Have you ever wondered what the soles in our footwear are designed for? Well, the answer to this can vary depending on the features you need in the shoe. A popular choice in the market is the TPR sole that stands for Thermoplastic rubbers. It is extensively used for manufacturing footwear with shoe platforms, rubber boots, or wooden soles.
Basic Rundown of Benefits Provided by a TPR Sole
While TPR soles bring in a range of benefits, the commonly known ones are:
- Great features for pricing
- Economic and easy processing
- Amazing aesthetic versatility
- Completely recyclable
- Anti-slip material
- High traction and grip
- Water-resistant design
- Better flexibility
Before we understand more about the TPR soles, let us decode the different types of soles available in the market.
Types of Shoe Soles
When you scour the market for reliable shoes, you will come across a range of sole options that include:
As obvious by the name, leather soles are created from animals’ skin post-treatment, providing a rather elegant look & feel. However, they might not provide the right amount of comfort and grip. That is why leather soles are mixed with high-quality rubber to allow the shoes to be stable while you walk.
Leather soles made from vegetable oak leather that is pit tanned are waterproof and abrasion-resistant.
Dainite soles serve as an elegant alternative to leather soles as they pack in double thickness. These dainite soles are found decked in the traditional brogues. Generally, there isn’t a lot of difference between dainite or leather soles. However, they could be long-lasting in comparison to leather.
Regular wear shoes or work shoes flaunt polyurethane or natural rubber soles. High-quality rubber soles can ease your walking techniques while adding to the traction factor.
4-TPR or Thermoplastic Rubber Soles:
Thermoplastic rubber soles are a popular and conventional material used for injecting your soles. The TPR soles are light in weight as compared to PVC soles. Plus, they have more elasticity to them while packing in the potential to handle regular wear &elegantly tear from hard weather.
More about the Thermoplastic Rubber Soles
TPR is a unique mix of plastic and rubber that has recently popped into the market. TPR is a thermoplastic that is created from high-quality synthetic rubber. That is why TPR tends to melt into its liquid form when heated& turns back to solid post cooling.
Unlike the latex that is crafted from the rubber tree sap, thermoplastic rubber is created from polymer SBS or Styrene Butadiene Styrene. Even though natural rubber & synthetic rubber come from different processes & have varying chemical content, they still have properties similar to rubber. They both provide elasticity.
However, there is a striking difference between the two rubber variants. Natural rubber soles are hard to recycle after it goes through retreading. On the other hand, synthetic rubber has the potential to be recycled again & again. That is why TPR is used in a range of industries, including shoe manufacturing.
Given that TPR can be recycled, there might be no residue left behind in the production cycle. It is important given the fact that any production mistakes can be taken care of & then redesigned. It helps keep the production cost down.
TPR has become very popular in the past few decades as it is a cheaply available material that is easy to design, temperature flexible, high grip, anti-slip, & can be molded in various colors. Further, TPR soles can be used for shoes meant to withstand roads that are runny and slippery. These soles can also be used for shoes that are fitted perfectly for outdoor activities.
It is also ideal for producing waterproof shoe soles that come with a rough texture compared to your regular rubber sole. It is also light in weight. Thermoplastic flaunts the molding and melting properties that are seen in plastic. TPR also flaunts a shiny texture post melting while natural rubber packs in a matte-like finish.
This sole material can either be soft like gel or hard like molded plastic. Materials crafted from TPR, especially those created to be soft, might become a bit sticky post-exposure to particularly high temperatures like something above 30 or 40oC. The elasticity flaunted by the TPR rubber sole does match the one seen with cross-linked rubber.
TPR Shoe Soles: What is in it?
Thermoplastic rubber sole & foxing strip use was patented back on 15th April 1975. This particular material belongs to a copolymer group, which is known as the thermoplastic elastomers or TPE. A popular TPR variant is Kraton, which is found in shoe construction. It is also used in the form of an adhesive ingredient.
TPRs are good for the environment as they are easily recycled and lead to zero wastage.
