| abstract |
The invention relates to a method for cleaning a liquid crystal mixture (7), wherein the liquid crystal mixture (7) is conveyed through a first electrodialysis cell (2) and a concentrate solution (14) is conveyed through a second electrodialysis cell (8), which adjoins the first electrodialysis cell (2) and is separated by an ion-exchange membrane (9), and an electric field is produced transversely to a direction in which the liquid crystal mixture (7) is conveyed through the first electrodialysis cell (2) by means of an anode-cathode assembly (15, 16) arranged outside of the electrodialysis cells (2, 8), such that ionized constituents of the liquid crystal mixture (7) are lead away at the ion-exchange membrane (9) and separated from the liquid crystal mixture (7). The liquid crystal mixture (7) can be conveyed through the first electrodialysis cell (2) over a time period of more than one hour, preferably of more than four hours. A membrane having a breakdown voltage of more than 10 volts, preferably of more than 80 volts, and especially preferably of 400 volts and more, is used as the ion-exchange membrane (9), and a voltage drop that is as large as possible but lies below the breakdown voltage is effected at the ion-exchange membrane (9). |