Ko te Polyethylene terephthalate (PET) he polymer ahua tioata he tino pai te parenga matū, te rewa me te hurihuri.Ko te waerau he mea tito i nga waeine tukurua e whakaatuhia ana i te Whakaahua 1. Ko ia waeine he 1.09 nm te roa o te tinana me te taumaha ngota o te ~200.Ina puta mai i te hohenga o te waikawa terephthalic me te ethylene glycol, ka kapi ki te taha maui e H- me te taha matau ki te –OH.Ko te polymerization ka haere tahi me te hanga wai ka tangohia i raro i te pāmahana teitei me te korehau.Na te noho o te wai i roto i te ahua rewa ka tere te whakakore i te hanganga kia tino whakamarokehia te polymer i mua i te whakarewatanga o te miro muka.

Ko te whakakai kakara ka honoa ki te mekameka aliphatic poto ka waiho te waerau hei ngota ngota uaua ka whakaritea ki etahi atu polymers aliphatic penei i te polyolefin, te polyamide ranei.Ko te kore o te neke o te wahanga i roto i nga mekameka polymer ka hua te tino pai o te waiariki.He tau toharite o te 100 waeine tukurua mo ia rapoi ngota ko te roanga o te mekameka polymer angamaheni he 100nm me te taumaha ngota mo te 20,000.Ko nga taumata teitei o te polymerization ka nui ake te kaha o te muka engari ko te rewanga me te pumau o te whakarewa ki te iti noa o te makuku ka paheke te hydrolytic.Ko te inenga o te tohu toharite o te polymerization ka mahia ma te rewa rewa (ma te ine i te maturuturunga iho o te pehanga i roto i te orifice) te pokey ranei o te polymer kua waimeha i roto i te whakarewa tika.Ko te mea whakamutunga ko te inenga o te roa o te mekameka polymer e mohiotia ana ko te Intrinsic viscosity or IV and the value for a typical fiber grade polymer is 0.6 dl/g in 60/40 w/w ranunga o te phenol me te tetrachloroethane whakarewa.Ko te IV i roto i te whakarewa o muri e pa ana ki te Mv (Viscosity average molecular weight) o te polymer na te taurite Mark Howink (Equation 1).