As open-ear headphones become more popular, people care more about comfort, durability, and waterproofing. This is especially true for swimming headphones.
Choosing the right materials and process is key to making high-quality products.
We are a Chinese open-ear headphone manufacturer focused on innovation and quality.
We use two main processes for making ear hooks: core material overmolding and silicone overmolding.
Core material overmolding uses TPE (thermoplastic elastomer).
Silicone overmolding uses either solid silicone or liquid silicone.
Each method has its own advantages and meets different needs.
1. Core Material Overmolding vs. Silicone Overmolding
1.1 Core Material Overmolding
This process involves passing a titanium alloy wire through TPE.
The end of the wire is then attached to an SR (Shape-Retaining) material and molded with injection technology.
This helps connect the ear hook to the motherboard and improves comfort and stability.
This process is used for entry-level open-ear headphones.
It provides good durability and stability while keeping costs low.
1.2 Silicone Overmolding
In this process, the titanium alloy wire is covered with silicone and heated with a vulcanizer.
This helps shape the silicone and bond it to the wire.
There are two types of silicone used: solid and liquid.
Silicone overmolding provides better comfort, stronger waterproofing, and longer lifespan.
It is ideal for swimming and sports headphones. However, it is more complex and expensive than core material overmolding.
2. Solid vs. Liquid Silicone in Overmolding
Both solid and liquid silicone have unique benefits.
The best choice depends on product requirements.
2.1 Manufacturing Process
- Solid Silicone: The raw material is mixed with additives, pre-formed, and then vulcanized.
- Liquid Silicone: Two liquid components are mixed, injected into a mold, and cured.
2.2 Product Performance
- Appearance: Solid silicone may have slight mold lines. Liquid silicone has a smooth and fine surface.
- Physical Properties: Solid silicone has a wide hardness range and stable flexibility. Liquid silicone is softer, more elastic, and may have better aging resistance.
2.3 Efficiency and Cost
- Efficiency: Solid silicone takes longer to vulcanize, making it less efficient. Liquid silicone cures faster and is better for mass production.
- Cost: Solid silicone is cheaper but requires high equipment and labor costs. Liquid silicone is more expensive but requires less labor, reducing costs in large-scale production.
For products with multiple colors and small orders (less than 5,000 units per color), solid silicone is more flexible and cost-effective.
3. Production Process of Solid Silicone Overmolded Ear Hooks
Using the OPENEAR Bone F1 bone conduction swimming headphones as an example, the mid-stage processing is crucial.
It involves overmolding the ear hooks and back hooks with silicone, which ensures comfort and waterproofing.
3.1 Titanium Alloy Wire Lubrication
Before overmolding, the wire ends are soaked in a special lubricant.
This prevents blockages and ensures the silicone wraps smoothly around the wire.
It also reduces material waste.
3.2 Wire Winding
A copper wire is wound around the titanium alloy wire and earphone core.
This ensures a strong connection and stable electrical transmission.
Precision is essential to prevent loose connections that can affect comfort and sound quality.
3.3 Silicone Encapsulation
Workers manually wrap silicone around each wire.
Silicone is soft and flexible, so it evenly covers the entire part.
This process improves waterproofing and comfort.
However, it is slow and requires skilled labor, increasing production costs.
3.4 Vulcanization
After encapsulation, the ear hooks are heated in a platform vulcanizer.
This process hardens the silicone and bonds it to the wire.
Each machine can process four ear hooks at a time.
Each cycle takes about 200 seconds, limiting daily production to about 700 units.
The high-temperature vulcanization process ensures a fixed shape and a strong silicone-wire bond, improving durability.
3.5 Manual Cleaning and Surface Treatment
Workers inspect and clean each ear hook by hand.
They remove excess silicone and check for imperfections. This step ensures a smooth, flawless finish.
3.6 Grinding and Polishing
Ear hooks go through a grinding machine to remove sharp edges and improve smoothness.
Special polishing materials, similar to small stones, are used.
Grinding takes up to four hours per batch, with a maximum of 3,000 ear hooks processed daily.
This step improves comfort and prevents irritation from rough edges.
3.7 Washing and Air Drying
Polished ear hooks are washed to remove silicone dust and debris.
Then, they are air-dried to ensure a clean surface before further processing.
3.8 Final Polishing and Quality Control
Workers manually polish hard-to-reach areas.
This ensures a perfect shape and smooth surface.
After this, the ear hooks go through painting, printing, wire cutting, soldering, and function testing.
Each part is inspected to meet high-quality standards before final assembly.
4. Balancing Cost and Performance
The solid silicone overmolding process produces 400-500 ear hooks per day.
Since it involves many manual steps and requires skilled workers, production speed is slow, and costs are high.
However, the superior waterproofing, durability, and comfort make it the best choice for swimming and outdoor sports headphones.
We constantly improve our process to maintain high quality while keeping costs competitive.
5. Conclusion
Solid silicone offers excellent waterproofing, comfort, and durability, making it perfect for high-end open-ear headphones.
Our OPENEAR Bone F1 headphones use this advanced technology to deliver top performance in extreme conditions.
If you are a wholesaler or brand looking for a high-quality waterproof bone conduction headphone, OPENEAR Bone F1 is the best choice.
This product meets customer expectations with excellent performance and showcases your understanding of market trends.
We have extensive experience in international trade and can meet your specific needs.
Contact us for detailed product information and customization options.
Let’s work together to create unique products and stay ahead in the market!
