What is stain resistance in paints? How to test stain resistance?
- April 19, 2017
- Posted by: MahaChem
- Category: Coating, ST
You will find paints labelled with anti-stain or stain resistance when you go to paint shop to buy a can of paint. Are you familiar with the term, ‘stain resistance’? Do you know what kinds of stains that the paint is able to resist and how does paint companies test it?
Types of Stains Tested in Stain Resistance Test
The stains which paint company tests consist of common household stains. They can be divided into hydrophobic and hydrophilic stains as showed below:
- Hydrophobic stains : These stains are oil based materials such as cooking oil, newspaper ink, crayon, lip stick, pencil etc.
- Hydrophilic stains : These stains are water based materials such as tea, coffee, soya sauce etc.
Stain Resistance Test Procedure
The stain resistance test procedure is as shown below.
- Applying two paints side by side on a black colour PVC sheet. One of the paint is the market standard, and the other paint (Our Sample) is a newly formulated paint which we wanted to know the performance. Let the paint dry for 7 days.
- Apply a few types of stain horizontally on both paints. Wait for 15 minutes.
- Use a wet cloth to wipe off half of the stained areas.
- After dried, examine any residues of the stains left on the paint film. The paint film with good resistance will have less stains. The surface of paint film can only be either towards more hydrophilic or more hydrophobic. As “Like attract Like”, hydrophobic surface will attract hydrophobic stains and hydrophilic surface will attract hydrophilic stains which make it more difficult to clean. Paint companies will try to achieve a balance of hydrophobic and hydrophilic properties on the surface of paint film. They also use the additives to prevent penetrating of stains into the paint film. In the below photo, the Sample A which formulated by Maha has better resistant to the stains of colour pencil and 2B pencil than the market standard.
The picture below shows our sample has better stain resistance than the market standard.
Do you need our help in attaining stain resistance paint? See below what we can offer to you.