Smartwatches are immensely popular because of the many functionalities they have. After all, who doesn’t like to be able to read their messages directly while activities such as heart rate or stress level are also measured! However, from a technical perspective, there are challenges in assembling the small, complicated components and parts.

In the case of smartwatches, the requirements of skin contact must be taken into account and materials that are difficult to bond are often used. The case below illustrates this.

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 odour resistance). In addition to the good adhesion of silicone rubber to polycarbonate, a very small amount of adhesive must also be applied accurately and quickly using a manual dosing method.

Bonding silicone rubber is not easy because of the low surface energy. The company tried various adhesive technologies and invested a lot of time and resources to solve the problem, unfortunately without desired results. It started to look like the company wouldn’t be able to produce the product.

The Solution

Then Bostik was called in and asked about a possible solution. The product specialists tested several Born2Bond products which showed that the cyanoacrylate Born2bond Ultra HV sealant (adhesive and primer) offered unparalleled adhesion compared to any other technology they had tried.

The Results

Since implementing the Born2Bond™ Ultra HV kit in its production lines, the manufacturer has been able to:

• Improve the overall product aesthetics thanks to the precise application
• Increase capacity thanks to the fast fix time of 15 seconds
• Improve the aesthetics on black substrates due to the low blooming properties

Furthermore, there was no need for the manufacturer to invest in equipment or increase production space.

Bostik Born2Bond™ Ultra HV offers:

• Low odour
• High-performance capability due to being less brittle than conventional instant adhesives
• Multi-substrate bonding
• Long open time
• Fast curing time
• Low fogging