The Effect of Hydrostatic Pressure on Physical Properties and Microstructure of Spruce and Cherry
-
Voichita Bucur
Summary
The effect of hydrostatic pressure on the density, the ultrasonic velocities and the microstructure of spruce and cherry wood has been studied. Generally speaking, under hydrostatic pressure wood becomes less heterogeneous and less anisotropic than natural wood. In spruce, crushing and buckling of the thin-walled cells in the earlywood takes place. This also has the effect of disrupting the medullary rays, which assume a zig-zag path through the structure. Cherry has a much more homogeneous structure, and the main effect of the hydrostatic pressure is compaction of the vessels by buckling of the walls. The fibres are scarcely affected by the treatment. The width of the earlywood zone decreased after the application of pressure by 26% in spruce, and by 11% in cherry. The average density was increased by the hydrostatic pressure by 26% for spruce and by 46% for cherry. The densitometric profile of spruce demonstrates significant changes following the pressure treatment, with the minimum density DMin increasing and the maximum density DMax decreasing. For cherry, the densitometric profile is shifted rather uniformly towards higher densities, and the annual ring profile is spatially slightly compacted but otherwise similar to that of untreated wood. The anisotropy of wood (expressed by the ratio of acoustic invariants) decreased by 56% for spruce and by 33% for cherry. The structural damage in spruce is predominantly found in the radial (R) direction, and this corresponds to a reduction of 73% in the velocity of the longitudinal ultrasonic waves in the radial direction, VRR. In cherry, the structural damage is mainly in the transverse, T direction. The velocity of the longitudinal ultrasonic waves in the transverse direction, VTT is reduced by 44%. The medullary rays in cherry seem to be the most important anatomical feature influencing the propagation of ultrasonic waves.
Copyright © 2000 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- Identification of Indoor Rot Fungi by Taxon-Specific Priming Polymerase Chain Reaction
- Characteristics of Spruce [Picea abies (L.) Karst] Latewood Formed under Abnormally Low Temperatures
- The Chemical Nature of Kiln Brown Stain in Radiata Pine
- Microdistribution of Some Copper and Zinc Containing Waterborne and Organic Solvent Wood Preservatives in Spruce Wood Cell Walls
- X-Ray Diffraction as an Analytical Method in Wood Preservatives
- Modifications of Hybrid Walnut (Juglans nigra 23 x Juglans regia) Wood Colour and Phenolic Composition Under Various Steaming Conditions
- Incorporation of 13C-Labeled Coniferyl Alcohol into Developing Ginkgo biloba L. Lignin Revealed by Analytical Pyrolysis and CuO Oxidation in Combination with Isotope Ratio Monitoring-Gas Chromatography-Mass Spectrometry
- Atomic Force Microscopy (AFM) Investigation of Langmuir-Blodgett (LB) Films of Sugar Cane Bagasse Lignin
- Comparison of Acetic Acid Lignin with Milled Wood and Alkaline Lignins from Wheat Straw
- Monitoring of Lignin and Hemicelluloses in Spent Cooking Liquor during Kraft Delignification
- Preparation of Wood with Thermoplastic Properties, Part 1. Classical Synthesis
- Preparation of Wood with Thermoplastic Properties, Part 2. Simplified Technologies
- The Effect of Hydrostatic Pressure on Physical Properties and Microstructure of Spruce and Cherry
- Application of Liquefied Wood to a New Resin System—Synthesis and Properties of Liquefied Wood/Epoxy Resins
- Lab-Scale Synthesis of Isotopically Labeled Formaldehyde for the Production of Formaldehyde-Based Wood Adhesives
- Confirmation of the Presence of Formaldehyde and N-(Methylene)morpholinium Cations as Reactive Species in the Cellulose/NMMO/Water System by Trapping Reactions
- Compressive Creep of Wood under High Temperature Steam
- Literature Reports
Articles in the same Issue
- Identification of Indoor Rot Fungi by Taxon-Specific Priming Polymerase Chain Reaction
- Characteristics of Spruce [Picea abies (L.) Karst] Latewood Formed under Abnormally Low Temperatures
- The Chemical Nature of Kiln Brown Stain in Radiata Pine
- Microdistribution of Some Copper and Zinc Containing Waterborne and Organic Solvent Wood Preservatives in Spruce Wood Cell Walls
- X-Ray Diffraction as an Analytical Method in Wood Preservatives
- Modifications of Hybrid Walnut (Juglans nigra 23 x Juglans regia) Wood Colour and Phenolic Composition Under Various Steaming Conditions
- Incorporation of 13C-Labeled Coniferyl Alcohol into Developing Ginkgo biloba L. Lignin Revealed by Analytical Pyrolysis and CuO Oxidation in Combination with Isotope Ratio Monitoring-Gas Chromatography-Mass Spectrometry
- Atomic Force Microscopy (AFM) Investigation of Langmuir-Blodgett (LB) Films of Sugar Cane Bagasse Lignin
- Comparison of Acetic Acid Lignin with Milled Wood and Alkaline Lignins from Wheat Straw
- Monitoring of Lignin and Hemicelluloses in Spent Cooking Liquor during Kraft Delignification
- Preparation of Wood with Thermoplastic Properties, Part 1. Classical Synthesis
- Preparation of Wood with Thermoplastic Properties, Part 2. Simplified Technologies
- The Effect of Hydrostatic Pressure on Physical Properties and Microstructure of Spruce and Cherry
- Application of Liquefied Wood to a New Resin System—Synthesis and Properties of Liquefied Wood/Epoxy Resins
- Lab-Scale Synthesis of Isotopically Labeled Formaldehyde for the Production of Formaldehyde-Based Wood Adhesives
- Confirmation of the Presence of Formaldehyde and N-(Methylene)morpholinium Cations as Reactive Species in the Cellulose/NMMO/Water System by Trapping Reactions
- Compressive Creep of Wood under High Temperature Steam
- Literature Reports
