PTT project  

PTT Feature

PTT is short for polytrimethylene-tereph-thalate, the first PTT is made by Shell Chemical and DuPont, they produced PDO from petroleum process and bio-corn process, by polymerization reaction with PTA to produce PTT, then after spinning the new polyester fiber-PTT fiber is made. PTT fiber, PET fiber and PBT fiber all belong to polyester fibers. PTT fiber has combined the features of polyester, nylon, and acrylic fibers. It is good in antifouling and dye. It is soft and high resilience. The tensility is as good as spandex fiber, but easier to process, which is very suitable for textile and apparel fabrics. Besides, PTT also has the feature of dry and comfortable, stiff and smooth. Therefore, PTT will gradually replace polyester and nylon in the near future as the most important fiber in 21st century.


PTT fiber has polyester’s stability and nylon’s softness, its performance in the following:

  1. PTT fabric is soft and with excellent drape.
  2. PTT fabric has comfortable elasticity. (Better than polyester PET, PBT and PP fabric, and similar to PA-6 or PA-66)
  3. PTT fabric has excellent elongation recovery ( it can restored to its original length after 20% elongation)
  4. PTT is good at dyeing and printing ( general disperse dyes can be dyed from 98degree to 110 degree); good in color fastness , light fastness and stain resistance
  5. PTT fabric has bright colors and non-ironing feature.
PTT has a wide adaptability. PTT is suitable for pure yarn, cellulose fiber, natural fiber, synthetic fiber composite, carpet, clothes, underwear, sport suit, swimsuit, and socks.


The application of PTT is broad. Other than making it into fiber for clothes and carpet material, it can also be used for engineering plastics, film material and other field. PTT also has a broad application prospects in the field of film, container, electronics/instrument, household applications, auto parts, furniture since the PDO production cost is reduced. The production technology of PTT is basically the same with PET. The technology is mature. However, since the PDO capacity is not big, it is mainly controlled by Shell and DuPont, which is not readily available in market, thus the industrial production of PTT is subject to certain restrictions.

DMT method is the ester exchange reaction between Dimethyl terephthalate (DMT) and PDO, to polymerize into PTT. Between a molar ratio of 1.2 to 2.2, metatitanic acid ester as catalyst, the ester exchange reaction is carried out in the range of 140 to 220 degree. Then the Ti-Sn compound will be the polycondenstation catalyst to carry out the PPT polymerization under vacuum state from 250 to 270 degree.

PTA Method

High purity PTA and PDO is direct esterificated to continuously polymerize into PTT. The esterification reaction is the autocatalysis reaction of PTA. When it reaches the required degree of polymerization, the polymer will be transferred into Finisher, under 260 to 275 degree, adding butoxy titanium or dibutyl tin oxide or the mixed of the two as catalyst. The condensation byproducts shall be removed under certain vacuum degree until the polymer viscosity reaches a certain degree. Due to the current low cost, the PTA method is still the leading method to produce PTT. 


Huitong has the PTT polymerization technology of maximum capacity of 60,000 ton/year, welcome the investors to contact us for technical consult and communication.