Lumber, Plywood and Particle Based Products

INTRODUCTION

As the world population continues to grow, the use of wood will continue to play a major role as a raw material for meeting human needs. There are many advantages to using wood. Wood is very versatile, requires a low energy input to process, and is a natural, non-toxic, biodegradable and renewable resource.

Wood products can be broadly categorized into the following two groups. The first group includes lumber, plywood and particle-based products such as particleboard, waferboard, oriented-strand board and composite lumber. A second group includes fibre products such as paper, fibreboard and hardboards.

This article will focus on lumber, plywood and particle-based products. For each of these three product groups we will examine the products themselves, their uses, the manufacturing process and contemporary changes to the market.

1. SOFTWOOD LUMBER

Canfor is Canada's largest producer of softwood lumber. Although the Canadian lumber industry includes both softwood and hardwood lumber sectors, in British Columbia and Alberta the majority of the forests are softwood. Softwood sawmill products are determined by thickness with:

• boards
  being less than two inches thick,
• dimension lumber
  is two to four inches thick; and
• timbers
  are 5 inches or thicker.

Value-added products, such as finger-joined lumber, fascia boards and tongue and groove panelling are a growing arm of the lumber product line.

Sawmilling also produces by-products such as wood chips, sawdust and shavings. These provide the raw material for the manufacture of fibre products such as pulp and paper and are used in the production of energy.

Uses

As there is a wide range of softwood species, woods with similar strength qualities are sold in "species groups" such as Spruce Pine Fir (SPF) to simplify marketing. The majority of softwood lumber is used for residential construction and remodelling. Some species such as white pine and western red cedar are also used in millwork or specialty products.

Softwood lumber is classified according to quality by using a lumber grading system. The whole board is assessed for looks and strength. Knots, the slope of the grain, pitch, checks, stain and obvious defects are some of the characteristics used in this evaluation. The specifications assure a minimum level of strength and appearance. Softwood lumber can be split into two broad use categories, construction and re-manufacture.

Lumber for construction has three general categories: stress graded, non-stress graded and appearance lumber. Stress-graded and non-stress graded lumber are used where structural integrity is the primary requirement. Appearance lumber, as one would expect, has looks as the primary requirement, with structural integrity as an important, but secondary need.

Lumber for remanufacture will be cut to smaller sizes and used as component parts in other products. Thus the grading here reflects the expected yield in subsequent cutting: factory grades, industrial clears, ladders stock to name some examples.

Lumber Manufacturing

Lumber manufacturing today is all about information integration. Information must flow between the mill and the managed forest. The mill needs to know what to expect in terms of logs coming in and foresters need to know about log values. Information must also flow between the sawmill and the marketing divisions. Marketers need to know what products the mill will be producing over the next three months so they can sell them and the mill needs to know what products customers are going to want in the future.

The sequence used in processing a log into lumber products is as follows:

Lumber Market Changes

The BC lumber situation has undergone serious changes over the last ten years. Wood costs have gone up more than 75% between 1992 and 1996 due to social and environmental pressures. The cost of labour is also very high. In addition, there has been reduced harvests, competition from engineered wood products, and increased competition from low-cost short-rotation plantation forests in South America and Russia. To deal with these issues, sawmills have had to change the way they do business. Efficiency, technology and product development are key factors in the survival of today’s lumber industry.

Sawmill efficiency is crucial to the viability of the business. The lumber industry is changing from a low-tech sector to one which is increasing its use of sophisticated equipment. Canfor uses technological advances such as laser scanners, x-ray imaging equipment and computer simulations to improve its productivity and competitiveness.

Data analyses and forecasting trends play an important role in efficiency as well. For example, mill inputs and outputs are analysed to see how well the mill is doing in maximizing wood recovery from the logs. The purpose is to constantly fine-tune the mill’s computers and lasers to control the saws and get the most value from each log.

Data is also used in the important activity of analysing product trends. What products should the mill be producing to maximize value? This prediction is important because the mill wants to be producing what will bring in the greatest return on its costs. The decision about which product to make depends on the logs available, the commitments already made to customers and the market prices.

Searching for the optimum set of conditions for the mill is important. By running computer simulations, where different mill parameters are modified, the virtual outcomes can be analysed. The results indicate how the mill might be adjusted so that the highest value product is produced, which will bring the mill higher profits. Maximizing the recovery from the log, while at the same time meeting market and customer profiles is a constant juggling act for today’s sawmills.

It is clear that a more technologically advanced sawmill is able to compete more effectively in a tough global market. One outcome of this move to technology is a change in the skill requirements of the workforce. Recruiting and retaining skilled workers is becoming an important challenge. In addition the increased interest in market-focussed, higher value-added products requires greater corporate investment in research and development. Today’s product development is much more team oriented with wood scientists working with marketing divisions and the mills.

2. PLYWOOD

Plywood is a panel product composed of 3 or more thin layers of wood that are glued and united under high temperature and pressure. The grain of each layer runs at right angles to the grain of the layer it faces. Plywood is light, strong, stable, waterproof and very versatile. These properties make it the product of choice for many construction applications. It is easily cut to size and nailed. The large sheet size is convenient for roofing or flooring jobs. Plywood can be manufactured in a variety of thicknesses and is graded as decorative or structural.

Uses

Structural plywood is used extensively in residential and commercial construction and in industry. Construction uses include light-frame structures, roof and wall sheathing, subfloors, underlayment and siding. Industrial uses include plywood for van liners, furniture, cabinetry, signs, pallets, crates and concrete forms. Plywood is also used in the manufacture of engineered building components such as I-beams.

