Main features of ABS
Plastic ABS resin is the most widely used and widely used polymer. It combines the various properties of PB, PAN and PS organically, and has excellent mechanical properties of toughness, hardness and rigid phase balance. ABS is a terpolymer of acrylonitrile, butadiene and styrene, A represents acrylonitrile, B represents butadiene, and S represents styrene. After actual use, it was found that: ABS plastic pipe is not resistant to sulfuric acid corrosion, and it is pulverized and broken in case of sulfuric acid.
Because of its three compositions, it imparts good performance; acrylonitrile imparts chemical stability, oil resistance, certain rigidity and hardness to ABS resin; butadiene increases its toughness, impact and cold resistance; Styrene gives it good dielectric properties and exhibits good processability.
Most of the ABS is non-toxic, impervious to water, but slightly permeable to water vapor, and has a low water absorption rate. The water absorption rate at room temperature is not more than 1% per year and the physical properties do not change. The surface of the ABS resin product can be polished to obtain a highly glossy product. It is 3-5 times stronger than ordinary plastics.
ABS has excellent comprehensive physical and mechanical properties and good low temperature impact resistance. Dimensional stability. Electrical properties, wear resistance, chemical resistance, dyeability, finished product processing and mechanical processing are better. ABS resins are resistant to water, inorganic salts, alkalis and acids, are insoluble in most alcohols and hydrocarbon solvents, and are readily soluble in aldehydes, ketones, esters and certain chlorinated hydrocarbons. ABS resin has low heat distortion temperature and is flammable and has poor heat resistance. The melting temperature is 217 to 237 ° C, and the thermal decomposition temperature is above 250 ° C. Many of the modified ABS materials on the market today are doped with water and recycled materials. The performance of the customer's molded products is not very stable.
(1) Material properties
Good comprehensive performance, high impact strength, chemical stability, and good electrical properties;
It has good weldability with 372 plexiglass, and is made into two-color plastic parts, and can be chrome-plated and painted;
High impact, high heat resistance, flame retardant, enhanced, transparent, etc.;
The fluidity is a little worse than HIPS, better than PMMA, PC, etc., and the flexibility is good;
Suitable for general mechanical parts, wear-resistant parts, transmission parts and telecommunications parts.
Amorphous material, medium fluidity, large moisture absorption, must be fully dried, plastic parts with glossy surface requirements must be preheated and dried for 80-90 degrees for 3 hours;
It is advisable to take high material temperature and high mold temperature, but the material temperature is too high to be easily decomposed (decomposition temperature is >270 °C). For high precision plastic parts, the mold temperature should be 50-60 ° C, for high gloss, heat-resistant plastic parts, the mold temperature should be 60-80 ° C;
If you need to solve the water trap, you need to improve the fluidity of the material, adopt high material temperature, high mold temperature, or change the water level.
If the heat-resistant grade or flame-retardant grade material is formed, after 3-7 days of production, plastic decomposition products will remain on the surface of the mold, resulting in the surface of the mold being bright, and the mold needs to be cleaned in time, and the surface of the mold needs to be increased in exhaust position;
The cooling speed is fast, the mold casting system should be thick and short. It is advisable to set a cold material hole, and the gate should be large, such as: direct gate, disc gate or fan gate, etc., but the internal stress should be prevented from increasing. Adjustable gates are available if necessary. The mold should be heated, and wear-resistant steel should be used;
The material temperature has a great influence on the quality of the plastic parts. If the material temperature is too low, the material will be short of material, the surface will be dull, the temperature of the silver wire will be too high and the temperature will be too high, and the silver strip will appear, and the plastic parts will change color and foam;
The mold temperature has a great influence on the quality of the plastic parts. When the mold temperature is low, the shrinkage rate, elongation, impact strength, bending resistance, compression resistance and tensile strength are low. When the mold temperature exceeds 120 ° C, the plastic parts are cooled slowly, the mold is easily deformed, the mold release is difficult, and the molding cycle is long;
The molding shrinkage rate is small, and it is prone to melt cracking and stress concentration. Therefore, the molding conditions should be strictly controlled during molding, and the plastic parts should be annealed after molding;
The melting temperature is high, the viscosity is high, and it is not sensitive to shearing. For plastic parts larger than 200g, screw type injection machine should be used, the nozzle should be heated, and the open type extension nozzle should be used, and the injection speed is high speed.
(3) Bonding problem
According to different needs, you can choose the following adhesives:
1.G-977: One-component room temperature curing soft elastic anti-vibration adhesive, resistant to high and low temperature, different viscosity bonding speed for several seconds to several hours to cure;
2. KD-833 instant adhesive can quickly bond PC plastic in seconds or tens of seconds, but the adhesive layer is hard and brittle, and it is not resistant to hot water immersion above 60 degrees;
3. QN-505, two-component adhesive, soft rubber layer, suitable for large-area bonding or compounding of PC plastic.
ABS plastic tube
ABS plastic tube
However, the high temperature resistance is poor;
4.QN-906: two-component adhesive, high temperature resistance;
5.G-988: One-component room temperature vulcanizate, after curing, the elastomer has excellent waterproof, anti-vibration adhesive, high and low temperature resistance, 1-2mm thickness, initial solidification in about 10 minutes, basic curing in 5-6 hours , has a certain strength. It takes at least 24 hours to fully cure. Single component, no need to mix, apply after standing after extrusion, no need to warm.