GB2104562A - Non woven thermoplastic fabric - Google Patents

Abstract

A non woven material comprising a layer of a matt of generally discontinuous thermoplastic microfibres, i.e. of diameter up to 10 microns, bonded together at localised regions disposed across the matt. The bonding may be thermal with or without pressure (e.g. ultrasonic heating) and/or by print bonding. The product may be embossed.

Description

SPECIFICATION Non woven thermoplastic fabric The present invention relates to non woven fabrics more particularly to non woven fabrics composed predominantly of synthetic thermoplastic fibres with desirable fabric-like characteristics. The non woven material in accordance with the invention comprises a layer of a matt of generally discontinuous thermoplastic microfibres (having an average filament diameter of up to 10 microns) bonded together at localised regions disposed across the matt - e.g. at discrete spots or zones or along intersecting or non-intersecting lines. Such localised bonding, e.g. print bonding, increases the strength of a single layer matt.A wide variety of thermoplastic polymers can be used for the fibres of the matt, e.g. polyolefins such as polypropylene and polyethylene, polyamides, polyesters, polyurethanes, and cellulose acetate; a matt may be composed of microfibres of 2 or more different polymer types.

Matts of thermoplastic microfibres suitable for localised bonding according to the invention are available commercially and are described for example in the article "Superfine Thermoplastic Fibres" in Industrial and Engineering Chemistry, Vol. 48, No. 8 and in US Specifications Nos.

3 715 251,3 704 198,3676242and 3 595 245 and UK Specification No. 1 21 7 892.

Manufacture may comprise melt extruding continuous micro filaments and baking these by means of an air blast into microfibres which are deposited as a matt on a receiving surface, the deposited microfibres interiocking mechanically and to a certain extent by welding to provide a coherent matt.

The invention also provides a plurality of matts of thermoplastic microfibres bonded together face to face at localised regions, e.g. at discrete spots or zones or along intersecting or non-intersecting lines. Adjacent matts may be of the same or different thermoplastic polymer composition.

The method of bonding a single layer matt or of bonding one matt to another in a laminate can be spot bonding by thermal means with or without pressure (e.g. ultrasonic heating) and/or print bonding using (preferably synthetic) bonding materials which may have the characteristics of softness and strength in order to build these properties into the fabric. In the formation of a laminate, one or more of the matts may be previousiy subjected to localised bonding according to the invention or may be a plain matt as initially produced.

The preferred form of single layer and laminate finished fabrics according to the invention is convoluted in three dimensions, an effect suitably produced by an embossing technique with male and female embossing members (e.g. rollers), the procedure yielding an undulatory sheet which (apart possibly from the bonded regions) is of substantially constant density over its area. A variety of embossing patterns are possible according to the fabric end use, the embossing generally imparting improved softness and loft to the product. The embossing step may involve the application of heat to the fabric and/or one or both embossing members; a certain degree of surface heating of the fabric can give it an anti-linting finish.

Bonding patterns applicable to single layer matts and laminates according to the invention include a regular array of dots and a diamond pattern of two intersecting sets of parallel bond lines.

The material can be prepared in varying weights depending on end use but in most cases the preferred weight does not exceed 100 g/m2 lying generally in the range of 40-60 g/m2.

Fabrics according to the invention can be used as sterilizable medical wraps or for table stationary - e.g. table cloths, napkins, etc.

1. A non woven material comprising a layer of a matt of generally discontinuous thermoplastic microfibres bonded together at localised regions disposed across the matt.

2. A non woven material substantially as hereinbefore described.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (2)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Non woven thermoplastic fabric The present invention relates to non woven fabrics more particularly to non woven fabrics composed predominantly of synthetic thermoplastic fibres with desirable fabric-like characteristics. The non woven material in accordance with the invention comprises a layer of a matt of generally discontinuous thermoplastic microfibres (having an average filament diameter of up to 10 microns) bonded together at localised regions disposed across the matt - e.g. at discrete spots or zones or along intersecting or non-intersecting lines. Such localised bonding, e.g. print bonding, increases the strength of a single layer matt.A wide variety of thermoplastic polymers can be used for the fibres of the matt, e.g. polyolefins such as polypropylene and polyethylene, polyamides, polyesters, polyurethanes, and cellulose acetate; a matt may be composed of microfibres of 2 or more different polymer types. Matts of thermoplastic microfibres suitable for localised bonding according to the invention are available commercially and are described for example in the article "Superfine Thermoplastic Fibres" in Industrial and Engineering Chemistry, Vol. 48, No. 8 and in US Specifications Nos. 3 715 251,3 704 198,3676242and 3 595 245 and UK Specification No. 1 21 7 892. Manufacture may comprise melt extruding continuous micro filaments and baking these by means of an air blast into microfibres which are deposited as a matt on a receiving surface, the deposited microfibres interiocking mechanically and to a certain extent by welding to provide a coherent matt. The invention also provides a plurality of matts of thermoplastic microfibres bonded together face to face at localised regions, e.g. at discrete spots or zones or along intersecting or non-intersecting lines. Adjacent matts may be of the same or different thermoplastic polymer composition. The method of bonding a single layer matt or of bonding one matt to another in a laminate can be spot bonding by thermal means with or without pressure (e.g. ultrasonic heating) and/or print bonding using (preferably synthetic) bonding materials which may have the characteristics of softness and strength in order to build these properties into the fabric. In the formation of a laminate, one or more of the matts may be previousiy subjected to localised bonding according to the invention or may be a plain matt as initially produced. The preferred form of single layer and laminate finished fabrics according to the invention is convoluted in three dimensions, an effect suitably produced by an embossing technique with male and female embossing members (e.g. rollers), the procedure yielding an undulatory sheet which (apart possibly from the bonded regions) is of substantially constant density over its area. A variety of embossing patterns are possible according to the fabric end use, the embossing generally imparting improved softness and loft to the product. The embossing step may involve the application of heat to the fabric and/or one or both embossing members; a certain degree of surface heating of the fabric can give it an anti-linting finish. Bonding patterns applicable to single layer matts and laminates according to the invention include a regular array of dots and a diamond pattern of two intersecting sets of parallel bond lines. The material can be prepared in varying weights depending on end use but in most cases the preferred weight does not exceed 100 g/m2 lying generally in the range of 40-60 g/m2. Fabrics according to the invention can be used as sterilizable medical wraps or for table stationary - e.g. table cloths, napkins, etc. CLAIMS

1. A non woven material comprising a layer of a matt of generally discontinuous thermoplastic microfibres bonded together at localised regions disposed across the matt.

2. A non woven material substantially as hereinbefore described.