| The nonwoven industry is experiencing a treamendous explosion in all fields due to high efficience and low cost. Nonwoven wipes make up a big market share and sales are predicted to continue increasing in the next few decades. With the increasing consumption of petroleum-based polymer products, more attention has been paid to the environmental problems associated with their non-renewable nature and disposal. Hemp fiber is an abundant alternative source with good mechanical properties and biodegradable characteristics. However, not enough research has been done on its application on nonwoven wipes.Firstly, the hemp fiber properties were compared with other common degradable green fibers. Nonwoven fabrics made from hemp fibers and bicomponent fibers for household and industry wipe applications were produced in this study, using airlaid and bonded by thermal bonding. Four blends of hemp and bicomponent fibers were developed.Secondly, the influence of hemp fiber content and process on the mechanical properties and water absoprtion properties were evaluated. Through the orthogonal test of water absorption, the significance of each factor was found and the best process was advised.A combination of thermal bonding and needlepunching was used to improve the mechnical properties of the web. Two layers of web using the combination bonding process were also developed. The properties of these two kinds of nonwoven fabrics were tested and compared with the wipe products in the market. It was concluded that:(1)Hemp fiber has high moisture regain compared with cotton and rayon, it has good mechanical and antibacterial properties. Compared with polyester, it stands out with its biodegradable characteristics. Hemp fiber is an ideal alternative saurce for nonwoven wipe.(2) The best blends and process was figured out. When the hemp portion increased, the bursting strength of the wipes initially increased and then decreased. The best mechanical properites were gained when the hemp fiber percentage was50percent. The change of strength with the increasing bonding temperature shared the same trend as the hemp portion and the best mechanical propeites were achieved at175℃. The higher the presurre on canlender and slower of the process speed, the better mechenical properites. In this study, it was suggested3300Pa and20m/min.(3)25percent hemp fibers showed the greatest water absorption capability.175℃and20m/min was suggested for the process. While pressure on the calender showed no big impact on the absorption capability. The results of orthogonal test indicated that the fiber content is the main factor on waer absorption, followed by thermal bonding temperature and process speed.(4) The mechenical properties were greatly improved by the multi-bonding process. However the water absorption capability showed no big change. Two layers through multi-bonding process had the similar mechanical property as one layer through multi-process, however the absoprtion percentage increased. Taking all factors into consideration,the single layer of web bonded by needlepunching and then thermal bonding was strongly recommended.(5) Hemp fiber nonwoven fabris showed slightly weaker dry strength and abrasion resistance than conmercial wipes, but higher wet strength and comparable absorption capability. |
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