Design of Polyethylene based multilayer extrusion blown film for manufacture of leak free packaging

Abstract

Flexible packaging is a growing market and the majority of flexible package applications are for the food industry. The demand for process optimization and reduced production costs has led to an increase in flexible packaging. And reducing wastage in production line, during storing and transportation is a critical aspect which food product anufacturers are highly concerning.These wastages are higher for liquid products packing flexible materials. That is due to contamination in the seal area. Most of the time liquid products are packing in Vertical-Form-Fill-Seal (VFFS) machines. Therefore seal through contamination is highly occurring while packing of liquid products. The study uses three types of liquid and semi liquid products such as tomato sauce, spicy oil and water based perfume. Since the aggressiveness of these products leak percentage is higher with current material structures.Hence target of this study was to develop a PE based blown film extrusion material which can be used for the laminate structures for these selected products. Newly developed Linear Low Density Polyethylene (LLDPE) was replaced the sealant material of existing structure of those products. Also all the tests were carried out for both existing material structure and new material structure with developed LLDPE. The existing sealant material was blown using 80% LLDPE and 20% Low Density Polyethylene (LDPE) in all 3 layers. But newly developed sealant material was blown incorporating Polyolefin Plastomer (POP) and metallocene LLDPE materials to the inner and middle layers. The study tests a combination of different sealing temperatures and dwell time to determine the optimal sealing condition.Then optimal sealing condition was applied to the production line in order to trial them material structures. Leakages tests were conducted to the packed sachets and final results were determined. Developed blown film extrusion LLDPE film was shown good results compared to the existing material. From new sealant material leak percentage of tomato sauce, spicy oil and water based perfume could be reduced by 20%.