TPU Thermoplastic polyurethanes

TPU or Thermoplastic polyurethanes

Mainly divided into polyester and polyether type of points, it is wide range of hardness (75-95), abrasion resistance, oil resistance, transparency, flexibility, and in daily necessities, sporting goods, toys, decorative materials and other fields are widely used, flame retardant TPU soft PVC can also be replaced in order to meet the growing field of environmental requirements.

1 Introduction thermoplastic polyurethane elastomer (Thermoplastic polyurethane):
The elastomer is a so-called glass transition temperature below room temperature , elongation at break > 50% , the recovery force is removed relatively good polymer material. Elastomeric polyurethane elastomer is one of the more specific categories, polyurethane elastomer hardness range is wide, a wide range of properties , the polyurethane elastomer is between a class of rubber and plastic polymer materials.
Heated plasticization , the chemical structure with little or no crosslinking , the molecule is substantially linear, however, there are certain physical crosslinking . Such polyurethane called TPU.
Two characteristics of TPU main characteristics are:
Wide range of hardness : TPU by changing the ratio of the reaction components , you can get different hardness products , and with the increase in hardness , and its products still maintain good flexibility and abrasion resistance.
High mechanical strength : TPU products carrying capacity, impact resistance and shock absorption properties .
Cold outstanding : TPU glass transition temperature is relatively low , at minus 35 degrees still maintain good elasticity, flexibility and other physical properties.
Processing performance : TPU thermoplastic material can be a common processing methods for processing, such as injection molding , extrusion, calendering and so on. Meanwhile , TPU polymer materials with certain properties can be processed together complementary polymer alloy .
  TPU
Oil, water , mildew resistant .
Recycling is good .
TPU [1] as an elastomer is between a between rubber and plastic material, which look out from its rigid , TPU elastic modulus of rigidity can be measured . Modulus of elasticity of the rubber is usually 1 ~ 10Mpa, TPU at 10 ~ 1000Mpa, plastic ( nylon , ABS, PC, POM) in 1000 ~ 10000Mpa. TPU fairly wide range of hardness from Shore A 60 ~ Shore D 80 and the entire range of hardness with high elasticity ; TPU in a wide temperature range of -40 ~ 120 °C, a flexible , without the need for plasticizers ; TPU on oil ( mineral oil , animal and vegetable fats and lubricants ) and many solvents have good resistance ; TPU as well as good weather resistance , very excellent resistance to high-energy radiation properties. Known as abrasion resistance, tear resistance , bend strength are excellent scrambling ; tensile strength , elongation , long-term low compression , etc. are significant advantages of TPU .
TPU performance presented here include three aspects: mechanical properties, physical properties and environmental performance.

1 Mechanical properties : TPU mechanical properties of the elastomer include: hardness, tensile strength, compression properties, tear strength , resilience and wear resistance, immunity flexion , etc., and the mechanical properties of TPU elastomers , except those performance, there is a high shear strength and impact energy and so on.
(A) Hardness : Hardness of the material to resist deformation , nicks and scratches of the ability of a target. TPU usually Shore hardness A (Shore A) and Shore D (shore D) durometer , Shore A is used for relatively soft TPU, Shore D for hard TPU. Hardness TPU structure mainly by the hard segment content is determined , the higher the hard segment content , TPU hardness will rise. After the increase in hardness , TPU also change other properties , tensile modulus and tear strength increases , rigidity and compressive stress ( load capacity ) to increase , decrease elongation , increase in density and dynamic heat resistance, increased environmental performance . TPU hardness and temperature there is a certain relationship. Cooling from room temperature down to mutation (-4 ~ -12 °C), no significant change hardness ; temperatures in the mutant , TPU sudden increase in the hardness becomes hard and loses its elasticity , which is due to the result of the soft segment crystallization .
(B) hardness and modulus and elongation hardness and tear strength of the relationship as well as relationships . With the increase in hardness TPU , 100% modulus and 300 % modulus increased rapidly, elongation decreased . This is due to the hardness of the increase was due primarily the result of increased hard segment content . Hard segment content is high, they more easily form the hard segment phase crystal or crystalline form secondary structure increases the number of physical crosslinking restricted material deformation. Subject the material deformation stress must be increased , thereby increasing the modulus , and elongation decreased . TPU relationship between hardness and tear strength , with the increased hardness , tear strength rapidly, and the reasons are the same as explained modulus .
TPU formulations and performance can be very many kinds of permutations and combinations . But in reality , and industrial production design formula , but because materials ( polyol and polyisocyanate and chain extender ) each restriction , so that the true for the development of a high-end applications is very difficult.

4 Use a variety of molded TPU uses:
Car Parts
Ball coupling ; dust cover ; pedal brakes ; locks the firing pin ; bush
Leaf spring bushings ; bearing ; shock components ; inside and outside decoration ; snow chains , etc.
Industrial Machinery & Parts
All kinds of gear ; seals ( mainly from abrasion and oil effect ) ; shock components ; modulo needles ; bushings ; bearing
Cover class ; connector ; rubber sieve ; printing rollers , etc.
Fashion Accessories
Ms. bra straps , clothing elastic belt.
Footwear
Softball shoes , baseball shoes, golf shoes, soccer shoes, soles and shoes forefoot
Ms. heel ; boots ; safety boots , high-grade soles
Other
The caster ; handle ; strap, etc.
Pipe & Hose
High-pressure pipe ; medical tube ; hydraulic pipe ; pneumatic tube ; fuel pipe ; coated tube
Ducts ; fire hose , etc.
Film & Sheet
Rotational band ( with some stretching effect ) ; cushion ; diaphragm ; keyboard plate ; composite fabric , etc.
Wire & Cable
Power communication cables ; computer wiring ; automotive wiring ; exploration cables
Other
Various circular pipeline ; circular band ; V -belt ; belt ; slip tapes
Calender
Software slot, cans ; film composite sheet fabric bags , etc.
Blow Molding
Various types of vehicles with a box type ; various container classes
Blown film
Thin, wide film ( medical , hygiene products )
Solution
Welding materials ; adhesive ; leather, synthetic leather , rope , wire, gloves and other coatings
Ink binder : with good wear resistance , high toughness , anti -stick back excellent performance characteristics .
Main advantages: excellent adhesion ; low viscosity ; good flex resistance ; excellent wear resistance ; high gloss ; excellent weathering performance .
Solvent system: ketone solvents
Applications : All kinds of shoe inks, printing inks, coating paste and so on.
  TPU
TPU thermoplastic polyurethane, a polyester and polyether type of points , it is wide range of hardness (60A-85D), abrasion resistance, oil resistance, transparency , flexibility, and in daily necessities , sporting goods, toys , decorative materials and other fields are widely applications , flame retardant TPU soft PVC can also be replaced in order to meet the growing field of environmental requirements. TPU brand many brands of varying quality , select TPU is best assessed through detailed feasibility studies, or can not get the optimal cost-effective results.