| 摘要 |
<p>Polymeric modifications for thermoforming applications in conventional equipment, understanding as such those that have not been designed or modified specially for the thermoforming of polypropylene, in which the modified polymer is an isotactic homopolymer polypropylene and the modifying polymer is high density polyethylene, understanding as such ethylene homopolymers and ethylene copolymers and alpha-olefins of a density equal or larger than 0.935 gr/cm3. The modifying polymer has a fluidity index, measured according to ISO-1133 standard at 190 DEG C and 21.6 kg, inferior to 50 gr/10 min and a proportion between 5 and 25 % in weight. This modification can be done by means of mixing both fused components in high shear polymer mixing equipment, such as mixing rollers, internal mixers, double spindle extruders, etc., all of which are well known and extensively used in the thermoplastic polymer industry. The polypropylene thus modified has properties that are essentially the same as unmodified polypropylene, and presenting the characteristic that it can be molded in conventional thermoforming equipment, with a wide range of process conditions and operating in a continuous manner, a fact that is not possible with unmodified polypropylene.</p> |
