Means for preventing dry burn in a paper-plastic dunnage bag

#1. Field of the Invention

#This invention relates generally to paper plastic dunnage bags.

#2. The Prior Art

#FIG. 1 is a fragmentary elevational view of a paper plastic dunnage bag in a typical use environment.

#FIG. 2 is an enlarged fragmentary cross-sectional view of the bag of FIG. 1 and showing in dotted lines the bag in deflated condition and showing in full lines the bag in inflated position to illustrate additional details of the parts.

#FIG. 3 is an elevational view of the diffuser means taken on line III--III of FIG. 2.

#Referring to FIG. 1, an inflatable disposable paper plastic dunnage bag is shown generally at 10. Such a bag is made from multi-layers of high grade paper, as shown at 11 on FIG. 2, with inner walls 12 and 12a of leak-proof polyethylene film. A valve 13 is mounted in the wall 12 and comprises a valve of the automobile tire type wherein an actuate air inflow is permitted with no outflow. Thus, a spring-pressed valve head is shown at 14 which seats against a valve seat 16 and which is carried in a valve body 17. An air inlet 18 can be selectively closed by a snap-in cover 19 carried on the end of an arm 20. A T-shaped handle 21 extends from the other side of the valve member to facilitate manipulation of the valve and the bag during inflation thereof.

#In usage, deflated, or partially inflated, bags are simply placed in an open space 22 between a load illustrated in FIG. 1 as constituting any typical load having part A and part B on opposite sides of the space 22 and which parts A and B are loaded on pallets 23 and 24, respectively. Compressed air is then applied to the valve inlet 18 until the required pressure is reached. When the shipment reaches its destination, the bags are simply punctured and discarded.

#The inner wall of leak-proof polyethylene film forming the inside bladder of the inflatable dunnage bag is customarily provided as a high density polyethylene which is linear in molecular structure. Thus, when air is initially introduced into the inlet 18 of the valve, there is sometimes a tendency of such airstream to set up vibratory forces and high frequency vibrations which tend to produce holes or ruptures in the polyethylene film. If that occurs, the bag will be prematurely broken and will lose its functional utility. Under the circumstances, some effort has been made to correct such problem which is frequently referred to as "dry burn" by taping a loose flap of polyethylene film on the opposite inside surface of the bladder. However, such loose flap is not completely reliable and may actually be destroyed itself by the vibratory air forces since the flap is so thin as to be practically negligible insofar as its influence on the inrush of air is concerned, when the bag is in a deflated condition.