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All kinds of plastic raw materials molding and injection molding conditions

Time：2022-03-07 14:50:07 / Popularity： / Source：

Raw material name Full name in English Molding conditions
ABS Acrylonitrile - Butadene - Styrene 1. Select proper sprue and gate according to fluidity.
2. Select appropriate fusion state corresponding to gate position.
3. Due to high pressure forming, retraction inclination must be more than 2°.
4. Forming shrinkage must be around 0.5%.
5. It is often used for gold-plated products, and precautions are as follows: (1) Temperature of material tube should be high, about 220℃~250℃ (2) Injection temperature should be slow (using secondary pressure method), and injection pressure should be low; (3) ) No release agent; (4) No shrinkage sag and flow marks of weld lines; (5) No scars on the surface of finished product.
6. Heating temperature is 180~290℃, mold temperature is 50~80℃, material tube temperature is 200~230℃, ejection temperature is 200~240℃, injection pressure is 700~1500kg/cm², and minimum operating temperature is 260℃.
7. Use a hot air dryer, drying temperature is 80~100℃, it takes 2~4 hours (below 0.3%), and temperature of the first stage is 220~240℃; second stage is 210~240℃; third stage is 210~240℃; first stage is 180~230℃; fourth stage is 150~180℃; mold surface temperature is 50~90℃, and injection pressure is 500~2100kg/cm².
8. Temperature setting: nozzle 203~295℃, front section 220~295℃, middle section 210~290℃, rear section 180~210℃; screw speed 70~150rpm, mold temperature 10~80℃, pressure holding 30~60%, back pressure 100~250kg/cm².
9. Density 1.04~1.06g/cc, deformation temperature 82~122℃, molding shrinkage rate 0.4~0.8%, specific gravity 1.0~1.2, linear expansion coefficient 0.00006~0.00013/℃, molding shrinkage rate 0.3~0.8%, thermal deformation temperature 66~107℃ (88~113℃).
AS(SAN) Styrene-Acrylonitrile Styrene-Acrylonitrile 1. If molded product is likely to crack, pay attention to design of molded product. In special cases, use a retraction tilt of more than 1°, and pay attention to mold without a low-sag part.
2. Molding shrinkage rate is about 0.45%, heating temperature is 170~310℃, hot air dryer is used, drying time is 2~3 hours (below 0.1%), drying temperature is 80~100℃, and material tube temperature is 180~290℃.
3. Temperature setting: nozzle 205~240℃, front section 190~235℃, middle section 180~230℃, rear section 180~210℃; screw speed 70~150rpm, mold temperature 35~80℃, injection pressure 700~2300kg/cm², holding pressure 30~60%, back pressure 100~200kg/cm².
4. Linear expansion coefficient 0.00006~0.00008/℃, molding shrinkage rate 0.2~0.7%, thermal deformation temperature 91~93℃ (88~99℃), glass transition temperature 125℃, conductivity 0.0003cal.cm.s.sm/ ℃, density 1.06~1.08g/cm³, tensile strength 650~800kgf/cm², elongation rate 2~3%, elastic coefficient 32000~37000 kgf/cm², 2.1~3.2kgf.cm/cm, Rockwell hardness M80, transparent, water absorption 0.2~0.3%.
CA Cellulose Acetate 1. Material must be pre-dried, drying temperature is 75~80℃, drying time is 2~6 hours, and specific gravity is 1.29.
2. Forming shrinkage rate is about 0.5%.
3. Heating temperature is 170~265℃, and mold temperature is 20~80℃.
CAB Cellulose Acetate Butyionate 1. Heating temperature 170~265℃, mold temperature 20~80℃.
2. Drying temperature is 75~80℃, and drying time is 2~6 hours.
CP Cellulose Propionate 1. Heating temperature 170~265℃, mold temperature 20~80℃.
EVA Ethylene Vinyl Acetate Copolyn 1. Temperature setting: nozzle 185℃, front section 166℃, middle section 160℃, rear section 150℃; maximum screw speed, mold temperature 35~45℃, back pressure 10kg.
