Precision in small doses: Tips for the precise dispensing of two-part adhesives

摘要

There is a growing demand for the precise metering, mixing and dispensing of small amounts of two-part technical materials like adhesives, potting compounds, en-capsulants and sealants - including elec- trically or thermally conductive variants. This is driven by manufacturers in the electronics, medical device and automotive industries requiring increased functionality in seemingly ever-smaller formats. In parallel, these engineers are looking for high-accuracy material application in a robust and consistent process. They want precise quantities, uniformly mixed in the correct ratio, to be applied in exact locations. Two-part formulations can offer superior cured performance but can be difficult to process. A typical method involves weighing out the constituent parts, mixing in a container with a spatula and loading into a dispensing syringe barrel for application. There may be a vacuum degassing or centrifuge step to remove entrapped air. Some suppliers offer respite from this procedure by providing their materials in a pre-mixed, degassed and frozen packaging. However, there are extra costs associated with shipping and storage, which are partly offset by the material being ready to use after thawing.