Plastic and nonmetallic article shaping or treating: processes – Mechanical shaping or molding to form or reform shaped article – Plural sequential shaping or molding steps on same workpiece
Patent
1981-01-30
1982-11-02
Silbaugh, Jan H.
Plastic and nonmetallic article shaping or treating: processes
Mechanical shaping or molding to form or reform shaped article
Plural sequential shaping or molding steps on same workpiece
264537, 264544, 264550, 264553, 2643287, B29C 1704
Patent
active
043572944
ABSTRACT:
The present invention relates to an improvement in a method for thermoforming of containers from thermoplastic materials in which method the rim of the container is formed as an integral part of the pre-form from which the container is thermoformed. The pre-form is obtained by introducing thermoplastic material into a closed space and then mechanically compressing the material. The improvement of the present invention relates to improved uniformity of flow of the thermoplastic material into the closed space, the use of a closed space defined by surfaces having a surface roughness in the range of 50-125 .mu.m rms and to a modified sequence of steps for forming the pre-form in which the compression of the thermoplastic material is commenced prior to the completion of the introduction of the material into the closed space. The process may be used in the manufacture of containers, e.g., for the packaging of margarine, from polyethylene or polypropylene.
REFERENCES:
patent: 3602946 (1971-09-01), Curetti et al.
patent: 3906066 (1975-09-01), Barrie
patent: 4005164 (1977-01-01), Procter
patent: 4187274 (1980-02-01), Arnason
Hetherington Brian L.
Kelly Peter Y.
Du Pont Canada Inc.
Silbaugh Jan H.
LandOfFree
Manufacture of plastic containers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Manufacture of plastic containers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Manufacture of plastic containers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-623745