Abstract: A process and an apparatus for producing hollow bodies of thermoplastic material by a blow molding procedure use a blow molding mold comprising at least two portions, with at least one means by which the mold portions are urged towards each other in the mold-closing direction and are locked together when the mold is closed. The locking means carries a large part of the forces resulting from the blow molding pressure and possibly also at least a part of the forces required for squeezing surplus material off the preform to be expanded in the mold. The forces applied by the locking means are transmitted to the mold portions, with the interposition of at least two spaced-apart hydraulic force-transmitting means. The hydraulic force-transmitting means are hydraulically connected together in order to render uniform the forces which act on the mold portions.

Abstract: A method for producing at least a polymer surface layer on at least part of the inner surface of a hollow article that is at least partially of plastic, comprising coating said at least part of the inner surface of the hollow article by establishing a low pressure gas atmosphere within the hollow article, formin a polymerizable plasma within the article by excitation of the gas atmospher within the article by high-frequency electromagnetic energy, and allowing polymerization of the gas atmosphere to take place, whereby a polymerized coating is applied to said part of the inner surface, the gas atmospherre that forms the plasma containing a component that predominantly forms chains at sufficient speed and can be polymerized under the particular plasma conditions, and a component that forms predominantly branching or cross-linking points and can be polymerized under the particular plasma conditions.

Abstract: In a process for the production of a hollow body such as a fuel tank from thermoplastic material, the wall thereof is subjected to a two-step treatment to influence the permeation properties of the material. In the first treatment step the wall is subjected to the action of a gas mixture containing fluorine and oxygen while in the second treatment step the wall is subjected to the action of a gas mixture which contains fluorine but is oxygen-free.

Abstract: In a connecting arrangement having at least first and second parts, the first part includes at least one portion whose cross-section is adapted to the contour of an opening in the second part. The connection is made by a relative displacement whereby the first part is relatively introduced into the opening in the second part. The first part has a plurality of retaining projections which are arranged in mutually displaced relationship in the direction of the relative displacement for insertion of the first part into the opening of the second part. Which of the projections is operative for fixing of the second part in the end position thereof depends on the relative position of the second part in its end position relative to the first part.