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.
Properties of medium density fiberboards made from renewable biomass.
The goal of this study was to determine the comparative properties of dry-formed medium density fiberboards (MDF) made from renewable biomass (wheat and soybean straw) and those from conventional soft wood fiber. The MDF properties evaluated were modulus of elasticity, modulus of rupture, internal bond strength, thickness swell, and screw holding capacity. The results show that MDF made from wheat straw fiber and soy straw fiber have weaker mechanical and water resistance properties than those made from softwood fiber. Soybean straw is comparable to wheat straw in terms of both mechanical and water resistance properties to make MDF. Water resistance of MDF decreased drastically with increasing straw fiber composition. Wheat straw fiber and soybean straw fiber should be physically or chemically treated to increase their water resistance property for MDF production.