Amino Silicone Softener And The Easy-Care Finishing Of Cotton Fabrics

The easy-care finished cotton fabrics could attain remarkable SA rating, however, the tensile strength decreased to some extent simultaneously, which reduces the wash and wear durability of the fabrics. So how to decrease the tensile strength loss during easy-care finish has been an major concern for the industry. According to some literatures, amino silicone softener can improve the SA rating and the wrinkle-resistance by from 20°to 70°of the finished fabrics effectively. In this research, amino silicone softeners were selected for the easy-care finishing of cotton fabrics to improve the strength retention by reducing the amount of ultra-low formaldehyde finishing agent of SDP1.Nowadays, there are many kinds of amino silicone softeners which performances are different from each other, so work of screening softeners which can improve the SA rating of fabrics effectively is very necessary. So, amino silicone softener 8417 with excellent performance was selected, the WRA of the fabrics finished by 8417 increased by 50°,but its tensile strength retention still retain more than 70%. The effect of the amount of SDP1 and the amino-modified silicone softener 8417 and the impact of curing temperature and time on the treated fabric were researched by single factor experiments, so the appropriate dosage of SDP1 and 8417, and the preferable curing temperature and time were found. Then an optimal formulations and process conditions were achieved by orthogonal experiments. The optimal formulations and the process conditions:SDP1 is 80g/L,8417 is 80 g/L, curing temperature is 150℃, and curing time is 3 min. Under the optimal formulations and process conditions, the treated fabric with preferable performance was obtained. The WRA of the finished fabric was above 260°, DP rating reached to 3.3. the tensile strength retention was more than 50%, and the formaldehyde release is less than 75mg/Kg.The influence of different structure of fabrics on the performance of the finished fabrics was studied. The result indicated that the DP rating of poplin fabrics is higher than that of oxford fabrics by 0.2, but its tensile strength retention is lower than that of oxford fabrics by 5%～7%; For the poplin fabrics with the same yarn count, the weft density has greater effect on the finishing performance, the DP rating improved with the increases of weft density of fabrics, and the finishing performance of treated poplin fabrics is almost independent with its warp density.The optimal easy-care finishing process in this study and the traditional easy-care finishing process in our laboratory were compared. The results showed that the finishing performance of the former was better than that of the latter:the tensile strength retention of the finished fabrics by the former process was higher than that of the latter by 6%, the whiteness was better slightly, the formaldehyde release was relatively lower, the DP rating of the both process were nearly the same. And the cost of the finishing process in this study was cheaper.Finally, the reasons for tensile strength loss of the fabrics which was resulted in amino silicone softener were studied. According to some literatures, the tensile strength loss of easy-care finished cotton fabrics by formaldehyde-based N-methylol reagents have been attributed to two main factors:acid-catalyzed depolymerization of cellulose molecules and crosslinking of cellulose molecules by crosslinker. The results indicated that 90% of tensile strength loss of finished fabrics was from the process of pre-drying, when only amino silicone softener 8417 was used, And the tensile strength loss caused by acid-catalyzed was fewer. However, When cotton fabrics were finished only by finishing agent SDP1,94% of tensile strength loss of finished fabrics was result in the process of curing. When cotton fabrics were finished by softener 8417 and finishing agent SDP1 together, more than 23% of tensile strength loss took place at stage of pre-drying, and 27% of the tensile strength loss was caused by the process of curing. The strength loss in the pre-drying stage was caused by softener 8417, and the main reasons of strength loss in the curing stage were the crosslinking of cellulose molecules by SDP1 which restricted the mobility of cellulose chain. According the analysis of the infrared spectrum of silicone 8417, there was reactive group Si-H in the structure of silicone 8417, and the result of SEM of the finished fabrics by 8417 indicated that the silicone 8417 can form a film on cotton fibers, but its fastness of washing was undesirable. However, according to the information above, the detailed reasons for the tensile strength loss of treated cotton fabrics was difficult to find, so it need to be studied further.