|
Contact Us
|
|
Dongguang Zhansheng Silicone Technology Co.,Ltd.
Email: info@zs-silicone.com
Whatsapp:+86-13556708445
Skype:sophiacbvs
|
|
|
| Your current location£ºHome » News » Hot news » What supports the physical strength of the silicone rubber seal? |
What supports the physical strength of the silicone rubber seal?
|
|
Edit£º Browse£º619 Date£º2019-10-18
|
The relationship between formula and physical properties: all kinds of silicone rubber products have their specific performance and process requirements. In order to meet the requirements of its physical properties, the most suitable polymer and coordination agent should be selected for the rational formula design. First of all, the relationship between the formula design and the physical properties of silicone rubber should be understood. The physical properties of the vulcanized silicone rubber are closely related to the design of the formula, and different material varieties and dosage in the formula will produce performance differences.
I. tensile strength
Tensile strength is the ultimate strength of silica gel products to resist tensile failure. It is one of the important indexes of silicone rubber products. The life of many silicone rubbers is directly related to the tensile strength. For example, the durability of rubber cover and silicon rubber shock absorber of conveyor belt is improved with the increase of tensile strength. The tensile strength is related to the structure of silicone rubber. When the content is small, the second valence bond of intermolecular interaction is small. Therefore, when the external force is greater than the intermolecular interaction, the intermolecular sliding will occur and the material will be destroyed. On the contrary, if the molecular weight is large, the intermolecular force increases, the cohesion of the rubber material increases, and the chain segment is not easy to slide during stretching, then the damage degree of the material is small. All other factors that affect the intermolecular force have an effect on the tensile strength. For example, NR / Cr / CSM have crystalline substituents on the main chain of these adhesives, which greatly improve the valence force between molecules and the tensile strength. This is one of the main reasons for the good self reinforcing properties of these silicone rubber. Generally, the tensile strength of silicone rubber increases with the increase of crystallinity. The tensile strength is also related to the temperature. The tensile strength at high temperature is far lower than that at room temperature. The tensile strength is related to the cross-linking density of the root. With the increase of the cross-linking density, the tensile strength increases. After the maximum value appears, the cross-linking density continues to increase, and the tensile strength will decrease significantly. The tensile strength of vulcanized silicone rubber decreases with the increase of crosslinking energy. Natural silicone rubber, which can produce tensile crystallization, breaks at the early stage of weak bond, which is conducive to the orientation crystallization of main bond, so it will have higher tensile strength. DM / M / D can also improve the tensile strength (except for carbon black reinforcement, because of the heat generation of carbon black). The relationship between the tensile strength and filler is that the reinforcing agent is one of the important factors affecting the tensile strength. The smaller the material diameter of filler, the larger the specific surface area and the higher the surface activity, the better the reinforcing performance.
II. Tear strength
The tearing of silicone rubber is caused by the crack or crack in the material which expands rapidly and leads to the failure phenomenon. There is no direct relationship between tear strength and tensile strength. In many cases, tear is not proportional to tension. In general, the tearing strength of the polysilicon rubber is higher than that of the noncrystalline rubber. Tear strength is related to temperature. In addition to natural silicone rubber, tear strength decreased significantly at high temperature. The tear strength of silicone rubber filled with carbon black and white carbon black is obviously improved. The tear strength is related to the curing system. Polysulfide bond has high tear strength. High sulfur content, high tear strength. However, the tear strength will be significantly reduced if too much sulfur is used. The use of flat accelerant can improve the tear strength. The tear strength is related to the filling system. Various reinforcing fillers, such as carbon black, white carbon black, brilliant white and zinc oxide, can obtain high tear strength. Some coupling agents such as laurane can improve tear strength. In general, the addition of softener will reduce the tear strength. For example, paraffin oil will make the tear strength of SBR extremely unfavorable. Aromatic oil has little change.
III. constant elongation stress and hardness
Constant elongation stress and hardness are important indexes of material stiffness, and they are the force needed for vulcanizate to produce certain deformation. They are related to large tensile deformation, and they have good correlation, and the change rule is basically the same. The higher the molecular weight of silicone rubber is, the greater the effective crosslinking constant elongation stress is. In order to obtain the specified constant elongation stress, the crosslinking density of silicone rubber with small molecular weight can be increased appropriately. Any structural factor that can increase intermolecular force. All of them can improve the deformation resistance of vulcanizate. Constant elongation stress and crosslinking density have great influence. With the increase of crosslinking density, the constant elongation stress and hardness of both pure rubber and reinforced vulcanizate increase linearly. It is usually realized by adjusting the varieties of curing agent, accelerant, assistant curing agent and active agent. The promotion of sulfur has more significant effect on increasing the constant elongation stress. Polysulfide bond is beneficial to increase the constant elongation stress. The filler can improve the constant elongation stress and hardness of the product. The higher the reinforcement performance and hardness, the higher the constant elongation stress. With the increase of hardness, the fixed extension stress increases. On the contrary, with the increase of softener, the hardness decreased and the constant elongation stress decreased. In addition to the addition of reinforcing agent, the hardness of alkylphenol formaldehyde resin can reach 95 degrees and the styrene resin is high. The hardness of the system can reach 85 degree by using RS resin and H accelerator.
IV. wear resistance
The characterization of wear resistance is the ability of silica gel products to resist the material loss due to the surface damage under the action of friction. It is a mechanical property closely related to the service life of silicone rubber products. Its forms are;
1. Wear and tear: the uneven and sharp rough objects on the surface are continuously cut and scratched. As a result, the contact points on the surface of the silicone rubber are cut and broken into tiny particles, which fall off from the surface of the silicone rubber, and the abrasion strength is proportional to the pressure and inversely proportional to the tensile strength. It decreases with the increase of resilience.
2. Fatigue wear, contact with friction surface
|
|
Previous£ºExploring the Benefits of Dog Lick Mats
|
|
Next£ºAdd interest to life and choose silica gel products for life
|
Print |
Close
|
|
|
sophiacbvs
+86-13556708445
