NO853812L - FLOR FABRIC. - Google Patents

Description

The invention relates to a non-woven material which preferably consists of polyester filaments and is suitable for use as a carrier web in roof webs which are resistant to aircraft fire and radiant heat. Such roofing membranes are mostly coated with bitumen on one or both sides, but may also have a coating of elastomers or plastomers.

For the improvement of the fire conditions of such roof tracks according to

DIN 4102/part 7, layered fabrics are often used such as e.g. is described in DE-PS 28 27 136 or in DE-GM 77 39 489 as a carrier.

It is also proposed to produce flor materials from flame retardant fiber raw materials. However, the use of such fiber or thread raw materials in the production of the necessary fleeces did not lead to the desired full result. A spread of the fire in the lower layers of a roof covering could thus not be prevented. Also flame retardant additives for bitumen masses or polymer masses showed no result. In the event of a fire, the flame-retardant additives burn off with the bitumen, so that the remaining fluorine material and the lower layers are no longer protected by these additives.

Furthermore, it is proposed to equip the flor fabric with an i and

known per se flame-retardant finish which, at the processing temperature of the coating compound and the roof membrane, also remains inert, but at a higher temperature forms a strongly closed, preferably foamy layer.

Admittedly, these proposals all constitute a clear improvement

of the fire situation, but is however very laborious in execution.

Surprisingly, it was now found that the fire ratio of fluorescent substances, resp. of roofing sheets produced from it, is clearly improved when the flour distributed in the binder contains inert small-volume solid particles. Inert means that the solid particles are resistant to attack by heat and fire, i.e. they

are not or are only difficult to ignite. Small-volume solid particles are understood to mean those whose spatial expansion is small to the effective opening width of the soil layer as defined for geotextiles in booklet 56 (1983) of communications from the Franzium-Instituts fiir Wasserbau und Kusten-ingenieurwesen der Universitat Hannover, page 379- 381.

Examples of such solid particles are inorganic powdered products with an average particle diameter of up to 100 um, preferably 0.5-20 um. Such products with a special ball shape can e.g. consist of calcium carbonate, kaolin, silicate and similar minerals.

For special areas of application, ground glass fibers with a diameter of 5 to 100 ym, preferably 10-25 ym and an average length of 10 ym to 300 ym, preferably 50 - 200 ym alone or in a mixture with other solid substances or fibers are also suitable. In addition to ground glass fibres, other inorganic fibrous products can be used, e.g. ceramic or mineral fibres. However, fibers with a flame-resistant finish can also be used.

The fluorescent substances according to the invention can consist of fibers or filaments of the known synthetic polymers. However, preference is given to a fleece fabric of needle-like filaments of polyesters fixed with a binder, preferably polyethylene terephthalate, which was formed according to the known spun bond method, i.e. by depositing freshly spun polyester filaments into a fleece.

For the production of fluorescent substances, the binders are often used in the form of aqueous dispersions or aqueous solutions. Known binders in the form of aqueous dispersions are mono-, co- or terpolymers of acrylic acid esters, acrylic acid amides, acrylonitrile, butadiene and styrene.

However, binders based on water-soluble urea-formaldehyde, maleic-formaldehyde, phenol-formaldehyde condensates or water-dispersed polymers of vinylidene chloride and vinyl chloride which are used alone or in a mixture are particularly suitable for the production of the fluorine substance according to the invention.

The binders can be applied according to different - e.g. in "Florstoffer", G. Thieme Verlag. Stuttgart, New York, published by J. Lunenschloss and W. Albrecht 1982, pages 177-199, methods discussed. The most common method is foularding in a trough with a subsequent pair of press rollers. When heat is applied, water is removed from the binder, and the binder-filament bond is formed.

The solid particles are preferably added to the aqueous binder bath and kept suspended by stirring.

Deposition of the solid particles can be prevented by stirring, but also by adding a thickening agent, e.g. on the basis of soluble cellulose derivatives.

In the aqueous bath, the binder must be contained in a concentration of from 15 to 40%, preferably 18-25%. The fibrous or powdery substances are used in a proportion from 10-150% referred to the solid binder.

By showering a flower with a suspension of e.g. ground glass fibers and a binding agent, a cotton fabric is obtained which forms a composition of polyester filaments, ground glass fibers and binding agents.

However, aqueous baths with the suspended additives can also be poured from one side, e.g. on the upper side of the floor, or by raking or with the help of rotating rollers, is distributed evenly on the surface of the floor. The binder, sometimes used in excess, flows through in the form of a filtering cloth. Surplus binder is collected, strengthened with the aforementioned fibrous or powdery additives and fed back into the binder cycle. A layer-like accumulation of fibrous resp. powdery additives which then penetrate the flor.

After evaporation of the water introduced into the fleece with the aqueous binder suspension and curing of the binder, the fleece material according to the invention is formed.

With the same result, the fleece fabric according to the invention can be formed when a fleece is impregnated with the aqueous binder bath according to the Foulard method and fibrous or powdery substances are sprinkled or sprinkled on the impregnated fleece in a thin layer. It is then advantageous when the impregnated fleece contains so much binder bath that, by diffusion and absorption, the sprinkled substances are completely impregnated by the binder bath.

Decisive is the small spatial expansion of the solid particles, i.e. small in relation to the effective opening width of the flour layer. This ensures a good penetration of the flour material with the solid particles, in contrast to a layer formation when larger solid particles are added. Depending on the type of application of the binder, a more or less distinct density gradient of the solid particles over the flour layer thickness is also to be observed, which can be set in a targeted manner depending on the area of application.

Example

A needled filament pile ("Trevira spunbond" type 13) with a basis weight of 150 g/m and a single filament titer of 4 dtex was stretched in a needle frame (size 43 x 33 cm) and showered with a suspension of a commercially available water-soluble heat-curable melamine derivative -formaldehyde resin solution and a ground microcrystalline calcium carbonate with a mean particle diameter of 1 µm (eg Omyalite 90 from Omya GmbH). The excess suspension contained in the impregnated flor was pressed out in a press rolling mill with a line pressure of 300 N/cm. The suspension used contained melamine derivative-formaldehyde resin in a concentration of approx. 15% referred to dried resin. The ground calcium carbonate was in the suspension in a concentration of 50% referred to dry resin. The suspension was kept suspended by stirring. After drying on a tension frame at a temperature of 180°C and a residence time of 4 min. the flour weight was 209 g/m 2 corresponding to a binder/calcium carbonate mixture of 39%. Investigation of tensile strength gave a value of 520 Newton per 5 cm strip width measured in the longitudinal direction of the fabric at an expansion of 35%. The ground calcium carbonate was contained in the overall cross-section of the flor material.

When the flour material was burned, a solid, structurally charred layer formed.

Claims (5)

1. Floss made of fibers or filaments fixed with a binder, characterized in that the fluff distributed in the binder contains inert small-volume solid particles. 2. Polyester filaments made of needles, with a binding agent attached and laid down according to the spunbond method, characterized in that the filling material distributed in the binding agent contains inert small-volume solid particles. 3. Fluorescent material according to claim 1 or 2, characterized in that the solid particles are inorganic powdered products with an average diameter of up to 100 µm, preferably 0.5 - 20 µm. 4. Method for producing a fleece material according to one of the preceding claims, characterized in that the solid particles are added to the aqueous binder and applied with this to the fleece. 5. Method for producing a fluff material according to one of claims 1-3, characterized in that the solid particles are sprinkled or sprinkled on the fluff equipped with the binder in a thin layer.