The automobile light-weight led to the demand for modified plastics for automobiles, and the automotive industry has become the fastest growing area for modified plastics. The biggest application areas for modified plastics are household appliances and automobiles. The automobile industry has become the Modified plastic demand the fastest growing areas, the next few years is expected to domestic automotive modified plastic demand average annual growth rate will be above 15%.
First, the introduction of modified plastic
1, modified plastic classification
Modified plastics refers to by adding the right modifier, after blending, filling, enhancing, copolymerization, crosslinking and other physical and chemical methods of common plastics and engineering plastics modified to improve its toughness, strength, tensile , Impact resistance, flame retardancy and other properties of the resin / plastic.
Therefore, the upstream of the modified plastics industry chain is PE, PP, PVC and other synthetic resins, which are modified by physical or chemical methods to obtain modified plastic resins, and then the modified plastic products are obtained through processes of extrusion, injection molding and rolling, Excellent performance, modified plastic products are widely used in home appliances, automobiles, construction and other industries.
Modified plastic industry chain
According to the modified function, modified plastics, including flame retardant resins, toughening resins, plastic alloys, functional masterbatches and other species, each species can be subdivided into different materials, and because of their own Performance differences, applications are also different.
Modified plastic classification
Modified plastic classification and use
2, modified technology
Modification techniques include physical methods such as blending, filling and enhancing, and chemical methods such as copolymerization and cross-linking. The physical method is the most important modification method at present. In order to achieve specific properties such as blending and filling, a suitable modifier needs to be selected. The purpose of the modification.
(1) Modifier
Modifiers or auxiliaries can also be divided into processing aids and functional aids.
Processing aids are used to improve the processing of plastic rheology and forming properties of additives, including: Lubricants - to improve the flow of the substrate; Heat stabilizers, antioxidants - to improve the thermal stability of the substrate; Dispersion Agent - to improve the dispersion of the substrate; compatibilizer, coupling agent - to improve the compatibility of the substrate; bridging agent, tackifier - to improve the melt strength of the substrate.
Functional additives mainly used to improve the physical and chemical properties of the substrate, including: fillers, crystal nucleating agent - to improve the rigidity and strength of the substrate; impact modifier - to improve the impact of the substrate; flame retardant - - to improve the flame retardancy of the substrate, the modified material can effectively prevent, delay or stop the flame propagation when it is attacked by fire source; stabilizer - to improve the weatherability of the substrate; conductive coating filler, anti Electrostatic agent - to improve the conductivity of the substrate, antistatic agents can reduce plastic in the processing and use of static electricity accumulation, reducing the surface resistivity of the material; plasticizer - to improve the hardness of the substrate; foaming agent - Change the density of the substrate; pigment - to change the transparency of the substrate, color.
Use of some modifiers
(2) modification method
Resin modification methods can be divided into physical methods and chemical methods, including filling, blending, enhancing, copolymerization, crosslinking, etc., the current mainstream of modification technology is based on the filling, blending, enhanced, etc. Modified technology.
Filling is mineral, modifier filler and plastic blend, plastic shrinkage, hardness, strength and other properties can be improved; blending is the incorporation of one or more other resins, modifiers or minerals, To improve the original performance; enhance the glass fiber is blended with plastic to enhance the mechanical strength of plastic.
Modified technology
For filling, blending and enhancing the modified formula once identified, the downstream production equipment for the specific operation is not high.This technical characteristics determine the modified plastic production process is the key to the modified formula design, from the current In the light of the situation, the original formula of general-purpose large-size modified plastics is basically in an open market, while the formula of high-performance specialty modified plastics is in the hands of leading companies in various segments.
3, application areas
Modified plastics are better than common plastics in flame retardancy, strength, impact resistance, toughness and other aspects of performance. They are widely used in downstream applications. They are mainly used in the fields of home appliances, automobiles, construction, office equipment and machinery. Among them, household appliances, automobiles Is the largest of its two application areas. In 2015, the consumption of modified plastics in China is already close to 10 million tons. As the scientific and technological progress and industrial upgrading, its downstream applications are still expanding.
