This Part of BS 7164 describes a method for the preparation and examination of water extract.
NOTE. Water extracts more or less completely many non-rubber constituents of raw natural rubber, such as proteins, various naturally occurring mineral salts and other soluble material. It extracts emulsifiers, stabilizers and coagulants from raw synthetic rubber. From compounded rubbers, water extracts glue, gelatine, and other proteins, certain accelerators, starch, glycerine, alkalis, soaps, calcium sulfate, and non-volatile residues from blowing agents, such as sodium carbonate and sodium chloride.