Authors : Thitivara Poonsawat, Porntip Sae-Bae, Manlika Bunphami, Thassaneewan Wetchaiyoc and Piyaporn Jatamaneerat
Abstract: Hemp is original used by Hmong people, the mountainous tribe in Northern Thailand. Hemp cloth by Hmong is coarse fabric with traditional process. To introduce hemp into the industry, hemp need to be process as ordinary spinning yarn. This research aims to study the effects of water retting and chemical retting on properties of hemp fibre. Hemp was obtained from Northern Thailand and then retted using water and chemicals. The chemical retting was done by soaking hemp bark in 2% NaOH at 120�C for 20 min under pressure. Bark was soaked in a tank of water for 9 weeks in the water retting process. Fibres from the 2 processes were investigated for chemical properties and the spinnability of a hybrid hemp/cotton mixture using ring spinning technique. The results show that hemp fibres from different retting processes were affected on percentages of extractive, protein, hemicellulose and lignin of fibre. Hemp at 9 week of water retting showed the percentage of cellulose, hemicellulose and lignin at 72.7, 4.3 and 16.6%, respectively. The composition of chemical retted hemp fibres resulted in 83.4% cellulose, 0.1% hemicellulose and 12.7% lignin. The Degree of Polymerization (DP) of chemical retted hemp was lower than the DP of hemp fibres from the water retted process. Spinnablity test by spun hemp/cotton at a ratio of 1:1 by weight showed that the fineness, twist and strength of spun yarn from hybrid water retted hemp/cotton (hempw/cotton) were higher than those from hybrid chemical retted hemp/cotton (hempc/cotton). Futuremore, the intensive effect of water retting on bast fibre quality should be investigated.
Thitivara Poonsawat, Porntip Sae-Bae, Manlika Bunphami, Thassaneewan Wetchaiyoc and Piyaporn Jatamaneerat, 2016. Effect of Water and Chemical Retting on Properties of Hemp Fibre and Hybrid Hemp/Cotton Spun Yarn. Journal of Engineering and Applied Sciences, 11: 1991-1995.