Automotive modified plastics
Automotive industry has become the fastest growing area of modified plastic demand.According to the market consulting firm Marketsand Markets is expected in 2018 the global automotive plastic market is expected to increase from 21.616 billion U.S. dollars in 2012 to 4.6112 billion U.S. dollars, consumption is expected to be 2012 From 7.1 million tons in 2011 to 11.3 million tons in 2018, with a CAGR of 13.4% from 2013 to 2018 (CNK: "The market capitalization of global automotive plastics will exceed US $ 46 billion in 2018" and "2018 Global demand for automotive plastics will reach 11.3 million tons. "This is mainly due to: First, the global automotive production growth rate stability; Second, the light vehicle makes the amount of cycling modified plastic increased.
The growth rate of domestic automotive modified plastics is much higher than the global average. The growth of domestic automobile output in the past many years are much higher than the growth rate of global automobile production, domestic bicycle plastic dosage is much lower than that of developed countries such as Europe and the United States, the development There is huge space. In particular, China is already the largest market for new energy vehicles in the world. New energy vehicles need the support of lightweight technology. Therefore, the demand growth of domestic automotive modified plastics will be higher than the global average and become the downstream growth of modified plastics Fastest area, according to ASG Consulting is expected in the next 5 years, the domestic automobile modified plastics industry compound annual growth rate will exceed 26%.
Second, the car lightweight and automotive modified plastic demand
Lightweight car is the future direction of the development of the automotive industry, especially for new energy vehicles, the weight reduction directly implies an increase in mileage.Researches have shown that the weight of the vehicle can be reduced by 10%, fuel efficiency can be increased by 6 to 8 %, The weight of each reduction of 100kg, 100 kilometers of car fuel consumption can be reduced 0.3 ~ 0.6L, 100 km CO2 emissions can be reduced by about 5g ("lightweight design of car technology route analysis"); for pure electric vehicles, vehicle weight Reduce 10kg, driving range can be increased 2.5km ("Lightweight car technology status and application of the main channel analysis").
1, lightweight car technology
Car lightweight as a systematic project, not simply for a single weight loss, local weight changes will largely affect other parts of the car, so the car is lightweight in the automotive manufacturing process Set design, manufacturing, materials technology together with the systematic project.
When designing lightweight vehicles, three factors need to be considered: structural safety of the vehicle body, stiffness analysis, and light weighting factors (Analysis of Current Status and Main Approaches of Automotive Lightweighting Technology)
(1) body structure safety
Car body and interior decoration lightweight premise is the car safety, body stiffness, fatigue durability, handling stability and vibration comfort to meet the requirements.Car body structure is designed to protect the safety of the occupants of the vehicle belongs to the passive safety of the car Category, the safety of body structure will directly affect whether the car can meet the frontal collision, side collision, rear collision, roll and low-speed collision of these passive safety requirements.
At present, the passive safety regulations of all countries are: ECE / EEC and FMVSS. The passive safety standard (GB) of our country mainly refers to the European legislation system.
(2) Stiffness analysis
The overall stiffness of the body is the relationship between the body load imposed by the outside world and the amount of deformation of the body after the load is applied.The body stiffness reflects how to control the deformation of the various parts of the body structure to meet the body assembly and use requirements Therefore, if the rigidity of the body is not designed properly, the vibration frequency of the body will be reduced, which will lead to the vehicle's comfort, service life, collision safety and NVH performance, etc. The design of modern body Is to minimize the quality of the body under the premise of maximizing the car body stiffness.
(3) Lightweight coefficient
Light Weight Index L (Light Weight Index) is currently an automobile industry to accept a larger evaluation of vehicle lightweight indicators.Light weight coefficient L value is smaller, said the body lighter to do better. Lightweight body weight coefficient The calculation formula is shown in Figure 11, where L is the light weight coefficient, CT is the static torsional stiffness of the vehicle body with the windshield, m is the mass of the white body frame without four doors and two covers, A is the projected area between the four wheels of the vehicle body .
