Common Elastic Materials
Common elastic materials include rubber, silicone, TPE, TPR, TPU, and soft PVC. Elastic products are widely used in many fields, such as phone cases, utensils (nylon + silicone), protective gloves, sealing rings, swim caps, baby toys, pet toys, and so on. People may have some misconceptions about these products, thinking that they are made of rubber or plastic materials, but in fact, these are all elastic products, and different elastic materials have significant differences. Engineers will match the appropriate elastic materials according to the application environment and properties of the product.
When selecting materials, they should be classified based on the material properties, mainly considering properties such as environmental protection, hardness, elasticity, corrosion resistance, temperature resistance, wear coefficient, processing technology, coloring, processing costs, etc. Of course, now most products will focus on the environmental friendliness of materials, being non-toxic, odorless, and not degrading any harmful substances during use, and factors related to different user groups and application scenarios will be considered more detailed.
Currently, the main elastic materials are rubber, silicone, TPE, TPU, soft PVC, etc. Let’s take a closer look at the specific characteristics of these elastic materials.
Difference between silicone and rubber:
Silicone and rubber have distinct differences in their performance under the same application environment, with changes in environment, time, temperature, and humidity. For example, in laboratory condenser tubes, both rubber and silicone are elastic materials, but silicone performs better at low temperatures (-20 to +220°C) and has better resistance to aging. The main difference between these two elastic materials is their molecular structure: rubber is mainly composed of carbon, an organic compound, while the main chain of silicone is composed of alternating silicon and oxygen atoms (Si-O).
Silicone can be colored in a variety of ways by adjusting the colorant, while most rubber products are black. This is because carbon black is added during the rubber compounding process, and the high-temperature condensation process of carbon elements and hydrocarbons can make the rubber very strong, greatly improving its wear resistance and anti-aging properties.
Related Silicone Products (11)
【Rubber】:
Rubber is divided into natural rubber and synthetic rubber. Natural rubber is processed from the latex of rubber trees and other plants, while synthetic rubber is obtained by polymerizing various monomer molecules. Rubber includes many types, such as natural rubber, SBR rubber, butyl rubber, nitrile rubber, isoprene rubber, and silicone rubber. Rubber has high elasticity and can produce large deformation under very small external force. After the external force is removed, it can return to its original state. Rubber can be artificially synthesized, has a low price, and has good physical and mechanical properties and chemical stability. It has excellent oil resistance, water resistance, solvent resistance, and high-pressure resistance, good compressibility, and excellent wear resistance. However, rubber is susceptible to aging, has poor radiation resistance, and poor low-temperature performance. Rubber is widely used in the manufacture of tires, pipes, tapes, cables, and other customized products.
【Silicone Rubber】:
The main component of silicone rubber is silicon dioxide. It is a thermosetting elastic material that is safe and environmentally friendly, insoluble in water and any solvent, environmentally friendly and odorless, chemically stable, with high adsorption performance, good thermal stability, and high mechanical strength. The disadvantage is that the tear strength and mechanical properties are poor, and it is not resistant to strong alkalis and hydrogen fluoride acid. It is widely used in construction, electronics, textiles, machinery, automobiles, medical and pharmaceuticals, chemicals, metals and paints, baby and toddler products, etc.
The manufacturing process of silicone rubber products is relatively complex, requiring a complete set of process flow such as mixing, coloring, cutting, molding, vulcanization, and trimming to produce the product. Silicone rubber products are thermosetting materials and will not melt when heated after vulcanization. They cannot be directly recycled for further processing, and the cost of silicone rubber products is usually higher than that of other elastic materials such as TPE, TPU, and soft PVC.
【TPE】:
TPE is a thermoplastic elastic material that can be recycled and produced by injection molding. TPE products have excellent coloring, environmental protection, a wide range of hardness, soft touch, superior weather resistance, fatigue resistance, temperature resistance, and processing performance, no need for vulcanization, high processing efficiency, and can be recycled. It can be secondary injection molded, coated and bonded with matrix materials such as PP, PE, PC, PS, ABS, or molded separately. It has excellent transparency, gloss, and comfortable hand feeling, and is widely used in adult products. It has good UV resistance, weather resistance, and high-temperature resistance, and is used for a long time outdoors.
However, the heat resistance of TPE is not as good as that of silicone rubber, and the elasticity decreases significantly with the increase of temperature, so the application range is limited. The compressive deformation, resilience, and durability are inferior to silicone rubber.
TPE has a wide range of applications, including various wire and cable, automotive parts, cushions, food packaging, cosmetics packaging, manual and electric tool kits, as well as medical devices such as transfusion bags, syringes, infusion bags, and gloves.
【TPU】:
TPU is a thermoplastic polyurethane elastic rubber with a wide range of hardness, high mechanical strength, outstanding cold resistance, good processing performance, good wear resistance, toughness, strong tear resistance, and resistance to oil, water, and mold. The disadvantage is poor weather resistance, poor compressive resistance, poor high-temperature resistance, and poor moldability. TPU processing methods generally include injection molding, blow molding, compression molding, and extrusion molding, among which injection molding is the most common. It is commonly used in construction, electronics and electrical appliances, textiles, automobiles, machinery, leather and papermaking, medical and pharmaceuticals, etc.
The elasticity and elastic recovery performance of TPU are better than that of TPE. The processing of high-hardness TPE is prone to product deformation, while TPU shows excellent elasticity in all hardness ranges, and the product is not easy to deform, and the rebound performance is satisfactory.
For some products with coating and molding, such as handles and wheels, both TPE and TPU can be used.
Difference in Hardness of 5 Types of Elastic Materials:
Silicone rubber generally has a hardness range of 0A to 70A, TPE has a hardness range of 0A to 100A, TPU has a hardness range of 65A to 80A, and rubber has a hardness range of 50A to 70A.