FR2673575A1 - Article comprising a thermoplastic body covered on one face with a melamine-resin decorative paper, and method of manufacturing such an article - Google Patents

Abstract

Composite article (1) comprising a thermoplastic body (2), a melamine-resin decorative paper (3) covering the body (2) on one face, and a textile structure (4) arranged as a bonding interface between the body (2) and the decorative paper (3). In order to manufacture the article (1), the textile structure (4) and the not yet cured decorative paper (3) are bonded, by hot pressing, and the thermoplastic of the body (2) is overinjected onto the textile face of the composite element (3, 4) thus obtained. Application: for example for the tops of washing machines and dishwashers.

Description

Piece comprising a body of thermoplastic material covered on one side with melamine decor paper and method of manufacturing such a piece.

 The present invention relates to a part, generally of essentially flat shape, comprising a body of thermoplastic material covered on one side with melamine decor paper.

The invention also relates to a method of manufacturing such a part.

 For the manufacture of generally flat bodies which must have a decorative face having good mechanical resistance (hardness), heat resistance, etc. properties, for example tops (so-called "tops") of household appliances such as washing machines -clothes, dishwashers etc.), we generally use particle boards covered on one side either with decorative paper impregnated with melamine resin, or possibly with a polyester laminate. This involves bonding between the panel and the decor paper or polyester laminate.

 To reduce the weight and the cost of such parts, it has also already been envisaged to produce the body in injected thermoplastic material, for example polypropylene, but the bonding of a decorative paper impregnated with melamine resin or a polyester laminate on this injected thermoplastic body poses adhesion problems. In addition, in general, in mass production, bonding causes many problems and should be avoided as much as possible.

 The present invention relates to a part comprising a body of thermoplastic material covered on one side with melamine decor paper, the connection between the thermoplastic material of the body and the thermosetting impregnation resin of the decor paper taking place without the use of glue.

 The invention also relates to a particularly simple process for the manufacture of such a part.

The part according to the invention comprises a textile structure arranged as a connection interface between the melamine decor paper
and the body of thermoplastic material.

 The invention is based on the surprising discovery that without the use of glue, it is possible to establish an at least mechanical connection of the fibers of the textile structure both with the melamine resin of the decor paper and with the thermoplastic material of the body if these two plastics are brought into the plastic state in contact with the textile structure.

 In the context of the invention, this textile structure may for example comprise a fabric or a nonwoven.

 This textile structure can be formed only of non-fusible fibers, in which case the connection of the thermosetting material of the decor paper and the thermoplastic material of the body with the textile structure is a purely mechanical attachment connection.

 However, according to another embodiment of the invention, the textile structure may comprise threads or fibers of thermoplastic material, in which case a physical connection may be established at least in part between the thermosetting material of the decor paper and the thermoplastic material body, on the one hand, and the textile structure, on the other.

The process according to the invention for manufacturing such a part comprising a body made of thermoplastic material covered on one side with melamine decor paper consists of
- cut a piece of melamine decor paper, not yet hardened, depending on the shape of the part to be produced,
- cut a piece of textile structure according to the shape of the part to be produced,
place the piece of decor paper and the piece of textile structure one on top of the other in a heated pressing mold, the textile structure being located on the side of the decor paper away from the decor face of the latter,
- hot pressing the piece of decor paper and the piece of textile structure in the mold so as to melt then harden the thermosetting resin of the decor paper and join the two pieces in the form of a composite element,
- Place this composite element in an injection mold and over-inject thermoplastic material, in this mold, on the textile side of the composite element, opposite the decor side.

Referring to the accompanying schematic drawings, a part according to the invention will be described below in more detail, as well as its manufacturing process; on the drawings:
Figure 1 is a cross section of a part according to the invention;
FIGS. 2 to 6 represent different stages of the production of the part according to FIG.

 The part I according to Figure 1 which can for example be a top ("top") of a household appliance such as a washing machine or a dishwasher, comprises a body 2 of thermoplastic material, for example polypropylene, covered on one of its faces, namely the face turned upwards on the household appliance, with a decorative and resistant layer 3, namely a decorative paper impregnated with melamine resin. These melamine decor papers have, in the cured state of the melamine resin, exceptional properties of mechanical strength (superficial hardness) and resistance to heat, for example to flame.

 On the part according to the invention, a textile structure 4, for example a nonwoven, is arranged as a connection interface between the melamine paper 3 and the body 2 of thermoplastic material.

