Treesearch

Native-state organization and distribution of cell-wall components in the secondary wall of woody tissue from P. mariana (Black Spruce) have been investigated using polarized Raman microspectroscopy. Evidence for orientation is detected through Raman intensity variations resulting from rotations of the exciting electric vector with respect to cell-wall geometry. Spectral features associated with cellulose and lignin were studied. The changes in cellulose hands indicate that the pyranose rings of the anhydroglucose repeat units are in planes perpendicular to the cross section, while methine...

Packaging, handling, and shipping methods and facilities have changed drastically since World War II. Today, most products are individually packaged and then combined into unitized loads for more efficient handling, storage, and shipping. The purpose of this manual is to promote the most effective use of wood and wood fiber in current packaging and shipping practices by providing a basic understanding of the many factors involved in selecting an optimal method of unitizing goods on pallets and slipsheets. The manual also provides a valuable place of reference for the numerous standards and...

For adhesive self-sufficiency, the wood industry needs new adhesive systems in which all or part of the petroleum-derived phenolic component is replaced by a renewable material without sacrificing high durability or ease of bonding. We tested the bonding of wood veneers, using phenolic resins in which part of the phenol-formaldehyde was replaced with carbohydrates. Our experiments show that the addition of non-reducing carbohydrates and various polyols to phenol-formaldehyde resol-resins does not adversely affect the dry- or wet-shear strength of 2-ply Douglas fir panels bonded with the...

Large 4 by 8 ft (1.22 by 2.44 m) panels were made using a steam injection method of pressing. Homogenously constructed flakeboards were fabricated from southern red oak, sweet gum, and a mixture of the two species using both isocyanate and phenolic resins. Isocyanate was especially suited to the process and 1-1/2 in. (38 mm) thick panels were pressed in less than 150 seconds. Phenolics on the other hand were susceptible to dilutions by steaming and required higher temperature to cure.

This report is for those who use or may want to use wood particleboard. The term bparticleboardc is used as defined in the American Society for Testing and Materials (ASTM) Standard D 1554, which includes flakeboards as a subclass of particleboards, and not as used in the lumber trade where the term is usually reserved for panels made of fine wood particles such as sawdust and planer shavings. Types and grades of particleboard are described and discussed in relation to end uses as nonstructural underlayment, stair tread, shelving, furniture, core material, cabinetry, structural sheathing,...

The objective of this study was to determine if corrugated fiberboard specimens that had been necked down with a common router would yield acceptable edgewise compressive strength values. Tests were conducted on specimens prepared using a circular saw and router, and the results were compared with those obtained on specimens prepared according to TAPPI Test Method T 811. The materials used in the tests included single-wall constructions of A, B, anbd c flutes and samples of double-wall and triple-wall corrugated fiberboard. The results indicated that there was no practical significant...

Paperboard components (linerboard adn corrugating medium) fail in edgewise compression because of failure of single fibers, as well as fiber-to-fiber bonds. While fiber-to-fiber-bond failure has been studied extensively, little is known about the longitudinal compression failure of a single fiber. In this study, surface alterations on single loblolly pine kraft pulp fibers were observed during compression in a devise built for use in the scanning electron microscope. Distinct changes were observed in the fibers subjected to compression loading, including dislocations (slip planes),...

“Both the strength and stability of compressively loaded paperboard are known to be adversely affected by cyclic changes in relative humidity. Current research at the Forest Products Laboratory (FPL) seeks to observe and explain this phenomenon and to develop a simple, practical test to determine allowable "working loads" in cyclicmoisture environments. A new research apparatus has been developed to measure creep strain, stiffness, and strength in constant and changing humidity environments. Early results link cyclic change in relative humidity with significant loss in compressive strength...

An American wood. Description of the distribution, growth, habit, wood, and wood properties of the species. Includes bibliographical references.

An American wood. Description of the distribution, growth, habit, wood, and wood properties of the species. Includes bibliographical references.