Delrin is POM material, which was made by DuPont after WW2. Delrin has wide using in CNC machining.
Features of CNC machining Delrin :
1. Delrin before CNC machining can be dry, preferably in the process of preheating (80 ℃ or so), the stability of the product size is good.
2. Breathability: Delrin permeability is small, only a fraction of PE.
3.Shrinkage: The high degree of crystallization of Delrin led to it has a very high shrinkage, can be as high as 2% to 3.5%.
4.Mechanical properties: Delrin mechanical properties are quite good, with a high elastic modulus, low friction coefficient and stability, good wear resistance, good self-lubricating. Has a high hardness and stiffness. And metal is very close. Dimensional stability, water absorption is very small, resistant to repeated impact, the intensity of small changes. Its tensile strength and modulus are close to steel. Fatigue strength is good. Is the thermoplastic material in the most resistant varieties of fatigue. Capable of more than one million times repeated load. Mechanical properties with temperature change is small, the copolymer is slightly larger than the homopolymer.
5.Heat resistance: The heat resistance of Delrin is poor, easy to degrade in the molding temperature release formaldehyde, usually in the granulation by adding stabilizer. With a high heat distortion temperature, homopolymerization of 136 ° C, copolymerization of 110 ° C. At 220 ℃ above decomposition, resulting in formaldehyde gas, can be used at 140 ℃ short-term use, long-term use temperature of -40 ~ 100 ℃.
6.Weatherability: Delrin poor weather resistance, long-term exposure in the atmosphere will be aging, long-term under the action of ultraviolet light, mechanical properties, surface powder and cracking. Outdoor applications to add stabilizers.
7.Chemical: The strong resistance of Delrin to chemicals, organic solvents, oils, weak acid, weak base, except to strong acid, phenols and organic halides, but to other chemicals it’s stable. In all engineering plastics in the poly Organic solvents and oil resistance is very prominent. The production of its masterbatch, but also more harsh than the general resin. Polyoxymethylene can not be colored with dyes because of its crystallinity.
8.Electrical: The electrical insulation of Delrin is good, almost free from temperature and humidity; also has excellent arc resistance, and can be maintained at high temperatures.