Rubber vs. EVA vs. Thermoplastics
©
EVA Soles
EVA is a copolymer product of ethylene and vinyl acetate. It’s a polymeric compound used for making footwear soles. It was developed by Chinese sportswear giant Anta, and has been used by luxury brands as well as Birkenstock for EVA version of its iconic Arizona sandals.
Properties:
Shock Absorption: EVA has the highest shock absorption property of any sole material. Being anti-vibrant and providing tensile strength as well as cushioning
Flexibility: EVA is softer and more flexible than rubber and TPR (Thermoplastic Rubber).
Weight: EVA is lighter than TPR and rubber soles.
Applications: EVA soles are commonly found in sneakers, running shoes, jogging shoes, leisure shoes, and walking shoes.
Low thermal conductivity: in cold weather your feet will stay warmer for longer.
Advantages:
Soft and relaxed cushioning.
Excellent insulation and slip resistance.
UV radiation resistance.
Thermal conductivity.
Disadvantages:
Gets dirty easily.
Not biodegradable.
Shrinks over time with use.
TPR Soles
Thermoplastic Rubber: It is obtained by blending rubber and plastic materials. It flows while hot but turns solid when cooled.
Properties:
Grip: TPR provides a strong grip on the ground.
Cost: TPR soles are cheaper than rubber soles.
Temperature Resistance: TPR is resistant to low temperatures.
Advantages
Cost effective
Disadvantages:
Heavier than EVA.
Less flexible and soft than EVA.
Low shock absorption.
Not wear-resistant.
Applications: TPR soles are commonly used in children’s shoes, casual shoes, and fashion shoes.
Rubber Soles
The primary source of natural rubber is cultivated from the latex in Hevea Brasiliensis trees.
Advantages:
Durability: Rubber soles are highly durable and long-lasting. They can withstand wear and tear, making them suitable for everyday use.
Wear Resistance: Rubber is resistant to abrasion, making it ideal for shoes that experience heavy use or rough surfaces.
Traction: Rubber soles provide excellent grip on various surfaces, reducing the risk of slipping.
Waterproof: Natural rubber is inherently waterproof, which helps keep your feet dry in wet conditions.
Chemical Resistance: Rubber soles are resistant to chemicals, oils, and solvents.
Disadvantages:
Weight: Rubber soles tend to be heavier than other materials like EVA or TPR (Thermoplastic Rubber).
Stiffness: While durable, rubber soles can be less flexible than EVA or TPR, affecting overall comfort.
Cost: Shoes with rubber outsoles are often more expensive due to the quality and durability they offer.
UV sensitity: UV exposure as well as exposure to the elements can cause yellowing
Environmental Impact: Natural rubber production has environmental implications, especially if not sustainably sourced.
Properties:
Comfort: Rubber soles are soft, flexible, and provide better traction.
Stability and Durability: Rubber soles offer more stability and durability compared to EVA.
Chemical Resistance: Rubber soles are resistant to chemical attacks.
Comparison
EVA soles are more comfortable and lightweight, while rubber soles are sturdier and more stable.
Rubber soles are superior to TPR soles in terms of wear resistance and overall quality.
Shoes with rubber outsoles tend to be pricier than those with TPR or EVA soles.
In summary, rubber soles are a solid choice for durability, traction, and wear resistance. However, consider the weight and flexibility based on your specific needs and preferences because EVA is softer and far more flexible than rubber. This allows for easy sole moulding & construction but more importantly an extremely comfortable sole to walk in.
Typically, this sole unit is used for constructing running trainers, but with fashion trends relaxing and people wanting more comfort in their smart attire, this sole has proven extremely popular!
Bonus
Lactae Hevea
Grown on large tropical plantations, the hevea tree conceals a precious and exceptional product: its milk. Spiral incisions are made into the tree’s bark, releasing this virgin hevea milk, which is then harvested.
The French company which has registered this name developed a proprietary baking process that causes the rubber to develop air bubbles which leads to better shock absorption, a lighter material and better thermo regulation properties.
The hevea milk is refined using a unique artisanal process, resulting in the incomparable and completely natural LACTAE HEVEA® sole.
The last shoe composition is fascinating. I’m curious to see how it plays out over time in comparison to the other options. Thank you for sharing this.