Pawan Kumar Poonia ¹, Sadhna Tripathi ¹

Affiliations
1 Forest Products Division forest Research Institute, Dehradun, Uttarakhand, IN

Abstract

Low permeability of many wood species causes problems during timber drying as well as impregnating with preservatives and resins. Microwave (MW) technology provides solutions to many of these problems. Microwave (MW) treatment influence heartwood permeability and improves preservative distribution and uptake. The effects of microwave radiation time and initial wood moisture content (MC) on the permeability of Populus deltoides Bartr wood specimens after microwave treatment were studied. The experimental study of MW treatment at 2.45 GHz frequency, 64.4 Wcm^-2 intensity and dipping in preservative revealed a remarkable increase in wood permeability.

Keywords

Microwave, Treatability, Retention, Dipping.

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Pawan Kumar Poonia ¹, Lambam Anamika Devi ¹, Sadhna Tripathi ¹

Affiliations
1 Forest Products Division, Forest Research Institute, Dehradun, Uttarakhand, IN

Abstract

The present study was carried out to investigate the efficacy of Eucalyptus tereticornis leaves extract against wood decaying white rot (Trametes versicolor) and brown rot (Oligoporus placentus) fungi. Methanolic extract at 0.5, 1.0 and 1.5% concentration levels were tested against Trametes versicolor and Oligoporus placentus by potato dextrose agar bioassay. Results revealed that the methanolic extract of Eucalyptus tereticornis leaves at 1.5% concentration exhibited complete inhibition of Trametes versicolor. However, 17.21% growth of Oligoporus placentus was recorded in treated petri plates at 1.5% concentration of extract. Qualitative analysis of the methanolic extracts revealed presence of appreciable amount of terpenoids, phenols, flavonoids, alkaloids, carbohydrates and tannins.

Keywords

Eucalyptus tereticornis, Extract, Fungi, Methanol, Oligoporus placentas, Qualitative Analysis, Trametes Versicolor.

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Pawan Kumar Poonia ¹, Sadhna Tripathi ¹, Inderjeet Kaur ¹

Affiliations
1 Forest Products Division, Wood Preservation Discipline Forest Research Institute, Dehradun-248006, IN

Abstract

Wood is one of the most sustainable, aesthetically pleasing and environmentally benign materials. Dry wood materials are susceptible to fire hazards and results heavy losses of life and materials every year; hence protection against fire is necessary. The present study deals with the treatment of plywood with two different fire retardant cum preservative compositions by vacuum pressure method to offer protection against fire and bio-deterioration. The performance of treated plywood against fire is tested by flame penetration test, inflammability test and rate of burning test as per Indian Standards. The results showed that the mean time taken by control i.e. 17:24 and 19:44 minutes was significantly different (P < 0.05) from both compositions "A" (32:07 and 30:32 minutes) and "B" (42:03 and 33:53 minutes) in Flame penetration test and Inflammability test respectively whereas, in rate of burning test the time of weight loss from 30 to 70 percent were 1:44 minutes in control which was significantly lower than both the composition "A" (26:22 minutes) and "B" (27:58 minutes). Hence, it may be concluded that both the formulations performed as per standard and it can be recommended for application.

Keywords

Fire Retardant, Flame Penetration, Inflammability, Rate of Burning and Wood.

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Sanjeet Kumar Hom ¹, Pawan Kumar Poonia ¹, Ajmal Samani ¹, Sadhna Tripathi ¹

Affiliations
1 Wood Preservation Discipline, Forest Products Division Forest Research Institute, Dehradun, IN

Abstract

Wood is dimensionally unstable and hygroscopic in nature due to presence of large number of hydroxyl groups in the polymeric constituents. Chemical modification is one way of improving this property and acetylation provides dimensional stability to wood, due to cell wall bulking. In the present study Pinus radiata wood samples were modified with pyridine catalyzed acetic anhydride by combination of pressure and heat treatment for different time periods. Weight Percentage Gain, Volumetric Swelling Coefficient and Anti-Swelling Efficiency were determined. Samples were immersed in waterfora time period of 1hr to 120hrs to calculate Volumetric Swelling Coefficient and Anti-Swelling Efficiency for estimating dimensional stability. Schedule of applying pressure of 20lbs per inch² at 120 °C for 1hr showed maximum dimensional stability.

Keywords

Chemical Modification, Acetic Anhydride, Pressure Treatment, Weight per Cent Gain, Volumetric Swelling Coeffident, Anti-Swelling Effidency.

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