Green Tire advantages
1,1
green tire having a good elasticity, rolling resistance, low fuel consumption, low heat, abrasion, puncture resistance, load capacity, ride comfort and the like advantage. Compared with conventional tires, it highlights the many advantages of environmental protection, energy conservation, new technology and new materials. High environmental 1.1
Since the conventional tire carcinogenic added rubber compounding agents, as the tread wear are distributed in the air, a serious pollution of the environment, while the world each year hundreds of millions of tires are discarded, they not only occupy a lot of space and are difficult to break down, causing a great threat to the environment, known as the “black pollution.” With the increasing awareness of environmental protection, while continuing efforts to reduce rolling resistance at the same time, have begun to pay attention to the materials used for manufacturing tires do not pollute the environment, and efforts to extend tire mileage to reduce the number of waste tires. After a lot of green car tires, have a tremendous effect on fuel economy and reduce pollution. Green tire will be widely used worldwide to save millions of barrels of oil per year, and significantly reduce CO emissions. 1.2 consumption
Black tire is made of the customary use of standard synthetic and natural rubber, cars at an elevated temperature, their structure and properties of the shield material are changed, while the wheel rolling resistance increases. Compared with ordinary tire green tire, reducing the weight of the tire, reducing the energy consumption of the composite material (hysteresis loss). Therefore, the green tire and the same size compared with the tire rolling resistance can be reduced 22 percentage -35 percentage, thus reducing vehicle fuel consumption and percentage -8 3 percentage that cars CO emissions declined, other properties such as abrasion , low noise, wet and dry roads etc. to maintain a good level of grip. 1.3 Safety Super
By optimizing the green tire carcass design, excellent flexibility of the tread to improve vehicle performance in the smooth pavement grip, so that more stable driving, braking distance is shorter, greatly improving driving safety sex. Studies have shown that green tire friction generated can be reduced by 15 percent car braking distance on wet or icy roads, the winter driving performance of the car increased by 10 percentage -15 percentage. This has great significance in reducing accidents and casualties.
2,2 Design Approaches green tire
Theoretically, there are ways to reduce vehicle weight reduction of fuel consumption, reduced tire rolling resistance and the use of lean burn engines. In fact, only reduce tire rolling resistance is the most practical way to green tire design, research results show that the tire mold, tire construction and tread design and materials have an impact on tire rolling resistance. To overcome the rolling resistance of the tire fuel consumed 14.4 percentage of the total fuel consumption of automobiles, rolling resistance and tread produced from only accounted for 49 percentage rolling resistance of tires, the proportion of the influence of other components are: the percentage of sidewall 14, a carcass 11 percentage , the percentage of the bead 11, the percentage of the belt layer 8, the percentage of the remaining member 7. Fuel consumption accounts for about tread direct result of 7.1 percentage. Reducing the rolling resistance of the tread and ensure good wet skid resistance of the tire will be green basic requirement.
green tire technology mainly selected from suitable types of plastic and with agents to improve the tread stock recipe start, supplemented by thinning the carcass, tire profile to optimize other design means to achieve the purpose of reducing the tire rolling resistance. It is expected that the introduction of design results oriented intervention and polymer molecular computer-aided design technology, will undoubtedly accelerate the green tire development process.
Structure 3,2.1 green tire design
2.1.1 carcass of radial structure
the tire structure can be divided into two types, i.e., a radial structure and a bias structure . The fundamental difference between radial and bias construction is that the structure of the carcass. Is the basis of the tire carcass, which is composed of a layered structure by a cord. An upper portion of a carcass layer of belt cords arranged in the circumferential direction, this structure makes the cord strength can be fully utilized, so the radial ply layers of less than 40 percentage -50 percentage bias tire.
By design, bias tire has many limitations, because the cross bias ply tire cords arranged in strong friction, carcass capacityEasy to heat and accelerated wear of the tread pattern, the layout of a cord which can not provide good handling and excellent comfort; radial tire of the steel belt there is good flexibility to adapt to the road surface is not rules shock, and durable. It also means that the ply structure much smaller friction during running, so as to obtain a longer tread life and better fuel economy. Advantage
the radial tire of the tubeless tire itself become possible. Tubeless tires have a recognized advantage, when the tire is punctured, the tubeless tire is not like (there is a common bias tire inner tube) as burst pressure but remains at a period of time, thereby improving safety.
Due to the special structure of the radial carcass, such that a road surface during traveling of the tire grip force, good results, as compared with the radial tire for automobiles equipped with car bias tire, the wear resistance can be improved 50 percentage percentage -100, -30 percentage reduction in rolling resistance 20 percentages, can save fuel consumption of about 6 percentage -8 percentage. Precisely because of this, the same model chosen radial tires good maneuverability than bias tires, better driving comfort choose.
