Hitachi Electronics Services Co. Ltd.

Mishima Paper Co., Ltd.

Hitachi Electronic Services, Co., Ltd.

Jiro Takahashi

Norikazu Yamagishi

Akira Aoyama

Itsuku Ohtawa

Tsuyoshi Mizutani

Mutsuharu Takesada

Tadayuki Ichiba

Fumitoshi Ishikawa

Yukio Tahara

A laminated paper, including a water soluble polyvinyl alcohol layer of 15-40 .mu.m thickness having an air permeability of 800,000 seconds/100 ml or higher, a total thickness of 40-100 .mu.m and a lengthwise softness of 50 g or less. The laminated paper has high air permeability, extremely superior in air tightness, water soluble, and easy to dispose and recycle. Furthermore, there is no static electricity generated, it is strong in heat sealing, and it has conversion performance. Plus, in the safety aspect, it is non-toxic, waste is safe, and when cushioning material 10 is formed, disposal process is easy as the water soluble PVA film and the paper base are both biodegradable. This laminated paper is an environment friendly industrial material.

Laminated paper for cushioning material

Sheets of laminated paper are stacked and made into air-tight flat bags with air inlets. After air is supplied into the bags, the air inlets are air-tightly closed to form shock absorbers 50 encapsulating the air. The laminated paper is made by stacking on a paper base a water-soluble polyvinyl alcoholic layer, having a saponification of 80 to 90 mol % and a degree of polymerization of 500 to 2500, to a total thickness of 90 .mu.m or less and a gas permeability of 800 thousand seconds per 100 ml or more. The air is introduced into flat bags 51 to 50 to 80% of maximum inflation to ensure their shock absorbing function. A package 100 is made by putting an appropriate number of discrete shock absorbers 50, or a continuous series of shock absorbers 50, in gaps between a casing 10 and the package content 70. The shock absorbers 50 need not be spread all over the entire surface of the package, so long as they are sufficient to provide the needed contact area to ensure a maximum static load of 0.07 kgf/cm.sup.2 (around 20 kg in normal packages).

Shock absorber and package with shock absorbers

Equipment which automatically manufactures cushioning material by filling air inside polyvinyl alcohol laminated paper and sealing the filled material into individual bags. The manufacturing equipment 1 is provided with a material roll 20 on which a sheet material of polyvinyl alcohol laminated paper is wound. The sheet material 10 is rolled out by a feeding roller 40 from the material roll 20, and the sheet material 10 in a known length, adjusted by a length adjusting device 50 having a roller 42 which goes up and down, is supplied intermittently to a bag forming device 100 located downstream thereof. The bag forming device 100 is provided with a pipe member 105 and a sailor 110, which is a guide plate to reverse the sheet material 10 and form it into a tubular shape, and the sheet material 10 is fed along the pipe member 105 after being formed into a tubular shape. Feed rollers 130 and auxiliary belt 120 are arranged at the periphery of the pipe member 105. The feed rollers 130 catch the superposed sections of both edges of the sheet material formed into a tubular shape and feed the material, inserting the superposed section into a center sealer 150. The center sealer 150 is provided with a heater and welds together the superposed sections. As a result of this welding, the sheet material is formed into a long tube. The center sealed tubular sheet material is further sent downstream from the lower end of the pipe member 105. Air is supplied from the top of the pipe member 105, and the air is filled inside the tubular sheet material. In such condition, the sheet material is sent to the end sealer/cutter. The end sealer/cutter 160 is provided with a pair of end sealers facing each other which weld the tubular sheet material into a bag shape and cut the material into individual bags with a cutter 165. At this time, the air amount is adjusted by the filled air amount adjusting device 170. The air filled cushioning material 200 is sent to the next process by a conveyor 210.

Manufacturing equipment for cushioning material

Growing community of inventors

Kanagawa, Japan

Jiro Takahashi