FR2528762A1 - Composite panels of polystyrene filled glass fibre mat - or cloth impregnated with polyurethane, made as sheet or mouldings for lining vehicle interiors etc. - Google Patents

Abstract

Panels are made by impregnating a mat or cloth of glass fibres with an activated polyurethane resin, transferring the impregnated mat to a sheet of silk, paper, card or fabric, sprinkling on to and into the interstices of the fibrous layer of polystyrene beads which have been pre-expanded to the size range 2-6 mm., overlaying polystyrene treated fibrous layer with a further layer of polyurethane impregnated fibrous mat or fabric covered in turn with a further layer of film, paper or fabric. The resulting sandwich structure is heated to 100-130 deg.C. for 30-120 secs. to further expand and fuse together the polystyrene particles and cure the polyurethane into a rubbery matrix, by storing or pressing depending upon whether a flat or shaped panel is required. Used esp. for mfr. of thin, stiff, tough, sound absorbent panels suitable for e.g. shaped linings for vehicle interiors.

Description

 The present invention relates to the field of manufacturing flat or molded thin panels based on polystyrene foam, and relates to a method of manufacturing such a polystyrene foam panel reinforced with glass fibers and impregnated with polyurethane.

 The invention also relates to a panel thus obtained.

 The manufacture of polystyrene foam is known per se. It generally consists of pre-expanding unexpanded polystyrene beads with a density of 600 g / liter to bring them to a density of 50 to 100 g / liter by passage through heat, then filling a mold with these pre-expanded beads, heating the inside of the mold, for example by steam passage, so as to cause the final expansion of the balls and their joining together, and thus to obtain a polystyrene foam.

 The foam thus obtained is in the form of a light, economical and good thermal insulating product and is of particularly advantageous use in the field of packaging and thermal insulation.

 Such foam is however brittle, and not very rigid, so that its use in small thicknesses is impossible, and it undergoes a continuous shrinkage for several months after its manufacture, which excludes its use for the production of parts or panels with geometry. precise. In addition, its resistance to temperature which does not exceed 800 C to 850 C, does not allow its use for parts which can be brought to higher temperatures, and its compact structure with closed cells makes it a reverberant of sound waves, which excludes it for all uses where a certain sound absorption is requested.

 The present invention aims to overcome these drawbacks.

 It has, in fact, for its object a process for manufacturing a flat or molded panel of polystyrene foam reinforced with glass fibers and impregnated with polyurethane, characterized in that it consists essentially in spray coating a mat of fibers of glass with a mixture consisting, on the one hand, of a polyol activated with a catalyst, an activator, and optionally a silicone oil, and, on the other hand, of an isocyanate, by means of a coating machine with at least two components continuously producing an intimate mixture of the products, arranging the mat of impregnated glass fibers obtained on a support consisting of a plastic sheet, a woven or nonwoven fabric, a sheet of paper, a cardboard, or the like , then to provide the upper face of the mat with glass fibers, by pneumatic spraying, or otherwise, with a layer of beads. of polystyrene pre-expanded by heat with a thickness of 2 to 6 mm, penetrating the glass fiber mat by filling its interstices and resting for some of them on the support forming a barrier, then depositing a second mat of glass fibers impregnated with an activated polyol - isocyanate mixture, identical to the first, on the layer of polystyrene beads, the upper beads of which penetrate into said mat by filling its interstices, then providing the upper face of this second mat with a cover in the form of a paper, a woven or nonwoven fabric, a sheet of cardboard, a plastic sheet, or the like, having a neutral or decorative appearance, and finally in subjecting the sandwich thus produced to a temperature between 1000 C and 1300 C for a time between 30 and 120 seconds so as to achieve complete expansion and joining of the pre-expanded polystyrene beads, and simultaneously formation by polymerization ation of a polyurethane elastomer, the sandwich can be subjected to temperature, either by passage in an oven, or between two hot plates compressing it very slightly for the production of flat panels with a clean and uniform surface, or even by positioning between a die and a heating punch allowing obtaining molded panels.