2. Tube temperature 150~180℃, nozzle 150℃, first section 150℃, second section 140℃, third section 120℃, mold temperature 30~40℃, injection pressure 600~800kg/cm², forming shrinkage The drying rate is 0.7~2%, the drying temperature is 40~50℃, and the drying time is 2~4 hours.
FR-PET Polybutylene Terephthalate 1. UL long-term heat resistance of 140 ℃, heat distortion temperature of 225 ℃.
2. Crystallization rate is slow, and the drying and processing conditions are strict.
3. Drying: 3 hours at 140℃ or 5~8 hours at 120℃.
4. Injection temperature: 235℃~250℃.
5. Mold temperature: 40℃~80℃.
HDPE High Density Polyethylene 1. Temperature setting: nozzle 210℃, front section 200℃, middle section 200℃, rear section 195℃; screw speed 140rpm, back pressure 15kg.
2. Linear expansion coefficient 0.00010~0.00013/℃, molding shrinkage rate 1.2~5.0 %, specific gravity 0.93~0.97, heat distortion temperature 43~49℃ (60~82℃).
3. Tube temperature 160~310℃, nozzle 190℃, first section 190℃, second section 180℃, third section 160℃, mold temperature 10~70℃, injection pressure 300~1400kg/cm², forming shrinkage The rate is 1.5~5%.
HIPS High Impact polystyrene 1. Temperature setting: nozzle 220~240℃, front section 210~230℃, middle section 200~230℃, rear section is 190~215℃; screw speed is 135~215rpm, mold temperature is 25℃, back pressure is 5-10kg, and specific gravity is 1.05g/cc.
2. Linear expansion coefficient is 0.000034~0.00021/℃, molding shrinkage rate is 0.2~0.6%, and thermal deformation temperature is 96℃.
LCP Type Ⅰ Liquid Crystal Polymer Type Ⅰ 1. Density 1.35~1.45g/cc, deformation temperature 198~310℃, molding shrinkage 0.1~1.4%.
2. Fast curing speed, resin temperature 390℃, mold temperature 120℃, injection pressure 400kg/cm², fast injection speed, short forming time, pre-drying at 170℃, 3 hours, glass fiber reinforced 85.
LCP Type Ⅱ Liquid Crystal Polymer Type Ⅱ 1. Density 1.35~1.45g/cc, deformation temperature 198~310℃, molding shrinkage rate 0.1~1.0%.
2. Fast curing speed, resin temperature 300℃, mold temperature 100℃, injection pressure 300kg/cm², fast injection speed, short forming time, pre-drying at 150℃, more than 4 hours, glass fiber reinforced 170, fluidity 210.
LCP Ⅲ Liquid Crystal Polymer Type Ⅲ 1. Density 1.35~1.45g/cc, deformation temperature 198~310℃, molding shrinkage 0.1~1.0%.
2. Fast curing speed, resin temperature 260℃, mold temperature 100℃, injection pressure 300kg/cm², fast injection speed, short forming time, pre-drying 140℃, 3 hours, glass fiber reinforced 230.
LDPE Low Density Polyethylene 1. Temperature setting: nozzle 140~190℃, front section 140~200℃, middle section 135~195℃, rear section 130~180 ℃; screw speed 210~220rpm, mold temperature 10~70℃, barrel temperature 150~310℃, back pressure 5-10kg, mold temperature 30~50℃, injection pressure 360~500kg/cm².
2. Linear expansion coefficient 0.00010~0.00020/℃, molding shrinkage rate 1.5~5.0%, specific gravity 0.91~0.93, thermal deformation temperature (38~49℃).
PA   1. Injection temperature and drying temperature must be high; injection pressure and holding pressure should not be too high or too long, male mold should be injected at high speed, and there should be an exhaust channel to prevent rubber from burning; back pressure 50~150kg/cm².
2. Plastic must not be put into melt tube before it reaches dry level. Because of strong water content, it is easy to get stuck in rod groove of feeding section, resulting in phenomenon that feeding is difficult.
3. When forming, nozzle is most likely to be cooled. If injection pressure is increased during cooling, check valve will be easily ruptured, so temperature control at nozzle must be appropriate. In order to prevent plastic from overflowing into mold due to feeding, it is advisable to use a controlled nozzle.
