Abstract: In an automatic arc welding method for welding metallic materials having a vertically curved weld line, a change in the arc voltage is compared with a arc length setting voltage and the resulting difference signal is used to control the vertical position of a welding torch and hold the same at a predetermined distance from the materials to be welded, while on the other hand in response to a signal generated from an obliquity detector made integral with the torch, the torch is controlled at an angle corresponding to the oblique angle of the materials to be welded and at the same time the welding speed is controlled at a constant value in response to a signal corresponding to the torch angle.

Abstract: The invention provides a novel method for the preparation of a polarizing film or sheet based on a polyvinyl alcohol which is easily prepared and easy to handle. The inventive method comprises first subjecting a substrate film or sheet of a vinyl chloride resin to exposure to low temperature plasma, the surface of the substrate is coated with an aqueous solution of a polyvinyl alcohol and dried so as that a coating layer of the polyvinyl alcohol is formed as firmly bonded to the substrate surface owing to the increased affinity of the surface by the plasma treatment, the thus polyvinyl alcohol-clad substrate is stretched as such unidirectionally and the stretched polyvinyl alcohol layer is treated with iodine to be imparted with a polarizing power. The adhesion between the substrate and the polyvinyl alcohol layer is so strong without an adhesive agent that the difficulty in the prior art in handling fragile stretched polyvinyl alcohol film is completely overcome.

Abstract: A method for reducing static electricity on the surface of a shaped article made of polyvinyl chloride resins, which method comprises the steps of (a) blending a surface active agent with the polyvinyl chloride resin prior to fabrication of the resin into a shaped article, (b) fabricating the resin admixed with the surface active agent into a shaped article, and (c) subjecting the shaped article to a treatment with low temperature plasma of a gas.

Abstract: A method of controlling the synchronized movement of a backing shoe in an automatic one-side welding of the type in which a light-transmittable backing material is placed in close contact with the back surface of the welding joint and a backing shoe adapted to be moved along with the movement of a welding apparatus is pressed through the backing material against the back surface of the welding joint just below a welding electrode whereby effecting the welding. The method employs photoelectric detectors which are embedded in the surface of the backing shoe contacting the backing material at four positions, i.e.

Abstract: A method for preventing bleeding of plasticizers on the surface of shaped articles of plasticized polyvinyl chloride resins. The method comprises the steps of (a) blending a urethane elastomer with the polyvinyl chloride resin together with the plasticizer and other optional additives prior to fabrication of the polyvinyl chloride resin composition into shaped articles, (b) fabricating the resin composition into desired shaped articles, and (c) subjecting the thus shaped article to a treatment with low temperature plasma of a gas. Carbon monoxide is preferred as the gas for the plasma atmosphere.

Abstract: The invention provides an effective method for subjecting the inner surface of a tubular body made of a plastic resin to a treatment with low temperature plasma according to which the tubular body is dipped in an insulating oil bath while the inside of the tubular body is filled with a plasma gas under a reduced pressure and electric power for the generation of a low temperature plasma is supplied to electrodes surrounding the tubular body in the insulating oil. Several of the problems in the prior art methods can be solved by the present invention such as undesirable thermal degradation of the tube surface by the evolved by the electric discharge, and power loss due to the generation of plasma outside the tubular body.

Abstract: An apparatus for automatically welding corrugated membranes of a type in which a welding torch is mounted on a head attached to the welding apparatus proper by way of an arc gear segment and the arc gear segment is driven through a pinion gear, whereby the head is moved along the arc gear segment to control the position of the torch. The arc gear segment is driven for angular movement by a drive motor mounted in the welding apparatus proper, and the arc gear segment includes a pair of rotatable small wheels provided at the ends of the arc gear segment and a cord such as a chain or rope extended around the small wheels and along the arcuate teeth of the arc gear segment, the middle portion of the cord being securely attached to the head adapted to be movable along the arc gear segment, whereby when the arc gear segment is rotated, the head attached to the cord is simultaneously moved through an angle which is two times that of the arc gear segment.

Abstract: In the inventive method, shaped articles of a plasticized polyvinyl chloride resin are subjected to the surface treatment by with low temperature plasma so that the undesirable phenomenon of bleeding of the plasticizer on the surface can be effectively prevented when the plasticizer for plasticizing the resin is a compound having at least one aromatic nucleus in a molecule or a combination of two or more of plasticizers including 10% by weight or more of a plasticizer which is a compound having at least one aromatic nucleus in a molecule.

Abstract: A novel method is proposed for preventing bleeding of plasticizers on the surface of shaped articles of plasticized polyvinyl chloride resins. The method comprises blending a limited amount of an organosilane compound represented by the general formulaCH.sub.2 .dbd.CR.sup.1 --CO--O--CH.sub.2).sub.a Si(R.sup.2).sub.b (OR.sup.3).sub.3-bin which R.sup.1 and R.sup.3 are each a hydrogen atom or an alkyl group, R.sup.2 is a monovalent hydrocarbon group, a is an integer from 1 to 6 and b is a number of 0, 1 or 2 with the polyvinyl chloride resin prior to fabrication of the resin into shaped articles, fabricating the resin admixed with the organosilane compound into a desired shaped article, and subjecting the shaped article to a treatment with low temperature plasma of a gas. Carbon monoxide is preferred as the gas for plasma atmosphere.

Abstract: A one-side welding facility having means pushing up backing metals against the butting part of the welding edges is mounted on guiding rails which are attached by means of magnets to materials to be welded and suspended therefrom, the facility being self-running thereon by an electric motor included therein. A pair of front and rear links having a spring therebetween are provided on the facility to push up the backing metal against the butting part. Thus, well conditioned one-side welding is stably provided with ease.