Abstract: Waste from stretch wrap films is recycled into non-blocking films useful as bags and liners as well as in food applications, by incorporating a polymer which contains cross-linked rubber particles, such as high impact polystyrene or an EPDM elastomer. The recycled films may include up to about 50 percent recycled stretch wrap with LLDPE and up to about 10 percent of the third polymer. The films may be single layer extrusions or multi-layer (A/B, A/B/A) coextrusions.

Abstract: In accordance with the invention a linear low density polyethylene is coextruded with a composition containing a LDPE and/or HDPE. The product film exhibits substantially no melt fracture and no surface defects.

Abstract: Recycling polyolefin material, e.g. biaxially oriented polypropylene film, coated with a chlorine-containing polymer, such as polyvinylidene chloride homopolymer and/or copolymer, and having a primer therebetween. First, a caustic solution is formulated containing from about 0.1 wt. % to about 50 wt. % caustic, and from about 0.05 wt. % to about 1.0 wt. % of a wetting agent. The formulated caustic solution is heated to a temperature from about 25.degree. C. to about 140.degree. C. The polyolefin material is soaked in the heated caustic solution until the material is separable from the chlorine-containing polymer. After separating the polyolefin material from the chlorine-containing polymer, the material is reprocessed into desired product by extrusion, molding or other product forming process.

Abstract: A method for extruding polypropylene containing vinylidene chloride polymers (PVdC). According to the present invention, the polymers are extruded using extrusion equipment coated with a fluoropolymer. This method improves the processability, alleviates thermal degradation of the PvdC, improves the extrudate quality by reducing discoloration and voids in surfaces of the extruded product and protects the equipment by reducing the corrosive wear.

Abstract: There are disclosed opaque, biaxially oriented polymeric film structures each comprising a thermoplastic polymer matrix material, e.g., polypropylene, within which is located a stratum of voids, and positioned within each of at least a substantial number of the voids is at least one spherical void-initiating solid particle (i.e., a cavitating agent) of cross-linked polystyrene (CLPS) which is phase-distinct and incompatable with the matrix material, the volume of the particle being substantially less than the volume of the void, with one generally cross-sectional dimension of the particle at least approximating a corresponding cross-sectional dimension of the void.Also disclosed is a method of preparing the foregoing film structure by extruding into a film a combination of the matrix material and CLPS particles dispersed therein, and biaxially orienting the film either simultaneously or sequentially.

Abstract: There are disclosed opaque, biaxially oriented polymeric film structures each comprising a thermoplastic polymer matrix material, e.g., polypropylene, within which is located a stratum of voids, and positioned within each of at least a substantial number of the voids is at least one spherical void-initiating solid particle (i.e., a cavitating agent) of cross-linked polystyrene (CLPS) which is phase-distinct and incompatible with the matrix material, the volume of the particle being substantially less than the volume of the void, with one generally cross-sectional dimension of the particle at least approximating a corresponding cross-sectional dimension of the void.Also disclosed is a method of preparing the foregoing film structure by extruding into a film a combination of the matrix material and CLPS particles dispersed therein, and biaxially orienting the film either simultaneously or sequentially.

Abstract: Head pressure and extruder torque in the extrustion of linear ethylene polymers such as linear low density polyethylene (LLDPE) are reduced by adding a small amount (less than 5 weight percent) of a thermoplastic polyurethane. Films extruded from the blend exhibit better surface appearance by reduction of melt fracture.

Abstract: A method for the extrusion of polyethylene resins, especially linear low density polyethylene resins and; more particularly, a method of high shear extrusion through the intermediary of which the frequently encountered melt fracture; for instance, such as the sharkskin melt fracture of linear low density polyethylene can be either reduced or even completely eliminated by effecting the extrustion at a high shear rate or shear stress over the lip section of a tubular or sheet extrusion die.

