Abstract: A printable, biaxially oriented polyolefin multilayer film which is low-temperature sealing on both sides and comprises a base layer and at least one sealing layer on each side of the base layer, the base layer containing a peroxide-degraded propylene homopolymer and each sealing layer containing an ethylene/propylene/butylene terpolymer and a propylene/butylene copolymer, one outer sealing layer containing a polydiorganosiloxane and silicon dioxide particles and not being corona-treated and the polydiorganosiloxane being added in the form of a masterbatch during the film production, results in a multilayer film especially useful as a packaging film.

Abstract: A transparent shrink film made from propylene useful for all-round labeling of essentially cylindrical containers, such as bottles, comprises a propylene polymer and has, at 100.degree. C., a shrinkage in the longitudinal direction of at least 10% and a shrinkage in the transverse direction of less than 2%. A process for producing the film is also provided.

Abstract: A polypropylene multilayer, coextruded, transparent, and metallizable film which has isotropic mechanical properties and contains a low-molecular-weight hydrocarbon resin and an antistatic agent in the base layer and an antiblocking agent in the outer layer is described. The film is free from lubricants in the outer layers. The invention furthermore relates to a process for the production of such films and to their use as, for example, packaging films or twist wrapping.

Abstract: A multilayered, white, biaxially-oriented polypropylene film is disclosed. The film has an at least three-layered build-up and has a base layer comprised of propylene polymers comprising up to 2% by weight of calcium carbonate having an average particle size of not more than 2.0 .mu.m and 0 to 25% be weight of titanium dioxide, an intermediate layer comprised of propylene polymers comprising 0 to 25% by weight of titanium dioxide, relative to the total weight of the intermediate layer; and a top layer comprised of a sealable raw material. The base layer and/or the intermediate layer of the film contain a total of at least 2% by weight of titanium dioxide.

Abstract: The present invention relates to a transparent, coextruded, multi-layer polyolefin film which is heat-sealable on both sides and has a base layer which comprises a peroxidically degraded polypropylene polymer and top layers which comprise heat-sealable ethylene-propylene polymers. The multi-layer film is characterized by high shrinkability in the longitudinal and transverse directions, in combination with excellent optical properties and good runability on high-speed wrapping machines and is especially useful as a packaging or wrapping film. The invention also relates to a process for the preparation of a film of this kind and to its use.

Abstract: A non-sealable, multi-layer polypropylene film which includes on top of a polypropylene base layer at least one top layer which includes a mixture of a propylene/butylene copolymer and an ethylene/propylene/butylene terpolymer, the mixture containing ethylene in an amount of about 0.1 to 7% by weight, propylene in an amount of about 68 to 95.9% by weight and butylene in an amount of about 4 to 25% by weight, relative to the total weight of the mixture. The layer thickness of the toplayer is not greater than 0.3 .mu.m. A process for producing the film is also described.

Abstract: A transparent, coextruded multilayer polyolefin film which is heat-sealable on both sides and has a base layer essentially comprising propylene polymers and outer layers essentially comprising heat-sealable olefin polymers is described. The propylene polymer of the base layer has been peroxidically degraded, its degradation factor A being in the range of about 3 to about 10. The heat-sealable olefin polymer of the outer layers is an ethylene-propylene copolymer having an ethylene content in the range of about 2 to about 8% by weight which has also been peroxidically degraded. Its degradation factor A is in the range of about 3 to 15. The film is useful as, for example, a packaging film.

Abstract: A shrink film which is comprised of a plurality of polyolefinic layers is disclosed. The base layer comprises polypropylene and a hydrogenated hydrocarbon resin admixture, and the top layers on each side of the base layer comprise polyolefinic sealable raw materials. The film possesses a shrinkability of more than 15% in the transverse direction and of less than 6% in the longitudinal direction, both measured at 90.degree. C. Also disclosed is a process for manufacturing the film comprising coextrusion followed by stretching of the film in the longitudinal and transverse directions, whereby stretching in the longitudinal direction is performed such that the double refraction value .DELTA.n of the longitudinally oriented film is not greater than 15.times.10.sup.-3.

