Abstract: The present invention relates to a process for preparing pre-expanded articles of a polyolefin resin wherein a blowing agent is incorporated into the polyolefin resin in an amount of 45 to 90 parts by volume with respect to 100 parts by volume of the resin and the pre-expansion is carried out at a temperature in the range of from Tm -35.degree. C. to Tm -20.degree. C., or a second external pressured gas which facilitate the impregnation efficiency of the blowing agent is further introduced in an amount of expressing an additional pressure more than 10 kg/cm.sup.2 with the blowing agent. Also, the present invention relates to pre-expanded articles of a polyolefin resin produced by the above process.

Abstract: A tenter frame clip which is at least partially constituted from a lightweight polymeric composite material. The clips are employed in tenter frames as components of clip-chain assemblies for grippingly engaging and advancing thermoplastic film webs, fabrics or foils through the tenter frame as the web is concurrently transversely stretched, and for the most part, are generally constituted from either cast iron or cast steel, depending upon the type and size of tenter frame may each readily weigh as much as five pounds, and even higher. The clips are usually extremely strong and tough in their construction and are each able to exert a gripping force of up to 1500 to 2500 pounds.

Abstract: A thermoplastic material web is stretched transverse to the machine direction along a stretch course which widens exponentially in the stretching zone, an improved stretching apparatus being used to effect such stretching.

Abstract: Terblends of linear low density polyethylene resins provide enhanced processability and improved output without losing overall film properties.

Abstract: The properties of linear ethylene polymers, especially linear, low density polyethylene (LLDPE), are improved by adding a chemically modified ethylene polymer to the base resin. The modification is brought about by the use of a free radical generator, preferably an organic peroxy compound such as benzoyl peroxide, optionally with an unsaturated silane such as vinyl trimethoxy silane. The use of the modified resin masterbatch enhances the crystallization of the polymer and improves the melt strength of the polymer, providing greater bubble stability in the blown tubular film extrusion process so that higher operating speeds may be employed. In addition, the films produced from the blends have improved antiblocking properties without significant deterioration of mechanical properties.