Home > Products > Materials > Polyester monofilament Polyester monofilament is thermoplastic engineering resin, which is produced mainly from polycarboxylic acid (dicarboxylic acid) and polyalcohol (diol). We have a line of monofilaments made of polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalate. The optimum grade can be offered in accordance with customer needs. Characteristics of polyester resin PET (polyethylene terephthalate)   Better in various heat properties than PBT Excellent in mechanical properties Excellent in chemical resistance and oil resistance Good in weather resistance Good in electric properties Capable of continuous use in temperatures from 120 to 140 degrees Celsius PBT (polybutylene terephthalate)   Low water absorption rate Good in dimensional stability Excellent in friction and abrasion properties Excellent in chemical resistance Good in electric properties Excellent in creep resistance and resistance to fatigue Capable of continuous use in temperatures from 120 to 140 degrees Celsius PEN (polyethylene naphthalate)   Excellent in heat resistance (continuous use temperature: approximately 150 to 160 degrees Celsius) Low permeability of gas or steam Excellent in chemical resistance Ultraviolet absorption property Higher mechanical properties, compared to PET General properties of polyester resin     Test Method (ASTM) PET PBT PEN Specific gravity D-792 1.38 1.31 1.36 Tm (°C) DSC 225～265 224～228 254～276 Water absorption (%) (23°C, 24hr) D-570 0.4 0.08 ＜0.5 Normal use temperature (°C) - 120～140 120～140 150～160 Chemical resistance Acids - ○ ○ ○ Alkalis - × × △ Organic solvent - ○ ○ ○     Use of polyester monofilament   forming fabrics and dryer fabrics for paper making Bristles for brushes   “ACRAS”(tapered bristle for tooth brush) Abrasive and grinding brush   Mesh cloth for screen printing Bolting cloth Belts Interlining cloth Member of cable Physical properties of polyester monofilament Here is the introduction of the representative grades of our polyester monofilament. The table below shows the physical properties of the general grades of polyethylene terephthalate (PET) and polynaphthalate (PEN) monofilament. PET monofilament has different types of shrinkage; elongation and Young’s modulus change according to the shrinkage ratio. Also, PEN monofilament tends to be higher in Young’s modulus and lower in elongation and shrinkage, compared to PET monofilament.   PET Type 1 PET Type 2 PET Type 3 PET Type 4 PEN Properties Shrinkage very high high medium low very low Elongation very low low medium high low Modulus very high high medium low very high Tensile tenacity [cN/dtex] 7.3 6.4 5.4 4.6 5.7 Elongation at break [%] 11 17 28 43 9 ?Young’s modulus [N/mm2] 15000 14000 10000 8500 24000 Boiling water shrinkage [%] 14 10 5.0 2.0 0.1   Shrinkage properties of polyester monofilament We can design the shrinkage property of polyester monofilament, according to customer requests. Heat resistance and hydrolysis resistance of polyester monofilament In general, long-term heat resistance of polyester monofilament is better than that of nylon monofilament. We can offer a high heat resistance type whose heat resistance is increased, in addition to a standard type having general heat resistance. Also, a type of polyester monofilament reinforced in hydrolysis resistance is available.