The Test Research Of Bubbled-root Irrigation Material Formula And The Evaporation Loss

Based on bubbled-root irrigation concept, on the one hand, through the experimentalmaterial, under the condition of different temperatures, low density polyethylene (LDPE) withdifferent content of ethylene/vinyl acetate copolymer（EVA）was studied after the yield stressof composite material, the fracture stress and elongation at break of the features, put forwardto the best material matching which could satisfy used, and studied the aging properties ofdisposable drip tapes after used in the field; On the other hand, in practice, the experimentswere conducted for the hydraulic performance of the irrigation, the comparative study theevaporation loss of different depth of bubbled-root irrigation, drip irrigation, flood irrigationin three different irrigation methods, the pressure flow characteristics bubbled-root irrigationof surface and underground. The main conclusions are as follows:(1) Bubbled-root irrigation device used a modular structure, so as to determine therequired material properties by the various components of production, the present stage ofbubbled-root irrigation materials are high density polyethylene, for the filling and the cover ofwater, in order to reduce water production deviation and main requirements material hassmaller molding shrinkage rate, high density polyethylene can meet the requirements, andshell requirements of bubbled-root irrigation must has high flexibility and strength, make itclosed port and is not easy to crack, through the promotion of bubbled-root irrigationtechnology in recent years, we have found that the shell material needs to be improved.(2) The yield stress are sample decreases with the increase of LDPE EVA content atroom temperature, low temperature environment and the high temperature environment, butthe elongation at break are increased with the increase of EVA content increases, the fracturestress of specimen at room temperature and low temperature environment are increased withthe increase of EVA content, under the environment of high temperature fracture stress afterthe first increases with the increase of EVA content and than decreases, reached the maximumat10%.And when EVA content is20%, the yield stress, fracture stress and elongation at breakof specimen are most closed under different temperature conditions.(3) Further analysis by using SPSS software for the test results to bubbled-root shellsample under different processing mechanics performance, temperature variation of the yieldstress, fracture stress and elongation at break were not significant, the influence of EVA content on the yield stress and elongation at break sample shows significant level, and theinfluence of the sample fracture stress impact was not significant. It is recommendconsideration of LDPE EVA content is20%in the production process of bubbled-rootirrigation.(4)According to contrast of two materials aging properties about bubbled-root irrigationand drip irrigation, the plastic made of polyethylene as the main raw material, the maindefects is the elongation at break decreased after affected by the temperature, EVA as amodifier can improve the toughness of the modified plastics under the appropriate content,and increasing the breaking elongation value. so it can be as bubbled-root irrigation deviceshell material that adding EVA to LDPE.(5) Under different irrigation methods about the bubbled-root irrigation (20cm depth),drip irrigation, flood irrigation, bubbled-root irrigation evaporation loss is minimum, dripirrigation and flood irrigation evaporation loss is relatively close, only about4%.Underdifferent depths, bubbled-root irrigation methods, according to the depth of the roots of thetree, the general promotion of20cm depth is common sense, it can be better than dripirrigation to reduce evaporation loss about15%.