Variation in pressure in liquid-filled plastic film bags subjected to drop impact

Abstract

The side-wall pressure in liquid-filled plastic film bags subjected to drop impact was measured using pressure sensors, and the relationship between the variation in pressure with time and the number of heat-sealed sides of the bag was investigated. The two samples A and B [130 × 300mm 2 (width × height)] made of transparent plastic film of 67μm thickness were used. Sample A was a liquid-packaging bag heatsealed at four sides, and sample B heat-sealed at three sides. The bags contained about 1,000mL of liquid. Pressure sensors were placed at 26 positions along the inner wall surface of the bag. The samples were held at a height of 0.5m and freely dropped onto wood floor, aluminum alloy, rubber and sponge plates on a concrete floor. The bottom drop test was carried out. Results indicate that the propagation speed of pressure is affected by the number of heated-sealed sides of the bag, and the maximum pressure by the type of floor material. © 2012 The Japanese Society for Non-Destructive Inspection.