| 摘要 |
516,262. Moulding hollow-ware. JACKSON, L. MELLERSH-. (Plax Corporation). July 21, 1938, No. 21671. [Class 87 (ii)] Hollow articles are moulded from organic plastic material by extruding a tubular body with an open end, closing the end, expanding the extruded body by internal fluid pressure into contact with a mould while the -body is still integral with the parent body, and separating the hollow body from the parent plastic material. The plastic material may be a cellulose derivative or a polymerization or condensation product such as methyl methacrylate or phenol formaldehyde resin. The end of the tubular body may be -closed by extruding material on to a cup-shaped mould or against a support such as a shear plate introduced between the moulds and the extrusion nozzle or against the bottom of the mould, the extrusion nozzle being lowered for this purpose and subsequently raised as the body is extruded. The moulded article may be separated from the plastic material in the extrusion nozzle by a shear blade moved across the nozzle or by a cutting sleeve moved axially of the nozzle or by pneumatic pressure within the tubular body accompanied by relative rotation or axial movement of the mould and nozzle. In one form material is extruded from an annular nozzle 23, Fig. 15, into a cup formed by members 30, 31 until a closed end is formed. The cup members are removed and the nozzle is applied to a mould 32, Fig. 18, where the material is further extruded and is finally expanded into contact with the mould by fluid pressure introduced through a passage 24. The neck of the hollow article is formed by a sliding sleeve 28 on the nozzle co-operating with a flared part of the mould. After moulding, the sleeve 28 is moved down further to shear the plastic material at the nozzle orifice. The nozzle is formed of two parts 25, 27, the inner part terminating in a mushroom head 26. The mould may be in two split parts 33 with a bottom plate 34. During extrusion, fluid may be admitted through the passage 24 to prevent collapse of the extruded body. The lower end of the passage 24 may be provided with a spring-pressed valve. The inner nozzle member 25 may be adjustable relative to the outer part 27. For moulding narrow-necked milk or other bottles, the neck portion may be formed by separate ring mem bers which may form a support for a shearing. blade. The ring members may be shaped to produce a doubled formation at the neck of the bottle which is finally shaped by a pressing tool. The mould members may be provided with jackets for heating and cooling. After moulding the article, the nozzle may be moved relatively to the mould to attenuate the material between them and shearing members moved in opposite directions to cut off the material, the lower shearing member serving to receive material cut by the upper member. Specifications 12976/09, [Class 70], and 407,663 are referred to.
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