How to Select High-Engineering Automative Plastic?


General used engineering plastics in automobile and flexible material option of CNC prototyping technology

Posted on: Sep 07, 2018, | By Tony, WayKen Project Manager

Nowadays, in the automobile industry, the substitution of plastics for expensive metal materials have become an inevitable trend of development. High-strength engineering plastics not only reduce the cost of parts processing, assembly and maintenance, but also make cars lighter, energy-saving and environmentally friendly.

According to the data, plastics and their composites are the most important lightweight materials for cars. Not only can it reduce the weight of parts by about 40%, but it can also reduce the purchase cost by about 40%. Therefore, in recent years, the usage in automobiles has rapidly increased, becoming the “new favorite” of automobile manufacturing.

Therefore, the consistency of the materials between the development stage and the production stage of an automobile is particularly important.

Question: is it possible the materials used in the prototype stage be consistent with those used in the final production?

In this article we will share you the material and option of CNC machining services in china during the prototype automobile department phase.

1.What’s the Mainstream Automotive Engineering Plastics?

At present, the most used general plastics in automobile plastics are polypropylene (PP), ABS resin, PVC and PE. Polyolefin materials constitute the main plastic parts of the car, following will list several mainstream automotive engineering plastics.

Polypropylene (PP)

PP can be used as a variety of auto parts, and now the typical passenger car, PP plastic parts account for more than 60. Main varieties of PP auto parts include: bumper, dashboard, door interior panel, air conditioner parts, battery case, cooling fan, steering wheel, among which the first five types account for more than half of the total PP dosage.

Polyethylene (PE)

By graft modification and filling toughening modification of high density PE and low density PE resin, a series of modified PE alloy materials with good flexibility, weatherability and coating performance were obtained. PE mainly USES the blow molding method to produce fuel tanks, ventilation pipes, flow deflectors and various storage tanks.

In recent years, the consumption of PE in cars has not increased, and it is worth noting that the development trend of car lightweight promotes the plasticization of fuel tanks. Plastic fuel tanks are officially used in cars in Europe. The main material is high molecular weight high density polyethylene (HMWHDPE).

Polyoxymethylene (POM)

It has excellent properties of resistance to friction and wear, long term sliding, forming fluidity, beautiful surface and gloss, and is also suitable for insert molding. For automobile chassis bushing, such as steering knuckle bushing, various bracket bushing, front and back plate spring bushing and brake bushing, etc., polyformaldehyde three-layer composite material is widely used.

The structure of the oil storage pit with certain regularity is determined by its special properties: it has both mechanical strength and rigidity of steel and excellent anti-friction properties under the condition of boundary lubrication. Other applications include door handles, seat belt mechanical parts, combination switches and mirrors.

ABS Resins

ABS resin is a ternary copolymer of three monomers, acrylonitrile, butadiene and styrene, which can be used to make automobile external or internal parts such as instrument housing, refrigeration and heating system, toolbox, handrail, radiator grid plate, etc. It can also be used to make dashboards, luggage, and miscellaneous box covers.

In recent years, the increase of ABS resin dosage in cars is not very large, which is mainly due to the fierce competition between ABS resin and PP resin, and the ABS itself also has the defects of poor weather resistance and discoloration, flammability, etc., so its application in the main parts of cars, such as automobile dashboard and grille, is also restricted.

Polyamide (PA)

Polyamide, which is commonly known as nylon, has high impact strength, friction and wear resistance, heat resistance, chemical resistance, lubricity and dyeing properties. As a structural part of the automobile, PA is constantly increasing and can be applied in the harsh environment around the engine.

2.Why Are CNC Machining Services  More Generally Used And Considering the Material Factors?

There are two commonly used automobile rapid prototyping process, 3D printing technology and CNC machining, while considering the final production grade material factors the CNC machining services have more advantages and wildly used than 3D printing, the range of available materials and main differences as below:

Additive manufacturing technology(3D printing)

Over the past few years, a variety of new rapid manufacturing technologies, generally called Rapid Prototyping and Manufacturing (RP&M), have emerged. The technologies developed include Stereo lithography (SL), selected laser sintering(SLS), fused deposition modeling (FDM), laminated object manufacturing (LOM), and three dimensional printing (3D Print).

The development of this technology has reached into many of the traditional fields, attracting the interest of artisans whose skill and knowledge has led to 3-D objects being used directly and indirectly as patterns and model for soft tooling.

CNC milling services in China

All 3D printing technology have a common important feature, the prototype part is produced by adding materials rather than removing materials, while the performance of 3D printing processing material only can close to final production material.

Technology Material Limitation Main usage at development phase
SLA Resin: photosensitive resin


Beige/foggy translucent



Easy transform

Being used directly and indirectly as patterns and model for soft tooling
SLS PA12 Powder Rough,


hard to do finish

Making initial prototypes and models
FDM Plastic filament Poor resolution and finish


Quality, not very strong

Making initial prototypes and models



CNC is the automation of machine tools by means of computers executing pre-programmed software dictates the movement. The most modern, sophisticated method of programming an NC machine is by using a three-dimensional model of the part to provide the data that guide the NC machine in producing the part.

As NC technology continues to develop, this programming method will eventually be used more and more widely.

The biggest advantage of CNC prototyping is the material is very close to the production material.

CNC machining services in Chin

3.CNC machining services in China

In the third quarter of 2018, our customers in Europe and North America sourced a lot of prototype parts by using our CNC machining services in China. We can offer our customers a wide range of quality standards which are fitting to the budget targets for the projects. Now we collaborate with the greatest part of Vehicle Constructor. I know Customers’ needs and i try, with our team to make the best to satisfy designer’s expectations in technical, qualitative and innovation terms.

CNC machining services in China

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