4. When switching to other plastics for injection, it should be noted that heating temperature of original nylon is above 270 ℃, and heating temperature of general material is only about 200 ℃. Therefore, melting cylinder must be heated to heating temperature of nylon before operation. Otherwise, it is easy to break check valve of screw and dispensing head.
5. It is necessary to pay attention to molding method to produce good results.
6. In order to prevent formation of waste edges, precision molds must be used.
7. When using molds for industrial products, attention should be paid to crystallization of molding materials when temperature rises.
8. Design of molded products must prevent dents and consider dimensional stability.
9. Forming shrinkage is about 1.5~2.5%.
10. Nylon 6 (PA6) heating temperature 220~300℃, mold temperature 100~160℃, material tube temperature 200~260℃, ejection temperature 220~300℃, injection pressure 700~2000kg/cm², minimum operating temperature 225 ℃, melting point temperature 215℃, molding temperature 10~300℃, drying temperature 75~100℃, it takes 2~6 hours, use dehumidification dryer, injection pressure 750~2000kg/cm2, first stage of material tube temperature is 230℃; second stage is 230℃; third stage is 220℃; fourth stage is 210℃; mold surface temperature is 25~70℃. Linear expansion coefficient is 0.000083/℃, molding shrinkage rate is 0.6~2.1%, and specific gravity is 1.1~1.4. Heat distortion temperature is 67~70℃ (149~185℃).
11. Nylon 66 (PA66) heating temperature 250~380℃, mold temperature 30~100℃, material tube temperature 240~300℃, ejection temperature 250~310℃, injection pressure 600~2100kg/cm², minimum operating temperature 260 ℃, melting point temperature 215℃, molding temperature 260~320℃, drying temperature 80~90℃, duration 3~6 hours, using dehumidifying dryer, linear expansion coefficient 0.00008~0.00013/℃, molding shrinkage rate 1.3~2.4% , specific gravity 1.1~1.4, heat distortion temperature 66~86℃.
12. Temperature setting: nozzle 235~265℃, front section 235~245℃, middle section 210~240℃, rear section 195~230℃; screw speed 100~105rpm, mold temperature 35~40℃, back pressure 5-10kg.
13. Density 0.94~1.14g/cc, deformation temperature 35~121℃, molding shrinkage rate 0.7~2.5%.
PAR Polyarylate, U-Polymer 1. Density 1.17~1.31g/cc, deformation temperature 95~175℃, molding shrinkage 0.8~1.0%.
2. Glass transition point 190℃, fast curing speed, resin temperature 370℃, mold temperature 130℃, injection pressure 1000kg/cm², fast injection speed, normal forming time, pre-drying 140℃, 6 hours, glass fiber reinforced 35 , liquidity 50.
PBT Polybuzylene Terephthalate 1. Temperature of melt cylinder should be controlled at 230~270℃, and mold temperature should be set at 40℃~90℃.
2. To obtain a glossy surface, it is advisable to heat up, and to perform adequate pre-drying if necessary. Required injection pressure is about 500~1300kg/m².
3. Temperature setting: nozzle 250℃, front section 245℃, middle section 235℃, rear section 230℃; screw speed 80rpm, mold temperature 40~120℃, back pressure 10kg, barrel temperature 230~270℃, injection pressure 300~1000kg /cm², drying temperature 100~140℃, it takes 2~8 hours.
4. Density 1.29~1.50g/cc, deformation temperature 50~110℃, molding shrinkage rate 1.3~2.4%, specific gravity 1.3~1.6.
     
PC Polycarbonate 1. When injection pressure is large, temperature in tube is too high or residence time is long, it is easy to thermally decompose, discolor and reduce physical properties. It should be noted that mold temperature is 85℃~120℃.
2. It is especially difficult to form thick finished products, because finished products are prone to residual stress, which will cause cracks in the future. Therefore, it is advisable to use powdered silicone as release agent, not liquid release agent.
3. High temperature and high pressure are required for forming, and a screw-type forming shuttle must be used.
4. Material should be pre-dried fully before use.
5. Gate and runner design should have small flow resistance.
6. Design of molded product should be close to thickness of body and avoid inlaying of metal parts. Furthermore, retraction inclination must be more than 2°.
