Document 5kjzL2RvBgJZd4yqqLnoDnpNz

Johns-Manville SEP i ? tw internal Correspondti:l y To- L. J. Ciancia 2 South Date: September 6, 197 4 From: S. M. Quint C_op'*'*' See Below C- Sublet REDUCTION OF THF USAGE IN PERMASTRAN CORE COATING We ran PVC/glass-epoxy test slabs concerning reduction of THF usage in PERMASTRAN core coating. Blendex 121 coating was used and the only variable was the weight ratio of THF to MEK. The results were as follows: Coating Tensile, Avq 4 (lb) % Change Standard Dev. (lb) A. (Control) 50/50 THF/MEK 582 -- 27 B. 40/60 THF/MEK 565 - 2.9% C. 30/70 THF/MEK 540 - 7.2% D. 20/80 THF/MEK 487 -16.3% (Note: PVC slabs were pressed from Denison 8-inch core.) 1[ PLAINTIFF'S 1 | EXHIBIT 1 \1 1I JM 687 1 71 ------------------------------- The results indicate that optimum ratio may be 40/60 or 30/70 THF/MEK but that this ratio produces about a 3-7 per cent bond strength drop. Although THF is really tough to purchase, we probably shouldn't change the THF/MEK ratio at the present^time but should keep in mind the reduction of THF usage fqferstjhe future . ^^ cc J. F. Nawn 2 South R. W. Heisler - 2 South UPD. W. French Denison C. G. Stelchek- Denison H. F. Lloyd Denison P. E. Dix R&D R. T. Hucks R&D ed MTC 010480 0A048A NITC