Texcraft Printing Ink System
Author: Bonny Francis Date Posted:17 July 2017
TEXCRAFT PRINTING INK SYSTEM
Textile inks are the most commonly used medium for printing on fabric. They are based on acrylic resins with pigment added as colouring. These are known as resin bonded pigments and need heat to bond them to the fabric. They may be purchased as premixed inks or as separate ingredients and mixed for individual strength and colour requirements. There are different bases for different end uses. Pigments are then added to these bases to create a multitude of colours and effects.
BASES OR EXTENDERS
EXTENDER is used on white or pale fabrics. It may be printed on most fabrics but has best fastness properties on cotton or poly/cotton blends. When printed on high percentage synthetic fabrics a synthetic fixative needs to be added. SEE ADDITIONS TO PRINT PASTES.
OPAQUE BASE is the opaque equivalent to extender. Itis used on dark fabrics. It is thicker on the fabric to cover the colour of the fabric and consequently leaves the fabric feeling much stiffer.
PUFF BASE is used for puff or raised effects, also opaque in effect.
PEARL LUSTRE/METALLICS is used for lustre effects. This ink may be pigmented for coloured lustre prints and is opaque.
FOR BEST RESULTS USE FABRICS THAT ARE CLEAN AND FREE OF SIZING
ALL BASES MUST BE HEAT SET THOROUGHLY TO REACH MAXIMUM WASH AND RUB FASTNESS. THIS IS EVEN MORE CRITICAL WITH OPAQUES AND METALLICS. HEAT SET AT 130ºC FOR 5-6MINS OR 150ºC FOR 3-4MINS WITH DRY HEAT. ALWAYS TEST PRINT AND CHECK FASTNESS BEFORE COMMENCING A PRINT RUN. TUMBLE DYERS AND DOMESTIC IRONS WILL NOT GIVE YOU THE FASTNESS ACHIEVED IN A COMMERCIAL OVEN.
USED TO COLOUR ALL OF THE ABOVE BASES
Full strength COLOURS are used at the rate of 30-40gms per kg/litre of extender base. Use less for pastel shades or add white. Adding white will give you a full bodied pastel. WHITE needs 250gms per kilo plus an extra 100g Binder/Kg. BLACK needs 60gms per kilo. For OPAQUE, PUFF & LUSTRE BASES you may need to double your pigment requirement to ensure good brightness and depth of colour.
PIGMENTS may be calculated by weight or by eye. Kraftkolour's EXTENDER BASE will take up to 70gms of pigment per kilo. If you exceed 70gms per litre of pigment you may need to add extra BINDER to the paste, refer below.
ADDITIONS TO PRINT PASTES
TEXPRINT FIXING AGENT LF - When printing with BASES on fabrics with above 50% synthetic content, add 5-10gms of FIXING AGENT (1-2teas) per litre to improve bonding. This improves the wash fastness of the finished print. Also with sized fabrics ie calico & teatowels FIXER will improve wash fastness. PRINTPASTE STABILITY IS EFFECTED BY QUANTITIES OF FIXER OVER 5GM. This product does stiffen the feel of the fabric slightly.
AMMONIUM SULPHATE - To thin ink down without the addition of large amounts of water and consequent flushing or bleeding of pigment. Use 10-50mls of 20% AMMONIUM SULPHATE SOLUTION per litre of ink depending on viscosity required. To make solution mix 100gms AMMONIUM SULPHATE with 400mls warm water.
BINDER ET- To allow the addition of more than 60gms of pigment per kilo of normal extender a BINDER is used to ensure good fastness. For every extra 5gms of pigment/Kg add 10gms of BINDER/Kg of printpaste. White ink needs an extra 100-150gms per kilo of BINDER. This also applies to OPAQUE, PUFF OR LUSTRE BASES once your pigment addition exceeds 60gms.
THICKENER ET-9 - To thicken inks use 5-15gms per Litre. THICKENER ET-9 may be used with all inks including OPAQUES. If ink has been thinned with Ammonium Sulphate the effect of this thickener is significantly reduced. Thickener ET-9 may be reduced 50/50 with water before adding to your ink. This will allow you to blend in the thickener more successfully.
UREA - To prevent ink drying in the screen in hot weather, stir in 5-10gms (1-2 teas) UREA per kilo of BASES. THESE AMOUNTS SHOULD NOT BE EXCEEDED OTHERWISE PRINT FASTNESS MAY BE EFFECTED.
LOW TEMP CATALYST - is added to the ink to improve the crosslinking or curing at lower temperature. The shelflife of the catalyst in the ink is 24 hours, after which time you will need to add more. Add 20-40g per litre just prior to printing.