| 摘要 |
Process for the manufacture of microporous sheets from ethylene-vinyl-acetate wastes and sheets so obtained, a process which makes use of the wastes produced in the processes of handling and stamping sheets of such material, wastes which can be reused by conversion by compression/sintering after placing in moulds, this being possible despite the prior process of foaming to which the ethylene-vinyl acetate has been subjected in order to confer microporosity upon it, altering the thermoplastic properties of the polymer, and because the wastes of the same are stored in hoppers separating them from the powder proceeding from shaping and punching, and from the trimming and punching of sheets, these being shredded, and then following the addition of additives being mixed and placed in moulds which pass into presses for compression/sintering. Different materials for homogeneous layers are placed in the moulds, these polymers being convertible by compression/sintering. The sheets obtained from the moulds may be prepared from wastes of microporous ethylene-vinyl-acetate powder, or trimmings and shredded wastes of the same polymer, or be manufactured using microporous ethylene-vinyl-acetate powder and recycled polyethylene (two layers) or of the polyethylene, ethylene-vinyl-acetate powder and polyethylene sandwich type (three layers), or a sandwich sheet of polyethylene, ground trimmings of microporous ethylene-vinyl acetate and polyethylene (three layers). The dimensions of the moulds will govern the dimensions of the sheets obtained, which will be surface-smoothed for flattening and squaring, giving rise to new reutilizable wastes. <IMAGE>
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