The use of plastics in automobiles

četvrtak , 13.10.2016.

China's auto market has been rapid development in recent years, the frequency of auto product replacement gradually accelerated, the growing number of scrapped cars, recycling market has great potential. Automobile industry is a typical resource-intensive industry, with a long industrial chain, involving a wide range of industry characteristics, but also need to practice green development, attention to the recovery of scrap cars.
To improve the level of recycling technology for end-of-life vehicles has a crucial role in changing the extensive development mode of the scrapped automobile industry, reducing the bearing pressure of the environment and the resource cost of the industry. However, there are still some problems such as the technical level of scrapped vehicle recycling and dismantling in China, the single mode of dismantling business and the unclear responsibility of producer extension, which restricts the transformation and upgrading of the industry and is not conducive to the comprehensive utilization of scraped vehicles. On the whole, the scrap car recycling level is not high mainly by four factors.

First, the regulatory requirements lag, is not conducive to industry development
To curb the assembly vehicle behavior, "scrapped vehicle recycling management approach" (State Council Decree No. 307) requirements, scrapped cars "five assembly" must be destroyed as scrap steel for sale. At the beginning of the enactment of laws and regulations, this requirement is very necessary, but with the development of the situation, this requirement makes some better car scrapped cars "five assembly" can not be re-manufacturing and other ways to re-circulation, Solution enterprise and remanufacturing enterprise development space, is not conducive to scrapped cars get effective recycling.

Second, the lack of producer responsibility, lack of technical support
Developed countries in the automotive industry are required to bear the car manufacturers to scrap the main responsibility for recycling dismantling, to carry out eco-design, dismantling dismantling enterprises to provide technical support to participate in recycling network construction, in order to facilitate the effective recovery of scrapped cars, fine Of dismantling and reuse. However, at present, most automobile manufacturers in our country are not involved in the design of the product's dismantleability, recyclable design consideration, product material identification system implementation is not in place, the actual recycling process for the back-end is not involved.

The use of plastics in automobiles

Third, the establishment of the vehicle scrapped information sharing mechanism, a large number of scrapped cars
At present, China's scrap car recycling dismantling enterprises in accordance with the price of iron and steel scrap for economic compensation, the price is far lower than the price of some informal traders. And most of our provinces and cities for the scrapped the formal retirement of the vehicle has not yet formed the relevant units, "the upper and lower linkage and effective coordination" of the regulatory mechanism, the future should improve the relevant measures to share scrapped information to promote the scrapped cars into the regular recycling channels. For example, for the vehicle to reach the retirement standard limit transfer; in the replacement of new cars, if the owners have scrapped the car under the name of the formal retirement, not on the license and the relevant procedures.

Fourth, the use of high value-added low level of constraints to enhance economic efficiency
At present, China's scrap car recycling is still the main sales of scrap steel, steel prices continue to fall lead to scrap car recycling industry profit level is low, or even into a loss. In addition, the scrapped cars in the recovery of non-metallic materials is also very unsatisfactory, fine separation of the low level of waste of resources is more serious. The sales of reusable parts is the main way to increase the added value of scrapped vehicles. In China, because of the limitation of laws and regulations, the lack of reusable standard and the low market acceptability, the reuse parts have not been effectively used. recycle and re-use.

Car manufacturers for the automotive product structure, material composition, dismantling technology, the best understanding of the producer as the product recovery and recovery of the main responsibility can effectively promote the industrial chain to enhance the level of recycling and reduce the product life cycle of the negative impact of the environment . EU and other developed areas of the automotive industry through the implementation of the automobile industry in the extension of the producer responsibility system, give full play to the producers in the product scrap recycling important role in greatly promoting the effective use of vehicle resources, and significantly reduce the product life cycle Environmental pollution.

The European Union introduced in 2000 2000/53 / EC (ELV directive) introduced the extension of the producer responsibility system, requiring automobile manufacturers to carry out easy recovery, easy dismantling design, limit of lead, mercury, cadmium, hexavalent chromium The use of harmful substances involved in the construction of scrap car recycling network, announced vehicle dismantling technical information. ELV Directive on the extension of responsibility for the production of automotive products, the requirements for improving vehicle recyclability, and promote the collection and recycling of discarded vehicles, reducing the impact of the product has played a significant role in promoting the environment.

China issued in 2015, "the management of hazardous substances and recyclable vehicle requirements" (hereinafter referred to as "management requirements"), provides since January 1, 2016, the M1 class of automotive products lead, mercury, cadmium, six Price of chromium, polybrominated biphenyls, polybrominated diphenyl ethers and other six kinds of hazardous substances and recyclable rate of the implementation of management, and require automobile manufacturers within the prescribed period to dismantle the dismantling of vehicles dismantling dismantling vehicle technology information. "Management requirements" clearly the automotive product manufacturers in hazardous substances with restricted use, recyclable rate control, dismantling information release and other responsibilities for the promotion of China's automobile enterprises to establish and improve the management of hazardous substances and recycling-related security system, Reduce the use of harmful substances, improve the level of recycling can have a positive effect.