From the calculation formula of the light weight coefficient L, it can be known that to reduce the light weight coefficient of the vehicle, it can be achieved by increasing the rigidity or reducing the mass of the white body.At present, the vehicle light weighting technology is mainly divided into three aspects: structural optimization design, Material applications and the use of advanced manufacturing processes. Among them, the use of lightweight alternative materials is widely recognized in the industry and the most promising lightweight technology currently used lightweight materials are high-strength steel, aluminum-magnesium alloy, modified plastics and Composites.
Low-strength steel refers to the strength of less than 201MPa steel, and high-strength steel mainly refers to the strength between 201MPa-550MPa steel, super strength steel refers to the strength of more than 550MPa steel.In the automobile manufacturing work, the steel material Is the use of more materials, but also the main components of the car structure, in the case of the same strength, the use of high strength steel can effectively reduce the thickness of the steel plate used in automobile manufacturing, which can radically reduce the weight of the car itself, which can be effective Reduce the light weight coefficient L.
Relative to steel, the specific gravity of the aluminum alloy is only 30% 2.68g / cm3. When the bending stiffness is equal, the weight loss potential of 49%; when the bending strength is equal, the weight loss potential of 38% The main application forms are the following: aluminum alloy forgings such as automobile suspension brackets, wheels and other structural parts; mold castings such as body shell and engine cylinder head; aluminum alloy pull-pull parts such as body structure; Pieces, covers and other rolled sheet; shell, high strength of the small castings.
The proportion of magnesium is smaller than the proportion of aluminum alloy, only 1/4 of the steel is 1.74g / cm3, which has great potential for light weight application.At present, the manufacture of automobile parts has been widely used for magnesium alloy, the dashboard skeleton, Skeleton, etc. More than 60 kinds of parts are made of magnesium alloy.
Compared with metal materials, modified plastics and composite materials have lower density and higher specific strength. At present, common modified plastics and composite materials mainly include modified PP, modified PVC, modified PE, fiber composite, metal Based composites, thermoplastic resin composites, etc. Modified plastics are mainly applied to the interior and exterior decoration of automobiles in the early stage. With the application of fiber-reinforced plastics, they have been applied to automobile structural parts nowadays, especially the development of carbon fiber composite materials technology, Automotive lightweight solutions based on modified plastics and composites are possible.
2, the new requirements of the lightweight of new energy vehicles
In recent years, the rapid development of new energy vehicles, according to high technology lithium (GGII) statistics in 2016 the global sales of new energy passenger vehicles reached 726,000, and including the Netherlands, Germany, France and the United Kingdom, including a number of countries have given Out of the schedule of the banned fuel vehicles, the development of new energy vehicles has been overwhelming, from the current technology point of view, the next few years, electric vehicles will be the main form of new energy vehicles.
Prohibited fuel car schedule
Electric vehicle charging a long time and fuel mileage has less than the fuel cell has been criticized for its short board. Charging time by the charge-discharge principle of lithium-ion battery, without changing the charge and discharge principle of the battery under the premise of improving space Limited, but to improve the mileage is to work hard, the easier way is to carry more batteries to improve the mileage, but more battery means not only charging longer, but also means that the weight of the car will be even more Heavy, the work efficiency will be lower, which is the consumption of 1Kwh power car will reduce the distance.If you want to increase the battery life without increasing the mileage, it must be achieved by increasing efficiency.
The most important method to reduce the weight of a car is to reduce the weight of a full electric vehicle by 10 kg and increase the driving range by 2.5 km. Will be important to reduce 500kg, carrying the same power in the case of life mileage will be able to upgrade 125km, so the desire for lightweight electric vehicle technology is very urgent.