7. Molding shrinkage rate is 0.4~0.7%, and specific gravity is 1.2~1.5.
8. Heating temperature 260~320℃, mold temperature 80~120℃, material tube temperature 260~310℃, ejection temperature 280~320℃, injection pressure 800~1500kg/cm², minimum operating temperature 260℃.
9. Use a dehumidifying dryer, drying temperature is 105~120℃ (below 0.02~0.03%), it takes 2~4 hours, and temperature of first section of the material pipe is 260~270℃; second section is 260~270℃ ; third stage is 240~250℃; fourth stage is 220~230℃; mold surface temperature is 40~60℃.
10. Temperature setting: nozzle 275~305℃, front section 270~275℃, middle section 265~275℃, rear section 250~270℃; screw speed 50~115rpm, mold temperature 60~120℃, injection pressure 700~2100kg/cm² , Back pressure 5-15kg.
11. Density~1.20g/cc, deformation temperature 120~146℃, linear expansion coefficient 0.000066/℃, thermal deformation temperature 129~135℃ (141℃).
PCTFE Polychlorotrifluoethylene 1. Design gates and runners with proper flow.
2. A high pressure injection molding machine is required.
3. Select molding conditions that can prevent discoloration.
4. Use anti-rust molds and materials for surface treatment.
5. Forming shrinkage is about 0.5%.
PE Polyethylene 1. High density PE material has obvious crystallization temperature, it is better to increase injection speed.
2. For thick meat products, it is particularly important to increase injection speed: it can improve surface gloss of product, prevent warpage, and reduce molding shrinkage rate.
3. Screw design and anti-reverse equipment are especially required to be precise. If there is any loss or scar, feeding will gradually slow down. (Amount injected into mold is reduced due to reverse flow of plastic, and molten material is returned to metering section, so that new material in feeding section is retained, causing metabolism to fail, resulting in phenomenon that quality of molded product is not solid, shrinkage is strong, and defect rate is high.)
4. Mold design (gate, runner) has fast material filling speed.
5. Adopt cooling method with uniform cooling speed.
6. It is better to use a screw molding machine with good fluidity; no high pressure injection pressure is required, and holding pressure should be longer by 30~60%.
7. Forming shrinkage is 2.5%, and right angle is 2.0%.
8. Design of molded products should prevent warping and deformation.
9. Under low pressure, heating temperature is 140~300℃, and mold temperature is 30~65℃; under high pressure, heating temperature is 150~300℃, and mold temperature is 50~70℃.
10. Temperature of high-density PE material pipe is 210℃, power supply for ejection temperature of next stage can be turned off, injection pressure is 500~1500kg/cm², and minimum operating temperature is 180℃.
11. Drying temperature is 85℃, it takes 1 hour, and temperature of first stage is 220~240℃; second stage is 200~220℃; third stage is 180~190℃; fourth stage is 160~170℃; mold surface temperature 30~70℃.
12. Temperature setting: nozzle 210~265℃, front section 200~255℃, middle section 200~250℃, rear section 190~240℃; screw speed 110~140rpm, mold temperature 45~50℃, back pressure 150~250kg/cm² .
13. Density 0.91~0.97g/cc, deformation temperature 32~95℃, molding shrinkage 0.5~2.5%.
PEEK Polyether Ether Ketone 1. Density 1.30~1.45g/cc, deformation temperature 151~300℃, molding shrinkage 1.0%.
2. Firing point is 334℃, glass transition point is 134℃, curing speed is fast, resin temperature is 400℃, mold temperature is 180℃, injection pressure is 1000kg/cm², injection speed is fast, forming time is long, pre-drying is 150℃, and it takes more than 3 hours, glass fiber reinforcement 30, fluidity 55.
PES/PESF Polyether Polyether Sulfone 1. Density 1.24~1.37g/cc, deformation temperature 174~214℃, molding shrinkage 0.5~1.0%.
2. Glass transition point 225℃, resin temperature 370℃, mold temperature 160℃, injection pressure 900kg/cm², normal injection speed, normal molding time, pre-drying 150℃, 3 hours, glass fiber reinforced 55, fluidity 70 .
