| 摘要 |
<p>PURPOSE: To prolong the life of a welding band at a welding station for welding a bag filled with a chemically attacking material such as salt by covering a copper layer further with a thin metallic protecting layer, in the melting band of a synthetic resin film consisting of a steel band with the end part covered with the thin copper layer. CONSTITUTION: The welding band 16 is formed of a steel tape or a steel band with a copper-plated end 18. The thickness of the copper layer of the copper- plated end 18 is preferably 40-60μm. The thickness of a metallic protecting layer to be formed on the copper layer is 2-5μm, preferably 3μm. When a chemically attacking material is an inorganic salt, the metallic protecting layer is preferably to be nickel.</p> |
