| 摘要 |
1,162,585. Printing apparatus; electrostatic. UNIMARK CORP. 19 July, 1967 [26 Sept., 1966], No. 33276/67. Heading B6C. In an electrostatic screen printer using powdered ink the screen image is carried on the peripheral wall 2 of a rotating drum 1 the ink being enclosed in a readily removable vertical stationary hopper 46, 47, within the drum. As the latter rotates the ink is vibrated within the hopper by "knocking means" actuated by the drum's rotation and passes through a filter pad forming the bottom of the hopper to the lower inner surface of the drum which is roughened to carry the deposited powder to the top of the drum for transfer to a rotating roller 26 within the drum which forces the powder through the image areas into the space between the drum and an article which lies above and is to be printed. An electrostatic field established between the drum and the article carries the powder to adhere to the latter. In an alternative apparatus the roller is placed near the lower inner surface of the drum and the powder is caused to pass through the image areas to articles passing beneath the drum.
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