Engineering plastics have good comprehensive properties, such as high stiffness, low stress relaxation, high structural mechanical strength, good heat resistance and good insulation, which enable them to be used in harsh organic chemical and material environments for a long time and can replace metal materials as building structural materials.

With the development of technology, the use of engineering plastics has been expanding and has extended to various fields such as automobiles, home appliances, airlines, medical treatment, sports, electronic devices, engineering and construction. With the development trend of lightweight automobiles, the application of automotive plastic parts is increasing.

First, let¡¯s take a look at how engineering plastics such as acrylic resin (PA), polycarbonate (PC), polyester chips (POM), polymethyl methacrylate (PMMA), polyurethane materials (PU), polyester (PBT/PET), and polyphenylene ether (PPO) are actually used in the automotive industry.

PA Materials

Acrylic resin, also known as polyester, has many types of PA used in industrial production, the most common ones are PA6, PA66 and PA610. Due to the influence of thermal deformation and water absorption capacity, the heat resistance of the products is poor

PA is a kind of engineering plastic with good performance, with excellent structural mechanical properties, significant corrosion resistance, wear resistance, heat resistance, high toughness and other characteristics. By improving and modifying its flame retardancy, it can be widely used in automobiles, electronic appliances, pneumatic tools and other fields.

In the automotive field, after PA is reinforced with glass fiber, its compressive strength, heat resistance and other properties are improved, and the price is relatively affordable, making it an ideal material for components near automobile engines.

Intake manifold is the most typical application of modified PA in automobiles.

In addition, modified PA is generally used as the preferred material for automobile hoods, automobile engine decorative covers, cylinder head covers, etc. Compared with metal materials, taking the cylinder head cover as an example, the application of modified PA can improve the quality by 50% and reduce the cost by 30%.

Many load-bearing components of automobiles, such as oil filters, wipers, radiator grilles, etc., can also be made of modified PA. PA is mainly used in the automotive industry to make plastic hoses (brake hoses, brake pipes), fuel filters, air filters, oil filters, centrifugal water pump housings, water pumps, fans, brake oil tanks, power steering fluid tanks, white windows, headlight housings, and seat belts.

PC material

Polycarbonate has outstanding fracture toughness and creep resistance, good heat resistance, and good cold resistance. The shrinkage rate is 0.5-0.7%, and the suitable thickness is 2-3.5mm. Adding glass fiber to PC can improve its shrinkage, mechanical strength and heat resistance. The steel strength will also increase when used for a long time at around 100¡ãC. Quenching can be used to improve the internal stress.

Introduction of key composite PC-ABS:

PC-ABS is a blend of PC and ABS, which is usually supplied in the form of powder after blending. If the two materials are simply mixed and processed directly by injection molding, the effect will be very poor and there will be separation; the advantage of PC is hardness and toughness, but the main disadvantage is stress cracking and high viscosity; the advantage of ABS is good fluidity, but low hardness; the blended material PC-ABS retains the advantages of both; PC-ABS has high hardness, relatively high rigidity and ductility, and also has a high level of stress crack resistance; its mechanical properties are between the two.

Through the modification, improvement, flame retardancy, fine grain strengthening and other modifications of PC, PC can significantly improve its flame retardancy and strength and other properties, making the modified materials widely used in auto parts, OA products, electronics and electrical, etc.

Modified PC is mainly used in automobile interior and exterior decoration because of its excellent heat resistance, impact resistance, and good rigidity and processing and circulation. The most widely used are PC/ABS aluminum alloy and PC/PBT aluminum alloy. PC/ABS aluminum alloy is also used to manufacture automobile instrument panel peripheral components, cold-proof panels, door handles, underflow panels, fixed brackets, steering column wire covers, decorative panels, air-conditioning units and accessories. PC/PET aluminum alloy can be used to make automobile air outlets and license plate covers. PC/ABS aluminum alloy can also be used to make automobile exterior parts, such as automobile wheel covers, rearview mirror housings, taillight covers, etc. PC/ABS has good formability and can be used to produce large and medium-sized automobile components, such as automobile bumpers. Guangzhou Aote Engineering Plastics Co., Ltd., your own professional engineering plastics consultant!

