[ Technical Textiles - What is PET and PA.]

This is given with reference to Industrial Yarn. Some of the trade names of PET products are Dacron, Diolen, Terylene, and Trevira fibers,[1] Cleartuf, Eastman PET and Polyclear bottle resins, Hostaphan, Melinex, and Mylar films, and Arnite, Ertalyte, Impet, Rynite and Valox injection molding resins. The polyester Industry makes up about 18% of world polymer production and is third after polyethylene (PE) and polypropylene (PP).PET consists of polymerized units of the monomer dimethyl terephthalate or ethylene terephthalate, with repeating C10H8O4 units. It contains the chemical elements carbon, hydrogen, and oxygen. If fully burned, it produces only carbon dioxide (CO2) and water (H2O). PET is commonly recycled, and has the number "1" as its recycling symbol. SOURCE. Wikipedia
What is PA.
It is theoretically possible to produce many different types of PA polymers and all tend to be labeled carelessly under the heading of "Nylon". Given the multitude of variants and range of physical and chemical properties this is unwise. In this data file we will try to be specific with regard to the variant being referred to but sometimes the source information is not always clear. The largest volume sales are of the PA 6 and PA 6/6 variants. The other materials tend to be specialist polymers at specialist prices. In most cases the information refers to these materials. As a general family the PA group is rigid, translucent with good fatigue, creep and wear resistance. Chemical resistance varies with the variant but is generally good. SOURCE http://www.tangram.co.uk/TI-Polymer-PA.html