 This textile structure can comprise either only non-fusible fibers, or a mixture of fusible and non-fusible fibers, for example a mixture of polyamide fibers and polyester fibers.

 For the production of the part I according to FIG. 1, a piece 3 of melamine decor paper not yet hardened is placed, cut according to the shape of the part to be produced, and a piece of textile structure 4 also cut according to the form of part to be produced, one on top of the other in a heated pressing mold comprising a female part 5 and a male part 6. The two pieces 3 and 4 are placed one on the other in such a way that the piece 4 of textile structure is located on the face of the piece of decor paper 3 remote from the decor face of the latter (FIG. 2).

 The mold 5, 6 is then closed to hot press the two pieces 3 and 4 so as to melt and then to harden the melamine resin of the piece of decor paper 3 and join the two pieces 3 and 4 in the form of a composite element (Figure 3).

 This composite element 7 which is easy to handle because it is relatively solid (the textile structure 4 reinforces the melamine paper 3 which is otherwise fragile) is then introduced into an injection mold (FIG. 4) comprising for example a part of female mold 8 and a part of male mold 9. In the example shown, the composite element 7 is placed in the female mold part 8 with the melamine-coated paper 3 facing the mold part 8, the bottom of which has a surface state corresponding to that which the decoration face of the final piece. The male mold part 9 has an injection orifice 10.

 After closing the mold 8, 9, a thermoplastic material 2 is injected through the injection hole 10 of the mold part 9 into the mold cavity, namely on the textile structure side 4 of the composite element 7. Thanks to its plastic consistency, the injected material 2 binds to the textile structure 4, by mechanical attachment to the fibers of the textile structure 4. When the textile structure 4 also contains thermoplastic fibers, a physical bond by partial melting of these thermoplastic fibers can also be established between the injected thermoplastic material 2 and the textile structure 4.

 After the injected plastic material 2 has hardened, a part 1 can be removed from the mold, comprising, according to FIG. 1, a body 2 covered on one of its faces with melamine paper 3 linked to the body 2 by a textile structure 4 intermediate (Figure 6).

 It should be noted that the above description has been given for illustration only and is not limitative and numerous modifications and variants are possible within the scope of the invention.

 Thus, the part 1 could be made of other thermoplastic materials than polypropylene, for example ABS resin (acrylonitrile-butadiene-styrene copolymer).

 In addition, the face of the body 2 of the part 1 remote from the decor paper 3, instead of being smooth as shown, could for example be provided with reinforcing ribs.

 The textile structure 4 can be used, for example, in the form of fabric, nonwoven, etc., consisting of non-fusible fibers or a mixture of non-fusible fibers and fusible fibers, for example polyester and polyamide fibers. In the first case, the connection provided by the textile structure 4 between the decor paper 3 and the body 2 of the piece 1 is established only by mechanical attachment, while in the second case, this mechanical attachment is partially replaced or reinforced by a physical bond obtained by partial fusion of the fusible fibers.

 Finally, the invention is applicable not only to the manufacture of tops of household appliances such as washing machines and dishwashers but can find many other applications requiring essentially flat, rigid parts, having a decorative face with good resistance. mechanical and heat as well as with a pleasant appearance.

Claims (5)

 1. Piece comprising a body of thermoplastic material covered on one side with melamine decor paper, characterized in that it comprises a textile structure (4) arranged as a connection interface between the melamine paper (3) and the body (2) of thermoplastic material.  2. Piece according to claim 1, characterized in that the textile structure (4) comprises a nonwoven.  3. Part according to claim 1 or 2, characterized in that the textile structure (4) comprises fibers of thermoplastic material.  4. Method for manufacturing a part according to any one of the preceding claims, characterized in that it consists of  - cut a piece of melamine decor paper, not yet hardened, depending on the shape of the part to be produced,  - cut a piece of textile structure according to the shape of the part to be produced,  place the piece of decor paper and the piece of run textile structure on the other in a heated pressing mold, the textile structure being located on the face of the decor paper away from the decor face of the latter,  - hot pressing the piece of decor paper and the piece of textile structure in the mold so as to melt then harden the melamine resin of the decor paper and join the two pieces in the form of a composite element,  - Place the composite element in an injection mold and over-inject thermoplastic material on the textile side of the composite element.  5. Method according to claim 4, characterized in that a pressing mold is used whose face in contact with the piece of decorative paper has a surface condition corresponding to that which the decorative paper must present on the final part.