METHOD OF EXTRUSION MOLDING AND APPARATUS THEREFOR

WIPO Patent Application WO/1991/010552

A1

A method of extrusion molding, wherein the fluidity of a molding material in a die is kept satisfactory and the productivity of molded items having a uniform thickness is greatly improved, and an apparatus therefor capable of carrying out the method with reasonable construction of the apparatus. Molding is carried out while the die provided with an extrusion opening gap adjusting means is resonated. Furthermore, preferably, to make smooth the flow of the molding material in the vicinity of an extrusion opening of the die where the flow is most likely to stagnate in general, the extrusion opening gap adjusting means is attached to a part of the die, which forms an extrusion opening portion, whereby molding is carried out while only this part of the die is resonated. As a preferable mode, to attain effective resonance, the resonance frequency of the extrusion opening gap adjusting means is made equal to the resonance frequency of the die, and the extrusion opening gap adjusting means is attached to a nodal portion of the resonance. Furthermore, the extrusion opening of the die is allowed to coincide with the loop portion of resonance, i.e. a portion where the effect of vibrations is the strongest, so that the frictional resistance between the molding material and the surface in the vicinity of the extrusion opening of the die is reduced.

FURUSAWA TOSHIHIRO (JP)
SATOH ATSUSHI (JP)
NAKAJIMA TAKASHI (JP)
MATSUGISHI NORIAKI (JP)

PCT/JP1991/000062

July 25, 1991

January 21, 1991

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IDEMITSU KOSAN CO (JP)
SEIDENSHA ELECTRONICS (JP)

B29C48/08; B29C48/30; B29C48/31; B29C48/32; (IPC1-7): B29C47/08; B29C47/12

JPS5751441A	1982-03-26
JPS524558A	1977-01-13

See also references of EP 0465660A4

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