Jun 26, 2007

Lemon Juice: Potential Abaca Fiber Bleach


Abaca, popularly known as Manila Hemp, is primarily used in the manufacture of marine cordage,pulp and paper products, nonwoven fabrics and disposable items. Many cottage industries utilize the best grade abaca fibers in the producton of quality items. Best grade fibers meet the standards for tensile trength, color, texture, luster and cleanness. Obviously,items produced from quality fibers (whitish in color) command a high price than those made from poor abaca (brownish in color).

People engaged in cottage fibercraft industries procure abaca fibers in bulk which are often improperly storedfor some time. Under this condition fiber discoloration occurs. To improve the color of abaca fibers, a bleaching treatment is applied. A study aimed at determining the best bleaching method for abaca fibers was conducted at the Visayas Stage College of Agriculture (VISCA). Abaca fibers from the middle sheaths of Linawaan variety were treated with chemical bleaches (sodium perborate, sodium hypochlorite, and chlorux with 10%, 20%, #)% and 40 % concentrations each) and natural bleaches (fresh mature camias leaves, camias fruit juice, and lemon juice at concentraitons of 20%, 40%, 60%, and 80% each). Fibers subjected to chemical treatments under a 30-minute heating at 85 f, while those treated with natural bleaches were soaked for six hours. Immediately after these treatments, the samples were thoroughly rinsed in cold water and then air-dried at room temperature.

Color

Untreated fibers (control) were ecru in colr which could be attributed to the darkening of the puld and the adhering impurities. When the samples were treated with chemical and natural bleaching agents, the color chaged. Fibers treated with lemon and camias fruit juices turned to light ivory and light ecru, respectively, in all treatments. Camias leaves produced a light cream color, except in one treatment with chemical bleaches which produced lemon frost fibers.

The change in color when treated with natural bleaches could be attributed to the acid contents of the bleaching agents-oxalic in camias and citric in lemons.

Texture and luster Texture of the fibers may either be soft, medium soft, medium coarse, and harsh or coarse. Among the natural bleaches, the treatment with lemon juice at 80% concentration produced medium soft abaca texture- the best result in this category. However, among the chemical bleaches, sodium hypochlorite solution gave soft abaca fibers - a performance better than that of lemon juice.

Tensile strength and elongation

A significant difference in tensile strength occurred amongthe various levels of concentration (10%, 20%, 30% and 40 %) using sodium hypchlorite solution. However, the stronger the concentration of sodium hypochlorite, the weaker the fibers become. This was also true with lemon juice. No significant differences in ellongation was observed among the four treatments using both the natural and chemical bleaches.

Cost benefit analysis

Cost benefit analysis showed that natural bleaching agents are cheaper to use than chemical bleaches.

Source: PCARRD Monitor Feb-Mar 1989, photo courtesy of img.alibaba.com