Of Western hemlock

The chemical reaction of western hemlock bark extract with... 

None of the residues produced a hardboard that was acceptable, with the exception of western hemlock slabwood. 

Soteland N (1971) Some attempts to characterize the oxidized lignin after ozone treatment of western hemlock groundwood Part II Nor Skogmd 25(5) 135-139... 

Tables 8.2.2 and 8.2.3 give typical results for two series of polydisperse lignin fractions obtained from acidic organosolv delignification of black cottonwood (Pla et al. 1986) and from alkaline delignification of western hemlock (Dolk et al. 1986). In both cases, LALLS allows accurate determination of low molecular weight values. The nearly identical dn/dc values for a given series of lignin fractions indicate the good reproducibility and accuracy of the technique. However, the second virtal coefficients, A2, vary considerably depending upon the fraction measured.

Comparison of the oxidatively-heating property of the soot which arises from the incineration of the sawdust of Western hemlock and accumniates in the soot collector set up at the top of the incinerator, with, the oxidatively-heating property of the sawdust of Western hemlock... 

It is shown in Fig. 101 that the calorific value of the soot is far larger than that of the sawdust of Western hemlock. 

It is shown in Fig. 102 that the soot heats oxidatively about 4.4 times as fast as the sawdust of Western hemlock. That is, it has been proved that the soot is very inflammable. It thus follows that sufficient care should be taken to handle every soot. 

Figure 102. Comparison of Ihe oxidatively-heating curve, of the soot, which arises from the incineration of the sawdust of Western hemlock and accumulates in the soot collector set up at the top of the incinerator and is charged in the draft cell, into which air is supplied, and is subjected to the adiabatic oxidatively-heating test started from a near 150 C, recorded in temperature increments of 3 K from the corresponding standard temperature, with, the oxidatively-heating curve of the sawdust of Western hemlock placed under the same conditions as the former.

Figure 21. Softwood bordered-pit membranes of western hemlock. (Reproduced from Ref 39. Copyright 1982, American Chemical Society.) (A) SEM of unaspirated pit in earlywood. Note porous periphery of the membrane. Rodlike bacteria are also present here, apparently filtered out onto the membrane during sample preparation split wood radial surface. (B) Light micrograph of aspirated pits (AP) in latewood cross section. (C) Light micrograph y aspirated pit and unaspirated pit (UP) in earlywood cross section. (D) Fully aspirated pit in earlywood. Note the reduction in porosity upon aspiration. (Compare to A above.)...

M DoUc, JF Yan, JL McCarthy. Lignin 25 Kinetics of Delignification of Western Hemlock in Flow-through Reactors under Alkaline Conditions. Holrforschung 43 91-98, 1989. 

Rhatigan, R.G. Milota, M R. Morrell, J.J. Lavery, M.R., Effect of High Temperature Drying on Permeability and Treatment of Western Hemlock Lumber, Forest Products Journal, 2003, Vol. 53, No. 9, pages 55-58. 

Herrick, F.H. Chemistry and Utilization of Western Hemlock Bark Extractives. J. Agric. Food Chem. 28, 228 (1980). 

Goldschmid, O., and H. L. Hergert Examination of western hemlock for lignin precursors. Techn. Assoc. Pulp Paper Ind. 44, 858—870 (1961). 

Herrick F W 1980 Chemistry and utilization of western hemlock bark extractives. J Agric Food Chem 28 228-237... 

Meyer R W, Kellogg R M, Warren W G 1981 Relative density, equilibrium moisture content and dimensional stability of western hemlock bark. Wood Fiber 13 86-96... 

Propiovanillone has been identified in Quercus rubra wood (152) and some phenylglycerol compounds are also found in various woody species. Thus, guaiacylglycerol (33) has been found in the sapwood of western hemlock (11) and the heartwood of Pinus resinosa (142). Further, the 1-O-glucoside and the 1-0-and 3-O-glucosides of p-hydroxyphenylglycerol have been reported from the inner bark of Larix leptolepis (105) and Picea glehnii (145), respectively, and an iso-prene derivative of the 3-(4-hydroxyphenyl)-propan-l-ol has been isolated from wood and bark of Zanthoxylum cuspidatum (86). 

Barton G M 1968 Significance of Western hemlock phenolic extractives in pulping and lumber. Forest Prod J 18(5) 76-80... 

Goldschmid O, Hergert H L 1961 Examination of Western hemlock for lignin precursors. Tappi 44 858-870... 

Barton G M 1973 The significance of western hemlock phenolic extractives in groundwood pulping. Tappi 56(5) 115-118... 

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