Herstellung einer poroesen Struktur aus thermoplastischen Polymeren

NOVELTY - To sinter polymers with narrow melting temperature range and high melt index, at least two different portions of similar polymer type with differing melting properties are employed. DETAILED DESCRIPTION - Different types of polymer may be used and mixed together. One type coats the other, the former having the lower melting temperature range. Portion(s) may be mixed with radiation-absorbent additive. A portion is co-extruded and/or granulated. The portion with the lower melting temperature range lies outside. USE - To sinter or meld plastics of the same type with a high melt index and narrow melting temperature range, forming a porus structure. A wide range of filter materials is cited. ADVANTAGE - If a plastic with narrow melting temperature range is heated, it is likely to collapse suddenly into a liquid, rendering sintering attempts futile. Using two types of the same plastic, which have different melting behavior, ensures one softens before the other; ideal for sintering. Given good mixing, a very uniform product results.