Electric vehicle lightweight technology
The biggest difference between electric vehicles and fuel cars is that a large part of electric vehicles from the weight of the battery, and the weight of the battery unless you find a higher energy density of materials or change the current lithium-ion battery system, it is difficult to lower down, thus alleviating the body , The weight of the interior, chassis, etc. is a more viable option for its lightweight.
A pure electric vehicle parts of the weight (kg)
Reduce the weight of the interior can be achieved through the use of more modified plastic, body and chassis weight reduction In addition to using the above-mentioned high-strength steel, aluminum-magnesium alloy, some researchers even proposed the concept of all-plastic body, made Integrated ultra-light new energy vehicles concept, ultra-light new energy vehicles mainly by the driving battery unit, driving system, steering system, aluminum body frame, composite body, plastic floor, etc., body curb weight can be reduced to 850kg Including the battery). The design of the all-plastic body is an important part of lightweight design of new energy vehicles. Compared with the traditional automobile body design, the design of the all-plastic body is an integrated, modular and integrated design concept, meanwhile, Achieve the function of highly integrated components, thereby reducing the number of components and reduce production costs.
3, car modified plastic
The role and status of modified plastics in the automobile industry is more and more obvious. At present, polypropylene (PP), ABS, polyamide (PA), polycarbonate (PC) Polyoxymethylene (POM), polybutylene terephthalate (PBT), reinforced polyurethane (PRT) and polyvinyl chloride (PVC) and other plastics are widely used in automobiles. In all automotive plastics , Polypropylene accounted for up to 37%, followed by polyurethane, accounting for 17.3%, ABS resin accounted for 12.3%, composites accounted for 11.5%, high density polyethylene accounted for 10.8%, polycarbonate accounted for 6.8% Methyl acrylate accounted for 4.4%.
Automotive modified plastic main varieties
Modification of plastic parts in the automotive application covers both interior and exterior trim, function and structural parts, with the development of fiber-reinforced technology, especially the development of carbon fiber composites, and even the body, chassis, etc. can be completely modified plastics and composites manufacture.
(1) modified plastic in automotive interior and exterior parts on the application
Dashboard
At present, dashboards are mainly in the form of hard dashboards and soft dashboards. Soft dashboards are generally adopted by more upscale cars while dashboards, vans and other models basically use hard dashboards. PP material, modified PP is mainly rubber toughening agent and inorganic filler materials; dashboard materials to PVC / ABS-based, PVC in the impact resistance and heat resistance is relatively weak, ABS machinery Performance and molding processing capacity is better, and can be combined with PVC, the two can be combined to form a complementary.
Door inner panel
Currently more commonly used in the manufacture of plastic door panels modified ABS, PP, made of them into a skeleton, and the surface with a layer of buffer layer, the buffer layer using PP foam, TPU, knitted polyester, etc. In GM, Chevrolet some Models, skeletons, panels are made of glass fiber reinforced unsaturated polyester sheet molding compound (SMC) material, in some cars will also be made of natural fibers and PP hot pressing made of this approach can effectively reduce the door Weight, reduce costs, noise performance has been significantly improved.
Body cover and chassis
Modified plastic body cover, compared with the metal cover, the body is more smooth, more precise size, and quality, noise, vibration and other conditions can be more optimized, so the modified plastic in the roof, hood, luggage compartment Covers, etc. Ford Motor Company uses SMC to make front fenders, cover plates and hoods; XeniaPC / PBT body panels are used in the new smart models from Dell Chrysler.
In the automobile chassis, due to the large load to be borne, there is a big problem in plasticization, and the main application is modified plastics such as modified PBT in the transmission suspension system and the wear-resistant moving parts of the steering system, Modified POM and other materials.
(2) modified plastic in the function of the structure of the application
bumper
Car bumpers are one of the major components that use modified materials. Most of the bumpers on the market today are made of plastic products. The bumper panels are made of PP, PC / ABS, PC / PBT and other materials. The skeleton is Wood or metal and other materials, the middle part is PP foam materials, etc. Such materials from the environmental point of view is not conducive to recycling, after continuous innovation in the production of bumper panels can be used TPO, the framework can be reinforced with glass fiber PP material, the middle part Foam PP can be used, bumper made of the same properties of the material, as long as the cleaning and drying before the recovery process can be.
