Dissertation > Excellent graduate degree dissertation topics show

The Relation of the Temperature of the Center Layer of Mat in the Hot-pressing Process to Mechanical Performance of MDF

Author: LiCuiCui
Tutor: XieLiSheng
School: Central South University of Forestry Science and Technology
Course: Wood Science and Technology
Keywords: MDF Central layer’s temperature Hot-pressing Mechanical performance
CLC: TS653.6
Type: Master's thesis
Year: 2008
Downloads: 27
Quote: 0
Read: Download Dissertation

Abstract


The heat-conduction of MDF in the hot-pressing is affected by a large number of factors, such as the hot-pressing temperature, moisture content of mat, density of panel, thickness of panel, and so on. Confirming hot-pressing technic mainly fixs the hot-pressing time under different hot-pressing condition. And the time of resin solidifying in the mat is the hot-pressing time in principle.Hot-pressing method was adopted to make dry-process fiberboard, and the temperature of the center layer of mat was measured continuously and automatically by advanced instrument in the hot-pressing process, and the mechanical performance of boards were measured by mechanical tester. Based on the analysis of the curves of temperature changing and the mechanics of MDF, some basic relations as follows of the central temperature of dry-process fiberboard to the mechanical performance was summarized:(1)When the orthogonal experimentation was adopted, the relations of the central temperature to mechanical performance is:①When maximum temperature of core is under 117℃and the hot-pressing time of central temperature after 105℃is less than 24s under different hot-pressing time, modulus of rupture (MOR)and modulus of elasticity(MOE)were strengthened obviously with the increasing of maximum temperature of core and the hot-pressing time of central temperature after105℃; When maximum temperature of core is over 117℃and the hot-pressing time of central temperature after 105℃is more than 24s under different hot-pressing time, modulus of rupture (MOR)and modulus of elasticity(MOE)were strengthened tardily with the increasing of maximum temperature of core and the hot-pressing time of central temperature after105℃.the results under different hot-pressing time is the same with the results under different hot-pressing temperature.②Effect of central temperature on MOE and MOR is very little under different moisture content and resin content; MOE and MOR are mainly affected by moisture and resin content.③When maximum temperature of core is under 118℃and the hot-pressing time of central temperature after 105℃is less than 24s under different hot-pressing time, internal bond strength is improved obviously with the increasing of maximum temperature of core and the hot-pressing time of central temperature after 105℃; When maximum temperature of core is over 118℃and the hot-pressing time of central temperature after 105℃is more than 24s under different hot-pressing time, internal bond strength is enhanced tardily with the increasing of maximum temperature of core and the hot-pressing time of central temperature afterl05℃.(2)when antitheses of single gene were adopted, the relations of the central temperature to mechanical performance is:①Mechanical performance improved obviously with the increasing of aimed temperature, and then leveled off. When the central temperature was 115℃, mechanical performance had been up to the standard, but strength had not been very high. When the central temperature was 120℃, mechanical performance had been very high, and leveled off.②when the central temperature was same, mechanical performance improved with the increasing of hot-pressing, moisture content and targeted thickness. When the thickness is thin, hot-pressing time can be prolonged properly.

Related Dissertations

  1. Preparation and Tribological Properties of TZ3Y20A-SrSO4 Ceramic Matrix Composites,TB332
  2. Reactive Hot-Pressing and Mechanical Properties of （ZrB2-ZrO2）/BN Composites,TB332
  3. Design and Implementation of Hot-pressing Module for RFID Tag-package Equipment,TP391.44
  4. Effect of Rigid Stretch during Stabilization of Polyacrylonitrile Fiber,TQ340.1
  5. Research on Microstructure and Evolution of TiB2-Al2O3 Composite Ceramics Synthesyzed by SHS,TQ174.1
  6. Preparation and Properties of Layered Ceramic Ti3AlC2,TQ174.75
  7. Preparation of Zirconia-based Dental Bioceramics and Measurement of Its Mechanical Performance,TQ174.75
  8. Experiment Study and Theoretical Analysis of SRC Columns under Fire Including Whole Process of Heating and Cooling,TU398.9
  9. Study on prformance of Ice-coating OPGW,TN818
  10. The Test Research on Durability of MDF Used in Furniture,TS653
  11. The Life Cycle Assessment of the Products of Panel Furniture,TS664
  12. Study on PDF Control Based on 2DF in Electro-hydraulic Servo System for Hot-Pressing of Wood-Based Panel,TS653
  13. Preparation of AlON Power and Hot-pressed Sintering Behavior of AlON Ceramic Material,TF124.5
  14. The Research of Fabrication and Performance In-situ MgO Reinforced Magneisum Matrix Composites,TB331
  15. Experimental Study of Chimney Effect as a Method of Architecture Natural Ventilation,TU834.1
  16. Study on Sintering Process of Sialon-based Refractories by Carbothermal Reduction and Nitridation of Microcrystalline Muscovite,TQ175.1
  17. Research on Composition and Emission Characteristics of VOCs Medium Density Fiberboard During Hot-pressing Section,X51
  18. Heat and Mass Transfer Hot-pressing Model of Medium Density Fiberboard,TS653.6
  19. Research on Formaldehyde Emission During Hot-pressing of Particleboard,TS653.5
  20. Grading milling and vacuum hot pressing sintering high Nb TiAl Alloys,TF124.5

CLC: > Industrial Technology > Light industry,handicrafts > Wood processing industry,furniture manufacturing industry > Processing > Wood-based panel production > Fiberboard
© 2012 www.DissertationTopic.Net  Mobile