Document LQmVpD5YQODXw62drgMZMmEq

(gr40^ Hr. A. T. Hiebergall C. W. Lehnert EXPANDED POLYSTYRENE TEXTURE cc: Mr. T. W. Richards - Portland Mr. J. B. Mobs - Tigard Mr. J. DiLorenzo - Portland November l, 1971 Portland Tigard PLAINTIFF'S EXHIBIT A couple years ago we were considering the manufacture of expanded polystyrene texture. There is a patent held by Willis Hamilton covering a formulation for this texture. At that time, Pete Chevis reviewed the whole patent history and concluded that our formula would not irafringe because we were eliminating the clay ingredient. We are now proceeding to install equipment at Acme to manufacture the polystyrene texture. We thought it would be well to review the patent situation even though we have no reason to believe Pete Chevis* conclusions are not still valid. The proposed formula has no asbestos and if this product is satisfactory it will differ from the Hamilton formula by lacking both clay and asbestos. We plan to proceed on the basis that we have no Infringement problems but thought it would be advisable to ask you to.review the file. I am enclosing the patent, the information Pete Chevis developed, our current proposed formula, and a proposal from American Flotation Company. The latter is a supposedly advantageous process to expand and shred polystyrene, but I see no purpose in our becoming involved with this in any way. I have learned that Kaiser Gypsum Co. is a licensee of Willis Hamilton. Kaiser also had difficulties with the expanding and shredding initially but that was as much as I could determine. If Kaiser could work it out we certainly can, and hopefully with out help from the outside. CWL:elz Enclosures i?ete chevis File, proposed formula, and proposal trom American Flotation c. C. W. L. SGP 0015863