Huntsman introduces first liquid TPU for footwear industry

As a first in the footwear industry, Huntsman introduced a liquid thermoplastic polyurethane (LTPU) that enables rapid manufacture of high-performing midsoles with circularity characteristic.

The new SMARTLITE O LTPU can be processed in a single step, which is easier to use than expanded forms of TPU, which require complex procedures including supercritical foaming and steam chest molding.

The new SMARTLITE O LTPU is easier to use, compared with other expanded forms of TPU.

The easier process also uses significantly less water and energy, and generates less waste and carbon emissions. In addition, SMARTLITE O LTPU can also be converted and repurposed into new materials either in its post-industrial or post-consumer form.

The new LTPU also includes a list of benefits:

• Easy to process: Processed on low pressure casting machines, it is simple to use, scalable and can help streamline shoe manufacturing. Short cycle times are resulted from in-situ polymerization, adhesive-free bonding of midsoles to TPU outsoles, and fast demold rates.

• High performance: With a density of 250kg/m3, the new LTPU produces superior, hydrolysis resistant midsoles that deliver long-lasting, step-in cushioning comfort with rebound of more than 50%.

• Circularity: SMARTLITE O LTPU can lower the carbon footprint of manufacturing processes, without compromising product performance and quality. With circularity initiatives, soling units featuring the new LTPU midsole and a TPU outsole can be mechanically repurchased.

• Freedom of design: New LTPU opens up new creative opportunities, delivering enhanced surface definition without silver lines or the popcorn effect. It is also easy to color and create striking fade effects.

Huntsman officially unveiled the new SMARTLITE O LTPU system at the SIMAC trade fair for footwear and leather goods industries in Milan. To launch this unique, lightweight product, the company has worked with the framas Group, which has the capacity to produce up to two million soling constructions per annum using the new Huntsman’s material.