Document aJ1mDdBw1zg4E1Vzv4VM26o1e

1 CONFIDENTIAL Steel Mill Product* Division Research and Development Department Mav 1973 1) Profax Boards Beginning Wednesday, May 16, 1973, a production run vas scheduled on K-4 machine using EP-5290. The recipe is asbestos and paper free. The run vas smooth and vas continued until Monday, May 21, 1973, when the machine started easily. Monday the production-vas- stopped. The boards vere shipped to Copperveld and the results are favorable. Jack Thebo said that the material is dustier than Profax 31. We have to correct it. Tuesday, May 22, 1973, the Armco-Middletovn boards #341 and #342 vere tried on Mark III X machine. Tvo pallets (one of each) vere produced vith 12.01 green scrap versus 10.01 for Profax 31. The boards presented some surface cracks. For that reason, under labora tory conditions, ve nailed a board directly on such a crack. The nev material (EP-5290) is strong and elastic enough as not to be affected by the surface cracks (the sample is in our lab). We have not received, as yet, the results from Armco-Middletovn. During these experimental runs ve have found that the recipe is lacking in green strength. For that reason, ve added to the regular recipe, a small amount of Bentonite (0.51). The green scrap vas lovered from 4-51 to 2-2.31 for a 24 hr. period. Monday, June 4, 1973, Corrugated B machine is scheduled to start under regular production basis employing the cool #685 for Copperveld. During May ve tried to reduce the filtered solid vhich passes through the screen. The usual screen vhich is used in production is 55 X 36 openings/sq. in. Under laboratory scale, me used tvo other screens: 80 X 60 and 100 X 92 openings/sq. in. -- -- The forming time vas: 1. 55 X 36 2. 80 X 60 3. 100 X 92 4.1 and 4.2 see 4.1 and 4.2 sec 4.1 and 4.0 sec 1537 <="7