High-Flexibility Polyurethane Slipper Systems

With a mission to provide polyurethane products that put customer satisfaction and standard quality at the forefront while making life easier for people, the environment and nature, Flokser has been continuously evolving in the textile and chemical sectors for 30 years and continues its chemical sector production under the "Flokser Kimya" brand.

Since 2016, our company has held the distinction of being the first R&D Centre in its sector; polyurethane systems are being developed for the footwear (slippers, soles, insoles, occupational safety), rigid (refrigerator, cold room panels, sandwich panels, spray, pipe insulation, decoration), moulded sponge, filter, integral (office furniture armrests, various auto parts, cables), adhesive and synthetic leather sectors. Some of the shoes and slippers that are an indispensable part of our daily lives need to be designed only for style and fashion compliance, while others must take into account the need for durability, elasticity, lightness and comfort. Due to its superior mechanical properties compared to alternative sole products (rubber, EVA, PVC, etc.), its potential to be produced in different shapes, textures and colours, and its ability to be formulated for application in many different properties and fields, polyurethane has become a highly preferred material in slipper and shoe sole applications in recent years. Within Flokser Kimya; polyurethane systems of different densities and hardness values applicable with injection and low-pressure moulding machines are produced for the manufacture of summer, winter, spring and sports soles, slippers, and single and double density occupational safety shoes and boots. In the slipper sector where our company has signed many firsts with innovative solutions in the Turkish market, it aimed to make a difference in the market again with its new polyurethane system featuring low hardness and superior elasticity properties. The visual of slipper samples moulded with our new polyurethane system, which is presented to the market as a 3-component system of prepolymer, polyol and catalyst, is given in Figure 1.

Figure 1: Polyurethane system with low hardness and high elasticity properties.

Our new product, which is shown visually in the slipper sample moulded in Figure 1, has the following important advantages compared to many polyurethane slipper systems in the sector.

With the new polyurethane system we believe will create a significant difference in the sector with the stated advantages, slipper samples moulded under customer conditions using a low-pressure moulding machine were examined for both reaction conditions and mechanical properties, and the results obtained are given in Table 1. • Low hardness, • Comfort and ease, • Superior recovery, • High flex resistance, • High elongation at break and tear elongation, • Use in different application areas.

Table 1: Technical properties of the low hardness and high elasticity slipper system

*Reaction and working conditions were obtained as a result of measurements made with a low-pressure moulding machine operating at 6000 rpm. ** According to TS EN 12222 standard, test results of samples are provided after conditioning for 24 hours at 23±2 temperature and 50% relative humidity. ***Sample thickness: 10 mm (Specific gravity < 0.40 g/cm3) The newly developed polyurethane system enables application under standard slipper production conditions in terms of reaction conditions such as reaction profile and mould opening time, and it is clearly seen from the performance test results given in Table 1 that it will create a significant difference in mechanical properties compared to its equivalents with its high flex resistance. While polyurethane systems providing high hardness values are generally used in slipper products, in recent years due to increasing consumer expectations for comfort and ease, the search of manufacturers has shifted towards products with lower hardness values. In response to this demand, our company, which created a significant difference in the sector in customer-focused work, aims to provide the production of slipper products with 40-45 ShoreA hardness values with high elasticity values with its newly developed system.

In the flex resistance test conducted according to TS EN ISO 17707 standard, the growth in the notch opened after 30,000 steps was found to be <4 mm, and quite superior performance was achieved compared to systems used in this field.

Another important advantage of the new polyurethane system we present to the sector is that in addition to slipper applications, it enables use especially in sports sole production due to its superior performance in elongation at break and tear resistance. As shown in Figure 2 and from the results of the elongation at break test conducted according to EN 12803 standard, it is seen that our newly developed product will exhibit superior performance for sports sole applications. With our new polyurethane system, which makes a difference compared to its equivalents in the sector in terms of application flexibility and end product mechanical properties and was developed at the Flokser Kimya R&D Centre, a system has been brought to the market that can be used both in the slipper sector and in sports and intermediate sole applications. Our company will continue to make a difference in the sector and lead the sector with customer-focused innovative solutions.   Serpil Yılmaztürk Güney R&D Manager Flokser Kimya     Oğuz Tükek R&D Director Flokser Kimya

Figure 2: Elongation at break test conducted according to EN 12803 standard of the slipper product with superior flex resistance and elongation at break properties.