بررسي اثر زمان پرس و مقدار رزين بر ويژگي هاي تخته فيبر نيمه سنگين )MDF( ساخته شده از كلش برنج

The effect of press time and resin content on properties of MDF produced from Rice straw.

In this study, MDF was produced from Rice straw. Variables for Medium Density fiberboard making were as following: - Resin content 8, 9.5, 11 (percent baced on oven dry weight of fiber) - Press time (4, 5, 6 minutes). There were 9 treatment conditions by combinations of the above factors and three replications for each combinations which resulted in producing 27 oards.The other production variables were constant. The anatomical properties of Rice straw such as fiber length, fiber diameter were measured respectively 810, 10.1 micron. L/D ratio of Rice straw fiber was measured 80.2. The physical and mechanical properties of MDF were determined according to DIN standard. The measurements of bending properties and IB of MDF revealed that the highest MOR, MOE, IB were obtained in variables combination of 11% resin content and press time of 6 minute and at this conditions thickness swelling of boards were the lowest. According to Duncans, test method the effects of press times (4 & 5 minutes) and resin content (8% & 9.5%) on bending properties were not significant statistically.