The variables that influence the particle removal efficiency of cleanr
oom 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 gre
ater. One application of a mat surface was sufficient to remove a low
concentration of similarly sized particles from a surface bur it could
require up to four mat surfaces to remove a high concentration of het
erogeneously sized particles. It was found with heterogeneously sized
particles that larger particles were removed first, thus allowing acce
ss to the smaller particles which could then be removed. If the mat wa
s soft, it allowed larger particles to sink into it and smaller partic
les than normal to be picked up.