Inkjet printing methods and inkjet printing systems

US11993082B2 · kind B2 · utility

Assignee

• Agfa NV · BE

Inventors

• Stefaan De Meutter · Ekeren, BE
• David Tilemans · Mortsel, BE
• Jens Lenaerts · Mortsel, BE

Key dates

• Filing date: Mar 5, 2021
• Grant date: May 28, 2024
• Expiry date: Apr 1, 2041

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B44C5/04
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

A grayscale inkjet printing method including the steps of: a) supplying a pigmented inkjet ink to a grayscale print head having nozzles with an outer nozzle surface area smaller than 500 μm2 and having an acoustic resonance period ARP of not more than 5.5 μs; and b) applying a voltage wave form for ejecting pigmented inkjet ink from a nozzle of the grayscale print head within one jetting cycle; wherein the pigmented inkjet ink has a viscosity of at least 3.8 mPa·s at jetting temperature and a shear rate of 1,000 s−1; wherein the voltage wave form for ejecting the largest ink droplet includes, in chronological order, a first ejecting pulse having an amplitude A1 and a second ejecting pulse having an amplitude A3 with the amplitude A1 complying with the relationship: 0.50×A3<A1<1.40×A3; and wherein a time period between the end time of the first ejecting pulse and the end time of the second ejecting pulse defines an idle time period including no other ejecting pulse, the time period having a duration between 1.5 to 2.5 times the acoustic resonance period ARP; and wherein any non-ejecting pulse having an amplitude A2 present during the idle time period complies with the relationship: …