| 摘要 |
A process for eliminating in plastic materials odour/taste-producing substances is described, the plastic material especially having the shape of water pipes, plastic containers or plastic film/sheeting for packing foodstuffs and pharmaceutical prepara- tions, or interior fittings of plastic. In the process, there is added, duri ng processing in the molten state, less than 0.5 wt.-%, prefer- ably 0.05-0.3 wt.-%, of a substantially hydrophobic aluminium silicate molecular sieve having a pore diameter of at least 5.5 .ANG., ans Si/Al molar ratio in the crystal lattice of at least 35, preferably 200- 500, and a sorption capacity for water at 25 .degree. C and 4.6 torr of less than 10 wt.-%, to the plastic material which subsequently is formed. The molecular sieve preferably has an average particle size not exceeding about 5 .mu.m. The plastic material is a polyolefin plastic and is preferably selected among ethylene plas- tics and propylene plastics.
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