Method for stencil plate making of stencil sheet for stencil printing
AssigneeRiso Kagaku Corporation
InventorsHideyuki Kinoshita, Yasuo Yamamoto
Life of this patent
Estimating the term…
Abstract
A micro porous plastic sheet is stencil plate made by a method for stencil plate making of a stencil sheet for stencil printing under the following conditions: heat is provided to form a negative image with TPH at −30≦Tp−Tm≦300° C. (Tp is heating peak temperature and Tm is melting temperature (melting point) of the sheet) and in 10≦To×100/Ts≦80% (To is current-carrying time period and Ts is current-carrying cycle), micro pores are closed by the pressure for stencil plate making of 0.1≦P≦1.0 MPa, and the thermal shrinkage rate of the sheet measured by TMA is set to 1≦STm-30≦20% (STm-30 is a thermal shrinking rate of the sheet at a temperature 30° C. lower than the melting point TM).
Claims4
A method for stencil plate making of a stencil sheet for stencil printing performed for a micro porous plastic sheet, comprising the steps of:
- providing required heat for melting a surface or inside of the plastic sheet to a form of negative image by heating means of a thermal head (TPH);
- thermally shrinking or heat melting micro pores in the heated area of said micro porous plastic sheet;
- and
- pressing the micro pores of the sheet for blockage wherein the following formula (1) and (2) concerning driving conditions for said thermal head;
- the following formula (3) concerning pressure for stencil making for pressing the micro pores;
- and the following formula (4) concerning thermal shrinking rate of said sheet are satisfied simultaneously,
- −30≦Tp−Tm≦300 (° C.) (1)
- (wherein, Tp represents heating peak temperature, and Tm represents a melting temperature (melting point) of the sheet)
- 10≦To×100/Ts≦80 (%) (2)
- (wherein, To represents current-carrying time period, Ts represents current-carrying cycle, To×100/Ts represents the ratio of To to Ts)
- 0.1≦p≦1.0 (MPa) (3)
- (wherein, P represents pressure for stencil plate making)
- 1≦STm-30≦20 (%) (4)
- (wherein, STm-30 represents the thermal shrinkage rate at a temperature 30° C. lower than that of the melting point of the sheet Tm in TMA (thermal mechanical analysis).
Dependencies are inferred from the claim text.