If you take a look at the sports watches available on the market, you will notice a common feature: the straps are almost all made of silicone.
Not only sports watches, but also many smart watches come with silicone straps as standard. They are lightweight, skin-friendly, sweat-resistant, and easy to clean. These advantages make silicone the preferred material for straps.
However, many customers are unaware that silicone straps, although seemingly simple, are not easy to make well.
Today, let's discuss from a product perspective, what exactly makes a good silicone strap difficult to produce.
First, let's talk about: Why are sports watches usually equipped with silicone straps?
Reason one: Skin-friendly and non-allergenic
The strap is a component that is worn against the skin for a long time. Metal straps tend to slide when sweating in summer, and leather straps get sweaty and have a smell. Silicone materials have good skin-friendly properties, do not cause allergies, and do not cause discomfort even after long-term wearing.
Reason two: Anti-sweat and waterproof
Sweating during exercise is normal. Silicone is inherently waterproof and resistant to corrosion from sweat. Sweat does not penetrate into the strap, and unlike leather straps, it does not become hard and smelly after being soaked in sweat. After washing with water, it is clean.
Reason three: Lightweight and stress-free
Silicone straps are lightweight and have almost no burden on the wrist when worn. For activities such as running, cycling, and swimming, the lightweight feature is a practical enhancement of the experience.
Reason four: Resistant to pulling and aging
During exercise, the strap will be repeatedly bent and pulled. Silicone has good elasticity and tear resistance, can withstand repeated bending, and is less likely to break. High-quality silicone can also resist ultraviolet aging and is less likely to harden or crack in outdoor use.
Reason five: Cost is controllable and has strong plasticity
Silicone can be made into various colors, textures, and surface effects to meet the personalized design needs of different brands. It is also suitable for large-scale mass production due to its relatively controllable cost.
But where is the difficulty in making a good silicone strap?
Difficulty one: Incorrect hardness selection, uncomfortable to wear
The hardness of the strap directly affects the wearing experience.
Too hard, the strap has poor fit and feels uncomfortable when worn on the wrist; too soft, the support is insufficient, and the strap is prone to deformation and loose fitting.
The hardness of sports straps is usually between 40-60 degrees (Shore A), but the specific selection depends on the thickness, structure, and wearing method of the strap. Even at 50 degrees, the feeling of a thin strap and a thick strap is completely different.
The difficulty lies in: The hardness needs to be matched with the structure. It's not just a matter of selecting a number, but rather determining it based on the width, thickness, and buckle structure of the strap.
Difficulty two: Inadequate surface treatment, becomes sticky when sweating
This is one of the most frequently reported problems by customers.
Silicone straps without surface treatment will become rough and sticky when sweating, making it uncomfortable to wear on the wrist and prone to absorbing dust and fluff. After removing the watch after exercising, the strap is covered with sweat stains and fluff, resulting in a poor experience.
The solution is to spray hand lotion. The hand lotion can form a smooth protective film on the surface of the strap, reducing friction resistance, resisting sweat and sticking, and reducing static electricity and dust adsorption.
However, the quality of the hand lotion spray is very different:
Too thin, the protective effect is insufficient, and it will lose effectiveness after a few uses.
Too thick, the hand feels greasy, and it is uncomfortable instead.
Insufficient curing, it will peel off after a period of use.
The difficulty lies in: The uniformity of spraying and the curing degree. This requires experienced operators and stable baking processes.
Difficulty three: Anti-tear strength, determining how long the strap can be used
The strap will be repeatedly bent during daily use - being put on, taken off, and during exercise when the wrist bends. The connection position between the strap and the buckle is the most stressed area.
If the anti-tear strength of the silicone is not sufficient, after a period of use, cracks will appear around the strap hole or at the buckle connection point, and in severe cases, the strap will break directly.
The tear resistance performance is related to the silicone formula and the vulcanization process. The selection of fillers in the formula and the control of the vulcanization degree will affect the final performance.
The key challenge lies in: the formula and the process need to be well coordinated. Just buying a bucket of silicone won't enable you to produce a durable strap.
The fourth difficulty: color batch consistency. Light-colored straps are particularly challenging.
Sport straps come in a variety of colors, such as white, gray, pink, blue... Light-colored straps particularly test the factory's color matching and rubber compounding skills.
If the color dispersion of the color rubber is uneven, the strap will show color differences or streaks; if the color difference control between different batches is poor, the customer will receive goods with mismatched colors and have to rework.
The difficulty lies in: the uniformity of rubber compounding and the repeatability of the formula. Each batch of rubber must be precisely mixed according to the recorded formula, and the vulcanization time and temperature must be stable to ensure color consistency between batches.
The fifth difficulty: light-colored straps turn yellow over time.
White or light-colored silicone straps may turn yellow after a period of use. This is one of the manifestations of silicone aging and is related to the raw material quality, anti-aging formula, and usage environment.
The difficulty lies in: anti-yellowing needs to be addressed at the formula source. Selecting materials with good anti-yellowing performance and using appropriate anti-aging additives can delay the yellowing. Strap made with cheap raw materials may change color significantly within two months.
How can customers determine if a silicone strap is well made?
As the purchasing party, after receiving the sample, you can judge from the following aspects:
First, feel the texture. Slide your finger on the surface and it should be smooth and not sticky. Press the strap and it should rebound quickly, without a sticky feeling.
Second, pull it. Gently pull the ends and the surrounding holes of the strap to feel the tear resistance strength. Good straps will quickly return to their original shape after stretching and will not deform.
Third, smell the odor. High-quality silicone straps have almost no odor. If there is a strong pungent smell, it indicates that there may be problems with the raw materials or vulcanization process.
Fourth, check the color. The color of the same batch of products should be uniform and consistent. If possible, you can compare the color plates of different batches.
Fifth, bend test. Repeat bending the strap and observe if there are any whitening or cracks on the surface. The surface of a good strap should not show any obvious changes after bending.
What can Hongxiangda do?
Hongxiangda has accumulated many years of production experience in the silicone strap category.
From rubber compounding and color matching to shaping, from spraying hand oil to laser engraving, every process required for the strap is completed in our own workshop. This means:
The hardness can be adjusted: according to your strap structure and wearing requirements, recommend an appropriate hardness.
The surface treatment is mature: the uniformity and curing degree of the hand oil spraying are stable, and it is not prone to脱落.
The tear resistance is guaranteed： the formula and process are well coordinated， and the strap can withstand repeated bending.
The color control is strict： each batch of rubber has a formula record， and the color difference between batches can be controlled.