| 摘要 |
PURPOSE:To prevent generation of bubbles in the completed product of a lamp tube, by successively inserting the lamp tube into a heating furnace while being circumferentially rotated from its longitudinal one end and heating the lamp tube in the heating furnace from one side of its insertion passage. CONSTITUTION:On a feed-in conveyor 3 a lamp tube 10, enclosed by a heat shirnking plastic tube 9, is placed and inserted into a heating furnace 1 through an inlet 1a while being circumferentially rotated from its longitudinal one end. As the lamp tube 10 is successively inserted into the heating furnace 1, the tube 9 is pressure laminated spirally in progress toward the direction of insertion from its left end side, and the air and the like are pressed out to an unheated portion, not left as the bubbles in the pressure laminated part finally discharged to the outside from the right end of the tube 9. |
