GRM INKS & DISPERSIONS

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Graphinks™ are graphene and related material (GRM) inks and dispersions that bring multi-functionality (high electrical and thermal conductivity, fire retardation, UV protection, etc.), produced via a high pressure homogenisation process that offers high yield and uniform size distribution. We have ‘standard’ Graphinks™ for different deposition methods from inkjet to screen printing and developmental formulations (DF) with different nanomaterials and solvent combinations.

Graphink-101 was developed using a Drop-on-Demand (DoD) Dimatix Materials Printer, DMP-2800 (FUJIFILM Dimatix Inc., USA) using Dimatix Materials Cartridges. Jetting profiles and cleaning procedure files can be sent electronically following purchase of the ink. This does not guarantee successful printing and will require optimisation at the customer’s end.

Graphink-102 and Graphink-103 are water-based graphene dispersions with no binders or rheology modifiers added. They provide you the freedom to formulate a water-based graphene ink suitable for application with their binder or additives of choice. In order to increase their viscosities for different printing methods we developed Graphink-1021 and Graphink-1022 contain cellulose rheology modifiers and binders. The rheological behaviour of these inks is thixotropic, which means they are highly viscous when in storage. The viscosity will drop significantly as shear is applied during printing processes and the viscosity will rebuild after printing which is important to maintain high-resolution printing patterns. These inks can be printed on paper, glass, plastics and textile substrates. Good coatings can provide sheet resistances of <5 Ω/□ (@25 μm print thickness). Because these inks are water soluble, we have developed a cross-linked version that can be used in aqueous environments - Graphink-1021X, for example, in biosensor electrode applications.

Graphink-1021 and Graphink-1022 were developed using a flatbed screen printing machine using screens with a waterproofed and hardened polyester mesh with mesh size ranging from 15 to 120. Depending on the printing technique and the machine, the viscosity of the inks may need to be reduced using deionised water only.

Cleaning: Reclaim excess ink from the screen using a spatula, use disposable cleaning wipes followed by rinsing and washing processes with detergent and water. Scrub the screen lightly with a brush, then wash out the screen with water and leave to air dry. Repeated cleaning processes may be necessary.Other printing/coating techniques include but are not limited to:

• Doctor blade / Meyer bar coating
• Spray coating
• Slot die coating
• Dip coating
• Curtain coating
• Flexographic Printing
• Gravure Printing