摘要 |
An improvement in the machine washing of solid soiled materials comprising withdrawing and recycling the wash liquor in contact with said solid soiled materials through a silicate cation exchange compound having some combined water and a particle size of at least 10 mu of the formula: (M2/nO)x.Me2O3.(SiO2)y wherein M is a cation of valence n exchangeable with calcium, Me is a member selected from aluminum and boron, x is a number from 0.7 to 1.5 and y is a number from 0.8 to 6, said silicate compound having a calcium binding power of at least 50 mg of CaO per gram, said silicate compound being maintained out of contact with said solid soiled materials, for such time that the recycling wash liquor has passed through said silicate compound at least twice, in the presence of other soluble washing and cleaning compounds, while reversing the direction of flow of said wash liquor through said silicate compound repeatedly. |