Patent GB-1130857-A (GB)
Title: Bandaging and dressing material and method of making same
IPC: D04H1/48
Filed: 1965-09-17
Abstract: 1,130,857. Bandaging or dressing material. HUYCK CORP. 17 Sept., 1965 [23 Sept., 1964], No. 39855/65. Heading A5R. [Also in Division B5] For absorbing body fluids, a bandaging or dressing material laminate structure comprises a contact layer formed from fibres of a thermoplastic resin which is hydrophobic and which is fusible only at a temperature higher than that temperature necessary to sterilize the structure, one surface of the structure being formed by the contact layer, and an absorptive layer formed from material which is absorptive; at least some of the fibres of the contact layer extend into the material of the absorptive layer, the exposed surface of the contact layer having been pressed to cause any projecting fibres to be laid down while being exposed to a temperature sufficient to cause fusion of at least some of the fibres of the contact layer. The layer formed from material which is absorptive may consist either of a single absorptive layer to provide a two-layer laminate structure or of an absorptive layer in combination with an intermediate layer interposed between the contact layer and the absorptive layer to provide a three-layer laminate structure. The laminate structure may include additional layers; one surface layer may consist of a woven or knitted gauze but each layer preferably is formed of fibres which may be interlocked into a continuous fabric by techniques other than weaving or knitting. A conventional adhesive tape may be applied to the exposed surface remote from the contact layer to provide an adhesive dressing. The contact layer preferably is formed of carded fibres of a thermoplastic resin having a softening temperature below 400F., for example polypropylene, polyvinylidene chloride or polyvinylidene dinitrile; such fibres, which preferably have a denier of from 1.5 to 6 and a length of from 1 to 8 inches, may be lapped to provide a batt consisting of from 6 to 10 layers of thermoplastic resin fibres. The absorptive layer for a two-layer laminate structure and the intermediate layer for a three-layer laminate structure preferably is a wadding of highly absorbent fibres, for example fibres of rayon, cotton or cellulose derived from hard or soft wood; the fibres may be wood fibres having a length of from 1 to 5 millimetres disposed in a paper-like array. The absorptive layer for a three-layer laminate structure preferably is formed of fibres of rayon or cotton or of a mixture of fibres of rayon and cotton, the fibres preferably having a denier of 3 and a length of from 1 to 2 inches; alternatively, foamed sponge or cotton gauze may constitute the absorptive layer. The laminate structure may be fabricated by applying a contact layer of fibres of thermoplastic resin either to one surface of a single layer of absorptive material or to the exposed surface of the intermediate layer of a sub-structure which comprises the intermediate layer and the absorptive layer. uniting the layers by forcing some of the fibres of the contact layer into the material of the absorptive layer, and subjecting the exposed surface of the contact layer simultaneously to pressure sufficient to cause projecting fibres to be laid down and to heat at a temperature sufficient to cause fusion of at least some of the fibres but insufficient to detrimentally affect the laminate structure for example by scorching. The uniting of the layers may be effected by a needling operation which carries fibres of the contact layer into the absorptive layer without causing any part of the absorptive layer to be carried to the exposed surface of the contact layer; the needling operation may involve the passage of barbed needles through the layers to provide from 100 to 200 needle penetrations per square inch. If the sub-structure comprising the intermediate layer and the absorptive layer is present, adhesive means additionally may bond the intermediate layer to the absorptive layer. The pressing and partial fusion of the fibres of the contact layer may be effected by passing the laminate structure between a pair of rollers, one roller being heated and arranged to contact the exposed surface of the contact layer, the other roller being non-heated and arranged to contact the exposed surface of the absorptive layer. The laminate structure may be subjected to further heat treatment by passage between a further pair of rollers, one roller being heated and ridged thereby to emboss the exposed surface of the contact layer. Such fabrication of a laminate structure consisting of a contact layer formed by a lapped batt of carded polypropylene fibres, an intermediate layer formed by a dense wadding of cellulosic fibres and an absorptive layer formed by a web of rayon fibres is fully described and illustrated in the Specification. Alternatively, the contact layer alone may be heat pressed and thereafter united to the absorptive layer or layers.