PS plastic (polystyrene)

English name: Polystyrene

Specific gravity: 1.05 g/cm3

Molding shrinkage rate: 0.6-0.8%

Molding temperature: 170-250℃

Drying conditions: —

characteristic

Main performance

a. Mechanical properties: high strength, fatigue resistance, dimensional stability, and small creep (very few changes under high temperature conditions);
b. Heat aging resistance: the enhanced UL temperature index reaches 120~140℃ (long-term outdoor aging is also very good);

c. Solvent resistance: no stress cracking;

d. Stability to water: easy to decompose in contact with water (use caution in high temperature and high humidity environments);

e. Electrical performance:

1. Insulation performance: excellent (it can maintain stable electrical performance even under humidity and high temperature, it is an ideal material for manufacturing electronic and electrical parts);

2. Dielectric coefficient: 3.0-3.2;

3. Arc resistance: 120s

f. Molding processability: injection molding or extrusion molding by ordinary equipment. Due to the fast crystallization speed and good fluidity, the mold temperature is also lower than that of other engineering plastics. When processing thin-walled parts, it only takes a few seconds, and it only takes 40-60s for large parts.

application

a. Electronic appliances: connectors, switch parts, household appliances, accessory parts, small electric covers or (heat resistance, flame resistance, electrical insulation, molding processability);

b. Car:

1. Exterior parts: mainly include corner grids, engine vent cover, etc.;

2. Internal parts: mainly include endoscope stays, wiper brackets and control system valves;

3. Automotive electrical parts: automotive ignition coil twisted tubes and various electrical connectors, etc.

c. Mechanical equipment: the belt drive shaft of the video tape recorder, the electronic computer cover, the mercury lamp cover, the electric iron cover, the baking machine parts and a large number of gears, cams, buttons, electronic watch casings, camera parts (with heat resistance, Flame retardant requirements)

Bonding

According to different needs, you can choose the following adhesives:

1. G-955: One-component room temperature curing soft elastic shockproof adhesive, resistant to high and low temperature, but the bonding speed is slow, the glue usually takes 1 day or several days to cure.

2. KD-833 instant adhesive can quickly bond PS plastic in a few 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 glue, soft glue layer, suitable for PS large area bonding or compounding. But the high temperature resistance is poor.

4. QN-906: Two-component glue, high temperature resistance.

5. G-988: One-component room temperature vulcanizate. After curing, it is an elastomer with excellent waterproof, shockproof adhesive, high and low temperature resistance. If the thickness is 1-2mm, it will basically cure in 5-6 hours and has a certain strength. It takes at least 24 hours to fully cure. Single-component, no need to mix, just apply after extruding and let it stand without heating.

6. KD-5600: UV curing adhesive, bonding transparent PS sheets and plates, can achieve no trace effect, need to be cured by ultraviolet light. The effect is beautiful after sticking. But the high temperature resistance is poor.

Material performance

Excellent electrical insulation (especially high-frequency insulation), colorless and transparent, light transmittance second only to plexiglass, coloration, water resistance, good chemical stability, average strength, but brittle, easy to cause stress brittleness, and intolerance Organic solvents such as benzene and gasoline. Suitable for making insulating transparent parts, decorative parts, chemical instruments, optical instruments and other parts.

Forming performance

⒈Amorphous material, low moisture absorption, does not need to be fully dried, and is not easy to decompose, but the coefficient of thermal expansion is large, and it is easy to produce internal stress. It has good fluidity and can be molded by screw or plunger injection machine.

⒉It is advisable to use high material temperature, high mold temperature, and low injection pressure. Prolonging the injection time is beneficial to reduce internal stress and prevent shrinkage and deformation.

⒊Various forms of gates can be used, and the gates are connected with the plastic parts arc to avoid damage to the plastic parts when the gate is removed. The demolding angle is large and the ejection is uniform. The wall thickness of the plastic parts is uniform, preferably without inserts, such as Some inserts should be preheated.

use

PS is widely used in the optical industry because of its good light transmittance. It can be used to manufacture optical glass and optical instruments, as well as transparent or bright colors, such as lampshades, lighting appliances, etc. PS can also produce many electrical components and instruments that work in a high-frequency environment. Since PS plastic is a difficult-to-inert surface material, it is necessary to use professional PS glue to bond in the industry.

Using PS alone as a product has high brittleness. Adding a small amount of other substances to PS, such as butadiene, can significantly reduce brittleness and improve impact toughness. This plastic is called impact-resistant PS, and its mechanical properties are greatly improved. Many mechanical parts and components with excellent performance are made from plastics.