Plastic article or earthenware shaping or treating: apparatus – Preform reshaping or resizing means: or vulcanizing means... – Coacting shaping surfaces
Patent
1982-09-14
1984-10-09
Silbaugh, Jan
Plastic article or earthenware shaping or treating: apparatus
Preform reshaping or resizing means: or vulcanizing means...
Coacting shaping surfaces
4253241, 4253421, 425343, 425384, 425388, B29C 1702
Patent
active
044758812
ABSTRACT:
A method and apparatus are disclosed for holding and feeding a continuous sheet (12) of plastic in an operation such as thermoforming. Articulations (13), such as alternating waveforms, are formed on the edges of the plastic sheet (12) by heating and pressing the edges, producing inwardly facing abutment surface at the edges of the sheet. The sheet is then passed into slots (34) in guide rails (32) with the inside surfaces (35) of the guide rails (32) engaging the abutment surfaces on the plastic sheet (12) to prevent the sheet from slipping out of the guide rails. The plastic sheet is thereby held firmly so that it can be passed through such thermoforming operations as heating in an oven (14), forming with a mold at a forming station (40), and cutting the formed articles away from the remainder of the sheet by a trim press (53). The sheet is advanced in increments through the thermoforming apparatus by a sheet advance mechanism (48) which alternately grasps the sheet to advance it and then releases the sheet while the forming and trimming operations are carried out. Sheet stretching guide rails (90) hold the sheet at the mold and are mounted to move outwardly to stretch the heated sheet as the mold engages the sheet. The stretch on the sheet is released as the mold disengages. The stretching of the sheet during forming compensates for the tendency of the formed sheet to shrink as it cools.
REFERENCES:
patent: 711840 (1902-10-01), Fernald
patent: 1574564 (1926-02-01), Farnsworth
patent: 1651744 (1927-12-01), Van Derhoef
patent: 1904268 (1933-04-01), Bronson
patent: 2240274 (1941-04-01), Wade
patent: 2414177 (1947-01-01), Smith
patent: 2502772 (1950-04-01), Winstead
patent: 3051361 (1962-08-01), Menkel
patent: 3119534 (1964-01-01), Lehnert
patent: 3227346 (1966-01-01), O'Brien
patent: 3240851 (1966-03-01), Scalora
patent: 3277224 (1966-10-01), Whiteford
patent: 3321561 (1967-05-01), Brown
patent: 3419937 (1969-01-01), Bally
patent: 3484839 (1969-12-01), Neumann
patent: 3551546 (1970-12-01), Gosper
patent: 3748078 (1973-07-01), Schott
patent: 3762322 (1973-10-01), Vines
patent: 3791567 (1974-02-01), Schott
patent: 3837782 (1974-09-01), Meissner et al.
patent: 3854861 (1974-12-01), Worrall
patent: 4043736 (1977-08-01), Andres et al.
patent: 4196164 (1980-04-01), Ward
patent: 4289470 (1981-09-01), Johnston et al.
"Thermoforming", Modern Plastics Encyclopedia 1980-1981 pp. 406-414.
"Brown Thermoforming Equipment", brochure published by Brown Machine Division, Koehring Company.
"Sentinel 2500", brochure published by Packaging Industries, Inc.
"Continuous Thermoforming Systems", brochure published by Brown, A Leesona Company.
"Model 42P Pressure and Vacuum Forming Machine", brochure published by Brown Machine Company.
Borst Rodney D.
Herr Daniel C.
Placon Corporation
Silbaugh Jan
LandOfFree
Thermoforming of plastic sheet material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermoforming of plastic sheet material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermoforming of plastic sheet material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1598167