Comparing with the successful experience in the polyethylene recycling industry of developed countries such as the European Union, China has not yet put forward definite requirements on the extension of the responsibility of the producers of automobile products, although the regulation of the harmful substances and recyclable rate of automobile products Production enterprises failed to play a major role in the recycling process of scrapped vehicles, participate in the construction of scrapped vehicle recycling system, and then the R & D and application of resource-based technology, the overall level of comprehensive utilization of scrap resources has yet to be improved. China should set up automobile production enterprises as the leading automotive product recycling industry system as soon as possible, implement the producer responsibility extension system, promote the upgrading and transformation of the industry, in order to prepare for the large-scale arrival of scrapped cars.


In view of the problems existing in the recycling of scrapped cars in China, the author thinks that we should proceed from four aspects.
First, from the regulatory level, it is recommended as soon as possible on the "scrapped vehicle recycling management approach" to amend, abolish the scrapped car "five assembly" must be destroyed as scrap steel sales restrictions, while drawing on the experience of developed countries in Europe developed in China Producer responsibility to extend the relevant laws and regulations, clearly the parties to the responsibility for enterprises to extend the responsibility of producers to provide legal basis and guidance.

Second, from the point of view of government management, it is suggested that all management departments should establish the vehicle scrapping information sharing mechanism to restrict and manage the scrapped vehicles entering the informal channels in all links and increase the scrapping rate of the regular channels.


Third, from the perspective of industry linkage, it is suggested that China's auto manufacturers should actively participate in the pilot extension of styrofoam densifier producer responsibility of automobile products, give full play to the leading role of automobile manufacturers, and explore a variety of producer responsibility extensions such as direct recovery, joint recovery, Embodiment.

Fourth, from the perspective of technology upgrading, it is recommended that automobile manufacturers and enterprises engaged in the recycling of end-of-life automobile products should cooperate in the development and application of advanced and applicable technologies for styrofoam recycling and utilization, and establish cooperative mechanisms for automobile manufacturers, recycling enterprises and resource recycling enterprises , Focusing on breaking green car dismantling technology, the old parts remanufacturing technology, automotive reuse of high value-added technology, open up the upstream and downstream industry chain, the real realization of the recycling of waste vehicle resources.

Different charging characteristics of metal and plastic

1. Metal trap
The crushed waste is conveyed through a pipe, and a metal trap is used to separate metal debris having a diameter of 0.75 to 1.2 mm during the conveyance.
2. Electrostatic separator
The mixture is crushed and put into electrostatic separator, which can separate metals such as copper and aluminum by using the different charging characteristics of metal and plastic.This method is suitable for the treatment of metal filled composite materials, cable materials and metallized plastics.
3. Dissolution separation
The plastic coated metal part was immersed in a suspension containing methylene chloride, a nonionic surfactant, paraffin and water to dissolve and separate the plastic coating.

4. Embrittlement separation
So that the mixed metal and plastic waste polystyrene compactor cooling to the brittle temperature of plastic, and then crushed, and then separated by wind sieve separation of metal and plastic.
5. Stripping of the cable sheath
In addition to the above electrostatic separation method, there are two kinds of dry and warm method can make plastic, rubber (including polyethylene) and synthetic rubber and natural rubber, And copper, aluminum wire effective separation.
(1) dry separation: with a far infrared device to the internal heating cable evenly, and then manually peel the skin.
(2) wet separation: the aluminum wire impregnated in the penetrant (surfactant) styrofoam recycling solution, heated to 70-90 degrees after stripping the skin, and then, and then organic solvent several consecutive cleaning, completely remove the tar can be.

