Feb 11, 2020. A common method for obtaining precise bondline widths is to add spacer beads to an adhesive. Unfortunately, if you are doing that yourself, you likely have not had many pleasant experiences. ACW can eliminate the pain by adding the spacers for you.
Spacer beads are a great way to give reproducible, precise bondline widths. Glass beads with narrow size distributions are available, the glass is inert in most environments, and only low concentrations of beads are needed to achieve the spacing objectives. These features result in a simple process and a negligible effect on bond strength.
The problems with spacer beads come when one adds the beads to the adhesive. The mixture is difficult to mix uniformly, essentially impossible to degas without vacuum mixing, and, in the case of syringe packaging, simply nightmarish to repackage. Without special equipment, it is quite possible that the modified adhesive will not be in spec for the process or the final product. And, if you are talking about a low temperature thermal cure adhesive with a short pot life at room temperature, YIKES!
But that special equipment is exactly what we use at ACW to provide uniformly mixed and completely degassed adhesives in syringes or bottles. Adding glass spacer beads at the onset of production is not a problem. Get in touch with us at email@example.com if you are interested in adhesives with glass spacer beads mixed in.