Abstract: A method for the operation of a thermoforming machine in which successive sections of a thermoforming web are formed includes the steps of continuously feeding a thermoformable web of plastics material into the entry of the thermoforming machine from an exit support roll of a substantially horizontal run portion of a conveyor, the exit support roll being movable forwardly in the direction of movement of the web and rearwardly in the opposite direction so as to respectively extend and retract the length of the horizontal run portion of the conveyor with the web flow speed at which the web is deposited initially on the conveyor and with the movement of vertically opposed male and female forming tools which are part of the thermoforming machine and which are able to advance and retract horizontally respectively in and against the web movement direction and to move vertically perpendicular to their horizontal movement.

Abstract: A web of thermoplastic material extruded directly into a set of tempering rolls is cooled on its upper and lower surfaces while the interior of the web is kept molten. The partially cooled web is fed onto a converyor on which it is fed to a thermoformer. The web remains on the conveyor until its surface layer in contact with the conveyor is reheated to a thermoformable temperature below that at which the web will stick to the conveyor. Apparatus for feeding a web of thermoplastic material from an extrusion to a thermoformer includes tempering rolls and conveyor means which can be adjusted in their relative positions and to control the length of conveyor means contacted by the web.

Abstract: A machine and process for continuously thermoforming molten thermoplastic sheet are provided requiring precise synchronism in the interaction between opposed successions of circulatable tooling steps. A single motor for all the driving mechanisms achieves the desired synchronism and a driven succession of tooling steps itself drives the opposed succession.