Abstract: An apparatus for controlling the thickness of a film molded by a melt extruding method provided with a plurality of cooling means for cooling the vicinity of a die lip close to a plurality of heating means and with many grooved holes in which the heating means are embedded and provided with air holes at the both ends thereof, whereby the temperature can be freely adjusted to the high and low set values in a short period of time, by which the time loss and material loss can be reduced.

Abstract: A method of providing uniform thickness of a synthetic resin film upon molding of the synthetic resin film with a die having a plurality of heating elements arranged adjacent a die lip of the die. The thickness of a film molded by the die is measured by cutting a sample of the molded film in a direction perpendicular to the direction of drawing of the film, and measuring the thickness of the sample in the direction of cutting with a film thickness measuring device. The measured values are then fed to an arithmetic unit. At the arithmetic unit, a corresponding relationship is calculated, based on the measured film thickness values, between a one-sided material portion of the film and the plurality of heating elements, and amounts of heat to be generated by the corresponding heating elements are individually controlled in accordance with the relationship.

Abstract: Disclosed herein is a cooling/guiding method and a cooling/guiding apparatus that will be used when a film of a thermoplastic synthetic resin or the like is to be produced by the inflation method or the T-die method.According to the invention, a thermoplastic synthetic resin film is continuously passed through a section constituted by a single or a plurality of air-introducing members having air intake ports, the air surrounding said film is vacuumed by said air-introducing members so that the pressure differential imparted to the film is balanced, and the film is guided into a predetermined path under the condition where the film is separated away from the air-introducing members.Therefore, the apparatus cools and guides the film without coming into contact thereto, and without cooling the film irregularly and without marring the film, making it possible to markedly increase the film-forming speed and quality of the film.

Abstract: A cooling and guiding device for continuous tubular thermoplastic synthetic resin films comprises a support ring, and another ring which is vertically spaced from the support ring, one of the rings being rotatable relative to the other; each of a plurality of flexible conduits has one end connected to the support ring and its other end connected to the other ring, and each has a gas connection to a source of gas under pressure. The rings and conduits form an envelope the minimum diameter of which can be adjusted by relative rotation of the rings to accommodate a tubular film passing through the envelope; and each of the conduits has a series of orifices extending throughout the length of the conduit and arranged to direct gas jets against the exterior of such a tubular film to cool the film and to prevent the film from coming in contact with the envelope.

Abstract: To the end of producing high quality film from thermo-plastic resin through inflation molding, there is provided an air ring which has a plurality of slits for guiding cooling air therethrough onto the film. These slits are defined by a plurality of frusto-conical channel defining bodies which are arranged like a set of nested boxes and are provided with different exit angles at their outlets. Through appropriate distribution of the air outlets for cooling the film, a uniform inflation molding becomes possible, allowing a greater molding speed at the same time. The broader ends of the channel defining bodies are mutually threaded in such a manner that they may be independently adjusted along an axial direction. With additional provision of a retractable annular plate at the outlet of a main cooling air channel and proper adjustment of the channel defining bodies, the air ring may be adapted to molding dies of different diameters.

Abstract: The upper and lower ends of numbers of curved cooling pipes are rotatably supported in the variable-type bubble water cooling apparatus according to the present invention. The cooling water is supplied to the pipes. The diameter of enveloping circle formed by these curved cooling pipes at a determined horizontal position is varied by relatively rotating the upper and lower support members of pipes. Thus, as the diameter of bubble passing portion of the apparatus can freely be varied, bubbles of variety of sizes can be produced by a single apparatus. Also, the cooling effects and positions are constant and the produced bubble has no unevenness of its thickness.