Stencil printing method for printing water-based ink

• US 7,370,576 B2
• Filed: 03/18/2005
• Issued: 05/13/2008
• Est. Priority Date: 03/23/2004
• Status: Expired due to Fees

• Current Assignee: RISO Kagaku Corporation
• Original Assignee: RISO Kagaku Corporation
• Inventors: Shibahara, Takuya, Nakamura, Akira, Hayashi, Yoshihiro, Naitou, Taku
• Primary Examiner(s): Evanisko; Leslie J.
• Application Number:
  US11/083,318
• Publication Number:
  US 20050211115A1
• Time in Patent Office: 1,152 Days
• Field of Search: 101116-120, 101/129, 101/491
• US Class Current: 101/119
• CPC Class Codes: B41L 13/06 with a single cylinder carrying the stencil
• CPC Class Codes: B41L 13/18 Inking units
• CPC Class Codes: B41M 1/12 Stencil printing; Silk-screen printing
• CPC Class Codes: B41N 1/248 Mechanical details, e.g. fixation holes, reinforcement or guiding means; Perforation lines; Ink holding means; Visually or otherwise detectable marking means; Stencil units
• CPC Class Codes: C09D 11/0235 Duplicating inks, e.g. for stencil printing

Abstract

A stencil printing method employs a stencil printing machine comprising: a drum which is rotatable and has a outer peripheral wall formed by an ink impermeable member and in which a stencil sheet is mounted on a surface of the outer peripheral wall; an ink supply device which has an ink supply unit provided on the outer peripheral wall of the drum and supplies ink on the surface of the outer peripheral wall from the ink supply unit; and a pressure roller which presses a fed print medium onto the outer peripheral wall; the method comprising: a step of mounting a stencil sheet on the drum; a step of plate-making the stencil sheet; and a step of transferring a water-based ink to a print medium by making the water-based ink pass through perforations of the stencil sheet.

Claims

1. A stencil printing method carried out by employing a stencil printing machine comprising:

a drum which is rotatable and has an outer peripheral wall formed by an ink impermeable member and in which a stencil sheet is mounted on a surface of the outer peripheral wall;

an ink supply device which has an ink supply unit provided on the outer peripheral wall of the drum and supplies ink on the surface of the outer peripheral wall from the ink supply unit; and

a pressure roller which presses a fed print medium onto the outer peripheral wall;

the method comprising;

a step of mounting a stencil sheet on the drum;

a step of plate-making the stencil sheet; and

a step of transferring a water-based ink to a print medium by making the water-based ink pass through perforations of the stencil sheet.

2. The stencil printing method according to claim 1, wherein the water-based ink has an ink viscosity at a shear stress of 10 Pa when the shear stress is increased from 0 Pa at a speed of 1 Pa/s of 500 mPa·

s or less at 23°

C.

3. The stencil printing method according to claim 1, wherein the water-based ink has an ink thread-forming length when a 15 mm diameter chrome steel ball is pulled out of the ink at 150 mm/s of 30 mm or longer at 23°

C.

4. The stencil printing method according to claim 1, wherein the water-based ink comprises an unsaturated straight-chain carboxylic acid-based water-soluble polymer.