Research And Development Of Continuous Press Producting Reconstituted Square Lumber

Timber resources are scarce in China, but China is a large agricultural country, therefore crop straw resources is rich. In recent years, using crop straw instead of the wood to produce the wood-based panel has become one of the hot research topics in domestic and international wood industry. The research shows that the physical and mechanical properties of wood-based panel recombination produced by straw biomass resources are the closest to solid wood. The hot pressing process is particularly important in the process of producing the reconstituted square lumber. At present, the existing continuous press was remoulded by the former QD-100-type hot press. The process conditions of producing reconstituted square lumber is not easy to control, and the operation is complicated. What is more, it can only produce a 400 mm length square lumber one time, the production efficiency is low.For these many reasons, we decide to design the continuous hot press which produced the reconstituted square lumber on the basis of the research of the existing continuous flat press. The main content of this study is to design a continuous hot press which can produce the reconstituted square lumber continuously and have high efficiency. The main work and conclusions of this dissertation are as follows.(1) The complete scheme design of the continuous hot press machine producing reconstituted square lumber was proposed. The flat type used the type of traditional continuous flat hot press. The broadside pressure device was added on the basis of flat hot press. Two kinds of scheme were selected and designed. After comparing the advantages and disadvantages of the two schemes, the second scheme was identified for the final compression scheme.(2) Based on the continuous flat press hot pressing plate size, pressure distribution and reconstituted square lumber size requirements, the continuous hot press length was determined to be 8000 mm,the width was determined to be 300 mm and the thickness was determined to be 80mm/50 mm. The hot pressing plate length range was equipped with 3 pressure section, and the high pressure was 5.5MPa, the middle pressure was 4MPa and the low pressure was 2MPa. Heating channel was reserved in the width direction of the hot pressing board, and electric heating was used.(3) Starting with three aspects which were the slab, slab heating and pressurizing feed part and holding length part, the finished plate board part and a transportation transmission part, we designed and calculated the hot press the key mechanism of the continuous hot press. Drawing the following conclusions: according to the surface pressure and the frame spacing, we selected the oil cylinder 2 pieces of Φ200/Φ160, 6 pieces of Φ180/Φ160 for the hot press; drive roller and the driven roller diameter were intended to be 810mm; roller chain specification was determined as follows: Ф17.5 × 380 mm chain roller diameter specification, spacing 19.05 mm, hardness 50 HRC.(4) The steel belt transmission system was designed, and the stress analysis has been carried on. Draw the following conclusions: when the strip thickness is 1.5mm, its stiffness satisfies the design requirements.(5) According to production requirements and press parts parameters, calculating the press motor power to take power for the entire final element by 1.5KW.(6) An ANSYS finite element analysis software was used to make static analysis of the frame plate. When the frame plate thickness was 40 mm, the maximum stress of the frame plate was 61.6MPa. When the frame plate thickness was 30 mm, the maximum stress of the frame plate was 59.7MPa, but frame plate material was 16 Mn steel, the yield limit strength was 345 MPa which was larger than the maximum stress of the frame plate. The stress satisfied the design requirements. The total maximum displacement of the frame plate was 0.059054 mm, when the frame plate thickness was 30 mm, the maximum displacement of the frame plate was 0.056072 mm. Because of the low level technical requirements of the hot pressing plate deflection, the frame plate deformation did not affect the restructuring of wood thickness. The overall design of the frame plate satisfied the requirements.