Process and apparatus for manufacturing bags of plastics materials having pressure or slide fastener strips joined by heat-sealing

Abstract

Abstract INTERMITTENTLY FED FASTENER STRIPS, WHICH ARE HOOKED TOGETHER, ARE INTRODUCED BETWEEN THE SPREAD-APART EDGES OF AN INTERMITTENTLY ADVANCED SHEETING WEB, WHICH HAS BEEN LAID TO FORM TWO PILES. THE STRIPS ARE HEAT-SEALED TO THE SHEETING WEB WITH THE AID OF PULSE-HEATED HEATSEALING JAWS. IN THE MANUFACTURE OF BAGS HAVING PRESSURE FASTNERS, AT LEAST ONE FURTHER ADVANCING STEP IS THEN PERFORMED AND THE FASTENER STRIPS ARE SUBSEQUENTLY JOINED TOGETHER BY HEAT-SEALING IN A SECOND HEAT-SEALING STATION WITH THE AID OF PREFERABLY PULSE-HEATED HEAT-SEALING JAWS. ONE OR MORE FURTHER ADVANCING STEPS ARE PREFORMED AND THE SHEETING WEB IS THEREAFTER SUBJECTED IN A THIRD HEATSEALING STATION TO A TRANSVERSE SEVERING AND HEAT-SEALING OPERATION BY A PREFERABLY CONTINUOUSLY HEATED SEVERING AND HEAT-SEALING TOOL, WHEREBY INDIVIDUAL BAGS ARE SEVERED AND CLOSED. IN THE SAME STATION, THE FASTNER STRIPS ARE CUT THROUGH THEIR HEAT-SEALED MODE. THE TIMING OF THE CLOSED POSITION OF THE JAWS, AND THE TIMING OF THE HEATSEALING PULSE ARE CONTROLLED INDEPENDENTLY OF EACH OTHER. THE TIMING OF THE HEAT-SEALING PULSES IS CONTROLLED SO THAT THE HEAT-SEALING PULSES ARE TERMINATED CONSIDERABLY BEFORE THE HEAT-SEALING JAWS ARE OPENED.

Inventors

• 👤 August Schwarzkopf

Bibliographic Details