WO1982001466A1

WO1982001466A1 - Process for manufacturing an anti-skid service tray

Info

Publication number: WO1982001466A1
Application number: PCT/CH1980/000132
Authority: WO
Inventors: Pierre Wernli
Original assignee: Pierre Wernli
Priority date: 1980-11-06
Filing date: 1980-11-06
Publication date: 1982-05-13
Also published as: EP0064492A1

Abstract

The process for manufacturing the anti-skid service tray consists in utilizing a mould made of two matching parts, internally delimited, one by a convex surface and the other by a concave surface, in introducing between the said parts or the mould, on the side of the convex surface, a soft cloth impregnated with a PVC layer on its side Facing said convex surface and, on the side of the concave surface, a polyester pasty mass, in heat pressing the two pans of the mould against each other so as to compress the polyester mass until it takes the final shape, and then in removing the tray from the mould.

Description

Method of manufacturing a non-slip service tray

A method of manufacturing a non-slip service tray is known, according to which paper sheets coated with or impregnated with thermosetting resins, for example melamine and phenol resins, are stacked on this stack, a flexible covered canvas at least on its upper face with a layer of thermoplastic material of the PVC type, then pressurized and hot molded the assembly thus obtained so as to give the laminated material its final shape. The non-slip plates obtained by this process have excellent qualities, in particular good rigidity, are relatively light, very resistant mechanically and chemically, and have excellent anti-slip properties. However their cost price is in some cases a

^• low. The subject of the present invention is a process for the manufacture of non-slip service trays of quality substantially equivalent to that of the trays mentioned above but of a much lower cost price. In this process one uses a mold formed ^'.de two complementary parts. ^" limited one by -one _{. on the} convex surface, the other by a concave surface. This process is characterized by the fact that a flexible fabric is introduced between the two parts of the mold, on the convex surface side. impregnated or coated at least on its fac turned towards this convex surface with a layer of thermoplastic material such as PVC, and on the concave surface side a thermoplastic or thermosetting material and that an action is exerted on this material to give it its shape final.then remove the molded tray. The forming of the material can be obtained by various known techniques, for example:

- by compression, hot or cold, said material ^• - - being pressed between the two relatively mobile parts of the mold;

- By transfer, hot or cold, said material being brought, in malleable form, between the two parts, relatively mobile or fixed, of the mold.

- By injection, said material being injected, in ^• liquid or pasty form between the two relatively fixed parts of the mold. By operating hot, the partial transformation is brought about, by polymerization, of said layer of synthetic rubber, which gives the platform particularly non-slip properties.

In a first implementation, said material will be introduced into the concave part of the mold and then this material will be super¬ posed on said fabric before forming. In a second implementation, the canvas will be placed on the convex part of the mold, then the said material will be superimposed on this canvas before forming. The canvas used will advantageously be made of artificial textile material, animal or vegetable, for example cotton. To prevent bubbles of gas or vapor remaining trapped after molding of the surface of the plate and thus create unsightly inequalities, it will be possible, if necessary, to use a perforated fabric facilitating the evacuation of gases and vapors . Two specific implementations of the method according to the invention have been described below, by way of example.

- 3 -

According to the first particular implementation, the procedure is as follows: a) a pasty mass composed at least in part of polyester is introduced into the concave part of the mold

5 or one of its derivatives, b) this mass is covered with a cotton canvas, the upper surface of which is impregnated with a layer of PVC, c) by relative displacement of the two parts of the mold, hot pressing this set,

D) the molded tray is removed and allowed to cool.

According to a second particular implementation, the procedure is as follows: a) The convex part of the mold is covered with a cotton canvas of which at least the face in contact with the convex surface is impregnated with a layer of PVC, b) a pasty mass of polyester is placed on this canvas, c) by relative displacement of the two parts of the mold, this assembly is hot pressed. d) the molded tray is removed and allowed to cool.

The molding temperature will advantageously be, in both cases between 80 and 150 ° C., the pressure between

2

. 30 and 60 kg / cm, and the duration between 15 seconds and 4 minutes

In case the material used gives off a lot of gas and vapor during molding, we can provide a canvas

25 whose PVC layer is perforated at a rate of 5 to 20

2 holes per cm, holes with diameters between 0.05 mm and 0.2 mm so as to avoid the formation of bubbles underlying the non-slip surface. This gives non-slip service trays 30 which have excellent quality and whose cost is relatively low. The processes described lend themselves particularly well to the manufacture of decorated non-slip trays. To this end, the canvases used may be printed with various patterns, such as flowers, landscapes, animals, imitation wood, photographs, road maps, etc.

Claims

DREAM N D I C A T I O N S

1) Method of manufacturing a non-slip service tray in which a mold forrr.é of two complementary parts is used, internally limited one by a convex surface, the other by a concave surface, characterized by the fact that there is introduced between said parts of the mold, on the convex surface side, a flexible fabric impregnated or coated at least on its face facing this convex surface with a layer of thermoplastic material such as PVC, and, on the side concave surface, a t-hermoplastic or thermosetting material, and that one exerts on this material an action capable of giving it its final shape, then withdraws the molded tray.

2) A method according to claim 1, characterized in that said material is placed in order in the concave part of the mold, then superimposed on this maté¬ riau said fabric before proceeding to form.

3) Method according to claim 1, characterized in that the canvas is placed in order on the convex part of the mold, then placed on this canvas said material before forming.

4) Method according to claim 1, characterized in that the molding temperature is ccr_prise between

- 80 and 150 ° C.

5) Method according to claim 1, characterized in that the molding pressure is between 30 and 60 kg / cm ² .

6) Method according to claim 1, characterized in that one uses a perforated fabric. 7) Method according to claim _, characterized in that said fabric has 5 to 20 holes

2 per cm.

8) Method according to claim 7, characterized in that the diameters of said holes are between 0.05 mm and 0.2 m.

9) Method according to claim 1, characterized in that one exerts a compression on said material to form it.

10) Method according to claim 1, characterized in that said material is injected.

11) Method according to claim 1, characterized in that said material is brought into the grinding wheel by transfer.

12) Method according to claim 1, characterized in that said material is composed at least in part of polyester or one of its derivatives.

13) Method according to claim 1, characterized in that the molding time is between 15 seconds and 4 minutes.

14) Service tray, characterized in that it is obtained by the implementation of the method according to claim 1.