Crocktec – colour fastness testing through rubbing (crocking)

The Crocktec is a crockmeter which is used to determine colour fastness to rubbing (crocking). A crocking test shows the resistance of the colour of a textile and other materials to rubbing off and staining.

The Roaches Crocktec is available in both motorised and hand-operated models and they are designed to allow everybody (with the correct consumables) to be able to perform fabric crocking testing procedures.

Advanced materials allow almost frictionless movement at the crank pin and arm guide frame, whilst allowing totally lubricant-free operation. If it is a requirement to perform high volume or extended tests then the Crocktec auto is the motorised version.

Key features

Roaches Orbis touchscreen controller.
Removable load weight to allow contamination free placement of crocking cloth.
The Roaches floating load weight allows a constant pressure for different thicknesses and textures of test substrate.
Constant internal monitoring of the motor, ensuring accurate stroke speed.
Unique method for stroke length check.

Why do we check rubbing fastness of fabric?

When two fabrics rub against each other, there can be a transfer of colour from one to another. This effect is unacceptable and there must be a test to recognise poor colour fastness and the transfer of colour under these conditions. This is Crocking. Assessment is carried out by making a judgment of the colour evident on the reference crocking cloth and grey scales.

What is Crocking?

Crocking is the method employed to accurately assess the quantity of colour transferred from one substrate to another during a controlled and reference test. The Crocking test is carried out using a set number of “rubs”, using a set rub length, during a set time with a set pressure at the point of rub. For added control it is also necessary to use a reference “crocking cloth” as the rubbing adjacent fabric.

What is the colour fastness rating?

Colour fastness rating is the means of evaluating the change in colour of a substrate and/or the transfer of colour from a substrate to an adjacent reference material, multifibre, during a test procedure. The rating is often evaluated by means of the grey scales and will be report as a grade between 1 & 5, with grade 5 being no visible change. Colour fastness rating will assess colour change and colour staining.

Consumables for use with the Roaches Crocktec colour fastness to crocking

Cotton lawn, also known as crocking cloths are used for testing the wet and dry rubbing fastness of textiles. Conforming to ISO 105 F09:2009 and approved by M&S and NEXT test methods. Supplied by the meter, in a 5 meter pack or as cut pieces in the following sizes: 5cm × 5cm or 10cm × 20cm (gimped or straight cut edges).
Grey scales for assessing change in colour or staining according to ISO or AATCC.
Roaches Crockmeter 16 mm rubbing finger.
Roaches Crockmeter 16 mm finger spring clip.
Roaches crocking block (ISO 105 X12 & AATCC 165) used for testing pile fabrics.
Self adhesive emery cloth for crockmeter/Crocktec – pack of 40.

More information

Product brochure: Roaches – Crocktec Auto.pdf