PET Polyethylene Terephthalate 1. Temperature setting: nozzle 280~295℃, front section 270~275℃, middle section 265~275℃, rear section 250~270℃; screw speed 50~100rpm, mold temperature 30~85℃, mold temperature of amorphous type is below 70℃, and back pressure is 5-15kg.
2. Use a dehumidifying dryer, barrel temperature is 240~280℃, injection pressure is 500~1400℃, injection molding temperature is 260~280℃, drying temperature is 120~140℃, and duration is 2~5 hours.
PI Polyimide 1. Density 1.16~1.64g/cc, deformation temperature 278~380℃.
2. Burning point 388℃, glass transition point 250℃, fast curing speed, resin temperature 410℃, mold temperature 200℃, injection pressure 800kg/cm², normal injection speed, normal molding time, pre-drying at 200℃, 6 hours , forming shrinkage rate is 1.6%, glass fiber reinforcement is 40, and fluidity is 75.
PMMA Polymethyl Methacrylate 1. This material is characterized by strong toughness and poor material flow, so it is suitable for low temperature molding. Rotation speed should be slow, so that temperature in the tube cannot rise.
2. When designing mold, runner and nozzle holes should be enlarged.
3. Acrylic molding is a technical process. During operation, a clean room should be provided to isolate dust, funnel should be clean, mold should be light, and white gloves should be worn to keep it clean.
4. General type: material tube temperature 180~240℃, injection pressure 750~2400kg/cm², mold temperature 40~70℃, drying temperature 70~75℃ (below 0.1~0.2%), 4 hours required, shrinkage rate 0.4 ~0.8.
5. Heat-resistant type: tube temperature 220~260℃, injection pressure 750~2400kg/cm², mold temperature 40~70℃, drying temperature 70~75℃ (below 0.1~0.2%), time required for 4 hours, shrinkage rate 1.1 ~1.2.
6. Drying temperature is 80℃, it takes 3~4 hours, and temperature of first section is 200~220℃; second section is 190~220℃; third section is 170~200℃; fourth section is 150℃ ~180℃; mold surface temperature 20~90℃.
7. Temperature setting: nozzle 185~215℃, front section 190~200℃, middle section 175~190℃, rear section 170~190℃; screw speed 80~200rpm, mold temperature 30~80℃, high pressure injection pressure, pressure holding It lasts for 2~3 minutes, and back pressure is 150~400kg/cm².
8. Density is 1.14~1.20g/cc, deformation temperature is 76~116℃, and molding shrinkage rate is 0.2~0.8%.
9. Coefficient of linear expansion is 0.00005~0.00009/℃, and thermal deformation temperature is 68~99℃ (74~107℃).
POM Polyoxy Methylene 1. Attention should be paid to temperature management during molding. POM material should not stay in melt tube for a long time, otherwise it is easy to overheat and turn yellow.
2. Melted gas is very thick, contact points of nozzle and flange are the most susceptible to corrosion, so good materials should be used.
3. Heating temperature 190~220℃, mold temperature 80~120℃, material tube temperature 170~225℃, ejection temperature 190~210℃, injection pressure 800~1500kg/cm², pressure retention depends on the wall of plastic part, the lowest operating temperature is 180℃.
4. Use a hot air dryer, drying temperature is 100~120℃, it takes 1~4 hours, and temperature of first stage is 190~215℃; second stage is 195~215℃; third stage is 180~205℃; fourth stage is 150~180℃; mold surface temperature is 60~120℃.
5. Temperature setting: nozzle 185~215℃, front section 190~200℃, middle section 175~190℃, rear section 170~190℃; screw speed 80~200rpm, mold temperature 30~80℃, injection molding temperature 195~250℃ , 700~1500kg/cm2, back pressure 100~200kg/cm2.
6. Density 1.30~1.45g/cc, deformation temperature 70~125℃, molding shrinkage rate 0.8~2.0%, specific gravity 1.4~1.6, linear expansion coefficient 0.000081/℃.
PP Polypropylene Resin
  1. PP material will begin to deteriorate from around 280℃, so heating temperature should be below 270℃, and its molecular orientation is very strong. When molding at low temperature, it is easy to warp and twist due to molecular orientation, so it should be paid attention to.
