What engineering plastics are used in the new energy vehicle industry?

Two major focuses of new energy vehicles: power battery and lightweight

At present, the early stage of the reform of the automobile industry is mainly electrification. During this period, the core components of the car are no longer the "three major parts" (engine, gearbox and chassis), but the three-electric system (battery, motor and electronic control), accounting for more than 50% of the cost of new energy vehicles. Among them, the cost of the power battery accounts for 90% of the cost of the three batteries. Therefore, the power battery system can be called the "heart" of new energy vehicles. The lightweight of new energy vehicles is mainly related to electronic materials, such as connectors, charging interfaces, and power battery peripheral materials. Replacing metal with plastic under the condition that the performance meets the requirements can reduce the weight by about 30%. At present, the weight of a pure electric vehicle can be reduced by about 100KG by using lightweight plastics.

The use scenarios of engineering plastics for new energy vehicles combined with automotive products need to meet the following performance requirements:

Chemical resistance, oil resistance, high and low temperature resistance;

Excellent mechanical properties, high fluidity and excellent processing performance;

Excellent surface properties and good dimensional stability;

It has good waterproof, moisture-proof, flame retardant, environmental protection and other properties and thermal conductivity;

Good dielectric resistance, suitable for electrical places;

Good weather resistance, good long-term performance, long-term use in harsh environments.

Power battery system

1. Power battery bracket

Power battery brackets require flame retardant, dimensional stability, chemical resistance, and high strength. At present, modified PPE, PPS, PC/ABS, etc. are mainly used.

2. Power battery cover

The power battery cover requires flame retardant, dimensional stability, chemical resistance, and high strength. At present, modified PPS, PA6, PA66, etc. are mainly used.

3. Power battery box

The power battery box requires flame retardant, dimensional stability, chemical resistance, and high strength. At present, modified PPS, modified PP, PPO, etc. are mainly used.

4. DC motor skeleton

The DC motor skeleton mainly uses modified PBT, PPS, PA.

5. Relay housing

Performance and automotive electronic control relay housing mainly uses modified PBT.

6. Connector

New energy vehicle connectors mainly use modified PPS, PBT, PA66, PA

Motor drive system and cooling system

1. IGBT module

The IGBT module is the core device of the new energy vehicle electronic control system and DC charging pile, which determines the energy utilization rate of the whole vehicle. In addition to the traditional metals and ceramics commonly used materials, PPS engineering plastics have gradually begun to be applied.

2. Automobile water pump

Electronic water pump rotors, water pump casings, impellers, water valves, etc. require high toughness, high wear resistance, and high strength. At present, modified PPS materials are mainly used.

The following is a list of 5 commonly used engineering plastics

1. PA

Polyamide, commonly known as nylon, has many types of PA in industrial use, commonly used are PA6, PA66 and PA610. Due to the influence of thermal expansion and water absorption, the dimensional stability of the product is poor, and the shrinkage rate is 1 to 2%. It is necessary to pay attention to the dimensional change of moisture absorption after molding. The water absorption rate is 100%, and it can absorb 8% when the relative moisture absorption is saturated. The suitable wall thickness is 2-3.5mm. 

PA is mainly used in the automotive field to manufacture hoses (brake hoses, fuel pipes), combustion oil filters, air filters, oil filters, water pump housings, water pump impellers, fans, brake fluid tanks, power steering fluid tanks , white shutters, headlight housings, seat belts.

2. PMMA

Polymethacrylate, commonly known as plexiglass, is resistant to outdoor aging and has excellent light transmittance. Suitable plastic products: transparent structural parts with certain strength requirements.

Due to its good light transmission properties, PMMA is widely used in automotive lighting signs, door glass and lamp glass covers.

3. POM

POM, commonly known as plastic steel, shrinkage 2-3.5% Appropriate wall thickness: 1.5-2.5mm.

POM is used in the manufacture of instrument panel glove box accessories, various valves, various impellers, various electrical switches and pinions on electrical instruments, various handles and door pins, etc.

4. PC

Polycarbonate, with outstanding impact toughness and creep resistance, good heat resistance and cold resistance. The shrinkage rate is 0.5-0.7%, and the suitable wall thickness is 2-3.5mm. Adding glass fiber to PC can improve its shrinkage rate, mechanical strength and temperature resistance. Long-term use at about 100 °C will increase the rigidity, and annealing can be used to improve the internal stress.

Introduction of the main synthetic PC-ABS:

PC-ABS is a blended material of PC and ABS, which is usually supplied in the form of pellets after blending. If the two materials are simply mixed and then injected directly, the effect is very poor, and delamination will occur; the advantage of PC is that it is rigid and tough, but the disadvantage is stress cracking and high viscosity; The advantage of ABS is that it has good fluidity but low surface hardness; in this way, the blended material PC-ABS retains the advantages of both; PC-ABS has high surface hardness, high rigidity and toughness, and high resistance to stress cracking; its mechanical properties are in between. In the automotive field, PC is mainly used in the manufacture of lampshade, left and right wheel guards, instrument bezel body (PC+ABS), left and right wind frame cover, middle wind frame cover (PC+ABS), rear bumper cushion.

5. PU

Polyurethane, according to the different polymerization products, is commonly divided into rigid polyurethane and soft polyurethane.

Polyurethane foam is widely used in automotive interiors and vibration-absorbing parts, such as coating materials, polyurethane rigid plastic sheets, polyurethane elastomers, seat soft foam materials, decorative parts, sofa leather, and roof accessories; The most widely used are various soft and hard polyurethane foam materials, which have vibration isolation, sound insulation, noise reduction, thermal insulation; PU can also be made into automotive polyurethane coatings, adhesives, sealants, etc. The representative parts of PU on the car are dashboards, rearview mirrors, bumpers, seat cushions, headrests, steering wheels, dashboard anti-vibration pads, pillar trims, front headliners, window frames, ceiling and side roof frame decorations, door linings, sun visors, rear roof frame decorations, etc.

Nanjing Haisi Extrusion supply twin screw extruder for engineering plastic compounding. 

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