To ensure robustness and optimum sound absorption properties, bathtub manufacturer BSB (Bañera sobre Bañera) and its direct supplier Handcrafted Industrial Projects, both based in the Spanish city of Valencia, have worked closely with polyurethane systems partner BaySystems to produce extremely hard-wearing hotel bathtubs using the filler-free polyurethane system Multitec® Advanced Foam - with considerable success. The shape of today's bathtubs is created by thermoforming a polymethyl methacrylate (PMMA) or co-extruded PMMA with acrylonitrile-butadiene-styrene (ABS) thermoplastic film. To ensure that the molded part has the necessary stability, the reverse side of the thermoformed film has to be reinforced. The solution devised for this purpose was in the form of the new, filler-free polyurethane dual-component spray system Multitec® Advanced Foam.
As per the company, the material's excellent reactivity and easy handling ensure cost-efficient reinforcement of thermoformed films based on PMMA or ABS. The system is applied just like a coating without any need for plasticizers or solvents and is processed without glass fibers or fillers on high- or low-pressure equipment, thereby eliminating need for energy-intensive annealing process. Till now, the reinforcement of the film base on PMMA or ABS has been done in many cases using a time-intensive manual process that involved laminating the film with unsaturated polyesters and cut glass fibers. Two further drawbacks in addition to this time-consuming and labor-intensive hand lay-up process are the use of styrene as a solvent and co-reactant, and the need for annealing during the curing phase.