粉体印刷法 (第1報)

粉体スクリンプリント法のプロセスについて

抄録

Usually, viscoelastic ink is used to reproduce the images by printing. Provided the image reproduction with powder ink instead of viscoelastic ink is called powder printing method, there are various processes in this method.
The object of the work is to make clear the process by using powder ink in place of customary ink in the screen process printing.
The equipment used in the experiment is shown in Fig. 1. The magnetic brush method used for development of Electrophotograpy was applied to the method furnishing the powder ink, and D-C voltage was applied between the brush with a mixture of powder ink and the metal base plate of printing materials.
The polarities of voltage applied to the magnetic brush were selected properly to the charge sign of powder ink given by rubbing with carrier (iron flake). For example, when the powder ink was charged positively, positive voltage must be applied to the magnetic brush.
The relation between the weight of powder ink deposit and the applied voltage is shown in Fig. 2. When the powder and the carrier were mixed as a constant ratio, as the applied voltage was rised, so the weight of powder ink deposit inclined to increase. But the curve was saturated at a certain voltage.
Fig. 3 shows the relation between the weight of powder ink deposit and mixture rate. If the applied voltage was constant, as the mixture rate became larger, the weight of powder ink deposit increased almost linearly to about 20%.
In case of the printing materials baring high electrical resistance, it was difficult to print finely. any satisfactory images were not formed using the material of above 10¹⁶ Ohm by surface electrical resistance. And the good images were given below about 10¹⁴ Ohm. Then, the fine images were able to print on all materials by lowering the surface electrical resistance using proper methods.
The magnified photographs (X3) of the image produced by this process are shown in Fig. 4-Fig. 7.