High density fiberboard

UV curable coatings are applied to a variety of flat, rigid substrates, such as particle board, medium- and high-density fiberboard, wood veneers, polycarbonate, poly(methylmethacrylate), paper, and metal sheets and foils. An example of a formulation for UV curable coatings is in Table 7.1. 

On the whole, the SSL particleboard obtained by Shen cannot be compared technically with exterior-grade PF particleboard. The Shen procedure, however, has found no practical application yet, as the results obtained are still far from those obtainable with PF particleboard. In 1977 Shen mentioned that a short production trial run had been carried out at a waferboard plant although the preliminary results were promising, additional work was still required to modify the binder formulation and production parameters to meet the requirements of plant operation, and to obtain results comparable to those of PF particleboard. The Shen system, however, is used in the manufacture of some types of hardboard (high density fiberboard). 

Description of the container/closure system—K brief description of the primary and minimally functional secondary materials used in the packaging of the finished developmental API should be provided (e.g., double high-density polyethylene liner inside a fiberboard container/closure). Consideration should also be given to including appropriate acceptance criteria for the primary (i.e., product contact) material. The container/closure described in this section should be consistent with that used for stability testing of the compound, or exceptions should be noted. 

Manufacturing of medium-density fiberboards (MDFBs) from hngo-ceUulosic fibers has been increasing in recent years [113-115]. Structural fiberboards are being made from wood, other plant materials, and wastepaper. They are classified by density and can be prepared by dry or wet processes. These boards fall into two main categories high density (hardboard) fiberboards and MDFBs. The fiberboards are prepared by the dry process method, whereas the wet process method is apphed to both hardboards and low density insulation boards [103]. 

Solvent based, hot-melt, and water-based dispersion adhesives are typically used in producing technical laminates for the furniture and automotive industries. The market share for aqueous dispersions is about 40 %. The main products are heat-acti-vatable polyurethane dispersions, which provide excellent adhesion and extremely high bond strengths to a range of substrates. Important applications are furniture lamination (lamination of medium density fiberboard to decorative sheeting) and the lamination of moldings for interior automotive parts (e.g. dashboards, door interior panels) [73]. In North America, the total automotive adhesive market is estimated to be roughly 200 million (in 1997) [74]. 

Property enhancement by acetylation has been frequently reported over the years in other reconstituted wood products such as flakeboards, particleboards, and fiberboards [8,9,11,12,59-64]. Table 16 shows the laboratory decay test of low-density acetylated particleboards made from perishable albizzia wood. They were resistant to attack by Tyromyces palustris (brown rot), Coriolus versicolor (white rot), and Chaetomium globosum (soft rot) above 12% WPG. These acetylated boards with 20% WPG also exhibited an improved resistance to attack by the destructive Formosan termite, Coptotermes formosanus, in the laboratory. However, their performance was unsatisfactory in the wet tropics with a higher hazard of termite attack. High resistance to fungal and bacterial attack in acetylated southern pine and aspen flakeboards was evidenced in laboratory and fungus cellar tests [12]. 

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