How can you differentiate TRP soles from rubber?
Natural rubber or synthetic rubber soles are a variant of the polymer compound. Generally, rubber outsoles are soft to touch, pack in amazing flexibility, resistant to alkali/acid, perfect slip resistance, and so on. It is used widely in different types of sports shoe soles.
The shortcomings of rubber soles are heavier as compared to TPR and spit cream easily. Moreover, they are expensive in nature.
On the other hand, TPR outsoles mix in the properties of both plastic as well as rubber. The complete processing tech is simple. All that is needed is for the material to be injected into the mold with no need for vulcanization. It is used widely in casual shoes, children’s shoes, & fashion shoes.
TPR soles offer a competitive price range. However, the slip resistance and flex might not be as good as the former. It is easier to color fasten and is available in various styles, colors, and designs.
Why is it important to distinguish TPR from rubber outsoles?
Globally, the footwear industry has been facing a massive order decline. Buyers today are rather aggressive when it comes to pricing while demanding more quality & service. In an effort to capture the potential target market, manufacturers have started experimenting with different types of outsoles and even cut down the quality during the production.
It might lead to deception when sellers try to fool you by mentioning a TPR outsole as a rubber one. Now, this doesn’t actually mean that TPR is bad. It simply means that each has its own set of properties that is applicable in different scenarios. While one can be used for trekking, jogging, or other outdoor activities, the latter can be used for regular, casual wear.
If you are searching for the features brought in by the former, you might not want to settle for the ones brought in by the latter. So, the key is to know the right way to identify the rubber outsoles and the TPR outsoles and save you from getting fooled.
How can you distinguish TPR from Rubber Outsole?
In order to help you distinguish rubber outsoles from TPR, here we are going to share a list of methods you can use and save up on paying heavy charges.
One obvious way to distinguish rubber outsoles from TPR is to smell them before you pay for them. You might not expect this, but rubber outsoles generally smell similar to plastic, while the TPR outsoles do not have any obvious odor.
Apart from the smell, another way to differentiate rubber from TPR is to touch them and feel them for texture. Rubber soles are smooth to touch, while TPR doesn’t give you such a feeling.
Another way you can differentiate the two is to visualize them side by side. Rubber provides you a glossy finish, while TPR would bring in a matte finish.
4-Press & Grind:
Last but not least, you can make use of the press & grind technique to identify one from another. All you need to do is press hard & grind both the outsoles on your desk. You would notice that TPR is fairly easy to powder down while rubber shows no particular change.
Alternatively, you can also observe the bounce on your TPR shoes. Let the shoe drop down normally from a height and watch it bounce. If it bounces high enough, it is TPR, while leather might not bring in as much bounce. You can also easily wash off any dirt, debris, or mud that might have settled down on your TPR shoe outsole.
However, keep in mind that TPR might not be ideal for temperatures that rise above 50 degrees Celsius or below-45 degrees Celsius.
The bottom line
For someone in need of shoes with good ventilation, TPR soles are the way to go. They show excellent resistance to low temperature while bringing in a high coefficient for friction in slippery slopes. However, do practice caution when wearing TPR soles on surfaces with oil as the traction comes down massively. The next time you venture on the internet looking for a casual, daily use shoe, consider TPR as your top choice.
Brandon R. Katz is a registered professional nurse who has been instrumental in providing us with an informed opinion on the medical aspects of footwear. He graduated from NYU Rory Meyers College of Nursing with a Bachelor of Science in Nursing (BSN) and currently provides his services at a non-federal long-term care hospital in Brooklyn, NY.
Brandon proves to be the champion in the group of expert writers with his in-depth knowledge in foot health, how to take care of it adequately, and what shoes, socks, or insoles will be supreme for you. He has previously worked with hospitals where he has foreseen both inpatient and outpatient departments and has been a practicing nurse since 2009.
Brandon hails from Jersey City, NY, and has a loving family of four with a small popper called Rozo. His decision to become a nurse arises from the desire to be in the position of helping and rehabilitating people.