The Process Of Using Three Kinds Of Non-wood Material Produding Self-bongding Particle Board

People are increasingly anxious about the harm of free formaldehyde releasing from wood-based panel to their healthy and the environment. Therefore, it has become an important research topic that non-wood resources replace wood resources and adhesives are substituted by self-bonding raw-straw material or adding other materials. This thesis explored the non-gel particle board processing technology in which straw, wheat-straw and other non-wood resources were used as raw-straw materials and lignin was activator. The problems which are addressed in this thesis and corresponding conclusions are as follows:(1) Pre-experiments showed that lignin can be utilized as an activator in the production of non-glue wood based panel. After applying lignin as activator, the performance of non-glue straw particle board and straw-wheat straw particle board is improved significantly.(2) An orthogonal test was enforced in non-glue straw particle board experiment to obtain key parameters such as hot pressing temperature and time, the moisture content of billet, straw ratio etc. The optimum process parameters are 150℃, 6 min , 18% and 80% respectively.(3) An orthogonal test was employed in non-glue straw particle board experiment to obtain key parameters such as hot pressing temperature, lignin content, the moisture content of billet, straw - straw ratio etc. Then the optimum level of each factor was revealed by a comprehensive evaluation of the mechanical index. The results are pressing temperature 140℃, lignin content of 60g, billet water content 18%, straw-wheat straw ratio of 7:3, pressure 4MPa.(4) As the denseness of molecular structure of lignin is similar to that of glue, lignin plays an important role in non-glue bonding. Lignin becomes an activator when it mix with straw and wheat straw because there is a number of phenol structure units in lignin which activate the structure unit in straw and wheat straw. In the hot pressing process, pyrolysis of lignin in straw and wheat straw, coupled with the demethylation of lignin resulted from the reaction of catechol in lignin, improved uniformity of particle molecular and contributed to stronger integration of the scrap fibers to a certain extent.(5) An orthogonal test was enforced in non-glue cork particle board experiment to obtain key parameters such as hot pressing temperature and time, the moisture content of billet, the density of raw materials etc. The optimum level of each parameter was uncovered by a comprehensive evaluation of the mechanical index. The results are pressing temperature 130℃, 10% moisture content, pressing time 6min, density 0.8g/cm3, hot pressing pressure 2MPa.