Abstract: A polymer film having a thickness of 10 microns or less and improved barrier characteristics to both water vapor and oxygen is formed from a biaxially-oriented polypropylene film of isotactic polypropylene. The polypropylene is prepared by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The film has a permeability to water vapor of less than about 2.5 g/m2 day/25 ?m and a permeability to oxygen of less than about 2200 cc/m2 day/25 ?m. The film also has a haze properties of less than about 1%. The polypropylene contains 0.1 to 1% 2,1 insertions and has an isotacticity of at least 96% meso pentads. The isotactic polypropylene thus produced is then extruded into a sheet that is biaxially-oriented by stressing the sheet in the transverse and longitudinal directions to a draw ratio of at least about 6:1 in the transverse direction, and at least about 4:1 in the longitudinal direction.

Abstract: A polymer film having a thickness of 10 microns or less and improved barrier characteristics to both water vapor and oxygen is formed from a biaxially-oriented polypropylene film of isotactic polypropylene. The polypropylene is prepared by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The film has a permeability to water vapor of less than about 2.5 g/m2day/25 ?m and a permeability to oxygen of less than about 2200 cc/m2day/25 ?m. The film also has a haze properties of less than about 1%. The polypropylene contains 0.1 to 1% 2,1 insertions and has an isotacticity of at least 96% meso pentads. The isotactic polypropylene thus produced is then extruded into a sheet that is biaxially-oriented by stressing the sheet in the transverse and longitudinal directions to a draw ratio of at least about 6:1 in the transverse direction, and at least about 4:1 in the longitudinal direction.

Abstract: A polymer film having a thickness of 10 microns or less and improved barrier characteristics to both water vapor and oxygen is formed from a biaxially-oriented polypropylene film of isotactic polypropylene. The polypropylene is prepared by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The film has a permeability to water vapor of less than about 2.5 g/m2day/25 ?m and a permeability to oxygen of less than about 2200 cc/m2day/25 ?m. The film also has a haze properties of less than about 1%. The polypropylene contains 0.1 to 1% 2,1 insertions and has an isotacticity of at least 96% meso pentads. The isotactic polypropylene thus produced is then extruded into a sheet that is biaxially-oriented by stressing the sheet in the transverse and longitudinal directions to a draw ratio of at least about 6:1 in the transverse direction, and at least about 4:1 in the longitudinal direction.

Abstract: A polymer film having a thickness of 10 microns or less and improved barrier characteristics to both water vapor and oxygen is formed from a biaxially-oriented polypropylene film of isotactic polypropylene. The polypropylene is prepared by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The film has a permeability to water vapor of less than about 2.5 g/m2day/25 ?m and a permeability to oxygen of less than about 2200 cc/m2day/25 ?m. The film also has a haze properties of less than about 1%. The polypropylene contains 0.1 to 1% 2,1 insertions and has an isotacticity of at least 96% meso pentads. The isotactic polypropylene thus produced is then extruded into a sheet that is biaxially-oriented by stressing the sheet in the transverse and longitudinal directions to a draw ratio of at least about 6:1 in the transverse direction, and at least about 4:1 in the longitudinal direction.

Abstract: A heat-seal polymer film and method of forming such film is provided. The heat-seal film is formed from metallocene-catalyzed isotactic random copolymers of propylene and at least one other C2 to C8 alpha olefin, such as ethylene random. Such films show improved heat-seal characteristics, such as reduced seal initiation temperatures (SIT's) and improved heat-seal strength, as well as other improved properties.

Abstract: A polypropylene material is prepared from a blend of heterophasic propylene copolymers and propylene homopolymers. The material is prepared by blending the polymers while they are in a molten state, and forming a film or sheet from the polymer blend. The material has particular application to forming slit film tapes and similar materials. The resultant materials exhibit increased tenacity, elongation and toughness and greater surface roughness as compared to those materials prepared solely from propylene homopolymers.

Abstract: A method for the production of polypropylene fibers from a propylene polymer including isotactic polypropylene produced by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The polymer is heated to a molten state and extruded to form a fiber preform at a temperature within the range of about 170°-210° C. The fiber preform is spun at a spinning speed of at least 200 meters per minute and quenched at a heat transfer rate of no more than 12 joules per second fiber. The spun fiber is then subjected to a winding operation. The fiber may be drawn subsequent to the quenching operation and prior to winding. The cooled fiber preform may be drawn to produce a fiber at a draw ratio within the range of about 1.5-4.0 with shrinkage of the fiber over the range of the draw ratio at a variance of ±25% of the median of the shrinkage factor over the draw ratio.

