Despite the availability of several bio-based and biodegradable thermoplastic polymers, there are but a few matching coating applications, due to a lack of easily applicable and affordable bio-based and biodegradable coating formulations.

  • PLA is a commonly used but brittle biopolymer. Therefore, additives are used to improve its impact strength and flexibility. The use of plasticizers to this end often leads to problems of plasticizer migration due to a poor compatibility. 
  • Being an upcoming biopolymer PHA is still expensive, but is expected to become widely available at affordable prices in the coming years. However, its coating applications are underdeveloped as yet.
  • At present, the use of PLA in coatings is limited to extrusion coating on paper or cardboard, mainly for the production of drinking cups. 
  • The production of PLA dispersions often requires the use of solvents or a specific treatment, making them too expensive for the market.

Centexbel developed a formulation based on thermoplastic biopolymers to be used for textile coating that made an end to the above-mentioned drawbacks.
 

EP3875545A1

The Centexbel patent application can be downloaded from 

How did we solve the problem?

For this invention, Centexbel explored:

  • the formulation and use of a textile coating dispersion, comprising a powder dispersed in an aqueous medium
  • a matching textile coating process
  • The coating dispersions are made from bio-based components, limiting the use of fossil-based materials
  • The components of biological origin are often biodegradable containing but few or no organic solvents
  • The dispersions form coatings on a textile substrate, and this in a relatively short time
    • with a low migration of plasticizers, which is favorable to the environment
  • The dispersions are relatively stable and easy to apply
  • The coating can be washed with water with little or no degradation
  • The coating is resistant to abrasion
  • The coating can be made matt, glossy or embossed

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