GB892262A - Surgical masks - Google Patents

Abstract

892,262. Surgical masks. PLANTINGA, O. S., and DEKER, M. July 29, 1960 [July 30, 1959], No. 26581/60. Class 81 (2). A surgical mask formed of a flexible airpermeable material has a permanently moulded raised portion adapted to fit over the nose and mouth, a mouldable top edge adapted to fit over the bridge of the nose and means for securing the mask on the face. As shown, a mask of flexible air-permeable material comprises a triangular raised portion 10 and a strip of aluminium or other ductile metal 14 and ties 18. The preferred material weighs 3-10 ozs. per square yard and is formed of cellulosic fibres, with 10%-50% thermoplastic resin fibres such as copolymers of vinylacetate or vinyl chloride if the portion 10 is to be heat-formed or -sealed. A needle loomed fabric is prepared by passing barbed needles into a carded web of fibres to form an entangled mat. Preferably several layers are used with a resistance to air flow of less than 0.1 inch of water at a flow rate of 85 litres/minute per 100 square centimetres. A filter efficiency test is described. In the form shown in Fig. 1, a needle loomed fabric 23 is faced with gauze or other large mesh fabric 21, 22 preferably including a thermoplastic binding agent, the strip 14 being inserted between facing 21 and the fabric 23. The edges are heat sealed and the folds 15 are made. The portion 10 is moulded on a form and stabilized by heating or the application of a binding agent. A1- ternatively the portion 10 is formed around a form and a second form placed on top, the mask then being packed and sterilized during which the portion 10 is stabilized. An alternative form of mask is shown in Fig. 6. Specifications 468,529 and 836,397 are referred to.