 The subject of the invention is also a panel obtained by application of the method described above, characterized in that it consists essentially of two glass fiber mats coated with an activated isocyanate polyol mixture, which is polymerized in the form of a polyurethane elastomer, sandwiching a layer of expanded polystyrene penetrating intimately into the glass fiber mats, and by neutral or decorative outer layers of support, of paper sheet, plastic sheet, woven or nonwoven fabric, of cardboard, or the like, this panel being either in the form of a flat plate, lightly pressed or not, or in the form of molded panels.

 The invention will be better understood thanks to the description below, which relates to preferred embodiments, given by way of nonlimiting examples, and explained with reference to the appended schematic drawings, in which FIG. 1 is a view in side elevation of a device for coating glass fiber mat Figure 2 is a view similar to that of Figure 1 of an alternative embodiment of the device Figure 3 is a partial sectional view of a panel in accordance with the invention before final expansion and joining together of the polystyrene beads FIG. 4 represents in section the panel of FIG. 3 after said final expansion FIG. 5 represents in section an alternative embodiment of the panel of FIG. 3, and FIG. 6 is a view similar to that of FIG. 4 of the panel of FIG. 5.

 The process for manufacturing a flat or molded panel of polystyrene foam reinforced with glass fibers and impregnated with polyurethane consists in spraying a mat of glass fibers 1, with a mixture consisting, on the one hand, of a polyol activated with a catalyst, an activator, and optionally a silicone oil, and, on the other hand, an isocyanate, by means of a machine 2 with at least two components, which continuously carries out the intimate mixing of the products and the sprinkles on the mat 1. The machine 2 consists of two tanks 3 and 4 respectively containing the activated polyol and the isocyanate, and which are connected by two pumps 5 to a mixing head 6, to which the pumps 5 regularly convey under pressure the products from tanks 3 and 4. The mixing head 6 continuously mixes the two products and projects them in fine droplets onto the glass fiber mat 1, which is conveyed on a conveyor belt 7.

 The glass fiber mats used advantageously have a weight of the order of 150 to 300 g / m2 and a thickness of between 0.5 and 1 mm.

 The impregnated glass fiber mat thus obtained is placed on a support 8 (FIG. 3) in the form of a plastic sheet, a woven or nonwoven fabric, a sheet of paper, a cardboard, or the like. , and a layer 9 of pre-expanded polystyrene balls with a thickness of between 2 and 6 mm is spread, for example by pneumatic spraying, on the mat 1, the interstices of which are filled with the lower balls, some of which rest on the support 8 , which forms a barrier.

 The polystyrene beads used are advantageously of the type of those known under the trade name Styropore from the company BASF and have a starting density of 600 g / liter and from 50 to 100 g / liter after pre-expansion by passage through heat, steam or other.

 A second impregnated mat 1 identical to the first is placed on the layer 9 of pre-expanded balls, the interstices of which are penetrated by the upper balls of the layer 9.

 The second mat 1 is then covered with a support 8 ′, which may be identical to the support 8 and be made of paper, woven or non-woven fabric, plastic sheet, or cardboard, and may have a neutral or decorative appearance .

 The sandwich thus produced is then subjected to a temperature of between 1000 C and 1300 C for a period of between 30 and 120 seconds by passing through an oven, or by placing between two hot plates with very slight compression to obtain flat panels. with a clean and uniform surface (Figure 4), or by heating between a punch and a shaped die to obtain molded panels.

 Under the effect of this heating, the pre-expanded beads expand completely and join together to form a polystyrene foam, and, simultaneously, the activated polyol and the isocyanate react to form, by polymerization, a polyurethane elastomer.

The activated polyol-isocyanate mixture advantageously has the following composition
A. Isocyanate: 50 parts of an MDI isocyanate such as
the one known as the commercial
ciale Desmodur 44 V 20 from Bayer
B. Polyol: 100 parts of a polyol of the known type
under the trade name Desmophen
3,900 from Bayer
Activator: 0.05 to 0.3 part of an activator such as
the one known under the trade name
Dabco
Catalyst: 0.1 to 0.3 part of a catalyst such as
tin salts.