When the tire section width is increased, the rolling resistance is decreased. This is because the tire section width increases the rigidity of the sidewall portion is reduced, and the effect of increasing the deformation of the side portion of the smaller rolling resistance, the larger the influence of deformation of the tread portion is reduced due to the rolling resistance. Further, as the energy loss of the main part of the widened section width of the tire, a tread, a belt layer and the like is reduced. Thus increasing the tire section width is advantageous for reducing the rolling resistance.
If the bead filler height of the bead portion increases, the rolling resistance also increases. Because as the bead filler height increases, the volume of material generated hysteresis loss increases, the energy loss of the sidewall lower portion also increases. Further, the bead filler height increases due to the increased rigidity of the sidewall of the deformed sidewall portion is reduced, and the influence on the rolling resistance of the large deformation of the tread portion is relatively increased, which causes an increase in rolling resistance. At present, the development of the carcass structure design is low profile direction. 2.1.2 tread
to
increasing the radius of the tread, rolling resistance of tires may be reduced. This is because the ground plane produced tire tread radius increases flection deformed, bent section due to deformation of the flexible direction of the tire generated by the strain energy becomes smaller sake. That is, with an increase in tread rolling resistance is reduced radius, whichThe main energy loss due to the crown portion and the belt layer is reduced. Next green tire tread structures should develop towards the following directions:
(1) double layer of the tread bilayer tread of the tire with high-speed, stable, and wear resistance and low heat generation, typically by tread and a base tread composed of two parts, the tread base tread rubber having different dynamic modulus and tanδ. The relevant literature indicates that the dynamic modulus is larger than the tread dynamic modulus of the tread base (≥8.5 MPa), tanδ greater than 0.12, and the ratio of the thickness of the tread base tread thickness of 0.25-0.70.
(2) a foamed tread
foam tread is made of foam rubber, the tread rubber in addition to the general group of components, further contains between crystalline syndiotactic 1,2-polybutadiene (powder, average particle size 60 nm), together with other auxiliary blowing agents, antioxidants and the like. Tests showed that the tire tread is prepared using a foamed dry, especially on a wet road surface having good braking and traction performance on ice, even in the summer heat can surely maintain steering stability, durability and low fuel consumption therefore the development direction of the green tire tread rubber.
During the tire design must be able to reduce the rolling resistance without conflicting with reduced rolling resistance other properties (wet skid resistance, safety, oscillation, etc.). As a specific embodiment of reducing rolling resistance, it must be integrated into the rubber tire shape and configuration, in particular, to consider the impact on the belt layer composed of a composite material, a carcass ply rolling resistance. As the tire structure research, not only by past experience and intuition, but also with simulation technology to accelerate the development of low rolling resistance tires.
using the finite element method the structure of the energy equation of the rubber material for several decades, the transition from the linear elastic equation Mooney-Rivlin equation and recently introduced a large deformation nonlinear structural equations art. As many industrial rubber filling rubber material used in the tire represented by the storage modulus of 0-100 percent in the strain field, the loss modulus, tan8 these viscoelastic properties of the strain having a non-linear, as is generally understood Pei due to the effect of (Fletcher – Golden effects should be). Consider this equation nonlinear structure in recent years has also been raised. In the normal state the wheel rotation, strain deformation of the tire is also accounted for most of the controlledStrain viscoelastic art rolling resistance is particularly important for the control tire. In fact, by indicating the storage modulus in the rubber-filled areas of 0-100 percent strain, loss modulus, tan [delta] Structure of nonlinear equations viscoelastic properties of these elastic sticky applied to the FEA, the prediction accuracy can tire rolling resistance more traditional forecasting has greatly improved. As a result, reduce the tire rolling resistance of a tire design, the development of new materials and Formulation accuracy and efficiency improved correspondingly. It has been developed by finite element method using the rolling resistance of the tire, and further a method of green tire design.
Bridgestone developed a knife can significantly reduce rolling resistance, and can improve the eco-Bridgestone tire design technology known as wear of tire design technology.
The purpose Bridgestone development and design technology that, in the course of research and development of fuel-saving technology tire Province, mainly focusing on the eccentric deformation of the tire. By developing new tire shape, this eccentric deformation increase, can greatly reduce vehicle fuel has a great influence on the rolling resistance of the tire, and the wear resistance can be further improved.
