Apparatus for continuous welding or sealing of seams of plastic films

• Main Authors: HEYSE; KLAUS, KLENK; LUDWIG
• Format: Patent
• Language: English
• Published: 24.05.1988
• Edition: 4
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A flat film 11 is delivered from a supply roll 12 to a folding device with a tube forming part 17 and is folded into a tube envelope 23. The butt or overlap seam of the folded tube envelope 23 is covered with a sealing strip 14. The folded tube envelope 23 together with the sealing strip 14 is guided between a partial periphery of a sealing drum 2 and an electrically heated heating band 3 and is sealed under heat and pressure applied by the heating band 3. Electrical current is supplied to the endlessly revolving heating band 3 via feed rollers 6 and 7 from a current source 20 connected, via lines 21 and 22, to sliding contacts 8 which rest against the two sides of each feed roller. An endlessly revolving, cooled steel band 26 is in contact with the seam of the sealed tube envelope 18 and is guided around a cooling roller 9. The sealed tube envelope 18 is detached from the sealing drum 2 in the region of the cooling roller 9, and is guided over the cooling roller 9 and a deflecting roller 10 onto a wind-up roll 19.