 Thanks to the embodiment described above, it is possible to produce flat or molded panels having a final thickness of between 3 and 8 mm 2 and a weight of between 400 and 800 g / m2, of which 30 to 150 g of polyurethane elastomer.

 According to an alternative embodiment of the invention, not shown in the accompanying drawings, the panel is constituted by a superposition of several alternating layers of glass fiber mat and pre-expanded polystyrene beads. It is thus possible to obtain greater final thicknesses of the panels.

 According to an alternative embodiment of the method according to the invention, for a treatment of glass fiber mat 1 'of large thickness, the spraying of the activated polyol - isocyanate mixture is carried out on both sides of the mat 1' by passing the latter under a first coating machine 2 ′ by means of a conveyor belt 10, then by passing under a second coating machine 2 ″ by means of another conveyor belt 11 receiving the mat 1 ′ returned and operating in opposite direction of the belt 10, the mat 1 'thus coated being removed by a third conveyor belt 12 (Figure 2).

 The coating machines 2 'and 2 "are identical to the machine 2 described above.

 According to another characteristic of the invention, and as shown in FIGS. 5 and 6, the glass fiber mats are replaced by a sheet 13 of glass fibers of monofilament type, which is coated on one or both of them faces of an isocyanate activated polyol mixture, and which is disposed on a support 14 in the form of a plastic sheet, a woven or nonwoven fabric, a sheet of paper, a cardboard, or the like, and is provided with a layer 15 of pre-expanded polystyrene balls with a thickness of between 2 and 6 mm, the balls of the lower part of which penetrate the sheet 13 by filling its interstices and rest partly on the support 14 forming a barrier, another support 16 similar to support 14 and having a neutral or decorative appearance covering the layer of balls 15, the sandwich thus produced being subjected to a temperature of between 100 ° C. and 130 ° C. for a period of between 30 and 120 seconds, by passing through an oven , between heating plates antes under slight pressure, or between a punch and a shaped and heated matrix.

 The sheet of monofilament type glass fibers can advantageously be a sheet known under the trade name Unifilo having a weight of between 150 and 300 g / m2 and a thickness of between 2 and 5 mm.

 Thanks to the invention, it is possible to produce a panel of reinforced polystyrene foam, reinforced with glass fibers and polyurethane elastomer, this panel being able to be flat and with or without smooth and uniform surfaces, or even molded.

 The panels obtained by applying the method according to the invention have a very resistant and non-brittle foam allowing the production of panels with a minimum thickness of 2 mm, light and rigid. These panels do not undergo shrinkage after manufacture, so that they can be used for the manufacture of parts with precise geometry and excellent stability dimensions.

 In addition, the temperature resistance is improved, as well as the sound absorption characteristics, the product having a permeability to sound waves through glass fibers.

 Finally, the flexural rigidity module allows to reach 1200 to 1600 Newton for a thickness of 4.5 mm, the equivalent of a double-sided corrugated cardboard of the same thickness.

 The invention finds its application in the field of the manufacture of various products, such as trim panels for motor vehicles or for the building industry, packaging containers, insulation panels, etc.

 Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements, or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (9)