If the rotation of the tire load, the tire ground contact surface will be due to the deformation of the tire itself and generates resistance, thereby generating thermal energy can be lost as a king. The rolling resistance of the tire can be called a loss of the tire. By reducing the rolling resistance of the tire can reduce the fuel consumption of the vehicle.
In the past, through the development of less energy loss of the tread rubber can effectively reduce the rolling resistance, primarily through the development of a rubber material for the purpose of reducing rolling resistance. However, using less energy loss will wear rubber drop, which the development of low rolling resistance tires out of the problem.
New technologies developed by Bridgestone rolling resistance changing material (to reduce the rolling resistance) drop caused by using the new tire shape can greatly reduce the energy loss of the tire can be suppressed. Bridgestone believes this tire technology development and environmental considerations if the vehicles, such as trams (EV), etc. with, you expected to get a multiplier effect.
Bridgestone in 2003 on October 24 at the 27th Tokyo Motor Show with the demonstrated technology development tire test products. Experiments show that by loading (loading test tire size of 235 / 35R19, the number of passengers 4, the tire inflation pressure of 230 kPa), the abrasion resistance than the same kind of tires through specifications Plymouth50 tire high percentage.
The method of reducing drag 4,2.2
Generally, to reduce tire rolling resistance There are two basic approaches: (1) reducing the mass of the tire
is reduced to reduce the quality of the tire tire rolling resistance of the fastest, most effective way. In order to ensure the quality of the small tires, the tire performance in ensuring the premise must be a minimum thickness member. Tire manufacturer must be strictly controlled process to ensure parts reach the minimum thickness, it will never allow the plant to take measures arbitrarily increase the thickness of the part to solve production problems. Using an effective method of manufacturing lightweight material member of each tire is reduced in tire mass, using Kevlar belt layer is a steel belt alternatively an obvious example. (2) reducing the energy efficiency of a material
hysteresis loss) The second method of reducing the rolling resistance of tires to reduce the energy loss of the tire material (hysteresis loss). Polyester cord large hysteresis loss, but improved after appropriate, it is possible to launch a small hysteresis loss species.
5,2.2.1.1 green tire material
Natural rubber (NR) is a non-polar rubber, although it has excellent electrical properties, but easily swelled in a non-polar solvent, so the oil, organic solvent resistance is poor. NR molecule contains an unsaturated double bond, so the thermal oxidative aging, ozone resistance and UV resistance are poor, limiting its application in some special occasions. However, by modifying NR greatly expand the scope of application of NR. (1) epoxidized natural rubber
epoxidized natural rubber (ENR) is the natural rubber (NR) obtained by special chemical modification of natural rubber. Compared with NR, ENR having different thermal and viscoelastic properties, such as having excellent airtightness, adhesion resistance, wet skid resistance and good oil resistance. ENR can bind strongly polar fillers (e.g., silica), in the absence of fillers, vulcanized rubber can maintain ENR NR has high modulus and tensile strength. ENR 50 has good oil resistance and sister of Nepal, when used in a tire tread, in the absence of a coupling agent, ENR and silica strong interaction to improve rolling resistance and wet grip performance integrated an important factor, ENR25 and silica / carbon black fillers to get the best wear resistance. (2) grafted natural rubber
Currently the most studied are methyl methacrylate (MMA) graft copolymerized with NR, NR grafted MMA large elongation, high hardness, good impact properties, flex cracking resistance, dynamic fatigue properties, and better adhesion properties may be filled. Industrial mainly used to manufacture elastomeric articles having good impact properties, and the like without an inner liner of tubeless tires. If blended with SBR, can be used as bead apex rubber, the adhesion strength with which the green strength and significantly improved bead, and can increase the stiffness of the bead, the bead remains dimensionally stable. 2.2.1.2 polyisoprene rubber
Development of new synthetic polyisoprene 3,4-polyisoprene rubber (high glass gentle). Such rubber and natural rubber, styrene-butadiene rubber, polybutadiene rubber and grip performance can be improved with. Have successfully developed a copolymer of isoprene and butadiene, isoprene also studied successfully with styrene, butadiene terpolymers. Having good rolling resistance and wet road tread rubber grip the overall balance of properties.
Chinese patent ZL95110352.0 described the invention using the supported titanium catalyst bulk precipitation polymerization method of the isoprene the direct synthesis of trans-1,4-polyisoprene (TPI) powder technology. It is reported that, in the tread rubber to 20-25 parts by weight of equal amounts of TPI substituted SBR made cars and light truck radial tire semi-steel were obtained with good overall performance, and fuel consumption test hundred kilometers reduced by about 2.5 percentage Effect.