Elastic shim plate material for steel rail fastener
Technical field
The invention belongs to the rail fastener technical field, relate in particular to a kind of novel elastic backing material of using at rail fastening.
Background technology
Rail fastening be exactly on track in order to connect the part of rail and sleeper (or other types sub rail foundation), claim again intermediate fastening.Its effect is that rail is fixed on sleeper, keep gauge and stop rail with respect to sleeper in length and breadth to movement.Resilient sleeper-bearing belongs to railway bed accessory, is specially a kind of resilient sleeper-bearing that uses in railway, high-speed railway, especially a kind of resilient sleeper-bearing using under ballast aggregate under the solid concrete roabed plate, under platoon short slab railway roadbed.
Elastic properties of materials backing plate of the present invention comprises plate body, plate body comprises wearable elastic layer and buffering elastomer, buffering elastomer is positioned at below the wearable elastic layer, or between two wearable elastic layers, or be positioned among the wearable elastic layer, the face rigidity of buffering elastomer or Young's modulus are lower than face rigidity or the Young's modulus of wearable elastic layer.
Compare the backing plate of common railway fastener, the high-speed railway rubber bearing in use will exist following problem 1. rubber bearing under loading action, the internal stress that produces is high more a lot of than the backing plate of common line, same life cycle, the damaged situation of rubber bearing is relatively serious, and the permanentset that produces is larger than the backing plate of common line; 2. the railway rail pad that uses on China's common line at present partly adopts styrene-butadiene rubber(SBR), the weathering characteristics of this rubber is relatively relatively poor, under the factor effects such as heat, oxygen, ultraviolet ray and rainwater, can greatly reduce the work-ing life of elastomeric material, under the high frequency loading action, accelerate the weathering process of material simultaneously, caused the material premature failure, be usually expressed as the rubber stickness, can stick in rail foot; 3. the inefficacy of material will directly cause the variation of the quiet rigidity of backing plate, and universal law is that the rigidity value of rubber bearing increased before this, afterwards decay gradually again.The variation of backing plate rigidity will affect the stable of train; 4. under loading action, the recoverable deformation of rubber bearing is larger, easily causes fastener loosening, is difficult for keeping buckle press.
In addition, extensively adopted at present concrete sleeper on the railway of many countries, but because it lacks elasticity and the insulating property that sleeper has, therefore, introduce elastic properties of materials backing plate of the present invention as solving elasticity and Insulation Problems and not only have good elasticity, bearing capacity and weather resistance, longer service life, can play good shock absorption after application, decrease vibration and noise can be widely used in the engineering fields such as solid concrete roabed below buffer shock-absorbing, ballasted track ballast aggregate below buffer shock-absorbing and platoon short slab below buffer shock-absorbing.
Summary of the invention
The object of the invention is to propose a kind of comprehensive action that can frequently bear bed board dynamic intermittent shock load and string stress, have good compression set and dynamic fatigue property, heat-resisting air aging characteristic and alkaline-resisting characteristic are good, and have vibration damping and fall low noise elastic shim plate material for steel rail fastener.
Elastic shim plate material for steel rail fastener is characterized in that containing the component of following mass parts: benzene rubber (SBR) 1-4, terpolymer EP rubber 96 ~ 100, sulfide 5-10, carbon black 5 ~ 10, kaolin or metakaolin 15 ~ 25, softening agent 5 ~ 15.
The present invention utilizes polymer modification ethylene-propylene rubber(EPR) technology, by vulcanization crosslinking with add reinforced particulate, the backing plate resistance to elevated temperatures is improved, make simultaneously backing plate have low permanent compression set, adding of reinforcement further strengthened backing plate intensity, insulation, wear resistance and static deflection, adds simultaneously a certain amount of antiaging agent and auxiliary rheological agents, and the defective of backing plate is reduced, ageing resistance strengthens, and the resilient sleeper-bearing various aspects of performance satisfies the relevant industries technical requirement.
Resilient sleeper-bearing body material of the present invention is styrene-butadiene rubber(SBR) (SBR) modified EPT rubber, ethylene-propylene rubber(EPR) has excellent anti-ultraviolet, anti-ozone, heat-resisting, acid and alkali-resistance, water-fast steam, colour stability, electrical property, oil-filled property and normal temperature mobility, SBR rubber has good limit elongation and anti-fatigue ability, and has a good resilience, SBR modified EPT rubber provides high screen resilience simultaneously by flexural deformations and compressive set, reaching damping effect, and can absorb noise; Both add-on is SBR/ terpolymer EP rubber=(1 ~ 4)/(96 ~ 100).
