Project

Obtaining hydrophobic fabrics by microstructuring

A

Problem

Our client is a manufacturer of synthetic fabrics and wants to improve their hydrophobicity in order to reduce the adhesion of stains during regular use.

Objective

Enhance the easy-to-clean characteristic of fabrics without substituting or adding additives to the fabric. Finally, the technique selected to improve the hydrophobicity of the fabrics was microstructuring.
B

ATRIA Solution

Among all the techniques that we are currently working on at ATRIA, functional microstructuring was selected as the best option to generate hydrophobicity in our client’s tissues. The reason why this technique has been selected with respect to coatings or additives is that it does not require the introduction of new chemical compounds in the product or production process. By structuring the surface of the fabric, hydrophobic effects can be achieved.

In the first place, a bibliographic study phase was carried out, from which several interesting microstructures were extracted to improve the hydrophobicity of plastics. Among all the microstructures, 9 were chosen, which were tested on a laboratory scale using the hot stamping technique.This technique allows many structures to be tested on a laboratory scale to select the one with the best properties before moving on to the pilot testing stage on microstructured rollers.

Also, during these trials, key process parameters such as pressure and temperature were optimised. They were defined with which a high transfer of the microstructure to the fabric was achieved.

Once all the microstructures in the tissue had been marked, the final transfer was evaluated by confocal microscopy. To do this, the depth of the microstructure obtained in the fabrics is measured.

In addition, the improvement in hydrophobicity obtained by the fabrics with each microstructure was verified. For this, a goniometer was used with which it is possible to measure the static contact angle formed by the liquid with the surface of the tissue.
Finally, a microstructure was selected with which it was possible to obtain a contact angle greater than 120º, for which superhydrophobic fabrics were obtained.