LONG MATERIAL FOR BINDING

摘要

PROBLEM TO BE SOLVED: To provide a long material for binding which can be widely used and which is biodegradable because the refuse problem has been taken into consideration, by drawing biodegradable polylactic acid resin after it has been formed. SOLUTION: Polylactic acid resin having the average molecular weight as much as 20000 is extruded at 230 deg.C by a molding machine to form a band-form raw material. Thereafter, it is uniaxially stretched in the longitudinal direction at 140 deg.C to form the three times raw material. A pattern is formed on the surface by finally passing it through rollers to form a binding band (15 mm wide and 1 mm thick). A binding band made of polylactic acid itself shows sufficient physical properties by uniaxially stretching it. Any problems do not arise in particular even when a corrugated cardboard case in which an outdoor instrument (40 kg) of an air conditioner is packed, is continually swayed forward and backward and also sideways at an amplitude of 5 mm and at a frequency of 5-50 Hz at every 5 min cycle for one hour. It is buried in a depth of 10 cm for one year and thereafter, the appearance is evaluated. It is confirmed that the binding band is gradually decomposed by the enzyme in the ground.