Abstract: A laminated polyester film in which a coating layer whose main constituent component is a water-soluble or water-dispersible resin is provided on at least one side of a polyester film, wherein the water resistance value of the film is at least 90%, the discoloration after melt molding is no more than 10, and the haze value change after heating is no more than 20%. Adhesion, water resistance, recoverability, and whitening resistance after heating are all excellent.

Abstract: A porous thermoplastic resin film capable of functioning well as a separator of a cell is provided. The porous film is constituted with a thermoplastic resin and a filler, wherein XR defined by the following formula: XR=25×TGUR×d2/Y is smaller than 5, where Y(&mgr;m), TGUR (sec/100 cc), and d (&mgr;m) represent the thickness, the gurley value, and the average pore diameter of said film, respectively. The porous film constructed as shown above can reduce the internal resistance of a cell when used as a separator of the cell.

Abstract: A microporous film of polyethylene having an intrinsic viscosity above 5 dl/g is prepared from a homogeneous solution in an evaporable solvent. The film is cooled and evaporable solvent is evaporated at a temperature below the dissolution temperature. The film is stretched to produce the micorporous film and is passed through a calender. The microporous films with a porosity of up to about 70% by volume and a battery separator quality factor (F) of at least 2.5 are described. Battery separators formed from the microporous films are also described.

Abstract: Crystalline polymers are drawn using pressurized saturated steam having an absolute pressure of at least 2.0 kg/cm2 as a drawing medium. The steam is charged into an airtight container having a drawable material inlet for feeding a drawable material and a drawn product outlet for withdrawing a drawn product. Pressurized water is utilized to prevent leakage of the pressurized saturated steam through the inlet and outlet and to cool the drawn product, so that the product formed of a crystalline polymer has improved physical properties.

Abstract: The object of the present invention is to provide a method for producing a polyester film excellent in rigidity, toughness, dimensional stability, electric properties, etc. and less in thickness fluctuation and surface defects, hence very suitable as a film for various industrial materials such as magnetic recording media, capacitors, heat transfer ribbons and thermal mimeographic stencil paper. The first method of the present invention is a method for producing a polyester film, in which a film made of a resin mainly composed of a polyester is simultaneously biaxially stretched by a simultaneously biaxially stretching tenter oven, comprising the step of effecting small-ratio stretching at an area stretching ratio of 1.0005 to 3.

Abstract: A biaxially oriented polyester film whose thermal shrinkage factors satisfy relationships represented by the following expressions (1) to (5) at the same time when it is heated at 120° C. for 20 seconds: 0.001≦SMD≦0.1  (1) −0.1≦STD≦0.1  (2) −0.05≦S45≦0.05  (3) −0.05≦S135≦0.05  (4) |S45−S135|≦0.05  (5) wherein SMD is a thermal shrinkage factor (%) in machine direction of the film under the above conditions, STD is a thermal shrinkage factor (%) in a direction perpendicular to that direction under the above conditions, and S45 and S135 are thermal shrinkage factors (%) in a 45° direction and a direction perpendicular to the 45° direction under the above conditions when the machine direction of the film is 0° and a direction perpendicular to that direction is 90°, respectively, and a production method thereof.

Abstract: The present specification discloses a plastics material film (1) that is stretched beyond its yield point to about 100% to 400% elongation and thereafter only partially relaxed to release part of the elastic deformation component in the film to retain between about 20% and 80% of the elastic deformation in the film (1), the film thereafter being stored in this partially relaxed state whereby, when it is used, the retained elastic deformation capability is useable for the intended purpose of the film, for example, wrapping a load.

Abstract: A method of biaxially stretching a polymeric film along an overbias stretch profile having the steps of (a) imparting a sufficiently high temperature to the film to allow a significant amount of biaxial stretch; and (b) biaxial tenter stretching the film to a final first direction stretch parameter and a final second direction stretch parameter, wherein at least 75% of the final first direction stretch parameter is attained before no more than 50% of the final second direction stretch parameter is attained, and wherein the final first direction stretch parameter is no greater than the final second direction stretch parameter.

Abstract: Reformation techniques and apparatus. Typically employed to permit separate printing and finishing of multiple webs of paper, these techniques and apparatus utilize or provide heat and, in some cases, initial tension, to change dimensions (including repeat length) of the paper of one or more webs. Webs dimensionally-reformed in accordance with the techniques typically do not require subsequent variation of tension to maintain appropriate dimension, permitting any such tension variation to occur solely to enhance other aspects of the finishing processes.

Abstract: A method of biaxially stretching a polymeric film according to an overbias or overstretch stretch profile to a final first direction stretch parameter and a final second direction stretch parameter to provide a film having uniform properties. First, a sufficiently high temperature is imparted to the film to allow a significant amount of biaxial stretch. The film is then biaxially tenter stretched to a peak first direction stretch parameter that is at least 1.3 times the final first direction stretch parameter wherein the final first direction stretch parameter is no larger than the final second direction stretch parameter. Finally, the film is retracted in the first direction from the peak first direction stretch parameter to the final first direction stretch parameter to produce a film having uniformity of properties in the first direction.

Abstract: An apparatus and method for heat setting a traveling tow of synthetic filaments utilizing a high pressure dewatering nip roll mechanism to remove moisture from the tow prior to heat setting. The high pressure dewatering nip roll mechanism includes a pair of nip rollers exerting a pressure of between about 500 and 2000 pounds per linear inch of transverse nip contact on the traveling tow prior to the tow entering a heat setting apparatus such as a calender apparatus. Moisture content of the traveling tow is reduced to less than 10% moisture by weight and preferably less than 5%. Reducing the moisture content of the tow prior to heat setting reduces the energy required to heat set the tow and, contrary to the prevailing wisdom in the art, does not damage the unheat set filaments of the tow.