Kuraray's new process for film grades of its thermoplastic polyurethane Kuramiron gives material with consistently high quality, little variation in melt viscosity and low gel content, said Akira Matsumoto sales manager for Kuraray in an 28 Oct interview at the K 2010 show in Dusseldorf.
Stable melt viscosity is important for consistent TPU film production, while low gel content is crucial 'in eliminating "fish eye" - a common and unwanted film defect, Matsumoto added.
Kuraray has only recently developed the innovative control technology that allows such grades, said Matsumoto, noting the high concern among film converters about fish eye defects. A major use for TPU films is the covering for spiral-wound hose for conveying food ingredients, he said. This is a use where low fish-eye occurrence is valued by processors since a single fish eye is cause for film rejection, Matsumoto noted.
Japanese materials supplier Kuraray regards itself as a supplier of speciality TPUs, making only 1500 tonnes of its speciality Kuramiron types, and no commodity TPU types, Matsumoto said.
According to the Japanese group, the new process gives durable TPUs with excellent abrasion resistance, compression set and heat resistance.
Matsumoto claimed that the new TPU is superior to other TPUs in stability of melt flow viscosity.
Kuraray also makes very good soft-touch grades with no plasticiser, claimed Matsumoto. Thse are alloys with another material – whose nature he declined to reveal
“Such alloys also give good bonding to a range of engineering thermoplastics including ABS and polycarbonate for two-part mouldings,” he said.
High adhesion to engineering thermoplastics is valuable in many soft-touch uses where the TPU is over moulded on to a hard plastics for aa handle with good grip or pleasant feel.
Because of such attractive qualities, these Kuramiron TPU grades sell well despite their high costs, Matsumoto said.
Kuraray judges the time is right to try selling its TPUs in Europe, and used K to expose customers in the region to the materials, testing the waters against the strong domestic TPU producers in Germany and across Europe – a “very challenging” prospect, Matsumoto commented.