Lotus-Leaf Inspired Surfaces: Hydrophobicity Evolution of Replicas Due to Mechanical Cleaning and Mold Wear

Abstract

Inspired from the low wetting properties of Lotus leaves, the fabrication of dual micro/nanoscale topographies is of interest to many applications. In this research, superhydrophobic surfaces are fabricated by a process chain combining ultrashort pulsed laser texturing of steel inserts and injection molding to produce textured polypropylene (PP) parts. This manufacturing route is very promising and could be economically viable for mass production of polymeric parts with superhydrophobic properties. However, surface damages, such as wear and abrasion phenomena, can be detrimental to the attractive wetting properties of replicated textured surfaces. Therefore, the final product lifespan is investigated using mechanical cleaning of textured PP surfaces with multipurpose cloths following the ASTM D3450 standard. Second, the surface damage of replication masters after 350 injection molding cycles with glass-fiber-reinforced PP, especially to intensify mold wear, was investigated. In both cases, the degradation of the dual-scale surface textures had a clear impact on surface topography of the replicas and thus on their wetting properties, too.

An innovative process chain for the production of antibiofouling polymer parts using ultra-fast laser texturing

“…The replicability of laser-textured surfaces onto polymer parts through injection molding has been thoroughly explored in previous literature. However, only a limited number of studies have investigated the performance of replicated laser textures on polymer components [22], [23],…”

Ultrasonic micromoulding: Process characterisation using extensive in-line monitoring for micro-scaled products

“…Micro-injection moulding or micromoulding technology has evolved into an established and highly-repeatable manufacturing process over the last two decades for producing miniature products with intricate features and micro-nano textured surfaces [1][2][3][4][5][6]. Despite this, some inherent aspects of this technique can prove problematic for certain applications.…”