Fuel tank
In the production of fuel tanks, modified plastics also play an important role, according to a certain percentage of mixed resin, adhesive, PA and other materials, and then blow molding. In addition, you can also use ultra-high molecular weight polyethylene, copolymerization PA, EVOH resin materials such as fuel tanks.
Engine intake manifold
In the car's intake manifold there is a certain degree of difficulty in the production, mainly because of the shape of the intake manifold is more complex, the current modified plastic in the engine intake manifold manufacturing mostly using the AIM process for production, in Chrysler, Some models of Cadillac engines, the intake manifold on the application of glass fiber reinforced PA.
In the running of automobile engine, the temperature will continue to rise, so the components around the engine must withstand the high temperature of 220 degrees Celsius while maintaining high strength, if it is in the colder weather but also have to withstand low temperature performance, Therefore, the general use of PA66 material to ensure the performance of plastic parts.
Clutch execution system
The clutches are often used in high temperature environments and are subject to pressure lubricants, and metal materials are used in the traditional manufacturing process. However, in continuous experiments, it is even more obvious that the modified plastic makes the clutch execution system more advantageous. When manufacturing the clutch actuation system, Black 50% long fiber reinforced black LFRT raw materials, more stability, and cost savings.
(3) The application of fiber reinforced plastics in automobiles
Fiber reinforced plastic is a resin and reinforced fiber composite materials, the automotive industry mainly uses glass fiber reinforced thermoplastics, it has a small density, easy to shape, design flexible and beautiful, corrosion resistance, impact resistance, vibration resistance, thermal insulation, Easy to paint, high strength, low cost.
At present, front fenders, engine covers and tail plates made of glass fiber reinforced unsaturated polyester sheet molding compound (SMC) have been widely used in automobile bodies; glass fiber mat reinforced with glass fiber (felt) Thermoplastic Composites (GMTs) have been used primarily on seat frames, bumpers, battery trays, dashboards, floors, guards, hood covers, pedals, back doors and more.
(4) carbon fiber composite materials in automotive applications
Carbon Fiber (Carbon Fiber) is a fibrous carbon material, the diameter of which is usually a few microns, the carbon content is usually above 90%. Carbon fiber has a very good physical properties, the key mechanical indicators are tensile strength, tensile modulus Tensile strength refers to the maximum stress that a material can withstand before tensile fracture. Tensile modulus refers to the ratio of stress to deformation when material is stretched. The higher the modulus value is, the better the stiffness of carbon fiber is. In theory, the tensile strength of carbon fiber can reach 180GPa, tensile modulus is more about 1000GPa.
In addition to excellent physical properties, carbon fiber also has excellent chemical properties, such as corrosion resistance, high temperature resistance, good electrical and thermal conductivity, etc. Therefore, carbon fiber composite materials with various substrates made of carbon fiber composite materials first Aerospace and military fields have been widely used.
Carbon fiber composite material is not only superior to the mechanical properties of the metal material much better, and the density is much smaller, help to reduce the weight of the product, which is very important in the field of aerospace and other anomalies sensitive to weight.With the recent carbon fiber composite molding technology With the development and cost reduction, more and more applications are being made on the lightweighting of automobiles, and even car bodies can be manufactured. Its emergence makes it possible to realize lightweight solutions for vehicles based on modified plastics and composites.
Physical properties of carbon fiber composites compared with other materials
(5) Automotive lightweight solutions
To sum up, with the development of fiber reinforced plastics technology, especially the development of carbon fiber composite technology, the overall lightweight solution of automobile based on modified plastics and composite materials becomes possible. The main obstacle at present is the excessive price of carbon fiber , The large tow of carbon fibers used in the automotive industry is currently priced above $ 15 / kg, and the mid-size sedan, priced at about 300,000 renminbi, may only be used on a large scale only if the price drops below $ 10 / kg or below.
