the enveloping material 8a, 8b will commence consolidation first, while the core 9 needs some additional time to be cooled and therefore will consolidate a little later.
• this phase there is a very good contact between the internal surfaces 6a, 6b of the tool and the enveloping material 8a, 8b of the product blank 7, and the outer surface of the product therefore receives the shape and firmness desired, while the product's internal volume is still compressed beyond the desired volume and shape. Due to material 11 with low heat conductance in the region of the circumference, the enveloping material 8a in this region remains flexible for a longer period of time than the other parts of the enveloping material 8a, 8b.
• the piston member 4 is drawn back as shown on figure Id to a level h3 so that the pressure is reduced. More precisely the piston member is withdrawn to an extent where the cavity of the press tool, defined mainly by surfaces 6a and 6b, corresponds precisely to the desired volume of the finished product.
• the gas pressure in the core 9, which has barely begun to consolidate, will during this phase "blow up” the core again , ensuring that the core fills the entire internal void of the product in the way intended.
• the part of the enveloping material 8a, 8b that is in the region of the circumference of the product will due to the material with low heat conductance remain its flexibility to this stage, and therefore allow the core to blow up so the product finds its final shape.
• FIG. 2a-2d principally illustrates steps similar to figure la- Id.
• a press shape mould tool comprising a groove 10 in the surface of the piston member 4, so that the surface 8a of the product blank 7 will penetrate the groove and receive a corresponding shape.
• the core material 9 will to some extent enter into and be shaped by the groove 10 if the groove has a sufficient size.
• FIG 2 depicts only one groove it is evident that several grooves may be applied or an entire pattern of grooves and recesses, in order to provide the surface of the product with certain functional or visual structures.
• the grooves may be minute grooves or deep recesses, dependent on their objectives. Similar grooves and recesses may off course also be arranged in tool half 3 as in the piston member 4.
• the press shape mould tool 1 is depicted as an assembly of two approximately even halves 2 and 3. It is, however, also possible that the press shape mould comprises more than two parts, and the different parts need not be approximately evenly sized.
• the variations in the tool design is mainly influenced by the shape of the products, so that products with a simple geometry is preferably made in correspondingly simple tool shapes, while products of more complex geometry may require more complicated press shape moulds.
• the internal cavity 6a, 6b of the press shape mould 1 may have very different and more complicated shapes than the one depicted, depending upon the shape desired for the finished product.
• it may furthermore be required to provide special types of reinforcement in order to obtain the required flexibility of the product blank, e.g. fibre reinforcements with very short fibre fragments or the like. This is, however, conditions that are outside the frame of the present invention.
• the method may be modified in different ways without departing from the scope of the invention.
• several similar or non-similar products 7,, 7 2 , practise..7 n is shaped side-by -side in one press tool that comprises several similar or non-similar cavities, each receiving a core material and an enveloping material.
• the enveloping material constitutes one material only. It may e.g. be one material 8a on one side of the product and two or more - similar or different - layers 8 bl , 8 b2 on the other side of the core, all depending on the requirements to the product.
• the phase comprising withdrawal of the piston member 4 in several steps, or in a continuous, very slow backward movement.
• the time period before starting withdrawal and the way it is conducted, are mainly deciding for the density and the possible variations in density in the finished core.
• the time aspect off course also relates to the size of the product, as it takes a longer period of time to cool a large product than to cool a small product.
• the foaming core material has a particularly high viscosity, it is not strictly necessary to close the tool halves 2, 3 along their circumference prior to compressing the product blank 7 with the piston member 4.
• High viscosity of the core material 9 will contribute to hold the gas locked up for the time required by the method.
• the tool halves 2, 3 are closed only along parts of their circumference, or that closing occurs subsequent to initiated compression.
• the spirit of the invention still remains the same, that in a limited period of time the product blank 7 is exposed to a pressure that compresses the blank in excess of what is required to give it the desired final shape in order to ensure a best possible consolidated surface, and that the pressure is thereafter reduced, allowing the product to find its final, desired shape.
• orientation of the tool may be either horizontally, vertically or any other orientation.
• Examples of products suited for manufacture by the method according to the present invention are interior and exterior details of cars, like seat backs, door sides, details of the front and/ or rear, hereunder bumpers etc., as well as other products where lightweight and strong, shock absorbing components are required.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Composite Materials (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=19903938

Family Applications (1)

Country Status (4)

Families Citing this family (1)

Family Cites Families (5)

• 1999
  • 1999-11-04 NO NO995384A patent/NO995384A/no unknown
• 2000
  • 2000-10-23 EP EP00973269A patent/EP1237696A1/de not_active Withdrawn
  • 2000-10-23 WO PCT/NO2000/000349 patent/WO2001032391A1/en not_active Ceased
  • 2000-10-23 AU AU11798/01A patent/AU1179801A/en not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events