GB1004268A - Process for the moulding of articles of plastic material - Google Patents

Abstract

1,004,268. Moulding. SOC. DES MATIERS PLASTIQUES M.R.B., and D. BESSON. Dec. 15, 1961, No. 45027/61. Heading B5A. A process, for moulding thin walled plastics articles, part of the outside of which have textile material incorporated therein, comprises, arranging the layer of textile material over a perforated part of the mould, bringing the wall of the mould into contact with the plastics material in the fluid and polymerizable state, partially polymerizing with heat the plastics material which is in contact with both the mould and at least the marginal zone of the textile material until a solid film is formed, draining away the excess fluid and then completely polymerizing with heat the film and separating the finished article from the mould. The composition of a suitable material, consisting of a plastisol-mainly polyvinyl chloride and diethyl hexyl phthalate-, stabilizer and colouring agent, is given. Plastics materials which become cellular during the final polymerization may be used. For dip moulding, the mould 1 has holes 5, a groove 10, and a strip of cloth 15 tightly fitting into a groove 14 in the mould and having wires 16 detachably to hold the textile material 4. A sheet 17, of regenerated cellulose, polyethylene, polyester, or polyvinyl chloride is placed over the textile material. The mould is heated to 180-190‹ C., immersed in the plastics material, till it is covered with a solid film, withdrawn and left to drip and then put in an oven. The article is removed from the mould by turning it inside out. Alternatively, the textile material may be put in a perforated recess in a mould or on a grid forming the base of a mould. The inside walls may be covered with a wax or a silicone to facilitate the removal of the finished article. The mould, filled with the fluid plastics material, is put in an oven for a minute, and after pouring off the non- solidified material, is replaced therein. A screen 9 (Fig. 2, not shown) which covers the centre of the textile material may be used so that only the periphery is coated. Alternatively, the screen may be raised by legs above the textile material so that a predetermined thickness of the coating covers the textile material. A groove in the mould may form a plastic braid surrounding the edges of the textile material. The surface of the moulds may be smooth or comprise a relief pattern, e.g. that of leather. The fluid plastic material may be applied by other methods, for example by a spray gun.