Treesearch

Neutron imaging is a nondestructive evaluation technique with enhanced hydrogen sensitivity that allows researchers to monitor water content and transport in materials. In lignocellulosic research, this technique has typically been used to measure changes in moisture content, water transport and even local changes in the density of wood. Yet, studies looking into the combined effects of moisture-uptake, chemical modifications and thermal degradation are still lacking. This is perhaps due to the inherent limited availability of these instruments and their lesser spatial resolution compared...

Undervalued Hardwoods for Engineered Materials and Components was prepared to serve as a primary reference for the use of hardwood timber. It has been widely used and was recently updated and published by the Forest Products Laboratory (FPL–GTR–276). The use of hardwoods for particle composite materials and products was not included in the recent edition. A subsequent review of the literature revealed that several seminal research studies were completed on the use of hardwoods in engineered particle composite materials. This report, which serves as an addendum to Undervalued Hardwoods for...

Cellulose nanomaterials (CNs) are an emerging class of materials with numerous potential applications, including as additives or reinforcements for thermoplastics. Unfortunately, the preparation of CNs typically results in dilute, aqueous suspensions, and the lack of effcient water removal methods has hindered commercialization. However, water may also present opportunities for improving overall effciencies if its potential is better understood and if it is better managed through the various stages of CN and composite production. Wet compounding represents one such possible opportunity by...

Lignin, a renewable biopolymer recovered from the chemical processing of woody biomass, has potential to enhance the mechanical properties of epoxy resins with the added benefit of reduced contents of non-renewable petroleum-based polymers. Lignin-based epoxy resins were prepared by employing a carboxylated lignin as a cohardener using a “one-pot” method. The effect of lignin content and preparation method on mechanical properties, apparent morphology, and thermodynamic properties of the resulting epoxy resins were then studied. The results showed that elongation at break increased from...

Wood finishes (paint, varnish, and stain, for example) give a desired appearance, protect wood surfaces, and provide a cleanable surface. Many people consider appearance most important when choosing finishes for wood products. However, from a technical aspect, protection—from water, sunlight, and weathering—is most important for wood used outdoors. For wood indoors, appearance and a cleanable surface are generally most important. When selecting a finish, one should consider appearance, protection, cleanability, how properties of wood affect finish application, and how long it will likely...

In North America, most housing and commercial structures built prior to the 20th century used wood as the major structural material. The abundant wood resource formed the basic structure for most houses, commercial buildings, bridges, and utility poles. Today, houses and many light commercial and industrial buildings are made using modern wood structural materials. Recently, there has been increased interest in using wood for various types of transportation structures, including highway bridges. In this chapter, the features of various types of building systems are described. Emphasis is...

Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements and related fire performance data are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Because basic data on fire behavior of wood products are used to evaluate fire safety for wood construction, the second major section of this chapter provides additional information on fire behavior and fire performance characteristics of wood...

Many specialty treatments can be applied to wood to improve its performance. Treatments addressed in this chapter are those that make permanent changes in the shape of a wood product or improve properties, such as hardness, toughness, moisture resistance, dimensional stability, decay resistance, and mechanical or machining properties, through combinations with nonwood resources such as resins, polyethylene glycol (PEG), and acrylates.

Insects and other pests can travel between countries in pallets and other wood packaging materials through international trade. Because these pests can cause significant ecological damage, their invasion into non-native countries is undesirable. Heat sterilization is currently the most practical and environmentally friendly treatment to kill pests in solid wood materials and prevent their transfer between continents and regions. Consequently, regulations requiring heat sterilization are becoming more common. Two important questions should be considered in heat sterilizing solid wood...

Under proper conditions, wood will give centuries of service. However, when wood is exposed to conditions that allow the growth of wood-degrading organisms, protection must be provided during processing, merchandising, and use. The organisms that can degrade wood are principally fungi, insects, bacteria, and marine borers. Molds, most sapwood stains, and decay are caused by fungi, which are microscopic, thread-like microorganisms that must have organic material to live. For some of them, wood offers the required food supply. The growth of fungi depends on suitably mild temperatures,...