摘要:
A coextruded liquid crystal polymer ("LCP") film or sheet wherein a higher melting LCP layer is laminated to a lower melting LCP layer. These LCP components are coextruded from the same die. This film or sheet may then be laminated onto other materials at a temperature between the melting point of the lower-melting LCP and the higher-melting LCP, so that the latter LCP may maintain its shape, orientation, and mechanical characteristics while the lower-melting LCP component flows and bonds with the other material. When the higher-melting LCP layer is sandwiched between two lower-melting layers, the film or sheet may be laminated on two sides thereof.
摘要:
A flexible foamed liquid crystal polymer film or sheet having uniformly small cells or bubbles. The foam cells are essentially spherical and have mean diameters less than or equal to approximately 250 microns. The cell size distribution is relatively small. The foamed sheet is made by extruding the polymer through a die under pressure at a temperature near or below the polymer's melting point; a gas or chemical blowing agent is extruded with the polymer to produce foaming as the polymer exits the die.
摘要:
A process for producing LCP films that have improved tear resistance, improved balance of physical properties, and relatively wrinkle-free surfaces. An annular co-extrusion die is used to line the LCP with one or more surface layers of a nonadherent polymer before the LCP becomes shear oriented. The multi-layer tube formed by the co-extrusion is sealed, stretched and cooled by passing it over a sizing mandrel. The tube is slit open into a flat configuration.
摘要:
An improved apparatus and method for calendering of thermoplastic material are disclosed. An endless belt is interposed between the calendered material and the last calender roll which belt conveys the thermoplastic calendered sheet around the last calender roll and toward the stripper roll. The thermoplastic calendered sheet does not come into contact with the final calender roll surface. After cooling the film should strip easily off the endless belt. Consequently, problems originating in sheet adhesion to the final calender roll will be reduced if not eliminated.
摘要:
The present invention relates to polymer structures such as thermoplastic films having improved aroma barrier properties and methods for making the polymeric structures, which may be in the form of a resealable container. Aroma barrier is improved by incorporating a barrier layer of polymeric material including at least about 10 mole percent of polymerized cyclo-olefin moieties.
摘要:
A melt-blended polyethylene/COP composition suitable for making optically clear films with low coefficients of friction includes from about 70 to about 98 weight percent of a polyethylene resin and from about 2 to about 25 weight percent of a first COP resin component, the first COP resin component having a weight average molecular weight of from about 0.5 kg/mol to about 50 kg/mol and being present in an amount effective to increase the relative slip value of films made from the composition as compared with a like film made from the polyethylene resin alone.
摘要:
A method and apparatus providing improved Christmas tree lights. A strand of Christmas tree lights is encapsulated in a thin translucent film of polymer.
摘要:
A process for treating a liquid crystal polymer film which includes the steps of: heating a film obtained by extrusion molding of a liquid crystal polymer, while contacting at least one surface of the film with a supporting body, to melt the polymer; cooling the melted polymer to form a solidified polymer layer; and separating the solidified polymer layer from the supporting body. The process readily provides liquid crystal polymer films having excellent resistance to intra-layer delamination and high tensile strength and elongation, as well as excellent resistance to abrasion, dimensional stability when heated, and resistance to folding.
摘要:
A coextruded film comprising a transparent polymeric inner core layer of thickness less than 250 micron and two peelable outer polymeric layers. In a preferred embodiment, a 50 micron COC core film produced by this technique has a haze of ≦0.5%.
摘要:
The present invention relates to a heat-sealable film which consists essentially of a cycloolefin copolymer (COC), the glass transition temperature (Tg) of the COC being within the range from 30 to 55° C. The film or sheet has excellent low temperature heat-sealing properties and processing characteristics. The film may be free standing or laminated to other thermoplastic polymer film or films at low temperatures. Alternatively, a COC polymer with Tg in the range 30 to 55° C. may be coextruded with other thermoplastic polymer or polymer films in a coextrusion process to form a heat sealable film. The film of the invention is suitable for packing foods or other consumable items.