Through this case study, we will explore Bostik’s solution to optimize the design of smartwatches.

Better looking smartwatches with Born2Bond Ultra HV

Smartwatches are immensely popular because of their multiple features. Nowadays, with the immediacy in which we live, being able to read messages directly while monitoring other activities such as heart rate or stress level can be very useful.

However, from a technical point of view, the assembly of small and complicated components and parts presents difficulties. In the case of smartwatches, skin contact requirements must be considered and difficult-to-bond materials are often used. In this case study, we will learn about Bostik’s solution.

The challenge

A manufacturer of portable electronic devices used a silicone rubber as a wristband. Silicone was chosen because it meets the requirements for skin contact (biocompatibility, sweat and odor resistance). In addition to the good adhesion of the silicone rubber to the polycarbonate, a very small amount of adhesive must also be applied accurately and quickly using a manual dispensing method.

However, bonding silicone rubber is not easy due to its low surface energy. The company tried several adhesive technologies and invested a lot of time and resources to solve the problem, unfortunately without achieving the desired results. It seemed that the company would not be able to manufacture the product.

What was the solution?

They called our technical department and inquired about a possible solution. The product specialists tested several Born2Bond products, which proved that Born2bond Ultra HV cyanoacrylate adhesive (adhesive and primer) offered unprecedented adhesion compared to any other technology they had tested.

Improvements in the manufacturing process

By implementing the Born2Bond Ultra HV kit into their production lines, the manufacturer has improved the following aspects:

• Improved overall product aesthetics due to precise application.
• Increased capacity due to the fast 15 second cure time.
• Improved aesthetics on black substrates due to low blooming properties.
• In addition, there was no need for the manufacturer to invest in equipment or increase production space.

Technical characteristics of the Born2Bond Ultra HV kit

• Cyanoacrylate without blooming
• Viscosity: 1000 mPa.s
• Maximum gap: 0.2 mm
• Tensile strength: 16 MPa
• Fixing time : 10 s
• Temperature range : -40 to +80°C