Particleboard hardwood plywood paneling

Three Product Loading - Particleboard, Hardwood Plywood Paneling and... 

Particleboard decking and hardwood plywood wall panels can represent 80% to 90% of the total exposed surface of formaldehyde containing wood based products in new mobile homes. Kitchen cabinets, vanities, shelving and other built-ins are primarily made from industrial particleboard, MDF or hardwood plywood panels. 

The U.S.Department for Housing and Urban Development s rule 3280.308 established formaldehyde emission standards for particleboard and hardwood plywood paneling used in mobile homes. These standards took effect February 11, 1985. The certification program under this rule requires each manufacturer to develop a quality control in-plant testing program that relates to tests conducted in a large scale environmental chamber. 

Determining Formaldehyde Emission from Wood Products" FTM-2 - 1983 (16). In this method, particleboard and hardwood plywood paneling are tested under the following conditions ... 

In addition, the effect of ventilation rate on chamber concentration is different for each wood product type, i.e. particleboard, medium density fiberboard, hardwood plywood paneling. 

The H.U.D. formaldehyde standards of 0.2 ppm and 0.3 ppm for hardwood plywood paneling and particleboard, respectively, were chosen because the combination of these products at their specific loadings and air change rate would result in a chamber concentration of less than 0.4 ppm. This assumption was based on four studies. 

Upon completion of the chamber test, the hardwood plywood paneling or particleboard is removed and 12 each 7.00cm x 12.7 cm specimens are randomly cut from each board loaded into the chamber. For the surface monitor (FSEM) and the small scale test chamber(SSTC), one 30.5cm X 30.5cm board is cut from each board loaded in the chamber. These samples are immediately tested by the Equilibrium Jar for particleboard or the Two Hour Desiccator or FSEM or SSTC for all wood product types. The values obtained from each test are averaged and are then compared to the chamber concentration observed for that loading and air change rate. 

Figure 14 provides a graphical representation of 27 chamber tests conducted on a variety of veneer, print, a paper overlay finished hardwood plywood paneling. Even though it is not shown, a breakdown by different product type did not affect the correlation by anymore than 5%. As with particleboard, the cloud of points below 0.2 ppm represents current production made to meet the H.U.D. hardwood plywood paneling standard (0.2 ppm chamber). The group of points between 0.24 and 0.36 ppm chamber are from earlier chamber studies needed to define the curve. 

Approximately one million metric tons of urea-formaldehyde resin are produced annually all over the world. More than 70% of this urea-formaldehyde resin is consumed by the forest products industry. The resin is used in the production of an adhesive for bonding particleboard (61% of the urea-formaldehyde used in the industry), medium-density fiberboard (27%), hardwood plywood (5%), and as a laminating adhesive (7%) for bonding furniture case goods, overlays to panels, and interior flush doors, for example. 

Table 11.2 shows 2003 production of both sawn timber and wood panels for various regions of the world. Structural panel production is dominated by North America, mainly because structural panel products have enjoyed a dominant position in residential construction. The United States is a substantial manufacturer of softwood plywood for domestic production but only 10% is exported whereas half that volume is imported as tropical hardwood plywood. Europe manufactures and uses comparatively little plywood and OSB. Instead the region relies on its own lower quality domestic wood resources for the manufacture of other wood-based panels, e.g. particleboard and fibre-based board. Amazingly, panel production in Asia equals that of lumber, reflecting the inter-regional China-centric supply chain. 

The most widely used wood panel products are particleboard, softwood plywood, hardwood plywood, medium density fiberboard (MDF) and waferboard. The most common adhesive is urea-formaldehyde resin (UFR). Phenol-formaldehyde resins (PFR) are second in volume and melamine-formaldehyde resins (MFR) are a distant third. Recently,... 

The single largest end use for hardwood plywood is interior wall panels, generally 3-ply and 1/4 and thinner, and frequently machined with decorative v-grooves. Furniture, cabinets, door skins and a number of specialties complete an array of end use products. Many of the non wall panel products can be characterized as being industrial panels and are of 5 or more ply veneer core, 3-ply particleboard core, or 3-ply medium density fiberboard (MDF) core construction. Broad end use patterns indicate that interior wall panels represent approximately 55% of total hardwood plywood consumption. Furniture, cabinets, and fixtures represent about 30%, and door skins and specialty products about 15% (2), Potential sources of formaldehyde in two of the more typical hardwood plywood constructions are displayed in Figure 1. 

In-plant quality control and routine acceptance testing by property verification organizations such as the Hardwood Plywood Manufacturers Association and the National Particleboard Association require a method more efficient than the chamber for routinely monitoring trends in emission characteristics of products. The relationship between chamber and the small scale desiccator test observations is illustrated by a series of 76 tests accomplished during the past year on hardwood plywood wall panel products at a chamber loading rate of 0.29 sq ft per cu ft ... 

G. Gramp, W. Groah. "Evaluation of the relationship between formaldehyde emission from particleboard mobile home decking and hardwood plywood wall paneling as determined by product test methods and formaldehyde levels in experimental mobile homes." U.S. Dept. of Housing and Urban Development, 1982. 

Virtually all wood panel products such as plywood and particleboard are manufactured using either urea formaldehyde or phenol formaldehyde adhesives. Urea formaldehyde adhesives are used in hardwood plywood and in certain types of particleboards. These adhesives are not waterproof, and products made with them are normally used indoors for paneling, furniture, shelving and floor underlayment. 

Singh Walcott, J. St. Pierre, C. Ferrel, T. Garrison, S. Groah, w. "Evaluation of the Relationship Between Formaldehyde Emissions from Particleboard Mobile Home Decking and Hardwood Plywood Wall Paneling Determined by Product Test Methods and Formaldehyde Levels in Experimental Mobile Homes" Clayton Environmental Consultants, Inc., Report, Prepared on Contract No. AC-5222, H.U.D., March, 1982. 

The first three chapters deal with particleboard, medium density fiberboard, hardwood plywood, and softwood plywood, the four most widely used wood panel products. Chapter four compares these products with other consumer products. Chapters five through seven explain the basic chemistry of formaldehyde with cellulose and wood components and provide a current understanding of the nature of liquid urea-formaldehyde adhesive resins. The next two chapters present new analytical methods that might become useful in the future. Chapters eight and eleven through sixteen explain the complex nature of the latent formaldehyde present in the products and its correlation to formaldehyde emission from wood products. Chapters fifteen and sixteen describe currently popular formaldehyde reduction methods. The last two chapters discuss the problems involved in reducing formaldehyde emission by regulating air levels or source emissions. 

---