Card clothing usually has metal wire teeth which are specially shaped and which are arranged in dense arrays in order to carry out carding operations. Typically, card clothing is applied to a doffer, and which is used to carry out carding operations e. g. in sliver knit carding.

Metal teeth are effective to remove trash and to align the fibres of the carding material, but require periodic maintenance e. g. re-setting, and eventually complete replacement of the entire card clothing is required when excessive teeth tip wear has occurred.

Existing card clothing with wire teeth cannot be re-cycled economically, and therefore the entire structure i. e. worn wire teeth plus backing layer must be disposed of as scrap.

Up to now, it has always been thought that efficient and effective (mass production) carding operations can only be achieved using short length and relatively rigid bent wire teeth carried by a backing strip or carrier, and with the teeth being arranged in dense arrays.

The invention is based on the surprising discovery that relatively flexible elongate elements of non-metallic material may be used effectively as carding elements, even although such elements will be capable of deforming in a circumferential direction under load by reason of their flexibility.

Despite the flexibility of the elements, and the consequent less vigorous engagement with the carded material than would apply in the case of known metal wire teeth, it has been found that efficient removal of trash can be obtained, while at the same time acceptable carding i. e. orientation of the fibres can be obtained.

According to the invention there is provided card clothing for application to the outer surface of a rotatable cylindrical member which is to be used to carry out a carding operation on natural and/or synthetic fibrous material and which comprises: a carrier which can be fitted to the outer surface of the cylindrical member so as to encircle the cylindrical member; and sets of bristles secured to the carrier and which extend generally radially outwardly of the carrier when the latter is fitted to the cylindrical member: in which the bristles are flexible and made of non-metallic material, the bristles being spaced apart in clumps circumferentially of the cylindrical member so as to apply a carding action on the fibrous material during rotation of the cylindrical member.

Despite the fact that the bristles are flexible i. e. not rigid like conventional wire teeth, and are made of non-metallic material, it has been found surprisingly that the circumferentially spaced clumps of bristles have a very effective cleaning action on the fibrous material (to remove trash particles), and also can apply required fibre orientation.

The circumferential spacing of the clumps allows easy separation of trash from the card clothing (which may happen largely automatically by rotation of the cylindrical member).

When the bristles become worn, the carrier may be re-cycled, after replacement of worn clumps of bristles.

The carrier also may be non-metallic, and in one preferred form is a rigid or semi- rigid cylindrical sleeve of plastics material, and the clumps of bristles are embedded or otherwise secured at their radially inner ends to the sleeve.

In another embodiment, the carrier comprises a flexible elongate strip which can be wrapped around the cylindrical member, and the inner ends of the clumps of bristles are secured to the flexible strip in any suitable manner.

The flexible strip may therefore comprise a flexible foundation strip made of e. g. a 2 layer composite of an underlying layer of cotton and an overlying layer of resiliently deformable material e. g. foam rubber.

The spacing apart (S) of the clumps of bristles, and the bristle average height (h), and the ratios between spacer (S) and the bristle heights (h), will be determined by experiment, according to the fibrous material to be treated, so as to achieve required cleaning efficiency and fibre orientation.

Preferred embodiments of card clothing according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic end view of part of a first embodiment of card clothing according to the invention; Figure 2 is a view, similar to Figure 1, showing in more detail the means by which the card clothing of Figure 1 is mounted on the outer surface of a rotatable cylindrical member which is to be used to carry out carding operations on natural and/or synthetic fibrous material; and Figure 3 is an end view, similar to Figure 2, showing a further embodiment of card clothing applied to the outer surface of a rotatable cylindrical member.

Referring now to the drawings, there will be described embodiments of card clothing intended to be applied to the outer surface of a rotatable cylindrical member, such as a doffer, which is to be used to carry out carding operations on natural and/or synthetic fibrous material.

In the first embodiment shown in Figures 1 and 2, card clothing is designated generally by reference 10 and comprises a rigid carrier 11 in the form of a plastics or nylon ring or sleeve, and which is fitted to the outer surface of a cylindrical member 12 so as to encircle the cylindrical member 12.

Sets of bristles 13 are secured to the carrier 11 and extend generally radially outwardly of the carrier 11 when the latter is fitted to the cylindrical member 12.

The bristles 13 are flexible and made of non-metallic material, and are spaced apart in clumps 14 arranged circumferentially of the cylindrical member 12. The clumps 14 have average bristle height (h) which is slightly more than the circumferential spacing (S) between adjacent clumps 14.

The spacing apart (S) of the clumps 14 of bristles, and the bristle average height (h), and the ratios between space (S) and bristle height (h), will be determined by experiment, according to the fibrous material to be treated, so as to achieve required cleaning efficiency and fibre orientation.

Despite the flexible nature of the bristles 13 in each clump 14, and the non- metallic material from which they are made, the bristles are able to apply an efficient cleaning action i. e. removal of trash from a fibrous material which is to be treated, and also apply a satisfactory fibre orientation in the fibrous material.

The carrier 11 is conveniently mounted as a slidable fit on the outer surface of cylindrical member 12, and as shown has an in-turned flange 15 which locates in an axial slot 16 formed in the outer surface of the cylindrical member 12. This allows easy mounting of the card clothing on the cylindrical member 12, and subsequent removal when excessive bristle wear has taken place.

Referring now to Figure 3, a further embodiment of card clothing is illustrated, and which also has bristles 13 arranged in clumps 14 which are spaced apart circumferentially, with respect to cylindrical member 12, so as to apply required carding action on the fibrous material during rotation of the cylindrical member.

However, in this embodiment, the carrier takes the form of a flexible elongate carrier strip 17 which is a two layer composite of an underlying layer of cotton and an overlying layer of resiliently deformable material e. g. foam rubber.

The flexible elongate strip 17 is wrapped around the cylindrical member 12, and the inner ends of the clumps 14 of bristles are secured to the flexible strip 17 in any suitable manner.

The flexible elongate strip is secured to the outer surface of the cylindrical member 12, which it encircles, and is tightened circumferentially by pressing in-turned ends 18,19 pressed into longitudinal slot 16 in the outer surface of the cylindrical member 12, and retained therein by a metal spring clip 20.

The main benefits achievable utilising the embodiments of the invention are as follows: on the member, called mainly the doffer or final carrier, there is a suitable carrier with fibre action; there is no metal contamination; it is easier to set overall height parameters, than at present available with existing metal teeth; the entire card clothing assembly is recyclable; more competitive pricing structure of carrier body, ring base and bristle surface can be achieved, especially if they are all made of plastics or cotton/rubber; less maintenance of plastics components compared with metal parts.