Method of and apparatus for manufacturing fiber-reinforced plastics articles

• US 5,230,906 A
• Filed: 05/16/1991
• Issued: 07/27/1993
• Est. Priority Date: 11/24/1986
• Status: Expired due to Fees

• Current Assignee: Matthias Rath Holding B.V., Polytex Plastic SA
• Original Assignee: Polytex Plastic SA
• Inventors: Mueller, Bruno
• Primary Examiner(s): Nguyen, Khanh P.
• Application Number:
  US07/700,793
• Time in Patent Office: 803 Days
• Field of Search: 425/111, 425/122, 425/115, 425/117, 425/71, 425/106, 425/110, 425/384, 425/388, 425/305.1, 425/403.1, 425/89, 425/93, 264/46.8, 264/337, 264/87, 264/544, 264/134, 264/135, 264/136, 264/137, 118/404, 118/50, 118/405, 118/419, 118/423, 118/424, 118/426, 118/428, 118/40, 118/45, 156/500, 156/382, 156/501, 156/286, 156/285, 249/113, 249/135
• US Class Current: 425/89
• CPC Class Codes: B29C 51/06 using pressure difference for prestretching
• CPC Class Codes: B29C 51/365 Porous moulds
• CPC Class Codes: Y10S 425/119 Perforated or porous

Abstract

An apparatus used in connection with the construction of a duroplastic, fiber-reinforced article a fibrous web which includes continuously impregnating the web under subatmospheric pressure with a liquid, curable resin composition whose viscosity is gradually increasing. The prepreg thus obtained is covered on both its major surfaces by thin polymer sheets, then cut into the desired length, vacuum molded, pre-cured in the mold and finally cured outside the mold. Construction parts, car parts and boat bodies may thus be produced.

Claims

1. An apparatus for manufacturing fiber-reinforced articles comprising:

at least one supplying unit containing a fibrous web having an upper and lower surface,

a trough positioned adjacent to said supply unit which receives said web from said supply unit, said trough containing a liquified curable resin composition for impregnating said web and a means for manipulating said web,

an impregnating tower positioned in said trough having an open lower end and a closed upper end, said tower including in said upper end a means for connecting said tower to a vacuum source so as to introduce a vacuum to said upper end thereby raising said liquified curable resin composition into said tower from said lower end and extracting air pockets from said web, said tower also containing in said upper end a means for continuously passing said web first substantially vertically upwards from said trough and then substantially vertically downwards into said trough,

two supply rolls containing polymer foil positioned adjacent to said trough,

means for covering said web which receives said polymer foil from said supply rolls and which covers said web once it has passed through said trough on both of its surfaces with said polymer foil so as to form a covered prepeg, said means for covering positioned adjacent to said trough,

means for cutting said prepeg into desired lengths, positioned adjacent to said means for covering which receives said prepeg from said means for covering and cuts said prepeg into desired lengths, and

means for vacuum molding and curing said cut prepeg lengths to obtain the desired shaped and cured article, positioned adjacent to said means for cutting.

3. An apparatus according to claims 1 or 2, wherein said at least one supply unit is adapted to contain a web having a thickness of about 2 mm to 5 mm.

4. An apparatus according to claims 1 or 2, wherein said at least one supply unit is adapted to contain a web having a width of up to about 2 meters.

5. An apparatus according to claim 1 or 2, wherein said impregnating tower has an inverted U-shaped cross-section and a rim at said lower end.

6. An apparatus according to claim 5, wherein said impregnating tower is within said trough so that said rim of said inverted U-shaped opening is within said liquid resin curable composition in said trough.

7. An apparatus according to claims 1 or 2, wherein said means for continuously passing said web further comprises a deflection roller in said upper end of said tower around which said web passes from said upward direction to said downward direction.

8. An apparatus according to claims 1 or 2, wherein said tower contains a displacement body to limit the amount of resin within said tower.

9. An apparatus according to claims 1 or 2, wherein said means for manipulating said web comprises at least two deflection rollers which are horizontally mounted within said trough and below said tower and positioned so that said web may pass into and out of said tower vertically.

10. An apparatus according to claims 1 or 2, wherein said means for covering further comprises a pair of parallel, cooperating, positively driven compression rollers mounted outside said trough and on opposite surfaces of said web which receive foil from said supply rolls and compress said foil on opposite surfaces of said web.

11. An apparatus for manufacturing fiber-reinforced articles as in claim 1, wherein said means for vacuum molding and curing further comprises:

an air-tight casing having a lower surface, lateral surfaces and an upper surface with a central opening;

a porous main body located within said air-tight casing comprising aluminum granules held together by a cured resin;

an internal annular gas permeable conduit within said porous main body located beneath said upper surface of said air-tight casing;

a means for connecting said conduit to a vacuum source, extending from said conduit through said air-tight casing to permit vacuum molding of a prepeg; and

a generally flat upper mold portion having at its lower surface a circumferential holding ring having a smooth, non-frictional surface which holds said prepeg on said upper surface of said air-tight casing when vacuum molding of said prepeg occurs.

12. An apparatus for manufacturing fiber-reinforced articles as in claim 11, wherein said aluminum granules have diameters from about 0.1 mm to 4 mm, and weight ratios of aluminum granules to binder resin have values of about 1:

0.5 to 1;

0.15.

13. An apparatus for manufacturing fiber-reinforced articles as in claim 11, further comprising a means for connecting said conduit to a compressed air source, extending from said conduit through said air-tight casing to permit molding of said prepeg.

14. An apparatus for manufacturing fiber-reinforced articles as in claim 11, further comprising a heat source disposed above said upper mold portion for heating said prepeg while said prepeg is on said upper surface of said air-tight casing and held in place by said holding ring.

15. An apparatus for manufacturing fiber-reinforced articles as in claim 11, wherein said porous main body comprises a lower layer and upper layer of aluminum granules, the aluminum granules of the lower layer being larger in size than said aluminum granules of the upper layer.

16. An apparatus for manufacturing fiber-reinforced articles as in claim 11, wherein said porous main body comprises a lower, an intermediate and a top layer of aluminum granules, said aluminum granules of the lower layer being larger in size than said granules of the intermediate and top layers, and said aluminum granules of the upper layer being smaller in size than said granules of the intermediate and lower layers.

17. An apparatus for manufacturing fiber-reinforced articles as in claim 11, wherein said conduit and said porous main body are made of different materials and said conduit is thermally insulated against said porous main body by a gas-permeable insulating layer which surrounds said conduit.

2. An apparatus for manufacturing a prepeg comprising:

at least one supply unit containing a fibrous web having an upper and lower surface,

a trough positioned adjacent to said supply unit which receives said web from said supply unit, said trough containing a liquified curable resin composition for impregnating said web and a means for manipulating said web,

an impregnating tower positioned in said trough having an open lower end and a closed upper end, said tower including in said upper end a means for connecting said tower to a vacuum source so as to introduce a vacuum to said upper end thereby raising said liquified curable resin composition into said tower from said lower end and extracting air pockets from said web, said tower also containing in said upper end a means for continuously passing said web first substantially vertically upwards from said trough and then substantially vertically downwards into said trough,

two supply rolls containing polymer foil positioned adjacent to said trough,

means for covering said web which receives said polymer foil from said supply rolls and which covers said web once it has passed through said trough on both of its surfaces with said polymer foil so as to form a covered prepeg, said means for covering positioned adjacent to said trough, and

means for cutting said prepeg into desired lengths, positioned adjacent to said means for covering which receives said prepeg from said means for covering and cuts said prepeg into desired lengths.