大麻鲜茎剥皮机的设计与试验

为了减轻大麻收获劳动强度、提高大麻鲜皮剥制效率，该研究根据大麻茎杆分枝多、皮骨结合紧密等特点，采取揉搓分离与梳理分离相结合的皮骨分离方法，设计出大麻鲜茎剥皮机。该样机主要由揉搓机构、梳理分离机构、纤维收集装置、传动系统、机架、行走装置等组成，样机具体结构紧凑、移动方便、皮骨分离能力强等特点。试验结果表明：样机的揉搓分离机构能够使大麻鲜茎破裂，皮骨初步分离；梳理分离机构能将揉搓后粘连在韧皮表面的大部分麻骨去除，起到梳理鲜皮上屑骨的作用。样机的鲜茎出皮率为10.90%～21.36%，剥净率为61.50%～78.33%，生产率为108.67～174.22 kg/h，纤维强度为4.90～5.61 cN/dtex，可实现大麻鲜茎的皮骨分离。

Design and experiment on decorticator of hemp fresh stem

Abstract: The hemp is widely planted in China, which can be used for varieties of products including hemp cordage, durable clothing and nutritional products.. Because of hemp fiber excellent properties such as natural comfort and gas permeability, it is widely used in textile field. Hemp bast and bone are strong adhesive with the glue in fiber, so it is very difficult to peel off from hemp stem. In China, people usually peel off bast fiber by hand. There are a number of problems using manual peeling, such as low work efficiency, high labor intensity, and high cost. So, high efficiency stripping machine is necessary to designed for peeling off hemp bast in China.At present, there are two kinds of method to gain bast fiber from hemp stem. The fiber was separated from the retted stalk which has been immersed in water. Another way is to stripping the bast from the fresh stem first, then the dried bast is retted in pool in the factory. We can gain clean fiber in mass production by using the second method. According to the requirements, a new kind of stripper which used for separation hemp fresh stem was designed. But there are many branches at upper stem of hemp and the bast attached with hemp bone very firmly. In order to make the bast separated better from the stem, the rubbing-mechanism for stem and the combing-mechanism for bast were designed in this machine. The prototype is mainly consisted of rubbing-mechanism, combing-mechanism, the fiber collection device, transmission, frame, undercarriage and other components. This prototype has many characteristics such as compact structure, easy to move, strong separation ability, etc. The rubbing-mechanism is consisted of two pairs of straight-teeth pressure roller and two pairs of slanting-teeth pressure roller. When the machine works, the hemp fresh stem is broken first by the straight-teeth pressure roller of rubbing-mechanism. After that, the broken stem enters the pressure roller of slanting-teeth of rubbing-mechanism. In these pressure rollers, the straight teethes are arranged along both longitudinal and transverse axis of pressure rollers. So when broken stems enter the engagement area of a pair of pressure rollers, the broken stems are bent and extruded, and rubbed by the horizontal and vertical forces from slanting-teeth. The rubbing-forces make hemp stems better separated. Through the role of the rubbing-mechanism, the hemp bast is preliminary separated from stem. Another main device in the machine is the combing- mechanism which is consisted of a pair of drum barkers and a concave. When crushed hemp stems enter the combing-mechanism, the basts which adhere a lot of stick are clean out under the action of scraping and extrusion by the stripping drum and concave. The prototype performance test shows that rubbing-mechanism can make fresh stem separated preliminary, the combing-mechanism can remove most sticks which are adhesive with the bast. The quality of bast stripped by the machine is good and can meet the quality standards. Experiment results show that the rate of net bast to fresh stem is 10.90%-21.36%, the rate of net bast to total bast is 61.50%-78.33%, and the productivity is 108.67-174.22 kg/h. This stripper is easy to operate with good recurring, and hemp fresh-bast is effective separated.