UV-LED curable coatings for technical textiles
Published on 22 August 2018
Germany
Chemnitz
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About this good practice
The UV-LED curing technology is applied in coating and finishing processes of textiles. The focus of the developments is hereby on the chemistry and rheology of the coating and finishing formulations. For preparing the functionalised technical textiles and prepregs, typical textile coating and finishing technologies like bar or knife coating, padding, kiss roll or spraying are applicable. The specificity is that certain liquid applied coatings (such as PUR-acrylate systems) do not contain any solvents. Therefore, no thermal curing is possible and the curing has to be done instead via UV radiation. Specifically combined formulations form the basis for the coating process. They consist of pre-polymers, functional additives (for flame retardancy, UV protection or optical effects), coating monomers and a photo initiator. By exposure to UV light the photo initiator is activated and a chemical chain reaction is started. The coating is very fast cured (curing time ~1 s). As source of radiation modern UV-LED emitters are used. The developed technology of UV-LED curing offers textile companies an energy-efficient, resource-efficient, water saving, space saving and an eco-friendly method for functional coating of textile materials. By using special additives, additional functionalities (like improved abrasion resistance, soil repellency, hydrophobic, optical, and antimicrobial effects) could be achieved.
Resources needed
To use this technology it is necessary to integrate UV emitters into a textile finishing line. A flexible integration is feasible due to the modular and adaptable design of the emitters. The costs of an UV-LED emitter with a width of 2 m (incl. control and cooling system) amount to ca.120.000 €.
Evidence of success
The success of the described method is closely connected to the on-going interest of industrial partners to use the gained technical experience and research results. Customer orders from industrial partners are carried out. Furthermore, there is a high research demand in several topics, such as flexible and elastic coatings cured with UV-LED, curing of composites or combination of 3D-printing with UV-cured pastes (currently two running and two submitted projects at STFI).
Potential for learning or transfer
From a technological point of view, the described GP is transferable to other regions provided that the requested investment for machinery is available. The technology allows the development of innovative products in the field of technical textiles as well as of processes with high economic efficiency (material, water, and energy saving) and reduced energy costs.
Further information
Website
Good practice owner
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Organisation
Saxon Textile Research Institute
Germany
Chemnitz
Contact
Scientific staff