Comparison of the washing efficiencies of a laboratory washing device (Launder‐Ometer) and of automatic household washing machines with horizontal drums

AbstractThe objective of this study was to compare the cleaning result of a laboratory washing machine – Launder‐Ometer (LOM) – with that of drum‐type household washing machines, using detergent without bleaching agent, standard soiled fabrics and a colorimeter for assessing the washing result. The mechanical effect applied to the laundry in the household washers was not obtained in the LOM by increasing mechanical impact or the number of metal balls. Extended washing time did not improve removal of blood soil in the LOM, although it did increase removal of mayonnaise soil containing chlorophyll. However, in practice a washing time of 60–85 min is relatively long for a laboratory device considering the claimed time‐saving nature of these devices. None of the examined parameters affected removal of a red wine soil containing tannins, which was poor in all test combinations both in the household machines and in the laboratory washing machine. Bleaching agent is recommended for removal of this type of soil. In conclusion, conformity between washing results of the laboratory washing machine and the drum‐type household washing machines depends on the type of soiled test fabrics and other parameters in the washing process. Removal of blood soil differed most between the household machines and the LOM.