EPS is a thermoplastic material

EPS is a thermoplastic material, after heating foam, the volume per cubic decimeter containing 300 to 600 million independent airtight, containing more than 98% of the volume of air, so that it has many features of the structure.
First, thermal insulation performance
EPS has good insulation performance because it consists of completely closed polyhedral-shaped honeycomb structure, honeycomb diameter of 0.08 ~ 0.15mm, honeycomb wall thickness of 0.001mm. EPS consists of about 98% air and 2% polystyrene. Air entrapped in the honeycomb is a poor conductor of heat, and thus the thermal insulation of EPS (insulation) performance plays a decisive role. And other gases containing the foam, the air long-term stay in the honeycomb, so the insulation effect is stable.
(A) thermal conductivity
Thermal conductivity depends on density and temperature. EPS thickness decreases, heat radiation transmittance increases, when the thickness is less than 10mm is particularly evident. The water content of the EPS has a significant effect on the thermal conductivity. For every 1% volume of water absorbed, the thermal conductivity increases by 3.4%. Therefore, in any wall structure, the insulation must be kept away from condensate.
As the ambient temperature decreases, the thermal conductivity of the EPS foam will decrease. EPS foam is suitable for low temperature environments. Because the conduction and radiation to varying degrees with the density of the workpiece (ie cell wall thickness) and change, when the EPS density is too large or too small, its thermal conductivity will increase. At room temperature, when the density of EPS foam in the 30 ~ 40kg / m 3, the lowest thermal conductivity.
According to the above characteristics, if we want to choose EPS foam as insulation material, first, the ambient temperature should be less than 75 , the lower the ambient temperature, the lower the thermal conductivity, the better insulation performance. Secondly, we should also choose the density of EPS foam as a thermal insulation material. If we only from the thermal conductivity of the starting, you can choose the density of 30 ~ 40kg / m 3 or so of the EPS foam is better, with the increase in the density of EPS, EPS strength will rise, but the material consumption, cost Will rise. Therefore, we choose the density of EPS foam, we should consider its thermal conductivity, strength and cost of production and many other factors.
It is to be noted that, in addition to the above-mentioned density of the EPS foam, the molecular weight of the EPS (generally expressed as the relative viscosity value), the size of the EPS particles, the degree of adhesion (sintering) after the foaming process, Foam after its own aperture, etc., these factors are also the number of EPS foam plastic thermal conductivity has an impact. Obviously, we require EPS products after molding, the degree of bonding to a good degree of granularity requirements of smaller, and generally optional between 10 to 25 mesh, and should make the particle diameter is relatively uniform. As for the EPS after the pre-made aperture, that is, its internal with the pores, the more detailed the better. The size of EPS beads after pre-emission is mainly related to the process characteristics of EPS raw materials. The fine-grained foamed EPS beads can reduce convection, conduction and radiation heat transfer, so that the EPS bead shaped products can have good thermal insulation properties.
From the above, a variety of EPS raw materials, the thermal conductivity may be slightly different, but the difference is not large.
(B) the use of temperature
The maximum allowable temperature of the EPS foam depends mainly on the time and magnitude of the stress experienced under thermal conditions. Under the premise of not undermine the stress, styrofoam recycling short-term high temperature can reach more than 95 . However, in some cases, such as asphalt spreaders or hot melt adhesives, the contact temperature can be as high as 110 ° C for a short time and EPS foams can be tolerated. As the molding density is increased, the thermal stability is improved, while the maximum allowable temperature does not change. In the absence of any stress, EPS foam can be used at a maximum temperature of 85 .
Polystyrene foam structure is a non-crystalline plastic, from -180  to 95  glass transition temperature does not show a fundamental structural changes, so long-term use at very low temperatures.
Second, the mechanical properties
EPS foam deformation is increased with the load time increases. Only after two days of production can it reach its carrying capacity. The part just emerging from the mold is pressure sensitive because the condensation of steam and residual blowing agent in the cell causes a partial vacuum until the cell is sucked into the air to achieve pressure balance. It is necessary to allow the residual blowing agent to diffuse for a period of time because the blowing agent has a softening effect on the article.
EPS foam is a rigid foam class. In the case of a load, it exhibits viscoelastic properties, which are characteristic of a brittle material. Flexural strength, compressive strength and tensile strength are proportional to the apparent density of EPS foam.
Third, water absorption
Unlike many other foams, EPS foams are not hygroscopic and, even when immersed in water, absorb only a very small amount of water. Since the honeycomb walls are impermeable to water, the water can only move from the fused cells to the tiny cells It is understood that the amount of water absorbed (the amount of water penetrated) depends on the performance and processing conditions (especially when foaming) of EPE foam recycling raw materials during processing. As the density of EPS foam increases, water absorption and water vapor transmission rate decrease, and the diffusion coefficient of water vapor increases. For a certain density of molded parts, the better the sintering between the beads, the greater the water vapor diffusion resistance.

Oznake: EPS foam

INTCO EPS recycling

INTCO EPS is produced by the INTCO group can be made of polystyrene, the company plans to invest in the production of 400,000 tons of polystyrene project can be made, is a project total investment of 25 million US dollars, the new annual output of 120,000 tons can be made (PS), put into operation before the end of August 2004, two plans to start in early 2005, when the output will reach 240,000 tons, three will reach 400,000 tons of output.

 April 16, 2014 the latest offer: INTCO EPS recycling device started about 5 percent, the factory price go flat, the general guidance of ex-factory price of cash reported 13,000 yuan / ton, fire reported 13,400 yuan / ton, to discuss the main transaction, Can offer. Manufacturers can still inventory, take the goods in general.

INTCO EPS Storage Note:
1.EPS storage place should be cool and ventilated good is appropriate, in order to prevent the loss of too fast foaming agent to maintain an appropriate rate, the storage room temperature to 25  the following is better, and often maintain ventilation.
2.EPS contains flammable volatile blowing agent, in the storage state will be alleviated, so the original grain, foam or molded products place is strictly prohibited pyrotechnics, polystyrene recycling machine, static electricity or lightning, in order to avoid danger.
3. As far as possible the use of advanced materials, keep fresh, in order to obtain stable operating conditions and good products.