| 配方类型： |
PAPER |
| 配方说明： |
Paper-Coating Adhesive |
| 配方组成： |
Soda Ash/6
Caustic Soda/2
Dry Casein/100
Sodium Fluoride/2 |
| 配制方法： |
Prepare the adhesive solution as heavy as possible and dilute to the proper strength just before using.
Stir the adhesive solution in a heavy concentration at the preparation temperature for 1 to 2 hours to impart increased elasticity. Also stir until cold to prevent the forming of any scum on the top of the adhesive solution. The casein solution may be used "hot" or "cold" according to the practice of the individual operator. Time and choice of quantity of alkali to be used in the preparation of the casein adhesive will also vary with the individual mill as seen in formulae 1 to 18.
Ammonia, because of its volatility and cost, is frequently added at the end of the operation.
The order of addition of soda ash is governed by the presence of free acid in the casein. Excess acidity will result in foaming. Satisfactory results have been obtained with the following sequence: a Borax, soda ash, and ammonia b Caustic soda, sodium fluoride, and soda ash While the usual temperatures of 110 to 130'F., or |
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