- CLAIMS  1. A method of manufacturing a flat or molded panel of polystyrene foam reinforced with glass fibers and impregnated with polyurethane, characterized in that it consists essentially in spray coating a mat of glass fibers (1) with a mixture consisting, on the one hand, of an activated polyol with a catalyst, an activator, and optionally a silicone oil, and, on the other hand, of an isocyanate, by means of a coating machine (2) with at least two components continuously producing an intimate mixture of the products, placing the mat of impregnated glass fibers (1) obtained on a support (8) consisting of a plastic sheet, a woven or nonwoven fabric, a sheet of paper, a cardboard box, or the like, then to provide the upper face of the mat with glass fibers (1), by pneumatic spraying, or in another way, with a layer (9) of polystyrene beads pre-expanded with heat. thickness from 2 to 6 mm, penetrating the glass fiber mat (1) by filling its interstices and resting nt for part of them on the support (8) forming a barrier, then deposit a second mat of glass fibers (1) impregnated with an activated polyol - isocyanate mixture, identical to the first, on the layer (9) of beads polystyrene; whose upper balls penetrate into said mat (1) by filling its interstices, then providing the upper face of this second mat (1) with a cover (8 ') in the form of a paper, a woven fabric or non-woven, of a sheet of cardboard, of a plastic sheet, or other, having a neutral or decorative appearance, and finally to subject the sandwich thus produced to a temperature between 1000 C and 1300 C for a period between 30 and 120 seconds so as to achieve complete expansion and securing of the pre-expanded polystyrene beads, and simultaneously formation by polymerization of a polyurethane elastomer, the sandwich being able to be subjected to temperature, either by passing through an oven, or between two hot plates compressing it very slightly for the production of flat panels with a clean and uniform surface, or again by placing between a die and a heating punch allowing molded panels to be obtained.  2. Method according to claim 1, characterized in that the glass fiber mats used advantageously have a weight of the order of 150 to 300 g / m2 and a thickness of between 0.5 and 1 mm.  3. Method according to claim 1, characterized in that the polystyrene beads used are advantageously of the type of those known under the trade name Styropore from the company BASF and have a starting density of 600 g / liter and from 50 to 100 g / liter after pre-expansion by passage through heat, steam or other.  4. Method according to claim 1, characterized in that the activated polyol-isocyanate mixture advantageously has the following composition A. Isocyanate: 50 parts of an MDI isocyanate such as  the one known under the name  Desmodur 44 V 20 commercial  Bayer company B. Polyol: 100 parts of a polyol of the known type  under the trade name  Desmophen 3.900 from Bayer.  than tin salts. Catalyst: 0.1 to 0.3 part of such a catalyst  Dabco  than the one known by the name Activator: 0.05 to 0.3 part of an activator such  5. Panel obtained by application of the method according to any one of claims 1 to 4, characterized in that it consists essentially of two glass fiber mats (1) coated with an activated polyol-isocyanate mixture, which is polymerized in the form of a polyurethane elastomer, sandwiching a layer of expanded polystyrene (9) penetrating intimately into the glass fiber mats, and by external neutral or decorative support layers (8, 8 ′), in sheet form of paper, plastic sheet, woven or non-woven textile, cardboard, or the like, this panel being either in the form of a flat plate, lightly pressed or not, or in the form of a molded panel.  6. Panel according to claim 5, characterized in that the panel is constituted by a superposition of several alternating layers of glass fiber mat and pre-expanded polystyrene beads.  7. Method according to any one of claims 1 to 4, characterized in that, for a treatment of glass fiber mat (1 ') of great thickness, the spraying of the activated polyol-isocyanate mixture is carried out on the two mat faces tel ') by passing the latter under a first coating machine (2') by means of a conveyor belt (10), then by passing under a second coating machine (2 ") by means another conveyor belt (11) receiving the inverted mat (1 ') and operating in the opposite direction to the conveyor (10), the mat (1') thus coated being removed by a third conveyor belt (12).  8. Panel according to any one of claims 5 and 6, obtained by applying the method according to any one of claims 1 to 4 and 7, characterized in that the glass fiber mats are replaced by a ply (13 ) of monofilament type glass fibers, which is coated on one or both sides with an activated polyol - isocyanate mixture, and which is arranged on a support (14) in the form of a plastic sheet, a woven or non-woven fabric, a sheet of paper, a cardboard, or the like, and is provided with a layer (15) of pre-expanded polystyrene beads with a thickness of between 2 and 6 mm, the beads of which from the lower part penetrate the sheet (13) by filling its interstices and rest partly on the support (14) forming a barrier, another support (16) similar to the support (14) and having a neutral or decorative appearance covering the layer of balls (15), the sandwich thus produced being subjected to a temperature between 1000 C and 1300 C for a period of between 30 and 120 seconds, by passage in an oven, between hot plates under slight pressure, or between a punch and a shaped and heated matrix.  9. Panel according to claim 8, characterized in that the sheet of monofilament type glass fibers can advantageously be a sheet known under the trade name Unifilo having a weight of between 150 and 300 g / m2 and a thickness of between 2 and 5 mm.