The present invention adopts sulphur and superoxide compounded curing system, by the techniques such as curing temperature and vulcanization rate are regulated, control polysulfidic bond in sulfide (SX-), monosulfidic bond (S-) and (C-C) ratio of key, improve the heat aging property of resilient sleeper-bearing, and can prevent the cross-linking process molecular rupture, with tensile strength, tear strength, wear resistance and the high temperature resistant lancinating of improving vulcanized rubber, and make the resilient sleeper-bearing excellent heat resistance, have simultaneously utmost point low compression set and reversion resistance; The add-on of sulfide is 5 ~ 10.
The present invention adopts the carbon black of high structure level as the reinforced particulate of resilient sleeper-bearing material, and adds a certain amount of kaolin or wear resisting property and the erosion-resisting characteristics of metakaolin to improve resilient sleeper-bearing; Wherein the specific surface area of carbon black must be 100000m
2More than/kg, carbon content must be for more than 98.5%.Kaolinic Fe content must be for below 0.5%, and specific surface area must be 22000m
2More than/kg; Both add-on is carbon black/kaolin=(5 ~ 10)/(15 ~ 25).
The present invention adopts saturated and unsaturated fatty acids zinc salt as the softening agent of mixing process, softening agent is owing to having solubility in rubber, therefore has good physics lubrication in Rubber processing, also has simultaneously certain solution effect of moulding, plasticate, in the Rubber processing such as mixing, extrusion, softening agent significantly reduces natural rubber and elastomeric viscosity, especially reduce the compound viscosity after filled, improve the flow characteristics of sizing material, greatly reduce power consumption of polymer processing and sizing material temperature rise, enhance productivity, in refining process, the add-on of softening agent is 5 ~ 15.
The present invention adds a certain amount of compound antiaging agent in the resilient sleeper-bearing material.One of compound antiaging agent is without impact, phenolic type antioxidant that heat-resisting oxygen is good on the vulcanization of rubber and plasticity number; Another kind of antiaging agent component is the fluorescence screener, to reduce fluorescence intensity, fluorescence grade, effectively reduces the various hazardness that fluorescence brings, and increases substantially the photooxidation aging property of product; Both additional proportion is phenolic type antioxidant/fluorescence screener=(0.5 ~ 1.0)/(0.2 ~ 0.5).
The present invention also adds antifatigue, antistatic etc. some other auxiliary agent, and its add-on is 5 ~ 10.
Elastic shim plate material for steel rail fastener of the present invention, this resilient sleeper-bearing material adopts polymer modification ethylene-propylene rubber(EPR) technology, by vulcanization crosslinking with add the carbon black pellet reinforcement, and by adding a certain amount of auxiliary rheological agents and antiaging agent, make the resilient sleeper-bearing resistance to elevated temperatures be improved, make simultaneously backing plate have low permanent compression set, backing plate intensity, insulation, wear resistance, resistance of aging and static deflection are further strengthened, and the resilient sleeper-bearing material of production satisfies the requirement of industry correlation technique.
Embodiment
Basic recipe: benzene rubber (SBR) 1-4, terpolymer EP rubber 96 ~ 100, sulfide 5-10, carbon black 5 ~ 10, kaolin 15 ~ 25, softening agent 5 ~ 15.
Particularly, can be: benzene rubber (SBR) 1-2, terpolymer EP rubber 96 ~ 98, sulfide 7-8, carbon black 6 ~ 8, kaolin 18 ~ 20, softening agent 9 ~ 12.
The present invention also can add the compound antiaging agent that is comprised of phenolic type antioxidant and fluorescence screener, and both mass parts are 0.5 ~ 1.0 and 0.2 ~ 0.5.
The present invention also can add antifatigue, antistatic etc. some other auxiliary agent, and its add-on is 5 ~ 10.
More specifically, adopt formula to be (mass parts): styrene-butadiene rubber(SBR) 3; Terpolymer EP rubber 100; Sulfide 7.5; Carbon black 5; Kaolin 20; Softening agent 10; Antiaging agent 1; Other auxiliary agents 7.5.Performance to the resilient sleeper-bearing material is tested, and result is as shown in table 1.
The performance of table 1 resilient sleeper-bearing material
Table 1 shows, by the resilient sleeper-bearing material that above-mentioned technique and formula obtain, can fully satisfy the requirement of " the provisional technical qualification of passenger dedicated railway line non-fragment orbit fill-type backing plate " (No. [2008] 74, science and technology base).