INNOVATION BROUGHT ABOUT IN ACADEMIC SYSTEM

EXPOSURE FRAME

DR. E.A AKPAN

DEPARTMENT OF HOME SCIENCE AND MGT.

UNIVERSITY OF AGRICULTURE, MAKURDI

The exposure frame is a simple but effective instrument which has been approved by the Society for Dyers and Colourist, Bradford, England for use in testing the fastness of the dyed and printed textile to sunlight. The result obtained to be used for quality control.

Figure 1: Exposure frame

The frame (see fig. 1) is made of a shallow box with a lid of glass. The critical feature is that the space between the bottom of the box and the lid is 5cm. There is a free card board or plywood board which carries the test sample as shown in fig. 2. The hinge carrying the sample should be such that when closed, should have a little gap to allow air to circulate the inside of the box outside.

Figure 2: sample preparation

Preparation of sample for exposure

The sample should measure about 5cm to 20cm. This is fastened to the free card board or plywood board. Half of the board is covered with aluminium foil or an opaque material. The assembly is placed inside the frame and closed (see fig 3). It is then taken outside to an appropriate location for exposure. The frame should be tilted to an angle of 450 toward the direction of the sun during the exposure.

Light fading of a dyed textile is a catalytic reaction. When light energy strikes the surface of a dyed fabric, it causes the molecules to be in a state of agitation or random movement. When the molecules acquire enough kinetic energy, they break away from the fabric surface and become gaseous. Loss of molecules, translates as fading- loss of colour of the material. To stop this occurrence, some metallic salts are incorporated in the dye during or after dyeing as after - treatment. This will help to scatter the light and thus reduce its energy and this will render the fabric safe.

Figure 3: exposure fame with sample

Exposure time depending on the region could be from 11:00am to 05:00pm each day. A total of 40hours of exposure is considered appropriate to give a reliable result. If after that period of time there is no noticeable change between the exposed and unexposed portion of the sample, the dye or printed material is said to be satisfactory.

Sun fading, which is the gradual loss of colour of a dyed or printed textile material when exposed to the sun is one very serious problem facing textile manufacturers and is objectionable to textile product consumers. A test instrument that gives quick feedback information on the fastness characteristic of a dyed or printed material is a welcome development.

Today Nigerian textile product consumers claim that fading (whether wash fading or light fading) is the main reason why they reject Made in Nigeria textile and turn attention to buying foreign textiles to the detriment of Nigerian textile industry.

Those who used the exposure frame in their project work included:

Aende, David Washima (UE/13456/09), on “Dyeability of Sulphur Dye on Cotton, Wool and Silk and their Fastness to Sunlight and Washing”.

Dingba A. Sabrina (M.Sc/3497/10), on “Production of Selected Plant Dye and Application on Cotton Fabric and Testing for Fastness to Sunlight”.

Chief (Mrs) Akaazua Seember (PGD/2580/08), on “Testing and Assessment of Light Fastness Properties of Dylon Dye on Cotton Fabric”.

Amiseh, Iveren Rosemary (UE/20597/11), on “Production and Application of Onion Colour on Cotton Fabric and Testing for Fastness to Sunlight”.

Iganga, George E. (UE/20619/11), on “Production and Application of Dye from Walnut on Cotton and Testing for Fastness to Sunlight”.

Ijoko, Helen U. (UE/17759/10), on “Extraction and Application of Kola nut Dye on Cotton and Testing for Fastness to Light”.

Oyigeje, Samson O. (UE/20652/11), on “The Use of Alum and Vinegar as Fixative for Cotton on Dyed with Moringer and Kola nut Dye”.

Ameh Godwin (13/27755/UE) on “The use of colour from tick plant leaves for Dyeing Cotton Fabric and testing for Fastness to light”

Anupitan Isaac S. (14/30287/UE) on “Production and Evaluation of Mango Leaves Dye on Silk and Testing for Fastness to Light”

Koko Christian N (14/31197/UE) on ”Dyeing and Assessment of Light Fading of Cotton Fabric Using Dylon Dye”

Abah Alechenu (Thomas 13/27727/UE) on “Determination of Vinegar and Alum as Fixing Agent for Zobo Dye on Cotton”

References

Giles, H. (1994). A Laboratory Course in Dyeing. The society of dyers and colourist Bradford England.