Abstract: Process for the production of fibers formed from an ethylene-propylene copolymer characterized as a random copolymer of ethylene and isotactic polypropylene having a random ethylene content within the range of 2-12 mole %. The propylene content of the copolymer can have an isotacticity of at least 90% meso diads. The copolymer is heated to a molten state and then extruded to form a fiber preform. The fiber preform is subject to a spinning speed of at least 500 meters per minute. This is followed by drawing the spun fiber preform at a draw ratio within the range of 1:1-6:1 to produce a continuous fiber of the ethylene-propylene copolymer. A specific ethylene-propylene copolymer has an ethylene content within the range of 6-8%.

Abstract: A process for the production and treatment of a stereoregular propylene polymer such as isotactic polypropylene. The isotactic polypropylene can be produced by catalysis employing a metallocene catalyst or employing a Ziegler-Natta catalyst. A polymerization reactor is operated to provide for the reaction of propylene supplied to the reactor to produce a stereoregular propylene polymer fluff. A product stream containing unreacted propylene and the propylene polymer fluff is withdrawn from the polymerization reactor. The product stream is treated to separate at least a portion of the unreacted propylene from the product stream. The polymer fluff is heated to a temperature sufficient to melt the propylene polymer. Incorporated into the propylene polymer fluff in an amount within the range of 0.01-0.08 wt.

Abstract: A polypropylene material is prepared from a blend of heterophasic propylene copolymers and propylene homopolymers. The material is prepared by blending the polymers while they are in a molten state, and forming a film or sheet from the polymer blend. The material has particular application to forming slit film tapes and similar materials. The resultant materials exhibit increased tenacity, elongation and toughness and greater surface roughness as compared to those materials prepared solely from propylene homopolymers.

Abstract: A method for the production of polypropylene fibers from a propylene polymer comprising isotactic polypropylene produced by the polymerization of propylene in the presence of an isospecific metallocene catalyst. The polymer is heated to a molten state and extruded to form a fiber preform at a temperature within the range of about 170°-21° C. The fiber preform is spun at a spinning speed of at least 200 meters per minute and quenched at a heat transfer rate of no more than 12 joules per second per fiber. The spun fiber is then subjected to a winding operation. The fiber may be drawn subsequent to the quenching operation and prior to winding. The cooled fiber preform may be drawn to produce a fiber at a draw ratio within the range of about 1.5-4.0 with shrinkage of the fiber over the range of the draw ratio at a variance of ±25% of the median of the shrinkage factor over the draw ratio.

Abstract: A process for the production and treatment of a stereoregular propylene polymer such as isotactic polypropylene. The isotactic polypropylene can be produced by catalysis employing a metallocene catalyst or employing a Ziegler-Natta catalyst. A polymerization reactor is operated to provide for the reaction of propylene supplied to the reactor to produce a stereoregular propylene polymer fluff. A product stream containing unreacted propylene and the propylene polymer fluff is withdrawn from the polymerization reactor. The product stream is treated to separate at least a portion of the unreacted propylene from the product stream. The polymer fluff is heated to a temperature sufficient to melt the propylene polymer. Incorporated into the propylene polymer fluff in an amount within the range of 0.01-0.08 wt.

Abstract: Process for the production of fibers formed from an ethylene-propylene copolymer characterized as a random copolymer of ethylene and isotactic polypropylene having a random ethylene content within the range of 2-12 mole %. The propylene content of the copolymer can have an isotacticity of at least 90% meso diads. The copolymer is heated to a molten state and then extruded to form a fiber preform. The fiber preform is subject to a spinning speed of at least 500 meters per minute. This is followed by drawing the spun fiber preform at a draw ratio within the range of 1:1-6:1 to produce a continuous fiber of the ethylene-propylene copolymer. A specific ethylene-propylene copolymer has an ethylene content within the range of 6-8%.

Abstract: A heat-seal polymer film and method of forming such film is provided. The heat-seal film is formed from metallocene-catalyzed isotactic random copolymers of propylene and at least one other C2 to C8 alpha olefin, such as ethylene random. Such films show improved heat-seal characteristics, such as reduced seal initiation temperatures (SIT's) and improved heat-seal strength, as well as other improved properties.