HOME ECONOMICS

New Zealand Herald, Volume LXXIII, Issue 22525, 16 September 1936, Page 4

HOME ECONOMICS

DEMONSTRATION LECTURE | DYEING OF FABRICS Somo aspects of home dyeing formed tho subject at the monthly demonstra-tion-lecture givep under the auspices of tho Auckland Home Economics Association, in the Sedrlon Memorial Technical College last evening Tho president, Miss B. Carnachan, introduced' the speaker, Miss M. Aitchison, who was assisted by Miss I. Peebles. The dyeing of fabrics was; useful for economic as well as aesthetic reasons, Miss Aitchison said, for not only did it prolong the service of a garment, but, used cleverly, it added much to the beauty and atractiveness of materials. If carefully carried , out, the process was almost always a success and gavo great satisfaction. Many hints of practical value concerning the reaction of the various fabrics to the dye bath were given by the speaker, who said that wool and silk, the animal fibres dyed best, then rayon, which in some cases took on brilliant colours. and cotton, the vegetable fibres, did not dye so brightly, while celanese was much .more difficult to dye and needed special dyes for bright colours. Sainples of tho various fabrics, which had all been dyed in the same dye bath were then exhibited, showing the depth of colour taken by the various, materials. It was necessary to know a little about colour before attempting to dye, Miss Aitchison said, and the three primary colours, red, yellow ana blue and their resulting shades when blended were dealt with at some length.

Points to Consider To dye a coloured garment another colour was not always easy. For instance, a light colour could not be superimposed over a dark one, and the fact that two colours blended to give another colour had to be considered. When endeavouring to re-dyo a coloured fabric, it was- necessary therefore to neutralise or "grey" the existing colour. A practical demonstration of re-dyeing a piece of red material to a blue shade was then given. Lack of success in •dyeing garments a good black was often due, the speaker said, to not having greyed the original colour. The preparation of the dj'e bath was important, and should be carefully carried out to avoid spotting and uneven dyeing. The bath should be a container, such as a cut petrol tin, or a copper, which was large enough to hold sufficient water to completely cover the material and give, ample room for movement. This was essential to ensure evenness. The dye should not be poured in on top of the material, as this would cause streaking.

Use of Mordantii It was wise to commence with a solution which was too weak rather than too strong, said the speaker, as more dye could be added. Mordants, such as salt and vinegar, were sometimes used to "set" the dye. If salt were used it should be made into a solution and not be added while, the garment was in the dye bath, as' this caused streaking. The mordants frequently deepened the colour, so should be added before the colour was quite dark enough : The whole secret of dyeing, Miss Aitchison explained, was to give plenty of. time to the process and-to use plenty of water. The,; garment should be brushed free from dirt, have all tli<» hemS and thick parts unpicked, as these would dye a darker colour and might streak. It should also be freshly washed and thoroughly rinsed. Chemicals should not be used to remove stains, as these might have a reaction on the fibre, and the spot would then dye a different colour. The goods should be throughly wet before placing in the dye bath, the water in which should be very hot. New goods should be soaked in very hot water before being dyed to remove any dressing, and total immersion should take place immediately, the contents being kept in constant motion with a long rod. Finally, complete and thorough rinising in hot, then cool, water was necessary. After being squeezed dry, the garment should be shaken or rolled up in muslin, so that no two parts came in contact, as this was apt to cause streaking. If hung outside, it should be in the shade, as the sun would cause some parts to dry too quickly. If the dyed material was to match a sample it was necessary to wet the sample thoroughly to compare the colours, as they were always darker when wet.