This invention relates to thermoplastic interlayers for laminated safety
glass with superior vacuum de-airing at elevated temperatures and
superior tacking and edge sealing properties. The sheeting has surface
pattern on at least one of the surfaces characterized by flat surfaces
with substantially uninterrupted channels for airflow in at least two
non-parallel directions. The channels allow for rapid de-airing while the
area roughness parameter ratio AR.sub.p/AR.sub.t in the range of 0.52 to
0.62, ARt being less than 32 .mu.m, and area kurtosis less than 2.5,
allow for ease of tacking of the interlayer onto glass and edge sealing
after de-airing has been completed. Said surface pattern may also be
superimposed onto a pattern which is generated by melt fracture or other
means on at least one side to enhance de-airing and aid edge sealing.