| 摘要 |
PROBLEM TO BE SOLVED: To prevent absorption of moisture by providing a glass coating layer in a thread stopping groove of a fiber paper tube, to stabilize measurements and keep thread gripping performance for a long term. SOLUTION: The thread stopping groove 2 is provided near an end portion of a paper tube 1. The thread stopping groove 2 is composed of an introducing groove 3 having a generally V-shaped cross-section when the paper tube is cut in a longitudinal direction, and formed from a tilting wall having not less than two stepped portions; and a narrow grip portion 4 having a generally V-shaped cross-section when the paper pipe is cut in a longitudinal direction, and formed from a tilting wall having not less than one stepped portion on an extension line of the introducing groove 3. Glass coating liquid is applied or impregnated on the thread stopping groove 2 of the paper pipe, thereby forming a glass coating layer. COPYRIGHT: (C)2004,JPO&NCIPI
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