Study on Paper-Based Fiberboard and Vacuum Treatment
According to the required fiber quality and the technical conditions of manufacturing fiberboard, the technology on paper-based fiberboard manufacturing and vacuum treatment was studied. After thorough investigation, the optimum technical conditions have been gained as follows: hot pressing temperature 160¿, hot pressing time 6 min, forming pressure 11MPa and the quantity of adhesive 10 percent. After vacuum treatment by the steam jet system in conditions as chamber below 700 Pascal, temperature in chamber 80¿, treatment time two hours, the contained proportion and emission quantity of the urea formaldehyde resin meet the requirements of GBT11718-1999. In addition to this, the mechanical properties of the paper-based fiberboard are greatly improved at the same time.
Canola straw as a bio-waste resource for medium density fiberboard (MDF) manufacture.
Canola straw as an agricultural residue has been investigated for MDF production. The variables were steaming time (2, 5 and 8 min), the resin content (9% and 11%), and press time (4 and 6 min). Common physical and mechanical properties of experimental boards including modulus of rupture (MOR), modulus of elasticity (MOE), internal bond strength (IB) and thickness swelling (TS) were measured. Fiber properties of canola straw including length, diameter and cell wall thickness were determined. The results showed that all the tested mechanical properties improved with the increase of steaming time level. The results were close to the minimum requirements of MDF specified in the ANSI A208.2 standard. Dimensional stability of the MDFs improved as adhesive content increased. The IB values are positively affected by the increase of press time. MDF properties made from canola straw possess acceptable qualities as compared to those made from other non-wood plants. Furthermore, the fiber dimensions of canola straw were also in the range of reported values in hardwoods.
Effect of steam pressure refining and resin levels on the properties of UF-bonded red maple MDF
A study was undertaken to determine the influence of steam-pressure-refining levels on red maple (Acer rubrum L.) wood chips fabricated into medium density fiberboard (MDF) test boards using four urea-formaldehyde resin levels. Red maple chips were fiberized using a pressurized, double-disk refiner operating at six refining pressures (50, 60, 70, 80, 90, and 100 psi). MDF test boards were produced using the six groups of refined fibers at four urea-formaldehyde resin contents. Static bending (MOE and MOR), internal bond (IB), water absorption, and thickness swell properties were measured. An increase in refining pressure did not significantly affect MDF strength or dimensional stability properties (...)