JPS6346189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for bleaching coconut fibers which can be bleached to a beautiful white color without substantially changing the strength of the fibers.

Coconut fruits have a relatively large amount of brown fibers (commonly known as coir ahuaiba) between the epidermis and the seeds, and each fiber is usually 0.2 to 0.5 mm thick and 20 to 30 cm long. The fibers were lightweight, highly water repellent, heat resistant, and resistant to friction, making them useful as ``scouring pads.''

In recent years, it has been planned to use it in brushes, brushes, and even fabrics, which require bleaching. Since the use of hydrogen peroxide as a bleaching agent is traditional technology,
It was also used against coirhuaiba. As a result, although the desired "white" color was obtained, the coir aiba became extremely brittle and had no tension, resulting in only inferior strength. The main reason for this was that the surface material of the coir fiber was scraped off.

An object of the present invention is to provide a bleaching method that can bleach coir fiber to a beautiful white color without substantially affecting the surface material and without changing the strength of the fibers.
A first embodiment of the present invention will be described below. Prepare the following mixed solution as a bleaching solution.

In terms of weight ratio, caustic soda to 1000 parts of water......15 Stabilizer mainly composed of sodium silicate to the following hydrogen peroxide bleach...10 Surfactant......2 Concentration of 50% Mix 20% hydrogen peroxide to make a solution with a pH of 13 to 14. The hydrogen peroxide bleach stabilizer used was the trade name Hyper (product of Daito Pharmaceutical Co., Ltd.), and the surfactant used was the trade name Assist (product of Daito Pharmaceutical Co., Ltd.).
A weight ratio of 50 parts of coir fiber to 1000 parts of water is added to the mixture. Keep the temperature at about 25°C and soak the coir aiba for about 8 hours, stirring every hour. Next, discard the liquid and stir and wash under running water for about 30 minutes, as if washing coir fibers with water.

Take 50 parts of coir aiba to 1000 parts of water by weight, and add 3 parts by weight of acetic acid with a concentration of 30%. The water-washed coir fibers are added to the solution and soaked for 1 hour with appropriate stirring. After 1 hour, discard the liquid and wash the coir fibers with stirring under running water for about 15 minutes.

Next, the coir fibers are dehydrated in a dehydrator and air-dried. The product is combed and bundled to form a finished product.

Next, as a second embodiment of the present invention, when coir fiber is put into a bleaching solution, the temperature is kept at about 45°C,
After 1 hour, it was immersed with stirring, and after about 5 hours, it was taken out, washed with water, and then immersed in a solution obtained by adding acetic acid with a concentration of 32% to water in the same weight ratio as in the first example. In other respects, when the bleaching operation is performed in the same manner as in the first embodiment, the same effects can be obtained.

The reason for using acetic acid in the above explanation is that quantitative treatment in acid treatment can be performed accurately.

Therefore, it is appropriate that the temperature at which coir fibers are initially immersed in the bleaching solution is in the range of 20°C to 50°C. When kept at a higher temperature, it can be taken out in a slightly shorter time than when kept at a lower temperature.

In this way, according to the present invention, the bleached coir aiba becomes a beautiful "white" color, and the whiteness is
65.0 to 75.0 (visible wavelength millimeters) (according to the test results of the Tokyo Metropolitan Textile Industry Research Institute "Senko Somei No. 1-39"). Moreover, as a result of experiments, it was found that the color fading property is extremely low. The abrasion resistance, tension resistance, heat resistance, and restoring force are almost the same as before bleaching, and the water repellency is still good.
As a result, its range of uses has been greatly expanded to include brushes, ropes, mats, and fabrics.

Claims (1)

[Claims] 1. In a method of bleaching the epidermis of a coconut and the fibers between the seeds using a bleaching agent containing hydrogen peroxide as a main component, caustic soda is added at a weight ratio of 15% to 1000% water. Stabilizer mainly composed of sodium silicate for the following hydrogen peroxide bleach...10 Surfactant...2 Hydrogen peroxide bleach (concentration 50%)...20 The fibers were put in at a ratio of 50% and soaked at a temperature of 20°C to 50°C for several hours, then taken out and washed with water.
A method for bleaching coconut fibers, which comprises adding the fibers to a solution prepared by adding 3 parts to 3 parts to water, taking them out after about 1 hour, washing them with water, dehydrating them, and then air drying them.