The present invention relates to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby and, particularly, to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby, wherein the polyimide-based film is useful as a cover substrate for a flexible electronic device since flexure characteristics thereof, represented by yield elongation, are excellent.

A design method of a metal mask, a manufacturing method of the metal mask and a computer-readable storage medium are provided. The design method of a metal mask includes: calculating amounts of deformations of the metal mask in two directions perpendicular to each other based on a stretching force of the metal mask in use and deformation properties of the metal mask in the two directions; and compensating the deformations of the metal mask in the two directions by compensation amounts for the deformations, which are identical and opposite to the amounts of the deformations of the metal mask in the two directions, respectively.

A system for controlling the temperature of a film before and/or during application, the system including: a heat source for heating a film; and stretch rollers; wherein the heat source heats the film from an ambient temperature to a temperature from about 2° C. to about 40° C. above the ambient temperature, wherein the film is heated prior to or simultaneous to being stretched by the stretch rollers, and wherein the ambient temperature is below 15° C. The preheating system may be used to enhance binding and sealing properties of stretch films used for wrapping palletized products in a reduced temperature environment. Other embodiments of the preheating film system, and methods for its use, are described herein.

The method includes unwinding a thermoplastic film from a roll, stretching the thermoplastic film in the machine direction so that it plastically deforms and decreases in width, slitting the stretched thermoplastic film into the multiple mechanical fastening strips, and winding the multiple mechanical fastening strips into multiple rolls. The thermoplastic film has a first surface and a second surface opposite the first surface, and the first surface of the thermoplastic film bears a plurality of male fastening elements. In the method, the unwinding, stretching, slitting, and winding are completed in-line.

One aspect of the present invention provides a stretching apparatus for manufacturing a separator including a first stretching machine and a second stretching machine arranged in parallel with each other, in which the first stretching machine includes a plurality of first unit sections having different stretching ratios, and the second stretching machine includes a plurality of second unit sections having different stretching ratios, the overall stretching ratio by each of the first stretching machine and the second stretching machine is the same each other, and at least one stretching ratio of the first unit section and at least one stretching ratio of the second unit section are different from each other and a method of manufacturing a separator using the same.

A system for controlling the temperature of a film before and/or during application, the system including: a heat source for heating a film; and stretch rollers; wherein the heat source heats the film from an ambient temperature to a temperature from about 2° C. to about 40° C. above the ambient temperature, wherein the film is heated prior to or simultaneous to being stretched by the stretch rollers, and wherein the ambient temperature is below 15° C. A system for improving the application of film by transfer of electrostatic charge is also described. The preheating system and/or electrostatic charge system may be used to enhance binding and sealing properties of stretch films used for wrapping palletized products in a reduced temperature environment. Other embodiments of the preheating film system and electrostatic charge system, and methods for their use, are described herein.

Printed, breathable thermoplastic films, laminates, and methods of making films having a basis weight less than or equal to 15 gsm and a water vapor transmission rate of at least about 500 grams H.sub.2O/24-hour/m.sup.2, wherein the film has a ratio of the MD load at break to the CD load at break of less than about 10, and at least one of a machine-direction notched Elmendorf tear strength of at least about 5 g or a machine-direction notched trapezoidal tear strength of at least about 15 g.

A method includes applying a stress to a polymer thin film to stretch the polymer thin film along a first in-plane direction, and subsequently applying a stress to the polymer thin film to stretch the polymer thin film along a second in-plane direction orthogonal to the first in-plane direction to form an ultra-high modulus polymer thin film. Calendaring or hot pressing of the ultra-high modulus polymer thin film may improve its optical and/or thermal properties.

An UHMWPE film having a tensile strength of at least 2.0 GPa, a tensile energy to break of at least 30 J/g, an Mw of at least 500 000 gram/mole, and a Mw/Mn ratio of at most 6, and a film width of at least 5 mm. The film may be manufactured via a process which comprises subjecting a starting UHMWPE with a weight average molecular weight of at least 500 000 gram/mole, an elastic shear modulus determined directly after melting at 160° C. of at most 1.4 MPa, and a Mw/Mn ratio of at most 6 to a compacting step and a stretching step under such conditions that at no point during the processing of the polymer its temperature is raised to a value above its melting point. The film may be used as starting material in any applications where high tensile strength and high energy to break are important. Suitable applications include ballistic applications, ropes, cables, nets, fabrics, and protective applications.

A method of producing an optical panel assembly including the polarizing film in a continuous manner by laminating a polarizing film to a surface of a rectangular-shaped optical panel, is disclosed. The polarizing film is formed by performing a step of subjecting a laminate including a continuous web of a thermoplastic resin substrate and a PVA type resin layer formed on the substrate, to a 2-stage stretching consisting of a preliminary in-air stretching and an in-boric-acid-solution stretching, to reduce a thickness of the PVA type resin layer to 10 μm or less, and a step of causing a dichroic material to be absorbed in the PVA type resin layer.