Engineering plastics commonly used in automotive industry and flexible material option of CNC prototyping technology
Nowadays, the replacement of expensive metal materials with plastics is an inevitable development trend in the automobile industry. High-strength engineering plastics not only reduce the costs of processing, assembling and maintaining parts, but also make cars lighter, more energy efficient and more environmentally friendly.
According to the data, plastics and their composites are the most important lightweight materials for automobiles. Not only can you reduce the weight of parts by around 40%, but you can also reduce purchasing costs by around 40%. Therefore, their use in automobiles has increased rapidly in recent years and they have become the “new favorites” of automobile production.
The consistency of materials between the development phase and the production phase of a car is therefore particularly important.
Question: Is it possible for the materials used in the prototype phase to be the same as those used in final production?
In this article, we will introduce the materials and service options of CNC machining in China during the prototype phase of the automotive department.
1.What are the main engineering plastics for the automotive industry?
The plastics most currently used for automobiles are polypropylene (PP), ABS resin, PVC and PE. The main plastic parts of cars are made from polyolefins. Some common engineering plastics for the automotive industry are listed below.
Polypropylene (PP)
PP can be used in a variety of automotive parts. Today, PP plastic parts account for more than 60% in a typical passenger vehicle. The main types of PP auto parts include: bumper, dashboard, inner door panel, air conditioning parts, battery box, radiator fan and steering wheels. The first five types represent more than half of the total PP value.
Polyethylene (PE)
Through the modification of grafting and curing of high-density PE filler and low-density PE resin, a series of modified PE alloy materials with good flexibility, weather resistance and coating performance have been obtained. PE is mainly produced by blow molding to produce fuel tanks, ventilation pipes, flow baffles and various storage tanks.
In recent years, PE consumption in automobiles has not increased. It should be noted that the development trend towards lighter cars promotes the plasticization of fuel tanks. In Europe, plastic fuel tanks are officially used in cars. The main material is high molecular weight density polyethylene (HMWHDPE).
Polyoxymethylene (POM)
It has excellent friction and wear resistance, long-life lubricity, formability and beautiful surface and gloss, and is also suitable for recessed molding. For automobile chassis bushings, such as steering knuckle bushings, various support bushings, front and rear spring bushings and brake bushings, etc., three-layer polyformaldehyde composite material is widely used.
The structure of the oil storage well is determined with a certain regularity by its special properties: it has the mechanical strength and rigidity of steel and excellent sliding properties under the boundary lubrication condition. Other applications include door handles, seat belt mechanical parts, combination switches and mirrors.
ABS resins
ABS resin is a ternary copolymer composed of three monomers, acrylonitrile, butadiene and styrene, which can be used to produce external and internal parts of automobiles, such as instrument casings, cooling and heating systems, tool boxes, handrails, dashboards. radiator grille, etc. It can also be used to make panels, suitcases and various box lids.
In recent years, the increase in the dosage of ABS resin in automobiles is not very large, mainly due to the strong competition between ABS resin and PP resin. Furthermore, ABS itself has the defects of lack of weather resistance and discoloration, as well as flammability, etc., so its application in major automobile parts, such as: B. instrument panel and radiator grille, is also restricted .
Polyamide (PA)
Polyamide, commonly known as nylon, has high impact resistance, friction and wear resistance, heat resistance, chemical resistance, lubricity and dyeing properties. PA is becoming increasingly popular as a structural part of the automobile and can be used in the harsh environment surrounding the engine.
2. Why are CNC machining services more widely used and considering material factors?
There are two rapid prototyping methods commonly used in the automotive sector: 3D printing technology and CNC machining. Considering the material factors for the final quality of production, CNC machining services have more advantages and are more widely used than 3D printing. The range of materials available and the main differences are as follows:
Additive manufacturing technology (3D printing)
In recent years, a number of new rapid manufacturing technologies, commonly referred to as rapid prototyping and manufacturing (RP&M), have emerged. Technologies developed include stereolithography (SL), selective laser sintering (SLS), fused deposition modeling (FDM), laminated object manufacturing (LOM), and three-dimensional printing (3D printing).
The development of this technology has reached many traditional areas and aroused the interest of artisans, whose skills and knowledge have led to the use of 3D objects directly and indirectly as patterns and models for soft tools.
All 3D printing technologies have an important common feature: the prototype is made by adding material, not removing it, while the performance of 3D printing in material processing is only close to that of the final production material.
| technology | material | Limitation | Main use in the development phase |
| SLA | Resin: photosensitive resin
Beige/misty translucent |
Weak,
Simple transformation |
Can be used directly and indirectly as a pattern and template for smooth tools |
| SLS | PA12 powder | Hard,
hard to finish |
Production of the first prototypes and models |
| FDM | plastic filament | Poor resolution and processing
Quality, not very strong |
Production of the first prototypes and models |
NC MACHINING TECHNOLOGY (CNC machining)
CNC is the automation of machine tools by computers that run pre-programmed software and specify movement. The most modern and sophisticated method of programming an NC machine is to use a three-dimensional model of the part to provide the data that controls the NC machine in producing the part.
As NC technology continues to develop, this programming method will eventually find wider application.
The biggest advantage of CNC prototyping is that the material is very close to the production material.
3. CNC machining services in China
In the third quarter of 2018, our customers in Europe and North America purchased many prototype parts using our CNC machining services in China. We can offer our customers a wide range of quality standards that meet project budget constraints. We now work with most vehicle manufacturers. I know the needs of customers and I try to do the best with our team to meet designers' expectations in technical, quality and innovative terms.
