Fluoroplastic Etching Service
Adtech can chemically etch the surface of PTFE, FEP and PFA tubing, heat shrink sleeving and films.
Fluoroplastics are well known as 'non-stick' materials and have an extremely lubricious surface,therefore, bonding to other substrates is a problem.
The chemical etching treatment changes the surface finish by altering the polymers properties, making them very suitable for bonding with most adhesives e.g. epoxy resins, polyurethanes, silicone RTVs, etc.
How does the chemical etching process work?
The chemical etching process causes a reaction between the fluorine molecules in the surface of the material and the sodium solution. The fluorine molecules are stripped away from the carbon backbone of the fluoropolymer, which leaves a deficiency of electrons around the carbon atom. Once exposed to air, hydrogen, oxygen molecules and water vapour restore the electrons around the carbon atom. This results in a group of organic molecules that allow adhesion to take place.
What does a chemically etched material look like?
After the chemical etching process has been completed the surface of the FEP, PFA or PTFE is darkened to varying shades of brown. The darkness of the etched surface is not an indication of how good the surface is. As you usually get a variation in the depth of colour of the chemically etched surface.
How do you store chemically etched products?
Chemically etched material should be kept wrapped and in the dark as UV can breakdown the etched surface. The etched surface will also want to continually replace its electron deficiency and so will take molecules from the air, as it does this the surface becomes less suitable for adhesion.
Can you control the application of the etch to certain surfaces?
Yes, in most cases customers only require the inside or outside surface of the material to be treated. However, we can offer:
ID and OD for a set length
ID or OD only
ID and OD
Areas can be masked off to ensure the etch is only present in the area to be bonded.
Does the chemical etching process affect the materials properties?
No. The chemical etching process only changes the very top layer of the fluoropolymer surface, therefore, all of the other excellent material properties remain the same.