UMBRELLIT M 40 is an aqueous mixture of chromium (III) compounds which provides very good hydrophobic results due to a substantive bonding to the fiber. UMBRELLIT M 40 is suitable for finishing cardboard, release papers or coated special papers.
Stock solutions of UMBRELLIT M 40 are only stable in an acid pH range. A pH value above 4.5 leads to the precipitation of chromium hydroxide, which results in a slight blue coloring and clouding. These solutions are useless. UMBRELLIT M 40 can be combined with other additives such as cationic dispersions, cationic or non-ionic starch, polyvinyl alcohol and cellulose ether. The compatibility of the components must always be tested before use. In general, the product is processed as 1 - 3% stock solution. UMBRELLIT M 40 is easy to dilute with water. Soft water is recommended.
According to the current recommendation of the German legal regulations, it is permitted to use 0,45 g/m² UMBRELLIT M 40 on the surface of paper and board.