SE510331C2

SE510331C2 - Preparation of sandwich structure laminates containing lightweight core and reinforcing layers

Info

Publication number: SE510331C2
Application number: SE9801759A
Authority: SE
Inventors: Frithjof Kronblad
Original assignee: Sonoform Ab
Priority date: 1998-05-19
Filing date: 1998-05-19
Publication date: 1999-05-10
Also published as: SE9801759L; SE9801759D0

Abstract

The laminates are prepared by hot-pressing in a mould, using a low pressure moulding compound material to form the surface layer. A method for preparing a laminate material (1) with a sandwich structure containing a lightweight core (2) preferably comprising polyurethane or a similar material, comprises the following steps : (i) the core is laminated with a fibrous reinforcing layer (3) and a surface layer (4) comprising a low pressure moulding compound (LPMC) material ; (ii) the laminate is placed between two mould half sections inside a pre-heated moulding tool ; (iii) the tool is closed ; (iv) sufficient pressure is applied to the mould half sections in order for the LPMC material to completely fill out the tool cavities and penetrate the reinforcing layer, after which the LPMC material is allowed to cure ; and (v) the tool is opened and the laminate is removed. An Independent claim is also included for the laminate material made by this method.

Description

510.331 10 15 20 25 30 l i 2 Fig 1 visar ett snitt genom en första utföringsforrn av det uppﬁnningsenliga larninatet. 510.331 10 15 20 25 30 l i 2 Fig. 1 shows a section through a first embodiment of the inventive larnate.

Fig 2 visar ett snitt genom en altemativ utfóringsform av det uppﬁnningsenliga larninatet.Fig. 2 shows a section through an alternative embodiment of the inventive larnate.

Det i ﬁg 1 visade larninatet 1 innefattar ett lätt kämmaterial 2, företrädesvis av poly- urethan eller liknande. Vid tillverkning sammanställs ett utgångsämne genom att man omgivande det lätta kämmaterialet 2 i nämnd ordning anordnar ett ﬁárstärlmingsskikt 3 av ett ﬁbermaterial såsom glas-, kol- eller aramidﬁbrer sarnt ett ytterskikt 4 av ett LPMC-material (Low Pressure Moulding Compound), vilket är en varmpressmassa innefattande harts och fyllmedel samt eventuellt också armering.The larnate 1 shown in ﬁ g 1 comprises a light core material 2, preferably of polyurethane or the like. During manufacture, a starting material is compiled by arranging around the light core material 2 in said order a ﬁ annual solidification layer 3 of a ﬁ base material such as glass, carbon or aramid ﬁ as well as an outer layer 4 of an LPMC material (Low Pressure Molding Compound), which is a hot press pulp including resin and filler and possibly also reinforcement.

Det således åstadkomna utgångsärnnet placeras sedan mellan tvenne formhalvor i ett till omkring lOO-150°C uppvärmt forrnverktyg. Formverktyget stängs vareﬁer en kraﬁ anbringas för att pressa de båda formhalvor-na mot varandra, skapande ett över- tryck på 20-30 Bar. Vid samrnanpressningen kommer LPMC-materialet 4 att fylla forrnverktygets kaviteter. För att åstadkomma god samrnanbindning mellan bestånds- delamai larninatet 1 kommer harts och fyllrnedel i LPMC-materialet 4 att penetrera fórstärkningsskiktet 3 och vidhäﬁa kärnmaterialet 2. Förstärlcningsskiktet 3 fungerar också som ett spärrskikt för eventuell armering i pressmassan 4. Under det att form- verktyget är stängt kommer härdning av LPMC-materialet 4 att initieras och fortgå så långt att en stabil produkt kan uttagas ur fonnverktyget vid öppning därav.The starting core thus obtained is then placed between two mold halves in a forming tool heated to about 100-150 ° C. The mold tool closes every time a collar is applied to press the two mold halves against each other, creating an overpressure of 20-30 Bar. During compression, the LPMC material 4 will fill the cavities of the antique tool. In order to achieve a good bonding between the component laminate 1, resin and filler in the LPMC material 4 will penetrate the reinforcing layer 3 and adhere to the core material 2. The reinforcing layer 3 also acts as a barrier layer for possible reinforcement in the press mass 4. While the mold is closed, curing of the LPMC material 4 will be initiated and proceed to such an extent that a stable product can be removed from the molding tool upon opening thereof.

Vid den alternativa utfóringsforrnen enligt ﬁgur 2 byggs utgångsänmet upp på samma sätt som beskrivits i anslutning till utföringsforrnen enligt ﬁgur l med tillägget att man anordnar ett vidhäñningsskikt 5 mellan förstärkningsskiktet 3 och kärnmaterialet 2. Vidhäﬁningsskiktet 5 utgörs företrädesvis av en terrnoplast i form av en väv eller en film. Vid tillverkningen av larninatet l enligt denna utföringsforrn, på samrna sätt som beskrivs i anslutning till ﬁgur l, kommer vidhäﬁningsskiktet 5 att smälta sarnrnan med kärnmaterialet 2 och fórstärlcrringsskiktet 3 och åstadkomma en god fórbindning mellan dessa delar. Pressmassan 4 kommer att värmehärda samtidigt som den flyter ut i forrnutrymmet och penetrerar fórstärkningsskiktet 3.In the alternative embodiment according to Figure 2, the starting material is constructed in the same way as described in connection with the embodiments according to Figure 1 with the addition that an extension layer 5 is arranged between the reinforcing layer 3 and the core material 2. The extension layer 5 preferably consists of a a movie. In the manufacture of the laminate 1 according to this embodiment, in the same manner as described in connection with Figure 1, the adhering layer 5 will fuse the core with the core material 2 and the reinforcing layer 3 and provide a good connection between these parts. The press mass 4 will heat cure at the same time as it flows out into the mold space and penetrates the pre-reinforcement layer 3.

Claims

10 15 20 25 i 51-0: "331 Patent Claims

A method of making a sandwich laminate (1) comprising a light core material (2), preferably of polyurethane or similar material, characterized in that the method in the order given below comprises the steps of: - preparing a starting material by surrounding it the light core material (2) is arranged in said order; a drying reinforcement layer (3) of a ﬁber material and an outer layer (4) of an LPMC material, - placement of the starting seam between the two mold halves in a heated mold, - closing of the mold, - application of a collar ﬁ to press the two mold halves against each other so that the LPMC material (4) is caused to fill the cavities of the molding tool and penetrate the reinforcement layer (3) and the LPMC material (4) is made to harden, opening the molding tool and removing the laminate (1) thus obtained.

Method according to Claim 1, characterized in that a bonding layer (5) is arranged between the reinforcing layer (3) and the core material (2), preferably of a tin plastic in the form of a fabric or a strip.

Method according to Claim 1 or 2, characterized in that the molding tool is heated to 100-150 ° C.

4. A method according to any one of the preceding claims, characterized in that the mold halves are compressed to create an overpressure of 20-30 Bar.

Sandwich laminate (1), characterized in that it is produced by the method according to any one of the preceding claims.