A complete knowledge of shoe sole categories and their advantages and disadvantages

1.Polyurethane sole (PU)

Polyurethane is the abbreviation of polyurethane, the English name is polyurethane, it is a kind of high polymer material, made of A/B/C polyurethane foam, divided into oil and water-based two kinds. It is an emerging organic polymer material, known as the ‘fifth largest plastic’, mostly used in the manufacture of high-grade leather shoes, sports shoes, travel shoes and so on.

Advantages: low density, soft texture, good elasticity, comfortable and lightweight; good oxidation resistance, excellent abrasion resistance, flex resistance, high hardness; excellent shock absorption, non-slip performance; good temperature resistance; good chemical resistance; easy to corrode and environmental protection, not easy to wrinkle.

Disadvantages: strong water absorption, easy to yellow, easy to break, poor elongation, not water-resistant, easy to rot the bottom, poor breathability.

2. Leather sole

Leather sole is a kind of sole that can breathe automatically and drive the foot to breathe, with good breathability, not stuffy feet, and can automatically release the absorbed sweat to keep the feet dry. Leather soles are mainly made of cowhide and are more expensive. Its advantages are easy to shape, no change, fit, good elasticity, can reduce the impact and not easy to fatigue, ventilation, absorption of moisture, etc., at the same time, easy to process, easy to show the beauty of the shape. Hard texture is not easy to be pierced, but by water, oil soaked easily warped deformation or rot.

Its main features:

① good thermal insulation to ensure that the foot in the shoe at the right temperature

② light weight, the weight of each square centimetre in 0.95 ~ 1.05 grams, exactly the same density as water. It can waterproof and release moisture when the shoes are no longer wet to ensure that the shoes are in a comfortable state.

③ Unique three-dimensional fibre structure, the sole does not break when bending at 180 degrees. Can quickly adapt to the shape of the foot, can effectively support the impact of the ground, more effective than the same thickness of other materials to protect the foot sole.

3.EVA sole

Ethylene VinylAcetate-ethylene vinyl acetate copolymer, polymer material. Commonly used in jogging, jogging, casual shoes, foot training shoes midsole. Lightweight, easy to process, not wear-resistant, not oil-resistant.

Advantages: lightweight, good elasticity, good flexibility, not easy to wrinkle, has excellent colouring, suitable for all kinds of climate.

Disadvantages: easy to absorb water, not easy to corrode unfavourable environmental protection, easy to dirty.

4.MD bottom

MODEL or PHYLON is the collective name of the second high-pressure moulding product of EVA, MD sole must contain EVA, MD sole is also called PHYLON sole. For example, MD=EVA+RB or EVA+RB+TPR and some shoes are RB+PU.

Advantages: lightweight, elasticity, fine appearance, good softness; easy to clean; hardness, density, tensile strength, tearing, good elongation.

Disadvantages: not easy to corrode and unfavourable to the environment, easy to wrinkle at high temperatures, easy to shrink; poor durability, shock absorption will be reduced after a long time of use, poor breathability.

5. Rubber bottom (RB)

RB is the abbreviation of English rubber (rubber); hot compression moulding, natural rubber and recycled rubber. The quality of heavy, not oil-resistant, moulding bottom must be in the laminating surface grinding coarse, easy to shorten by heating, the colour is not consistent.

Advantages: good abrasion resistance, non-slip, elasticity, not easy to break, better softness, good elongation, shrinkage stability, good hardness, good bending, waterproof.

Disadvantages: heavier, easy to spit frost (is a quality problem), not easy to corrode (environmental issues); not hard, easy to be pierced; breathability, moisture absorption is not good, afraid of oil immersion, should not be worn in the car petrol stations and other places in contact with oil.

※ Rubber foam

The weight is lighter than rubber soles, with rubber smell, when pressed with fingers, the surface rebound is more obvious than general soles, and the wear-resisting performance is poor.

※ High-pressure polyethylene rubber sole

High-pressure polyethylene and rubber flavoured soles, rubber and plastic are used together.

Raw rubber sole: heavy, expensive, not oil resistant, not heat resistant. Easy to change colour.

6.TPU sole

The full name is thermoplastic polyurethane elastomer (ThermoplasticPolyurethane), which is a linear polymer material generated by the common reaction of diisocyanate and macromolecule polyol and chain extender.

Advantages: excellent mechanical strength, abrasion resistance, oil resistance and flex resistance, especially abrasion resistance Z is outstanding, good appearance, generous and high-grade.

Disadvantages: poor heat resistance, hot water resistance, compression resistance, easy to turn yellow in appearance, easy to stick to the mould in processing, harder, heavier, poor air permeability.