POM Material

Polyester chips, also known as plastic steel profiles, POM has the characteristics of high hardness, wear resistance, stress relaxation resistance, chemical corrosion resistance, etc., and is widely used in the fields of automobiles, electronics and home appliances. The automobile industry is the largest market space for POM materials.

Modified POM is particularly suitable for the production of automobile pumps, carburetor components, oil pipelines, power valves, universal bearings, motor gears, gears, door handles, dashboards, window lifts, switches, seat belt buckles, etc. The production of wear-resistant parts such as couplings, transmission gears, and rollers is the strength of modified POM. These parts have little wear on metal, reduce the amount of grease used, and increase the service life of the components. Therefore, they can generally replace copper, zinc and other metal materials to produce bearings, transmission gears, support rods, etc.

Automotive components made of POM are light in texture, low in noise, and easy to form and install, so they are increasingly widely used in the automotive processing and manufacturing industry.

PMMA Materials

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

PMMA is commonly used in automotive lighting signs, door glass and lampshades due to its good light transmittance.

PU material

Polyurethane materials are commonly divided into rigid polyurethane and soft plastic polyurethane materials according to the differences in the reactants of the polycondensation reaction.

Foamed polyurethane plastics are widely used in automobile interior parts to absorb vibration, such as coating materials, polyurethane hard plastic plates, polyurethane elastomers, seat soft foam materials, accessories, fabric sofa leather, ceiling decorations; various soft plastics and hard foamed polyurethane materials are used more frequently, in life there are vibration reduction, sound insulation and noise reduction, noise reduction, wall insulation; PU can also be made into car-matched acrylic paint, adhesives, sealants, etc. PU representative products in automobiles include dashboards, rearview mirrors, bumpers, seat sponge pads, headrests, steering wheels, instrument panel shock pads, support decorations, front roof linings, window frames, roof and side roof frame decorations, door wear-resistant linings, sun visors, rear roof frame decorations, etc.

PBT material

PBT is a good engineering project material with good toughness, fatigue resistance, high temperature resistance, good weather resistance, good electrical properties and low water absorption. Improving and modifying its flame retardancy can also significantly improve its heat resistance, strain rate, heat resistance and flame retardant grade. It is widely used in automobiles, toys and other fields.

In the field of automotive technology, PBT is widely used in bumpers, carburetor parts, bumpers, rear wings, automobile spark plug terminal boards, injection system parts, in-car instrument panels, automobile rectifiers, network accelerators and clutch pedals.

PBT is in fierce competition with PA, PC, and POM in the automotive industry. PA is easy to absorb moisture, and PC's heat resistance and chemical resistance are not as good as PBT. In the field of automotive applications, PBT will gradually replace PA because it has better water absorption resistance than PA. In the case of high humidity and very cold and humid air, because cold and humidity can easily lead to reduced plasticity, it is easy to cause corrosion at the connection points of household appliances, so modified PBT can be used. At 80¡æ and 90% humidity, PBT can still start normally, and the effect is good.

PPO Materials

PPO has good physical thermal properties, heat resistance and electrical equipment insulation properties, low water absorption, high strength and good heat resistance. It is widely used in kettle covers, valve cores, centrifugal water pumps, centrifugal impellers and other automotive water-related industries.

Modified PPO is mainly used in automobiles for parts with high requirements for heat resistance, flame retardancy, electrical properties, impact properties, heat resistance, and structural mechanics compressive strength.

For example, PPO/PS aluminum alloy is suitable for damp and cold environments with loads, strict insulation requirements, and better heat resistance. It is suitable for the production of parts such as car side panels, headlight laminated glass grooves, and taillight housings. It is also very suitable for the production of automotive electrical components such as connection boxes, fuse boxes, and leakage protection switch housings.

PPO/PA aluminum alloy can be used to make automotive exterior components, such as large and medium-sized partitions, rubber pads, rear spoilers, etc., because of its excellent structural mechanical properties, heat resistance, wear resistance, insulation, and impact resistance.

