GB2222185A

GB2222185A - Ignition resistant wadding

Info

Publication number: GB2222185A
Application number: GB8918909A
Authority: GB
Inventors: John Stuart Uttley; John Michael Higgins
Original assignee: John Cotton
Current assignee: John Cotton
Priority date: 1988-08-18
Filing date: 1989-08-18
Publication date: 1990-02-28
Anticipated expiration: 2009-08-18
Also published as: GB2222185B; GB8918909D0; GB8819667D0

Abstract

Ignition resistant wadding comprises a web of polyester fibres bonded with an emulsion of thermoplastic polyethylene polyester or acrylic resin. When exposed to an ignition source the thermoplastic binder melts, allowing the fibres to shrink back from the source thus reducing the chance of a fire. The emulsion may be sprayed onto the wadding or applied as a foam. Used in mattresses and upholstery.

Description

IGNITION RESISTANT WADDING The present invention relates to an improved ignition resistant wadding for use in textile products, mattresses, upholstery and the like, and .to a method of manufacturing such a wadding.

Conventionally, high bulk waddings may be manufactured by applying a resin binder system to a web of textile fibres. The resins are normally water based colloidal suspensions and are usually applied to the web by spraying.

The resultant waddings may generally be referred to as "spray bonded waddings".

A method to impart a degree of ignition resistance to such spray bonded waddings, is by using FR resin systems such as PVDC resin/Antimony Oxide compositions. This method suffers from the disadvantage that large quantities of resin are necessary to achieve the required ignition resistance, and this reduces the bulk and softness of the finished wadding.

An alternative approach as been to use a proportion of fibres with a low melting point in the wadding and applying heat to bond the textile fibres together. These are generally known as "thermally bonded waddings" and are recognised as having superior ignition resistance as compared with the conventional spray bonded waddings. The thermally bonded waddings will not ignite when subjected to ignitability tests such as defined in BS 5852.

The present invention relates to the "spray bonded" type of wadding, although it should be appreciated that the invention is not limited to the use of spraying as an application method.

According to the present invention there is provided an ignition resistant wadding for use in textile products, mattresses, upholstery and the like, comprising a web of textile fibres bonded together by the application of a composition including a thermoplastic resin. The thermoplastic resin composition may be used as a colloidal dispersion. a suspension, or a solution, and is preferably water based, for example a polyethylene emulsion known as "Primacor 4990" available from Dow Chemicals, a polyester emulsion known as "Stypol 44-5056" available from Freeman Chemicals or low molecular weight acrylic resin, eg Vinamull 43353 (Vinamull Ltd).

Studies to date have shown that not all polyethylene or polyester emulsions are suitable for use in the present invention, and it is thought that the difference between a suitable and non-suitable resin is probably due to a difference in the respective molecular weight of the two types of resin film, or to differences in the molecular weight, or to differences in the ability of the resin to maintain its structure and resist decomposing prior to melting. or perhaps a combination of two or more of these features are involved.

The textile fibres used to form the wadding are preferably polyester fibres.

The wadding of the present invention achieves the required ignition resistance in the same way as thermally bonded waddings due to the ability of the resin at the bonding points to melt when exposed to an ignition source, thereby releasing the textile fibres which then shrink or melt away from the ignition source creating a cavity about the source. In conventional spray bonded waddings, the resin does not melt to release the fibres when exposed to an ignition source, and the wadding therefortignities more easily.

According to a second aspect of the present invention there is provided a method of manufacturing an ignition resistant wadding. the method comprising arranging a plurality of textile fibres to form a web, and applying to said web a composition including a thermoplastic resin.

Conveniently, the resin is applied by spraying, and in order to achieve a good degree of impregnation into the wadding the resin may be sprayed first onto an upper surface of the wadding, the wadding then being turned over and further resin sprayed onto the under surface.

Alternatively, the resin may be sprayed onto both surfaces at the same time.

Other methods of application may be used, for example foaming the resin and causing it to impregnate the wadding as a foam.

The method further includes exposing the wadding with the resin applied thereto to a source of energy, which serves to drive off volatiles contained in the resin composition.

The source of heat is preferably a hot air oven, but other sources may be used, for example infra red.

Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings in which: Figure 1 is a schematic diagram showing the manufacture of the wadding of the present invention: Figure 2 is an illustration of an ignitability test performed on the wadding of the present invention.

Referring to the drawings, an ignition resistant wadding 2 is formed by arranging polyester fibres into a web 1, applying to the web 1 a composition 3 including a thermoplastic resin, and subsequently exposing the web to a source of heat 4 to evaporate the water contained in the composition.

The fibres are typically polyester fibres, and the thermoplastic resin may be any one of a number of suitable resins, e.g. "Primacor 4990" or "Stypol 44-5056".

When the wadding is subsequently exposed to an ignition source such as source 2, BS 582, the resin with which the wadding is impregnated melts, releasing the textile fibres which then shrink back from the source, thus offering good resistance to ignition.

In Figure 1, the wadding may be passed continuously or step wise past the spraying apparatus 6 and a gas fired oven 4. Alternatively, the heat source and spraying apparatus may be passed over the stationary wadding.

For thicker waddings, it may be necessary to turn the wadding over and also spray the composition onto the other side to ensure adequate impregnation of the composition into the wadding.

A further development of the present invention is envisaged, in which one or both surfaces of the wadding are consolidated by heating and cold calendering, the resulting product being ideally suited to quilting applications because the consolidated surface has sufficient strength to hold a quilting stitch without the necessity for a backing fabric normally used to hold a stitch in place.

Claims

1. Ignition resistant wadding comprising a web of textile fibres bonded together by a composition including thermoplastic resin.

2. Wadding as claimed in Claim 1, wherein said composition is a polyethylene emulsion.

3. Wadding as claimed in any previous claim wherein said fibres are polyester fibres.

4. A method of manufacturing ignition resistant wadding, comprising the steps of arranging textile fibres to form a web and applying a composition including thermoplastic resin to the web.

5. A method as claimed in Claim 4, wherein the resin is applied by spraying.

6. A method as claimed in Claim 5, wherein the resin is sprayed onto an upper surface of the web, the web is turned over and the resin sprayed onto the under surface.

7. A method as claimed in Claim 5, wherein the resin is sprayed onto both surfaces of the wadding simultaneously.

8. Ignition resistant wadding substantially as hereinbefore described with reference to the accompanying drawings.

9. A method of manufacturing ignition resistant wadding substantially as hereinbefore described with reference to the accompanying drawings.