Acetal Resin DELIN Vs. POM

DELIN is the trade name of POM produced by DuPont in the United States, that is, race steel POM.

Polyformaldehyde (English: polyformaldehyde) thermoplastic crystalline polymer. Known as "super steel" or "race steel", also known as polyoxymethylene. Abbreviated as POM, it is a polymer obtained by polymerization of common formaldehyde, with a low degree of polymerization and susceptible to thermal depolymerization. It can be used as the raw material of organic chemical industry and Synthetic Resin, and also used as drug fumigant.

Formaldehyde is a kind of hard and dense material with smooth and light outside, light yellow or white, thin-walled part is semi-glossy. Extinguishing characteristics for easy to extinguish, away from the fire after the succession of extinguishing, the flame is yellow at the upper end, the lower end of the blue, the occurrence of molten drops, there is a violent irritating formaldehyde flavor, fishy odor. Polyformaldehyde is a white powder, ordinary non-transparent, good coloring, specific gravity 1.41-1.43 g/cm3, molding shrinkage 1.2-3.0%, molding temperature 170-200 ℃, drying prerequisite 80-90 ℃ for 2 hours.

POM's long-term heat-resistant function is not high, but short-term can reach 160 ℃, in which the homopolymerization of POM short-term heat-resistant than copolymerization of POM higher than 10 ℃, but long-term heat-resistant copolymerization of POM instead of homopolymerization of POM higher than the next 10 ℃. Can be used in the -40 ℃ ~ 100 ℃ temperature scale for long-term use. POM is very easy to analyze, analysis temperature of 280 ℃, analysis of irritating and erosive gas occurs. Therefore, the mold steel should be used to produce erosion-resistant materials.

Mechanical function

POM strength, high stiffness, good elasticity, good wear resistance. Its mechanical function is excellent, than the strength of up to 50.5MPa, than the stiffness of up to 2650MPa, and the metal is very close to the mechanical function of POM with the temperature shift is small, copolymerization of POM than homopolymerization of POM shift is slightly larger.

POM impact strength is high, but the conventional impact is less than ABS and PC;

POM is sensitive to notch, out of the notch can make the impact strength landing as much as 90%. POM's fatigue strength is very prominent, 10 alternating load, fatigue strength of up to 35MPa, while the PA and PC is only 28MPa.

POM creep and PA similar, at 20 ℃, 21MPa, 3000h only 2.3%, and by the temperature is very small.

POM friction factor is small, good wear resistance (POM>Pa66>Pa6>ABS>HPVC>PS>PC), the limit of PV value is very large, self-smoothness is good.POM products on the grinding, high loads are prone to produce noise similar to screaming.

POM raw material performance characteristics and the difference between different types of POM

POM raw material synthetic resin" in a, also known as polyformaldehyde resin, POM plastic, steel, etc.; is a white or black plastic particles, with high hardness, high steel, high wear resistance.

1, POM for milky white opaque crystalline linear thermoplastic resin, with good overall performance and coloring, has a high modulus of elasticity, very high rigidity and hardness, specific strength and specific rigidity close to the metal;.

2, Tensile strength, bending strength, creep resistance and fatigue resistance is excellent, resistance to repeated impact, de-loading response is excellent.

3.Small coefficient of friction, abrasion resistance, good dimensional stability, good surface gloss, high viscoelasticity, excellent electrical insulation, and is not affected by temperature; good insulation resistance and is not affected by humidity.

4, Excellent chemical resistance: in addition to strong acids, phenols and organic halides, stable to other chemicals, oil resistance; mechanical properties are affected by the temperature is small, with a high heat distortion temperature.

5, The disadvantage is poor flame retardant, fire Xu Xu combustion, oxygen index ° small, even if the addition of flame retardant can not get satisfactory requirements, in addition to weathering is not ideal, outdoor applications to add stabilizers.

6, Homopolymer aldehyde high knot, mechanical strength, rigidity, heat distortion temperature than co-polymer aldehyde good, co-polymer aldehyde melting point is low, thermal stability, chemical resistance, flow characteristics, processability are better than homopolymer aldehyde, the newly developed products for the ultra-high-flow (rapid prototyping), impact resistance and reduce mold deposition of the grades, but also inorganic filler, enhanced grades.

7, POM raw material water absorption is greater than 0.2%, should be pre-dried before molding, POM melting temperature and decomposition temperature is similar to the poor molding, can be injection molding, extrusion, blow molding, rotomolding, welding, bonding, film coating, printing, plating, machining, injection molding is the most important processing methods, molding shrinkage 9 large, the mold temperature is appropriate to be higher or annealing treatment 9, or to add reinforcing materials (such as alkali-free) Glass fiber.

The difference between different kinds of POM

POM is divided into copolyformaldehyde and homopolyformaldehyde.

1, Co-polyformaldehyde is more flexible than homopolyformaldehyde.

2, Copolyformaldehyde than homopolyformaldehyde to hot water resistance and alkali resistance is better.

3, Homoxymethylene is about 10℃ higher than the melting point of copolyformaldehyde resin, and the heat distortion temperature is also higher.

4, Paraformaldehyde is more rigid than copolyformaldehyde resin, fatigue and repeated impact resistance and abrasion resistance and other mechanical properties are more excellent.

5, General grade, copolyformaldehyde than homopolyformaldehyde weather resistance is slightly better.