Abstract: Described is a transparent shrinkable film comprising a base layer prepared from propylene-containing polymers and a hydrocarbon resin. The base layer contains about 5% to 40% by weight of a propylene homopolymer, 0% to about 30% by weight of a hydrogenated hydrocarbon resin having a softening point in the range from about 80.degree. to 125.degree. C., and about 30% to 95% by weight of a random ethylene-propylene copolymer, the percentages being related to the total weight of the mixture. A top layer is arranged on either side of the base layer. The invention also describes a process for the manufacture of the film.

Abstract: A shrink film comprising at least one polyolefinic layer comprising polypropylene and a resin admixture is disclosed. The film processes a shrinkability of more than 20%, measured at 90.degree. C., in the transverse direction and of less than 8%, also measured at 90.degree. C., in the longitudinal direction. The film is manufactured by coextrusion followed by stretching in the longitudinal and transverse directions, whereby stretching in the longitudinal direction is performed such that the birefringence value .DELTA.n of the longitudinally oriented film does not exceed the range from 10.times.10.sup.-3 to 13.times.10.sup.-3.

Abstract: A molten film extruded from a slot die onto a take-off drum in a cooling system is first cooled on the circumferential surface of the take-off drum and by the ambient air, is subsequently passed into the water bath of a water trough in which the take-off drum is immersed, and finally is transferred from the water bath of the water trough into a post-cooling water bath, in which the film solidifies to an intermediate film having a desired final temperature of approximately 40.degree. C. When the film leaves the take-off drum, the partially solidified molten film has a mean temperature T.sub.u of between 100.degree. C. and 120.degree. C. For optimization of the dwell time of the molten film in the cooling system and in the post-cooling water bath, the drum diameter D of the take-off drum and the length L of the post-cooling water bath are determined by a specific relationship.

Abstract: A filter apparatus is provided comprising a number of cylindrical candle filters, each of which contains a displacement body forming a space of uniform width between itself and the candle filter. The filter material of the candle filter is supported by a cylindrical supporting body which has passages through which a plastic melt to be filtered can flow. A number of filter apparatuses can be arranged on concentric circles on a cylindrical filter housing so as to minimize the dwelling time of the plastic melt flow through the filters and to minimize the pressure loss over the length of the filters.

Abstract: In the process for the production of thin, biaxially stretched films from polypropylene, the latter is melted in an extruder and extruded from a slot die over the surface of a take-off roll. The plastic melt cooled on the surface of the take-off roll into an intermediate film is temperature-treated in the region of the take-off roll in a zone and the intermediate film is subsequently biaxially stretched and heat-set in a known way. At a take-off roll temperature T.sub.W of between 10.degree. C. and 100.degree. C., blowing air of a temperature T.sub.L greater than/equal to 30.degree. C. is blown onto the film surface on the air side not in contact with the circumferential surface of the take-off roll, the duration for this temperature treatment being at least 1.5 seconds.

Abstract: A process for the preparation of a biaxially stretch-oriented film having at least one opaque layer is described. The opaque layer is composed essentially of propylene polymer and fillers in a quantity of about 10 to 40% by weight, relative to the total weight of propylene polymer and fillers. In production, the granules are melted in a screw extruder, are forced through a die and are formed by cooling to give a preformed film. The preformed film is then stretch-oriented both along the machine direction and transversely perpendicular to the machine direction and is then heat-set. The fillers are added in the form of a masterbatch to the granules of unfilled polymers. The masterbatch should have a filler content of more than about 30% by weight.

Abstract: Disclosed is a screw extruder comprising a feed bush having a screw extruder coaxially mounted therein, and which, around its circumference, is provided with several longitudinally extending grooves distributed evenly in the circumferential direction. Adapters are disposed in the grooves which can be adjusted radially in the grooves relative to the extruder screw with the aid of adjustment mechanisms. Each adapter is connected to several bolts connected over the length of the adapter. The bolts pass through holes in the feed bush and are surrounded by helical springs, each of which is supported on the one side against a collar of the bolt and on the other side against a face of the hole. The bolts are of one-piece or two-piece design and may include at the outer bolt ends, rollers which are pressed against cam rings or a cam segment, which surround the extruder barrel in annular or semi-annular shape.