2. A high pressure forming machine must be used for high pressure forming.
3. Back off tilt may magnify. Runner and gate must be designed according to fluidity. Pay attention to control material temperature and mold.
4. Molding shrinkage rate is about 0.35%, heating temperature is 180~300℃, mold temperature is 20~80℃, material tube temperature is 220~270℃, ejection temperature is 210~280℃, injection pressure is 400~1000kg/cm², and minimum operation temperature is 200℃.
5. Gate design must pay attention to adhesion of molded product. Molded products must be designed to prevent dents and deformations. Forming shrinkage rate is about 0.8~1.5%.
6. Drying temperature is 60~90℃ with hot air, it takes 1 hour, and temperature of first section is 240~250℃; second section is 190~250℃; third section is 170~230℃; fourth section is 170~230℃; segment is 150~210℃; mold surface temperature is 20~60℃.
7. Temperature setting: nozzle 200~220℃, front section 190~215℃, middle section 190~210℃, rear section 185~200℃; screw speed 120~max rpm, mold temperature 20~70℃, injection pressure 700~1800℃ , extremely long holding pressure 30~70%, back pressure 120~200kg/cm².
8. Density 0.90~0.91g/cc, specific gravity 0.9~0.92, linear expansion coefficient 0.000058~0.0001/℃, molding shrinkage rate 1.0~2.5%, thermal deformation temperature 57~63℃ (96~110℃).
PPS Polyphenylene Sulfide Ether 1. Density 1.34~1.40g/cc, deformation temperature 110~265℃, molding shrinkage 0.4~1.4%.
2. Barrel temperature is 290~360℃, injection pressure is 500~1400kg/cm², mold temperature is 120~150℃, and injection molding temperature is 300~370℃.
3. Firing point 288℃, glass transition point 90℃, fast curing speed, resin temperature 320℃, mold temperature 150℃, injection pressure 600kg/cm², fast injection speed, short forming time, pre-drying at 140℃, 3 hours , forming shrinkage 1.6%, glass fiber reinforced 100.
4. Using a hot air dryer, drying temperature is 130~150℃, and it takes 2~3 hours.
5. Use a dehumidifying dryer, drying temperature is 120~140℃, and it takes 2~4 hours.
PS Polystyrene Polystyrene 1. Easy to mold.
2. When ejecting from mold, pay attention to cracking of bowl, select a suitable mold opening and closing mechanism.
3. If molded product is likely to crack, pay attention to design of molded product. In special cases, use a retraction tilt of more than 1°, and pay attention to mold without a low-sag part.
4. Molding shrinkage rate is about 0.45%, heating temperature of general type is 160~310℃, mold temperature is 40~70℃; heating temperature of impact-resistant type is 180~310℃, and mold temperature is 40~70℃.
5. Use a hot air dryer, drying temperature is 60~80℃, it takes 1~2 hours, temperature of material tube is 180~260℃, first stage is 190~215220~240℃; second stage is 210~240℃; third stage is 180~230℃; fourth stage is 150~180℃; mold surface temperature is 10~70℃. It takes 2 hours.
6. Temperature setting: nozzle 190~225℃, front section 180~225℃, middle section 160~220℃, rear section 150~200℃; screw speed 70~160rpm, mold temperature 20~80℃, back pressure 10~20kg.
7. Density 1.04~1.06g/cc, deformation temperature 65~106℃, molding shrinkage 0.4~0.8%, specific gravity 1.0~1.1.
8. Flow length 200~500L/t, linear expansion coefficient 0.00005~0.000083/℃, glass transition temperature 85~110℃, load bending temperature 68~105℃ (50~95℃), conductivity coefficient 0.0003cal.cm.s.sm/℃, density 1.03~1.05g/cm³, tensile strength 350~550kgf/cm², elongation rate 1.2~3.6%, elastic coefficient 22000~32000 kgf/cm², 2.1~3.2kgf.cm/cm, impact strength 1.9~2.4kgf.cm/cm, Rockwell hardness M60~84, transparent, water absorption 0~0.03%.
PSF Polysufone 1. Use a dehumidifying dryer, heating temperature 340~400℃, mold temperature 160~200℃, drying temperature 80~160℃, drying time 3~4 hours.
