Simple and rapid method for restoring anti-adhesive organosilane coatings on metal substrates

Application of organosilane coatings for improved anti‐adhesive properties enabling facilitated demolding in polymer processing

“…Exchangeable steel substrates of a special measuring device in an instrumented injection mold were activated by corona discharge or flame treatment and subsequently coated with an organosilane layer to introduce anti‐adhesive properties to the substrate surfaces. As proved in our previous study, the combination of a monopodal perfluoroalkyl silane and a dipodal silane provided excellent oil and water repellency (low‐surface energy), good durability and high thermal stability 45 . In addition, polysiloxanes are well known for their resistance against oxidation and chemicals 19,40 .…”

“…PFOS was chosen as the main component for this anti‐adhesive coating because it provides water and oil repellency, mechanical duration, and thermal stability 19,40 . BOS was added to further improve the durability and bond strength of the organosilane layer, relying on increased crosslinking densities, which were achieved due to increased amounts of hydrolizable groups provided by the dipodal silane 23,45 …”

“…For renewal of the anti‐adhesive coating in case of damage and wear, the primary organosilane layer was removed by flame treatment and a secondary coating was applied directly without any further activation step by another sequence of immersion and thermal curing. The mechanism of the developed recoating procedure was explored in detail in our recent publication 45 . It was revealed that the organic moieties of the coating were pyrolized upon flaming, while the inorganic components remained on the substrate surface, building a Si‐(O) 4 layer there.…”

“…Representative changes of the water contact angle during the coating and recoating procedure on the basis of ref. 45 [Color figure can be viewed at wileyonlinelibrary.com]…”

“…As presented in ref. 45, the recoating procedure based on flame treatment proved to be repeatedly applicable, providing constant quality and performance of the organosilane coating. More precisely, this refers to the anti‐adhesive properties, the thermal stability and the chemical composition of the coating.…”