Continuous Coating of Synthetic Fibers Using Hexamethyldisiloxane

Abstract

The aim of this work was to optimize hexamethyldisiloxane (HMDSO) discharges for a continuous deposition on polyester (PET) multifilament fibers (PET 167f136) and to characterize the as‐deposited coatings. Therefore, PET fibers/yarns were cleaned in a one‐step plasma process prior to the coating to ensure a clean and a well‐defined substrate material. XPS was used to investigate the silicon and carbon content. High levels of SiO4 bonds led to a hard and brittle, glass‐like coating. The coating thickness was around 100 nm. Tensile strength tests showed that increasing the heat treatment yielded a decrease in the initial tensile load of the fiber. To correlate the carbon content and wettability, contact angle measurements were performed; scanning electron microscope (SEM) showed a cauliflower‐like structure of the coatings.

Macroscopic Description of Plasma Polymerization

“…While up‐scaling of plasma polymerization processes can be achieved by regarding the similarity parameter, S , the process transfer of plasma activation and etching processes when using non‐polymerizable gases between various reactors is facilitated by considering the energy flux to the substrate, which is mainly determined by the sheath voltage, V sh , and the plasma power density, W / A , which in turn controls the ionization degree, n i / n gas , and is thus almost independent of pressure 11, 39. Recently, we demonstrated the scale‐up of a low pressure plasma process (plasma cleaning and deposition in a one‐step process) with HMDSO both to a (semi‐)continuously running web coater, and to an air‐to‐air operating fiber coater 38, 40…”

Plasma Treatment in Textile Industry

“…Another commonly used method of obtaining hydrophobic surfaces by plasma polymerization is the use of ultrathin SiO x (siloxane coatings) or amorphous hydrogenated carbon films on polymers due to their biocompatibility and wetting properties . Previous studies on plasma‐polymerized hexamethyldisiloxane (HMDSO) coatings on fabrics or directly on the fibres have shown a reduction of the friction on flexible substrates thanks to their hydrophobization by the retention of CH 3 groups within a SiO network . Lei et al performed a superficial copolymerization on polyester using fluid hydrogen silicone onto fabric through a corona plasma discharge.…”

Insight into the Reaction Scheme of SiO2 Film Deposition at Atmospheric Pressure

“…Among them, hexamethyldisiloxane (HMDSO) is very often used. Deposition of SiO 2 from HMDSO on foils, steel, wood or textile has been reported in the past . The atmospheric pressure plasma (APP) sources used for these processes are usually different modifications of dielectric barrier discharges (DBDs), where the treated surface is positioned on one electrode and in many cases serves as a dielectric barrier .…”