4, automotive modified plastic market analysis
(1) Global automotive modified plastics market
Currently the highest use of modified plastic is the German Department of Bicycle, the use of modified plastics reached 22% of 300-360 kg, the average European and American countries also reached 16% of 210-260 kg, China's passenger Only 8% of the modified plastic for bicycles is 100-130 kg.
In 2016, a total of 21.86 million passenger cars were produced in Europe and the United States while 24.24 million passenger cars were produced in China. The weighted average consumption of modified plastic for passenger cars worldwide was 152-191 kg, taking an intermediate value of 171 Kg In 2016, the global production of passenger cars was 72.1 million and the required modified plastic was 12.33 million tons. According to the unit price of 18,000 yuan / ton, the global market for modified automotive plastics in 2016 will be 221.9 billion yuan.
According to the forecast that the global production of passenger cars will reach 81.48 million by 2020 and the amount of modified plastic consumed by bicycles will increase under the light of the trend of automobile lightweight. Assuming that the amount of bicycle modified plastics increased to 200 kg by 2020, Market space will be close to 300 billion yuan, an average annual growth rate of about 7% from 2017 to 2020. The global automotive modified plastics market, the main players are large chemical companies such as BASF, PolyOne (PolyOne), Dow DuPont, Covestro and others.
(2) China's automotive modified plastics market
At present, there are thousands of enterprises engaged in the production of modified plastics in China. However, there are only over 70 enterprises above designated size (production capacity exceeding 3,000 tons). In terms of capacity, domestic enterprises account for about 73% and foreign or joint ventures account for about 27% %, But the market share from the point of view, the domestic market share of only 30%, while the foreign market share as high as 70% .At present have set up modified plastics production base in foreign large enterprises SABIC company, DuPont Company, SOLVAY, Dow, Germany BASF, LANXESS, BAYER, Celanese, Japan Asahi Kasei, Polyplastics, South Korea's Samsung, LG, Kumho, the Netherlands DSM companies.
Further specific to the field of automotive modified plastics, according to the domestic production of 24.24 million passenger cars in 2016 and the amount of bicycles modified plastic amount of 115 kg to calculate the domestic demand for automotive modified plastic 2.78 million tons, the market space at 400 (Calculated at 15,000 yuan per ton), but compared with 40% of the world's modified plastics used in the automotive industry, only about 10% of China, in addition the growth rate of domestic passenger cars is much larger than the growth rate of global passenger cars, According to the forecast of GIC, the production of passenger cars in China will reach 28.65 million units by 2020 (6.95% growth in 2017, 5.15% growth in 2018, 3.01% growth in 2019 and 4.75% growth in 2020) ) Around the domestic car with a huge potential for the development of modified plastics.
On the other hand, the Roadmap of Energy-saving and New-energy Vehicles Technology released by China Society of Automotive Engineers in October 2016 points out that by 2020, 2025 and 2030, vehicle quality will have to be reduced by 10% and 20%, respectively, from 2015 %, 35%. In addition, China is also the world's largest market for new energy vehicles. In 2016, sales of new energy passenger vehicles accounted for 43.7% of the world's total. In the next few years, it will grow at a rate of about 40% each year. By 2020, production will reach 200 million vehicles, new energy vehicles rely on lightweight technology more, so the amount of domestic bicycle modified plastic will show a substantial growth.
Conservative estimates Even if the amount of modified plastic for passenger car cycling in China reaches only 150kg by 2020, the market space will also be close to 65 billion yuan and the average annual growth rate will reach about 11% in 2017-2020. If the bicycle consumption reaches 2020 Now the global average of 170kg, the market space will exceed 70 billion yuan, the average annual growth rate of 2017-2020 will reach about 15%; if the amount of cycling to catch up with the global average of 200kg by 2020, the market space will exceed 85 billion yuan, The average annual growth rate from 2017 to 2020 will be close to 20%.