USE OF NON-WOVEN, NEEDLED FIBROUS MAT MATERIAL

Abstract: The invention relates to the use of non-woven, needled fibrous mat material as reinforcing material in a polymer binder/polymer matrix, a method for producing a composite material comprising at least a reinforcing material and a polymer binder/polymer matrix, in which the reinforcing material used is non-woven, needled fibrous mat material, composite material obtainable by this method, and laminate of which at least one layer comprises said composite material.

Description: Use of non-woven, needled fibrous mat material The invention relates to the use of non-woven, needled fibrous mat material. It is known for non-woven, needled fibrous mat material to be 5 used as carpet backing, filter material, backing material for coverings, cleaning cloths, and as a substitute for felt and the like. Surprisingly, it was found according to the invention that already bonded non-woven, needled fibrous mat material can be used 10 as reinforcing material in a polymer binder/polymer matrix. The invention therefore relates to the use of non-woven, needled fibrous mat material containing bonded fibres of polyester and/or polyamide as reinforcing material in a polymer binder or polymer matrix, the fibrous mat material being in the form of 15 cuttings. Such fibrous mat material is widely available, and is comparatively cheap. According to the invention, it is preferable for the fibres of the fibrous mat material to be bonded with an adhesive based on acrylate or melamine. 20 Non-woven, needled fibrous mat materials which are found to be satisfactory according to the invention are the commercial products Colbond ("dry laid needled and chemically bonded non-woven made from Diolen polyester staple fibre") and Coltron ("polyester filament, non-woven spray laid, needled and thermally bonded"). In 25 this case we are concerned with, for example, so-called geotextile materials which are used in roadbuilding. When it is used as reinforcing material the fibrous mat material is in the form of cuttings, and not in the form of webs or large sheets. Such cuttings are often obtained directly as waste 30 during the production and processing of the fibrous mat material in the usual applications. It goes without saying that it is also possible to cutting, A chop, cut or otherwise shred a web of the fibrous mat material in a order to obtain the reinforcing material in the form suitable for 35 use according to the invention. It is preferable for the surface area of the cuttings of the fibrous mat material to lie in the region of 1 mm 2 - 150 cm 2 , in particular Jωn 2 - 50 cm 2 . The fibrous mat material used according to the invention is of a weight which is, for example, of the order of magnitude of 100 - 500 g/m 2 . The non-woven, needled fibrous mat materials described above can be processed with conventional thermosetting binders to a composite product. The polymer binder is, however, preferably a water-soluble, thermosetting resin, for example a urea/melamine/phenol/formaldehyde resin or combinations thereof. In general, the thermosetting resins which harden under pressure and temperature, such as, resins for moulding powders and high-pressure and low-pressure laminates, can be used. Examples of suitable resins can be found in the book Urea Formaldehyde Resin, Beatmeyer, 1979 (ISBN 0-2901-04558-3). The invention also relates to a method for producing a composite material by combining a reinforcing material with a polymer binder or a polymer matrix, in which the reinforcing material used is non-woven, needled fibrous mat material containing polyester and/or polyamide, the fibres of the fibrous mat material being bonded with an adhesive and the fibrous mat material being in the form of cuttings. In the method according to the invention an already bonded fibrous mat material is thus again impregnated with adhesive. In the method according to the invention the same preferred embodiments as those in the application according to the invention described above are applicable. The method according to the invention can be carried out according to principles which are generally known for the production of composite materials based on a polymer binder/polymer matrix and a reinforcing material. For example, (a solution of) the binder can be applied to the reinforcing material by immersion, impregnation or spraying, following which hardening takes place in, for example, a mould. In general, a temperature of 70 - 220°C, preferably l4θ-l8θ°C and a pressure of 15 - 200 kg/cm 2 are applied here. The polymer binder is preferably used as a solution in water. This ensures a better distribution of the thermosetting resin. Besides, water is environmentally friendly. The proportion in which the non-woven, needled fibrous mat material and the polymer binder are used according to the invention can vary within wide limits. However, it is preferable to use at least 5 parts by weight of polymer binder (calculated as dry matter) per 100 parts by weight of needled fibrous mat material. In general, no more than 350 parts by weight of polymer agent to 100 parts by weight of reinforcing material will be used. If in the method according to the invention an aqueous solution of the polymer binder is used, it may be necessary to carry out an interim drying because too large a quantity of water adversely affects the appearance of the product. In general, the combination of reinforcing material and polymer binder can be pressed directly, i.e. when wet, if the total quantity of water of the combination does not exceed 15 % by weight. From a quantity of 1 % by weight of water onwards, however, it is preferable to dry, in order to avoid the abovementioned adverse effects. Besides, the combination can actually contain up to 200 % by weight of water before drying. The invention also relates to a composite material which is obtainable by the method described above. The invention also relates to a laminate, of which at least one layer contains the composite material according to the invention. It is, for example, possible to cover boards such as particle board with a non-hardened combination of reinforcing material and polymer binder, following which hardening takes place in the usual way, for example under the influence of heat and/or pressure. It is also possible to use the composite material as layers in sandwich structures. The sandwich structures according to the present invention can comprise a multiplicity of layers placed on top of each other. For example, a three-ply structure can comprise a core layer of known board material and two outer layers of the combination of reinforcing material and polymer binder according to the invention. It is also possible for the core layer of a three-ply structure to be formed by the combination of reinforcing material and polymer binder, while the outer layers are known sheet materials such as particle board or MDF. In the production of the sandwich structures use is made of a finished - i.e. already pressed - board, or of sheet material which is not yet hardened, i.e. the adhesive-coated fibres for particle board or MDF. It is also possible according to the invention to use the non-woven, needled fibrous mat material combined with already known reinforcing materials in a polymer binder or a polymer matrix. Examples of known fibres are the (adhesive-coated) fibres for particle board or MDF. Such a composite material can also be used in the sandwich structures discussed above. For example, non-woven, needled fibrous mat material (with already bonded fibres) in the form of cuttings or flakes can thus be impregnated with resin (polymer binder) in the bottom of a flat mould, following which hardening may or may not take place. A mixture of cuttings of the fibrous mat material and, for example, adhesive-coated cuttings is then placed on this layer and pressed onto the bottom layer already present in the mould. Another layer - for example, corresponding to the bottom layer already in the mould - is then applied. This produces a laminate with an identical top and bottom layer, the middle layer being a polymer matrix in which a mixture of reinforcing materials is present. Of course, many variations of such a method of working are possible. It is extremely surprising that the application or method according to the invention produces a composite material which has an attractive decorative effect - resembling, for example, marble or granite. It is also possible to sand the surface of the hardened composite material, as a result of which the surface feels like suede or velvet, and does not give the usual cold effect of, for example, melamine laminate. The decorative effect depends on, for example, the size of the cuttings and the colour of the cuttings or the resin. The use of non-woven, needled fibrous mat material produces a material with an unexpectedly high impact resistance and/or toughness and/or elasticity. Pressed products according to the invention have the advantageous property that they do not splinter or cut, or at least they have these tendencies to a much lesser degree than the products made from conventional moulding powders without the use of non- woven, needled fibrous mat materials as reinforcing material. The invention is explained further in the examples which follow. Eample I 500 g Colbond cuttings, impregnated with 30 % by weight of a conventional formaldehyde/urea resin, is pressed at a temperature of l6θ°C and at a pressure of 25 kg/cm 2 . A high-gloss marble effect is obtained. Example II Example I is repeated, except that the non-hardened composition is applied to both sides of particle board or MDF, while the hardening takes place under the conditions mentioned. A board which is suitable as a partition is obtained. If the surface of the board is sanded, a suede-like surface (fabric feel) is obtained, and not the cold effect of a melamine laminate. The board is easy to screw and nail. Example III The non-hardened combination of Example I, in which there is impregnation with 130 % by weight of resin, is pressed in a mould at l6θ° and at a pressure of 120 kg/cm 2 to produce a product of great toughness which is slightly translucent and has a marble effect. Compared with products made from conventional moulding powders, the product according to the invention has the advantage that it is less likely to splinter.

