تحقیقات علوم چوب و کاغذ ایران (Mar 2008)
The effects of Poplar clones age variations and production conditions on medium density fiberboard (MDF) properties
Abstract
In this study , MDF was produced from three clones of poplar (P.e. vernirubensis, P.e. costanzo, P.e.561.41). Age clones of poplar were 4 and 12 years. In addition to age variation , the influence of three production variables (steaming time , press time and resin content on MDF properties were investigated. Variations of each variable were as follow: - Steaming time (5, 10, 15 minutes) - Press time (3, 4, 5 minutes) - Resin content (9%, 11%) Fiber length and fiber diameter of 4 and 12 years old poplar clones (P.e. vernirubensis, P.e. costanzo, P.e.564.41) were measured 746, 25.23, 805, 25.76,751, 25.44 and 902, 31.62, 995, 29.23, 899, 26.83 micron respectively. MOR, MOE, IB, TS2, TS24 were determined according to DIN standard. Increasing steaming time decreased board's internal bond and bending properties. As expected, boards demonstrated better properties at higher resin consumption. Minimum of boards thickness swelling were obtained at 15 minutes steaming time because of fiber hydrophilic properties were decreased. There are no significant differences between 4 and 12 years old of clones for bending properties and IB of boards. The effect of age variation is only significant difference on thickness swelling of boards which it is lower for 4 years old clones.
Keywords