Next, we will take a look at how general-purpose plastics such as polypropylene (PP), polyethylene (PE), polyethylene (PVC), polyethylene (PS), and acrylonitrile-butadiene-butadiene copolymer (ABS) are actually used in the automotive industry.

Versatility generally refers to commonly used plastics with large total output, strong formability, low price. Versatility plastics include five major categories: polypropylene (PP), high-pressure polyethylene (PE), polyethylene (PVC), polyethylene (PS), and acrylonitrile-butadiene-butadiene polymer (ABS), all of which are thermosetting plastics.

PP material

Polypropylene, also known as pleated glue, is milky white and waxy, fully transparent, light in texture, has good fluidity during injection molding, and has a water absorption capacity of less than 0.02%.

The wide application of PP in the automotive field mainly has the following problems: easy to ignite (will drip combustibles) and ductility at low temperatures. For these problems, suitable additives are added in the actual application of the manufacturing industry to modify PP. Halogen-free flame retardants are added to PP for easy ignition; ductility under low temperature environment is usually modified by adding other ductile materials, rigid particles or elastomeric materials, such as plastic (EPDM), light calcium powder (TD), glass fiber (GF), etc. There are many automotive products made of PP epoxy resin, including various automotive dashboards, door rain shields, pole rain shields, bumpers, water tanks, and decorative panels. The application of PP in automobiles is increasing.

PE material

High-pressure polyethylene, one of the lightest plastics, transparent milky white waxy material, good waterproofness, corrosion resistance, resistance to organic solutions, good insulation. Shrinkage rate 1.5 ~ 4.0%, suitable thickness 1.0-2.5mm.

The main disadvantage of PE as an automotive material is that it is easy to ignite. The simplest and most commonly used method is to add appropriate halogen-free flame retardants to change the combustion properties of PE. Automotive products made of PE mainly include oil tanks, ventilation ducts, front seat decorative covers, air duct assembly (HDPE), upper and lower ventilation duct assembly, left and right wind frequency leaf connecting rods, left and right foot ventilation hole assembly, etc.

PVC material

The most commonly used plastic raw material in automotive plastic products should be polyethylene. Automotive plastic products made of PVC plastic can often be seen, such as PVC automotive dashboard skin, PVC plastic automotive steering wheel, PVC plastic wear-resistant lining, and PVC plastic automotive paving materials. This is not only because the price of PVC resin is economical, but also because the production and processing performance and overall structural mechanical properties are very good.

PS material

Polyethylene, also known as hard plastic, is a transparent glass-like material with good fluidity and non-water absorption. Due to the ductility of PS, it is often grafted and copolymerized with other ingredients. At the same time, it is grafted and copolymerized with butadiene to produce HIPS. After the composition contains plastic, the impact resistance and hardness are further improved.

PS is mainly used in the instrument housing, lamp cover, and lighting products in the car. Polyethylene can also be used to make outer packaging materials and heat insulation materials through foaming and molding, which are used to make roofs. In addition, it can be grafted and modified with other materials to obtain many types of PS family aluminum alloy plastics, such as SMA, which is used to produce automobile dashboard frames.

ABS material

Acrylonitrile-butadiene-butadiene copolymer, also known as super unbreakable glue, is white in color. The shrinkage rate is 0.4-0.7%, and the suitable thickness is 1.8-3mm.

Because ABS has many types, good surface treatment effect, and low price, it is widely used in the automotive industry. Due to the poor weather resistance of ABS, highly weather-resistant AES, ASA and other materials have been widely used in commercial vehicles to fill ABS. When the product needs to be surface treated (such as water transfer equipment, painting), ABS is selected; when no surface treatment is required, ASA and AES are used. The most typical automotive products are decorative bright strips, shift rocker heads, inner door handles, license plate decorative panels, rear spoiler assembly, rearview mirror itself, heat pipe radiator grille itself, guardrails, etc.

Guangzhou Aote Engineering Plastics Co., Ltd., your own professional engineering plastics consultant!