Claims: CLAIMS 1. Use of non-woven, needled fibrous mat material containing bonded fibres of polyester and/or polyamide as reinforcing material in a polymer binder or polymer matrix, the fibrous mat material being in the form of cuttings. 2. Use according to Claim 1, in which the polymer binder or the polymer matrix is a water-soluble thermosetting resin. 3- Use according to Claim 2, in which the resin is a urea, melamine, phenol or formaldehyde resin. 4. Method for producing a composite material by combining a reinforcing material with a polymer binder or a polymer matrix, in which the reinforcing material used is non-woven, needled fibrous mat material containing polyester and/or polyamide, the fibres of the fibrous mat material being bonded with an adhesive and the fibrous mat material being in the form of cuttings. 5. Method according to Claim 4, in which the composite material is manufactured at a temperature of 70-220"C and at a pressure of 15-200 kg/cm 2 . 6. Method according to Claim 4 or 5. in which the polymer binder is used as a solution in water. 7. Method according to Claims 4 - 6, in which at least 5 parts by weight and at most 350 parts by weight of polymer binder to 100 parts by weight of reinforcing material is used. 8. Composite material obtainable according to Claims 4 - 7- 9- Laminate of which at least one layer comprises the composite material according to Claim 8. ••**

Inventors: METS BENJAMIN, METS, BENJAMIN
Applicants: DESMEPOL BV, METS BENJAMIN, DESMEPOL B.V., METS, BENJAMIN
Application year: 1992
Main classification: B29C67
IPC codes: B29C70, C08J5, C08J11, D04H1