| 摘要 |
A process and an apparatus are disclosed for the manufacture of objects of crystalline polystyrene. The apparatus comprises a screw extruder (8) having a die (10) with an outlet of adjustable profile, mounted at the end of the screw (9) of the extruder, a roller press (12) having a plurality of temperature adjustable rollers (13, 14, 15) and at least one pair of draw rollers (16, 17) to draw the sheet, at least one of said draw rollers being temperature-adjustable, at least one sheet supporting roller (19) which is free to rotate about its own axis and is of low thermal conductivity at least on its surface, two switches (35, 36) controlling the build-up of the sheet in the region between the pair of draw rollers (16, 17) and the sheet supporting roller (19) which can be activated by detection of the position of the sheet by means of mechanical sensors or photocells, a device (20) for heating both edges of the sheet which can be positioned in relation to the breadth of the sheet and adjusted for temperature in relation to the thickness and the distance moved by the advancing sheet, at least one drawing device having chains (22) and sprockets (22 min , 22 sec ) acting on the edges of the sheet, at least one device (24, 25) for heating both sides of the sheet in relation to the part which is to be thermoformed, a forming device having a press component (29), a device for removing objects from the press component (29), a device (31, 32) for stacking the objects and a device (33) for grinding up the waste. |
