Cleanroom mats: An investigation of particle removal

The variables that influence the particle removal efficiency of cleanroom mats were investigated. The removal efficiency was generally found to be greater if the mat was of a softer type, the particles smaller, the particle size distribution more homogeneous, the distance between the particles greater, and the adhesive strength of the mat surface greater. One application of a mat surface was sufficient to remove a low concentration of similarly sized particles from a surface but it could require up to four mat surfaces to remove a high concentration of heterogeneously sized particles. It was found with heterogeneously sized particles that larger particles were removed first, thus allowing access to the smaller particles which could then be removed. If the mat was soft, it allowed larger particles to sink into it and smaller particles than normal to be picked up.