Ultra Low Density PU Slipper System

Ultra Low Density PU Slipper System The PU system sector stands among the most productive and dynamic fields in terms of new product development within the chemical industry. Examination of product lifecycles in this sector reveals the rapid development cycles characteristic of the field. Products are continually developed and introduced to market with higher mechanical properties that are softer, more flexible and less dense. The density trend in PU footwear systems provides the clearest illustration of this progression. In the 1990s, moulded density of shoe soles stood at 600 kg/m³, declining to 450-600 kg/m³ during the 2000s and further to 350-500 kg/m³ in the 2010s. Currently, shoe sole moulded density stands at 350-450 kg/m³ as standard, while slipper sole moulded density is 250-300 kg/m³. In the near term, moulded density slipper systems of 200-250 kg/m³ are expected to become standard. Key advantages of developing low density footwear systems include: • Lower cost (reduced raw material consumption) • Increased competitiveness of PU against EVA and other polymers • Enhanced comfort and lightness • Design flexibility in footwear (elimination of weight constraints for larger shoes) • Reduced environmental impact (lower raw material consumption and waste generation) Motivation for low density product development has intensified as economic difficulties, reduced purchasing power and escalating raw material prices have emerged in recent years. Footwear sector producers consequently seek low-grade raw materials and low-cost fillers to address these challenges. However, such solutions adversely impact product lifespan, flexibility and mechanical/physical properties. PU system manufacturers have accelerated research into low density products aimed at reducing footwear manufacturer costs without compromising final product quality. Recent advances in the PU sector have facilitated development of low density slipper systems. Novel resins and additives developed by Poleks Kimya have enabled ultra low density slipper systems. Additionally, advances by global producers in new generation surface active materials (silicones, etc.) affecting cell structure and openness, and new generation catalysts regulating PU reaction rates, have contributed to low density system development. Poleks Kimya, with an extensive footwear product range (FootPUR), ranks among the leading system houses in this field. This product family encompasses systems of varying density, hardness, flexibility and reaction rate (over 20 products with different properties). Low density, low hardness and high flexibility systems are particularly prominent in this range. The Poleks Kimya R&D team has completed R&D studies for the ultra low density slipper system and successfully completed pilot production and customer trials. The ultra low density slipper system developed by Poleks Kimya's R&D team achieves 25% lower moulded density compared to standard products. Dimensional stability, cell structure, skin quality and mechanical properties become critical at low density. The Poleks Kimya ultra low density slipper system delivers performance equivalent to standard slipper systems (Table 1). The system offers a broad working ratio range, good flowability in the mould and rapid demoulding time. The product provides high flexibility, fast rebound, fine cell structure, smooth skin and low temperature sensitivity. Additionally, the product can be used as a lightweight and comfortable middle-sole system in dual-density systems. Poleks Kimya can develop systems with different properties (harder/softer or faster/slower reaction rates, etc.) tailored to customer requirements through minor product modifications.   Yücel Aktay - Senior Chemical Engineer R&D and Technical Support Specialist Poleks Kimya San. ve Tic. A.Ş. Dr. Murat Baranak - Chemical Engineer R&D and Quality Control Manager Poleks Kimya San. ve Tic. A.Ş. Cihat Mıhla - Chemical Engineer R&D and Technical Support Specialist Poleks Kimya San. ve Tic. A.Ş. Mesut Gürgen - Chemist Technical Support and Business Development Executive Poleks Kimya San. ve Tic. A.Ş.