Cartridges

Cartridges are typically manufactured in bulk. After washing, cartridges are either sprayed-on or filled entirely with silicone oil emulsion. These cartridges are then sterilized in a heat tunnel so that the emulsion will be baked-on. The thin silicone layer formed by this process ensures that a cartridge will have a smooth gliding plunger. The cartridges are typically used in self-injector devices such as pen systems. In such cases, it is essential to use a low friction force to ensure optimum functionality throughout the product’s lifetime.

Silicone oil emulsion parameters are crucial for process optimization. Each step in the process including: cleaning, drying, spraying, filling, baking time, and temperature influence the end result. It takes the LE UT just minutes to provide highly accurate and repeatable silicone layer thickness distribution data about a single cartridge. Thus the emulsion siliconization process can be validated, controlled, streamlined as well as implemented.

Above is an image of a scanned cartridge. Areas with less then 15 nm of silicone are blue and areas with more than 200 nm of silicone are marked in red. The legend on the right side is measured in nm. The scan resolution is 36 lines on the cylinder with 200 points on each line. The cartridge is 52mm in length and 9.2 mm diameter.