Optimisation of the process of dyeing cotton fabric with natural dyes from jackfruit wood by immersion without heating
Authors: Rosyida Ainur , Suranto Suranto , Masykuri Mohammad , Margono Margono 
Published: October 2021

Purpose
This paper aims to examine the recipe for and standard methods of dyeing cotton fabric with natural dyes from jackfruit wood extract. The dyeing of the fabric was performed by immersion it without heating for a short time to obtain the best results.

Design/methodology/approach
The dyeing experiment using cotton fabric with jackfruit wood extract was conducted by immersion at room temperature. The independent variables studied were the mordant method, type of mordant, mordant concentration, salt concentration and dyeing pH. The dependent variables were colour strength and colour fastness to washing and rubbing. The orthogonal array L16 (45) was used in the study to obtain the optimal values for each parameter of the response variables. The multi-response signal-to-noise (MRSN) method was used to optimise the five response variables with different quality characteristics so that the best parameters could be obtained based on the highest MRSN ratio value.

Findings
The best parameters were obtained at an MRSN value of 4.5254 under A3B3C1D2E4 conditions, namely, the dyeing process with post mordant, aluminium nitrate type mordant, mordant concentration of 10 g/L, salt concentration of 15 g/L and dyeing a pH: of 10. Under these conditions, the value of K/S was obtained at 1.893, colour fastness to washing (GS: 4) and (SS: 4–5), dry rubbing (SS: 5) and wet rubbing (SS: 4–5).

Research limitations/implications
Obtaining a standard recipe and method for dyeing cotton cloth with jackfruit wood extract by immersion without heating is expected to lead to the development of natural dyes, and especially their application on an industrial scale. This standard and method can be used as technical guidelines by industry. The use of aluminum nitrate as a mordant will help achieve optimal dyeing results. The use of polyaluminium chloride (PAC) mordant, which has the potential to produce high colour strength, and papaya fruit sap, which has the capacity to increase colour fastness, still need to be developed to improve the results of natural dyes.

Practical implications
The standard recipe and dyeing method will be able to improve the results of the dyeing of cotton fabrics with natural dyes. Short immersion dyeing without heating and the optimal results obtained are the main attractions for their use by the textile/batik industry, as the process is easier and a lower cost. The results of dyeing with dark colours and good colour fastness mean the textile products are of the higher quality demanded by consumers, thereby increasing sales. This will encourage the use of and increase the need for natural dyes by industry, consequently reducing the use of synthetic dyes.

Social implications
The use of natural dyes, chemical mordant from aluminum salts, and natural mordant from papaya fruit sap in the dyeing process in the textile/batik industry in Indonesia will produce eco-textile and eco-batik products that are environmentally friendly and of high quality. This in turn will increase consumer interest and sales, meaning that the income and economy of workers in the textile industry/crafts sector will also increase. In addition, the use of natural dyes with the selection of a safe mordant (not containing heavy metals) will reduce the use of synthetic dyes, which pollute and damage the aquatic environment.

Originality/value
This study found a standard recipe and method of dyeing cotton fabric with natural dyes from jackfruit wood extracted by immersion without heating for a short time to obtain the best results. In addition, the discovery was of PAC, a new mordant which is effective in the use of natural dyes can give high colour strength to cotton fabric. In addition to the discovery of a new mordant, PAC, which has the potential to produce high colour strength, papaya fruit sap also has the capacity to increase colour fastness with the use of natural dyes from the flavonoid group.