•  On Jun, 30, 2019
•  admin
•   PVA Sponge Roller

One of our customers is using our PVA sponge in a process consist of red colour dye.  They are applying the red colour dye by PU roller, however, the access colour on the PU roller has to be removed by the PVA sponge.  After a few cycle of contact, the PVA sponge will become red in colour.

This is the first time the customer apply this process setup and they invite DST to contribute our knowledge in this colour dye process.

How the Sponge get Dye

During our visit, we have illustrated some fundamental saying that the porous structure in PVA sponge is actually provides a generous advantage for getting dye in a colorant solution.  Furthermore, about the colour fastness, the colorant is fixed in the PVA sponge and not easy to remove in ordinary cleaning unless chemical is introduced.

In general, PVA sponge is favour to darker colour then light colour.  Having said that, the crimson or navy blue colour has better colour fastness on the PVA sponge.

What is our Assessment on Colour Sponge?

Even though we know the process is using crimson or “red” colour solution and it is not surprise the PVA sponge may get dye out. 

Through some experiments about Colour Dye on PVA sponge, we also show that the colour dye is not reaction of oxidizing process between colorant and PVA sponge.  Perhaps PVA sponge material is stable in nature, it could works with both acidic and alkali detergent solution.

With some destroy tests by cutting the red-dye PVA sponge, we could understand the impact about the colorant penetrate into the PVA sponge.

How to Confirm the Colorant is changing Sponge Colour?

People may have used some analytical way such as FTIR to analyze the colour spectrum.  The spectrum will be further compare with the colorant standard spectrum.  Theoretically this is a correct approach but may be hard to get the conclusion about the source.

We have other approaches, which is more straight forward and easy.  We would propose to remove the colorant from the red-colour solution by adding activated carbon in the solution.  The colorant is a nano-size impurity which very hard to removed by mechanical filtration process.  However, the activated carbon is able to do the job. 

We have to confess that the activated carbon may not only remove the colorant in the solution, it may also remove some other organic matter, hydrocarbon and etc.  Again, we have to emphasize that this is an experiment method which to show proof about the colorant origin.

Base on the size discussion together with some simple experiments, we are able to illustrate the situation to the user.

DST has been supplying PVA sponge to Malaysia domestic and overseas market for many years, we have built up extensive knowledge in the PVA sponge product and application process.  PVA sponge colour dye is one of the topic we work closely.