How is the hardness of EVA divided and measured?

The hardness of EVA is divided into: foam tube and EVA material.

EVA foam tube is also called NBR foam tube, its hardness is divided into A + dense A dense B dense B + dense B dense and C dense, generally with B dense more. EVA materials are relatively common before 38-70 degrees, and 25 degrees below 38 degrees.

Generally, a C-type hardness tester is used to measure, select a relatively flat area, with a thickness of more than 6mm, and measure the strength of 1kg (a weight of 1kg can be placed on the top of the hardness tester).

Extended information: Content and performance.

The performance of EVA has a great relationship with the content of vinyl acetate (VA), when the content of VA increases, its resilience, flexibility, adhesion, transparency, solubility, stress crack resistance and impact performance will be improved; When the VA content decreases, the rigidity, wear resistance, and electrical insulation of EVA increase. In general, the VA content is in the range of 10% to 20%, and the VA content is more than 30%.

ethylene-vinyl acetate copolymer).

EVA hardness is available in the following types:

1. The hardness of high foaming EVA material is 5% 40%.

2. The secondary foaming hardness of EVA material is 40% to 55%.

3. The foaming hardness of EVA material is 55% to 75%.

Among them, EVA material hardness of 45-65 degrees is the most widely used, and 45 degrees EVA material is the worst reason: making EVA material is like making a slow head, the larger the fermentation of a rental and sales balance slow head, the softer it will be, the less EVA material is used, and the cost is reduced.

How is EVA hardness divided and measured? EVA coils have distributed foam tubing and EVA data. EVA foam tubing is also known as NBR foam tubing.

Its hardness is A + Density A + Density B + Density B and Density C. In general, b is more dense. EVA data is more common before 38-70 degrees, and 25 degrees below 38 degrees.

Ethylene-vinyl acetate copolymer, abbreviated as EVA, **: 1314, molecular formula: (C2H4)X.

C4H6O2)Y, Chemical Properties: Common Polymer. In the case of foamed EVA, the measurement is usually carried out using a C-type hardness tester, a relatively flat area with a thickness greater than 6mm, and a measuring force of 1kg (a weight of 1kg can be placed on top of the hardness tester).

As the EVA content in the copolymer increases from 5% to 40%, the density increases from g cm3 to g cm3.

The density is lowest when the EVA content is less than 5%.

EVA Profile:

Ethylene-vinyl acetate copolymer English abbreviation: EVA

Cod: 1314

Molecular Formula: (C2H4)X(C4H6O2)Y Chemical properties: universal spike polymer.

Water resistance: Mi Tsai knows the closed cell structure, does not absorb water, moisture-proof, and has good water resistance.

Corrosion resistance: resistant to seawater, grease, acid, alkali and other chemicals, antibacterial, non-toxic, tasteless, non-polluting.

Processability: No joints, and easy to perform hot pressing, cutting, gluing, lamination, etc.

Shockproof: high resilience and tension resistance, high toughness, and good shockproof cushioning performance.

Heat preservation: heat insulation, excellent heat insulation, cold protection and low temperature performance, can withstand severe cold and exposure.

Sound insulation: closed bubble holes, good sound insulation effect.

It can be measured.

Shore hardness tester is an instrument used to measure the hardness of rubber, foam, plastic and other substances, there are two types: pointer type and digital display type, and the models are Shore A, C type, and D type.

1.Shore A-type hardness tester is mainly used for hardness measurement of plastics, synthetic rubber and other related chemicals (hardness of leather, polyester, wax, etc.).

2.Shore C hardness tester is used to determine the hardness of rubber and plastic microporous materials containing foam with a stress of more than 50% compressibility, and can also be used for other materials with similar hardness.

3.Shore D hardness tester is suitable for hardness testing of high hardness materials such as general hard rubber, hard resin, acrylic, glass, thermoplastic plastic, printed plate, fiber, etc.

Yours is Shao A's or Shao D's, D's can be measured.

I learned that if you are measuring EVA sheet foaming, you should use C if you are measuring EVA harding, you can use A and D, when A value is greater than 90, use D, and if D value is less than 20, use A

As the VA content in the copolymer increases from 5 to 40, the density increases from g cm3 to g cm3, and the density is the lowest when it is less than 5.

Ethylene-vinyl acetate copolymer, English abbreviation: EVA, code: 1314, molecular formula: (C2H4)X(C4H6O2)Y, Chemical Properties: General Polymer.

When the vinyl acetate content in EVA is less than 20%, it can only be used as plastic. EVA has good low temperature resistance, its thermal decomposition temperature is low, about 230, with the increase of molecular weight, EVA softening point rises, processability and surface gloss of plastic parts decrease, but the strength increases, impact toughness and environmental stress crack resistance improve, EVA chemical resistance, oil resistance compared with PE, PVC slightly worse, and with the increase of vinyl acetate content, the change is more obvious.

In addition, its resistance to environmental stress cracking has been improved, and the capacitance of the filler has increased, so the method of adding more reinforcing filler can be used to avoid or reduce the decline of the mechanical properties of EVA compared with PE. EVA can also be modified to obtain new applications, and its modification can be considered from two aspects: one is to use EVA as the backbone of other monomer grafting; The second is to partially hydrolyze the EVA.

As the VA content in the copolymer increases from 5 to 40, the density increases from g cm3 to g cm3, and the density is the lowest when it is less than 5.