Decorative plywood uses hardwood veneers to face the panels. This type of plywood can be used in wall panelling and for furniture manufacturing.

Plywood Manufacturing:

The process in manufacturing plywood is as follows:

A range of softwood species can be combined within one plywood sheet, each having special characteristics that may affect the overall performance level of the product. For example Douglas-fir exhibits high strength and stiffness due to its high density, while sub-alpine fir has a greater moisture content. Canadian softwood plywood uses 13 different species for face veneer and 20 for the inner plies or layers.

Plywood Market Changes

The plywood market is changing in profound ways. Wood and labour costs are at all time highs. As well, market share is diminishing due to competition with Oriented Strand Board. These changes are forcing the development of new efficiencies and products.

Increasingly, plywood mills have become more automated and technical with ultrasonic veneer block scanning and new adhesives. Lathe technology is changing as the log resource base is increasingly smaller and lower in quality. Research is focussing on ways to optimize the use of each wood species, getting the greatest value out of each unit of wood. X-ray scanning is being considered as one possible method to determine the inside of the log and process it in the most appropriate and cost effective manner. Lasers, computer simulations, use of sensors and cameras, ultra-sonic grading and radio frequency drying are some other technologies being studied.

Technological innovation in the industry is focussing on quality and specialty product development. Current value-added plywood products include I-beams, tongue and groove plywood and preserved wood foundations plywood. Future developments of hybrid products (veneer combined with other panel and even non-wood products) are expected.

Laminated Veneer Lumber is not a panel product but is produced in a similar process to plywood. In this product, however, the grain of the veneers are all in one direction. Some characteristics are high strength and straightness. It also holds its shape and any length can be manufactured. Current uses are in headers over garage doors and large windows and in the flanges within I-beams.

3. PARTICLE- BASED PRODUCTS

The fibre by-products from sawmills and low grade logs can be used to manufacture a range of particle-based panels and lumber products such as particleboard, wafer board, oriented-strand board and composite lumber. The manufacturing processes for these products are quite similar and are dealt with below as one general process.

Uses

Particleboard

Particleboard is produced using glue and compression to form small particles of wood into a panel. By varying the wood particle size, the amount of resin used and final density, numerous types of particle board can be made. This product is used to manufacture home and office furniture, kitchen and TV/stereo cabinets, mobile home decks and underlayment for carpeted floors.

Waferboard and Oriented Strand-Board (OSB)

Waferboard and its newer version, OSB, utilize large strands of wood with a length of about 3 inches. OSB has all of the strands oriented in parallel patterns. The core of OSB has the strands oriented perpendicular to the length of the panel while the surface layers are horizontal. Waferboard strands are randomly oriented. Both products are formed in layers using a resin. OSB has very high strength and flexibility characteristics. The major use for OSB is for structural panels. Other uses and applications are similar to plywood.

Composite Lumber

Composite lumber is an alternative for structural softwood lumber. New products made from combinations of veneer and particle board include parallel strand lumber, laminated strand lumber, and oriented strand lumber. The manufacturing process of composites allows large sizes of lumber to be manufactured from small logs. The marketable characteristics of composites are large size, high uniform strength, and reliability. The overall strength of parallel strand lumber is superior to the best grades of Douglas-fir or southern pine lumber.

Other composites include specialty products such as floor joists with edges of laminated veneer and a particleboard centre. The long lengths and straightness of these joists are advantageous product characteristics. There also are a number of specialty I-beam products composed of composite lumber (or laminated veneer lumber) and OSB or plywood webs.

Particle-Based Product Market Changes

The range of new engineered products found within the particle-based product sector indicates an increasing use of research and technology to create new opportunities. As consumers become more concerned over the use of wood, particle-based products offer an attractive choice.

SUMMARY

The Canadian lumber industry is facing a number of challenges. Some of the major changes are:

• increased wood costs
• increased labour costs
• recruitment and retention of a skilled labour force
• decreased land available for managed forests
• competition from new products
• competition from countries with low wood, labour and environmental costs
• environmental issues

Producers must adapt to this changing marketplace. Staying competitive means improvement and innovation. Improvement focuses on the performance of existing products and the productivity of the manufacturing processes. Cost efficiencies through new technologies is one method of "improving". However, innovation focuses on product development, which is even more important for the Canadian industry’s future. The move into non-commodity, higher value markets offers more opportunity than simply lowering operating costs.

The development of a value-added sector in the wood products industry requires strong support from many levels. Working with customers to meet their specific needs and create niche markets, supporting research and development and maintaining a skilled and resourceful workforce are just a few of the challenges that face the industry in the years ahead.

For more information check out the following web site:

• Wood-Based Panel Products Technology Road III Softwood Plywood
  Industry Canada (1998)
• Canadian Lumber Industry Profile
  Industry Canada (1997)
• Sector Competitiveness Framework Series
  Industry Canada (1999)

References:

Dying or Flying? Strategies for riding the curve of change. Cawood, D and de la Roche, I (1999) Forest Products Journal .Jan/1999 Forest Education Modules: Plywood COFI. (1992) Wood handbook: Wood as an engineering material. Forest Products Laboratory. 1987 Agric. Handbook 72. USDA, Washington,D.C. Forest Products and Wood Science. Haygreen, J. and Bower. J. (1996) Iowa State University Press. Ames Iowa