Study on structure of needle head and seal mechanism of tree trunk injection

Structure of needle head and seal mechanism are key problems of tree trunk injection. It analyzed the current structure of needle head and seal mechanism, demonstrated the shortages for its sealing principle in this paper. A ring-shaped drill of tree trunk injector was successfully developed. The push in force of needle head is measured by CMT5105. Because the special form of the needles, the needle has good performance of sealing located in cambium and can expand its diameter as it goes into the tree trunk but not crack. In tree trunk injection tests, the needle can inject large volume of nutrition solutions and achieved remarkable economic results.