The Effect Of Modification On The Dyeability And Wearability Of The Hemp Fabric

The hemp has many excellent properties. but its content of cellulose fibers is low. content of lignin and hemicellulose are more, so there are many difficulties in the dyeing and finishing of hemp fabric. The subject in reference to the large number of other natural cellulose fiber processing and modification methods. modified the hemp fabric, in order to improve its dyeability and wearability.The subject used pure hemp fabric as raw materials. because the effect of the pre-treatment process will directly affect the dyeing performance of the fabric. So in order to meeting the requirements of the hemp fabric of staining and modification, first briefly discuss pretreatment of hemp fabric. In processing of scouring used two methods. acid and alkali scouring and enzyme scouring. Doing acid scouring on the removal of lignin in hemp fibers have a good effect, and with alkali scouring it can improve the capillary effect and maintain good strength of the hemp fabric. As Prickle enzyme to improve the fabric is more obvious, so selected three common enzymes in textile treated the hemp fabric, refined enzyme, pectinase enzyme, cellulose enzyme, and had achieved good results. Pectinase enzyme complexed together with the cellulose enzyme treat with the hemp fabric, the capillary effect of the hemp fabric from 14.5cm up to the present 17.8cm. length of fabric from the original 38.6cm bending down to 27.7cm. flexural strength from the original 573N down to 213N, show that the capillary effect and Rouran fabrics are given a greater degree of improvement. And one side of the fabric getting better compression performance improvement, the bending length of the fabric decreased from 0.604mm to 0.554mm, the pressure at the dividing point decline in value from 1.05cN to 0.87cN, the main compression hardness of the fabric from 11.2 to 9.8.Getting the good whiteness is significant to the fabric in the dyeing and finishing processing, selected two kinds of bleaching agent for bleaching of hemp fabric, hydrogen peroxide and peracetic acid bleach. Respectively, from the impact of various factors in bleaching, discussed the two in detail. finally arranged the process of bleaching of the hemp. Relative to hydrogen peroxide, the peracetic acid bleaching of hemp fabric is more effective to the removal of lignin, content of lignin before and after bleaching was 5.284% and 4.019%, and under the same conditions before and after hydrogen peroxide bleaching content of lignin was 5.284% and 4.525%. Finally, frist doing peracetic acid bleaching and next doing marijuana hydrogen peroxide bleaching can maintain a strong fabric and obtain better whiteness, its strength deprssed 13% and whiteness was 64.1, it can basically meet the dyeing and finishing processing needs.In reference to other hemp fiber modified methods, established the modified plans of the hemp fabric. By analyzing the uptake rate, color fastness, strength, fabric-evoked prickle, etc. researched the effect of the modification. Modified method selected alkali mercerization, ethylenediamine / sodium hydroxide / urea solution, cationic modifier 3-chloro -2- hydroxypropyl trimethyl ammonium chloride, thiourea / sodium hydroxide urea, N-methyl morpholine oxide (NMMO). all achieved certain results. In these, the properties of the hemp fabric modified by cationic modifier and NMMO are more excellent, they obtained good dyeing rate and better color yield in staining, kept good color fastness, also improved its prickle.The dyeing rate of hemp fabric after modification has been significantly improved. The dyeing rate of cationic modification fabric from 41% to 54%. increased by 13%, and then The dyeing rate of the fabric modifided by NMMO and ethylenediamine, increased 12% and 11%. And the K/S value of the fabric also received a higher, which the K/S value of the fabric modified by NMMO and cationic agent respectively reached 10.13 and 9.98. The difference of color DE decreased from 2.2. DE value of fabric modified NMMO was 1.2. Although the fiber modified has been injury, but at the same modification also made each component of the fiber more distribution. it is conducive to the increasing the strength of the fabric. So, the fabric strength was not significantly reduced, the rate of strength droping maintained at 13% or less, special fabrics modified by NMMO rate of strength droping even less than 1%, and the breaking elongation of the fabric had increased above 50%. While the dry and wet rubbing fastness and washing fastness of the modified fabric dyed all had reached 4 to 5 level above. From the prickle view of the fabric. Prickle of hemp fabric modified improved. The hairiness length o(?) hemp fabric modified NMMO is the shortest, from the original 0.423mm down to 0.324mm, the demarcation point pressure decreased from 0.98cN to 0.79cN.