Document 99468e10j56aD1mGJo47dLnZe

CUMBERLAND 9-0100 F. J. STOKES CORPORATION BSOOTABOR ROAD, PH I LiAJDELPIilA. 20, PENNSYLVANIA January 31, 1962 Mr. Art Auster I, DuPont DeNemours Co. Pigment Department Newport, Delaware Dear Mr. Auster: In the past, the F. J. Stokes Corporation has been proud and glad to work with the DuPont Company on preliminary tests and evaluations of new products. This same cooperative attitude has been shown by our company in assisting plant engin eers such as yourself in improving existing processes both for better efficiency as well as good cost savings. It was with the above philosophy in mind that we entered into the negotiation with your company through you on the vacuum processing of your dyes. It was generally thought that we could contribute both through the utilization of our lab equipment as well as the know how which we have built up in years of vacuum processing. However, upon receiving your product, there has been a question .on whether or not there is any advantage running your product in our equipment. A more thorough evaluation has resulted in the conclusion by the vacuum product staff and laboratory personnel that we would be doing you a greater sorvioe by advising you that it is not a feasible approach. We further feel that extreme difficulties would be recognized when running our vacuum equipment, and for this reason, we are withdrawing our offer to run it in our laboratory. Tour basic aims of improved drying schedule and a fine powdery finished product are not obtainable in a conventional vacuum dryer as designed today without some sort of external breaking. The material which you have gives every indication that it will adhere to the walls of the dryer during processing and cause considerable reduction in the thermal transfer in the unit. True, our model $9 assembly with scraper blades would remove .. the material from the dryer shell. However, it would not guarantee ' that the product would be of the mesh you desire without external grinding in a granulator or tornado mill. N39941 Mr, Art Auster 2- January 31> 1962 Based on the above, you can easily recognize why the best thing for us to do at the present time is to withdraw from this project. Please do not hesitate to call on us for infor mation on the vacuum dryers, and if we can help you in any way on other projects, we will look forward to doing so* Veiy truly yours, F, J. STOKES CORPORATION \- WilliLam J. Leighton Philadelphia Sales Office Vacuum Department. WJLtb DUP050054376