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 PBTExcellent in mechanical propertiesExcellent in chemical resistance and oil resistanceGood in weather resistanceGood in electric propertiesCapable of continuous use in temperatures from 120 to 140 degrees CelsiusPBT (polybutylene terephthalate) Low water absorption rateGood in dimensional stabilityExcellent in friction and abrasion propertiesExcellent in chemical resistanceGood in electric propertiesExcellent in creep resistance and resistance to fatigueCapable of continuous use in temperatures from 120 to 140 degrees CelsiusPEN (polyethylene naphthalate) Excellent in heat resistance (continuous use temperature: approximately 150 to 160 degrees Celsius)Low permeability of gas or steamExcellent in chemical resistanceUltraviolet absorption propertyHigher mechanical properties, compared to PETGeneral properties of polyester resin  Test Method(ASTM)PETPBTPENSpecific gravityD-7921.381.311.36Tm (°C)DSC225～265224～228254～276Water absorption (%)(23°C, 24hr)D-5700.40.08＜0.5Normal use temperature (°C)-120～140120～140150～160Chemical resistanceAcids-○○○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.  PETType 1PETType 2PETType 3PETType 4PENPropertiesShrinkagevery highhighmediumlowvery lowElongationvery lowlowmediumhighlowModulusvery highhighmediumlowvery highTensile tenacity [cN/dtex]7.36.45.44.65.7Elongation at break [%]111728439?Young’s modulus [N/mm2]150001400010000850024000Boiling water shrinkage [%]14105.02.00.1
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.