Haruo Sasaki

Development of an air cushioning material based on a novel idea

The air cushioning material introduced in this paper as a new packaging material represents a new steadying and cushioning system using air pressures. The material is a two-layer structure consisting of an airtight chamber (air chamber) filled with air and a urethane chamber holding flexible and resilient urethane that permits free air passage. Ordinary air cushioning materials have drawbacks in that they repeat expansion and contraction according to changes in atmospheric pressure and temperature during long storage or transportation to remote destinations. While their expansion may damage the case or the packaged object, their contraction may cause a drop in steadying pressures, so that the contents may move about inside and eventually sustain damage. The two-layer structure of the new material rectifies the shortcoming of ordinary air cushioning materials that they may be affected greatly by temperature changes. Also, the greatly improved flexibility of the packaging material opens up possibilities for far wider applications in packaging precision devices and machinery. The airtight chamber to be filled with air is provided with an air charge port and an air discharge port, which may be used to control the charged air pressure. The desirable air pressure is such that the urethane in the urethane chamber is compressed to about half the ordinary size. Since it can be checked visually or tactually, the charging of air, which used to be a delicate and rather difficult operation, is easy. Conventionally, most of the packaging materials were of throw-away type and thus handled as waste materials. The new air cushioning material, which is surfaced with a strong wear-resistant cloth, is designed for repetitive use, so that it will contribute greatly to the reduction of wastes if systematic recovery is carried out. Copyright

Pinhole inspection machine for sealed packages: for detection of pinholes of 0.5 μm or below

One of the most important processes in the food and pharmaceutical industries is the leakage detection of sealed packages to prevent pollution by bacteria. A high frequency, high voltage method is used as a highly reputed method for high accuracy inspection of ampoules and sealed food packages for pinholes. This paper outlines a pinhole inspection machine.

Repulpable pressure-sensitive adhesive tapes and labels

In recent years, Japan has been witnessing a mounting interest in the recycling of waste paper as a way of protecting the environment. Yet the manufacture of recycled paper has always been subject to the problem of plastic, metal or PE-laminated paper chips mixing in. Especially the contaminants from adhesive tapes and labels (stickies) have posed a difficult problem for the manufacturers of recycled paper. Therefore, the development of repulpable products substituting for them has long been an earnest desire for the industry. To solve this problem, a comprehensive investigation into the pressure-sensitive adhesive, the release agent and the base paper has been carried out, and repulpable PSA packaging tapes and labels that are well suited for the manufacture of recycled paper have been successfully developed.

Heat insulating cardboard composed of corrugated foamed polystyrene layer

Foamed polystyrene boxes are widely used in low-temperature physical distribution today. They have, however, a big problem with the way they are disposed of after use. On the other hand, corrugated cardboard boxes, which are low-priced, lightweight, collapsible and less bulky, have almost no problems of disposal after use, although they cannot adequately keep the contents fresh because of their inferior heat insulation and water resistance. To find a solution to these problems, we have developed a heat insulating cardboard consisting of a corrugated foamed polystyrene sheet core covered with a paperboard liner on both sides. We have also established technology for continuous production of long-sized material with the purpose of commercializing it through mass production. Tests to determine the basic characteristics revealed that the new cardboard material is equal to conventional cardboard in calorific value when burned, as well as in usability and decorative capacity and that it displays far superior heat insulation and moisture resistance. In transport tests on cut flowers and a processed marine product, it was also confirmed that the new material excels in the performance of preserving the freshness of the contents. Furthermore, a recycling test proved that the material is recyclable as waste paper. Copyright

The application, in the packaging industry, of bean-curd refuse from soybean processed food

An investigation was made on a way to put bean-curd refuse (okara) to practical use in moulding vessels and other utensils. The mixture of bean-curd refuse, pulp (fibres of paper) and calcium hydroxide in the ratios 100 : 10 : 5 (by dry weight) was suspended in 200 times its volume of water and heated at 50 to 80 °C for more than two hours. Some vessels or utensils were moulded from the residue of the filtered mixture and dried in a drying oven. The resulting products exhibited desirable characteristics — light, hard and waterproof, and had adequate strength for use for vessels such as gardening pots or dishes for serving food. Moreover, they degraded within about three months when buried underground. The products are not only suited to the practical use of bean-curd refuse but are also friendly to the environment. Copyright