What is TPU? - TPU stands for thermoplastic polyurethane and is a block copolymer consisting of alternating sequences of hard and soft segments. The proportion of hard and soft segments can be manipulated to produce a wide range of hardness. Different ratio of hard to soft segments will result in different hardness TPU. Its hardness can be highly customized and are available in a hardness range of 60A to 80D. TPU can be as soft as rubber or as hard as rigid plastics.  The hard segments are isocyanates, and can be classified as either aliphatic or aromatic depending on the type of isocyanate. The soft segments are made of a reacted polyol. The hard segment defines the TPU's processing temperatures, its continuous and upper use temperature limits, tensile strength, chemical resistance, and adhesion characteristics. The soft segment determines the TPU's lower service temperature limits, hardness, flexibility and compression set. TPU offers flexibility without the use of plasticizers.

TPU resin, Thermoplastic polyurethane possesses the high toughness, mechanical strength, bio-compatibility, and resistance against oil, chemical, hydrolysis, and bacteria. The soft segment is either a polyester or polyether type polyol. Polyester-based TPU's are preferred for applications requiring optimal physical properties and resistance to oil and hydrocarbons, while polyether-based TPU's should be considered for parts used in moisture- rich and cold temperature environments.

TPU main features:

· Abrasion, impact and puncture resistance

· Antimicrobial and fungal resistance

· Recyclable

· Chemical and hydrolysis resistance

· Easy-to-extrude

· High moisture vapor transmission

· Optical clarity

· Skin contact approved

· Soft

· Elastic

· UV resistant

Thermoplastic Polyurethane can be processed easily via conventional processing methods like injection molding, extrusion, blow and compression molding etc. They are easily molded into shapes to produce shoe sole, medical castor, air tube and several other applications as discussed above. It can also be compounded to create robust plastic moldings or processed using organic solvents. TPU features with both superior performance and processing flexibility is the ideal polymer for applications in a wide variety of markets. Such as footwear, tube, castor, wire and cable, film and sheet, compounding, adhesives and specialty molded parts.

Limitations of Thermoplastics Polyurethanes

• Drying time is required before processing can begin

• Not as cost-effective as other alternatives

• Narrower hardness range than other TPEs

• Narrow temperature range for processing

Please note: Drying is a critical step in ensuring TPU’s process effectively and that a good part is obtained upon molding. If moisture is not removed from the polymer effectively before processing, drying of molded parts would not take effectively leading to loss in properties and brittleness. Recommended residual moisture content For injection molding ≤ 0.05% For extrusion 0.02%