2. Density is 1.24~1.30g/cc, deformation temperature is 164~190℃, and molding shrinkage rate is 0.15~0.9%.
3. Glass transfer point 189℃, fast curing speed, resin temperature 350℃, mold temperature 130℃, injection pressure 900kg/cm², normal injection speed, normal forming time, glass fiber reinforced 30, fluidity 45.
4. Tube temperature 330~360℃, nozzle 330℃, first section 330℃, second section 320℃, third section 290℃, mold temperature 95~100℃, injection pressure 700~1000kg/cm², forming shrinkage rate of 0.7%.
PTFE Polyterafluorethylene 1. Heating temperature 260~340℃, mold temperature 100~160℃.
2. Glass transition temperature is 19℃, the copper foil tear strength is 7.1 lb/in, Z-axis thermal expansion coefficient of sheet is 73ppm/℃, dimensional stability is 0.8%, and ease of manufacture is 25%.
3. Low Tg, too soft at room temperature.
PU or PUR Polyurethane 1. Use a dehumidifying dryer, drying temperature is 90℃, it takes 1~4 hours, and mold temperature is 80~100℃.
2. Material tube temperature is 180~240℃, density is 1.14g/cm², shrinkage rate is 0.6~0.8%, water absorption rate is 0.02%. 2.5:1, L/D ratio 18~20.
PVAC Polyvinyl Acetate 1. Heating temperature 120~200℃, mold temperature 20~55℃.
PVC Polyvinly Chloride 1. Temperature in tube should be heated at 170-190℃, high temperature heating above 200℃ should be avoided, and mold temperature should be 50-60℃.
2. Retention time of plastic should be short. The slowest feeding method is used so that temperature in tube does not rise, and slow injection method is used to allow gas to be discharged from mold body. Exhaust hole of mold should be large, screw should be electroplated, and anti-return device should not be used. When operation is stopped, temperature must be lowered slowly, and internal stagnation material must be fully injected when operation is continued until defective finished product.
3. Control of material temperature is more important, and it is better to use a screw molding machine.
4. Gate and runner should be designed to have a small flow resistance.
5. Mold must be treated with corrosion-resistant surface.
6. Heating temperature is 149~213℃, mold temperature is 50~70℃, material tube temperature is 165~185℃, ejection temperature is 175~195℃, injection pressure is 1000~2800kg/cm², and minimum operating temperature is 165℃.
7. Use a hot air dryer, temperature of material pipe is 150~190℃, it takes 1~4 hours, drying is 80~100℃, and temperature of first section of material pipe is 180~200℃; second section is 180~200℃ ; third stage is 160~180℃; fourth stage is 140~160℃; mold surface temperature is 20~600℃.
8. Temperature setting: nozzle 185℃, front section 180℃, middle section 175℃, rear section 165℃; screw speed 60rpm; mold temperature 25~70℃.
9. Density 1.1~1.6g/cc, deformation temperature 55~100℃, molding shrinkage rate 0.1~0.5, linear expansion coefficient 0.00005~0.000185/℃, molding shrinkage rate 0.1~0.5%, thermal deformation temperature 57 ~74℃ (82℃).
PVDC Polyvinylindene Chloride 1. Heating temperature is 150~200℃, and mold temperature is 50~70℃.
SAN Styrene Acrylonitrile Copolym 1. Heating temperature 170~290℃, mold temperature 40~80℃.
TPU Thermoplastic Polyurethane 1. It must be fully dried before processing, and moisture content is preferably below 0.03.
2. Processing principle of recycled materials shall not exceed 25% of the total amount.
3. During processing, BS/PVC can be added to change fluidity or physical properties of TPU, but not more than 15% of the total.
4. Pp/LDPE can be used to clean material tube during color change processing.
5. Shrinkage rate is about 0.3-0.8%. During injection, increasing diameter of mold gate, increasing pressure holding time and injection pressure, and reducing mold temperature can reduce shrinkage rate of molded product.
Last article：Influence of gate on precision and mechanical properties of glass fiber reinforced plastic gear Next article：Design of Injection Mould for Plastic Roof Outer Decorative Plate of a New Energy Vehicle

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