Abstract: LLDPE films having excellent anti-block properties are disclosed which comprise a blend of LLDPE and vulcanized ethylene-propylene elastomer in the absence of additional antiblock additives, the amount of said vulcanized ethylene-propylene elastomer in said blend being sufficient to result in a film having a blocking force, when measured by ASTM method D-3354, of less than about 100 grams.

Abstract: The extrudability of linear polymers of ethylene such as low density copolymers of ethylene and C.sub.4 --C.sub.10 olefins (LLDPE) into thin films is improved by adding small amounts, e.g., 0.02 to 2 weight percent ethylene-vinyl polymer to reduce melt fracture, head pressure and to obtain films having excellent anti-blocking characteristics. Optionally, diatomaceous earth is added to further reduce blocking.

Abstract: Terblends of a major proportion of LLDPE (linear low density polyethylene) and minor amounts of LMW-HDPE (high density polyethylene of low molecular weight) and of HMW-HDPE (high density polyethylene of high molecular weight) give blends which are processable at higher rates, give lower extruder back-pressure and result in films generally superior to those made from LLDPE alone.

Abstract: Composition and films of linear ethylene polymers such as linear low density polyethylene containing up to about 3 weight percent of a blend of polyphenylene oxide and styrene resin exhibit excellent physical properties particularly impact strength.

Abstract: The processability of blends of linear polyolefins (particularly HDPE or LLDPE) and condensation polymers (particularly nylon) into extrudates is improved by the addition of small amounts of a fatty acid derivative such as fatty acid amide. The addition of fatty acid derivative results in reduced extruder torque and gives extrudates with smoother surfaces.

Abstract: The extrudability of linear polymers of ethylene such as low density copolymers of ethylene and C.sub.4 -C.sub.10 olefins (LLDPE) into thin films is improved by adding small amounts, e.g., 0.02 to 1 weight percent polyacetal fluoride to reduce melt fracture, head pressure and extruder torque.

Abstract: Polymer blends comprising a continuous matrix phase of thermoplastic polymer with a discontinuous phase of thermoplastic polymer distributed through it are produced by extruding a blend of immiscible thermoplastic polymers through an annular extrusion die which subjects the polymer blend to transverse shear forces prior to passing through the die lips. The application of the shear forces to the polymer blends produces improved uniformity of distribution of the continuous phase within the matrix, producing better properties in the finished article which may be a blown film or a blow molded product. The continuous matrix phase is suitably a polyolefin such as polyethylene and the discontinuous phase may be selected to provide the desired properties in the extruded article, for example, vapor barrier properties, strength, stiffness, and tear resistance. Typical polymers for the discontinuous phase are polyamides, EVA copolymers, polyacrylonitrile, polystyrene and various copolymers.

Abstract: A die geometry which reduces the incidence or degree of melt fracture in the extrusion of linear polyethylene homopolymers and/or copolymers is described.

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

Abstract: A resin composition is disclosed which comprises a blend of from about 40 to about 95 percent by weight thereof of a first polymeric component and from about 50 to about 5 percent by weight thereof of a second polymeric component, the blend being characterized by an interior region containing a disproportionately higher content of first polymeric component and an exterior region containing a disproportionately higher content of second polymeric component, the first polymeric component being selected from the group consisting of amorphous homopolymer of styrene or lower alkyl substituted styrene and amorphous copolymer of styrene and/or alkyl substituted styrene containing up to about 40 weight percent thereof of at least one other olefinic monomer copolymerized therewith and the second polymeric component being selected from the group consisting of crystalline homopolymer of propylene and crystalline copolymer of propylene containing up to about 30 weight percent thereof of at least one other olefinic monomer

Abstract: Beautifying patterns on the surface of extruded polymer products are produced by forcing molten polymer through a die which is coated with a controlled pattern of low surface energy material. Melt fracture of the polyethylene as it emerges from the die is produced at gaps in the coating material which may be silicon, inorganic or fluorine containing polymers.

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.