Mechanical Design 8 | Characteristics and Selection of Wood and Plywood [Comparison of FA jigs, formwork panels, LVL, and OSB]

This article compares wood and plywood used in factory automation (FA) equipment and industrial process design in terms of materials, manufacturing methods, durability, and safety. It also provides practical design and machining tips for fixtures, machine covers, workpiece supports, worktables, carts, conveyor guides, shipping crates, and other applications on the factory floor.

Introduction | How Wood and Plywood Differ from Metals and Plastics

Plywood, Solid Wood, LVL, and OSB Are Different Materials

Solid wood is an anisotropic material whose properties depend on the natural grain direction. Plywood consists of thin veneers bonded together, usually with the grain of adjacent layers at right angles to reduce directional differences within the panel. LVL (laminated veneer lumber) has veneers aligned mainly in the same grain direction to take advantage of longitudinal strength. OSB (oriented strand board) is a panel made by bonding long, thin wood strands arranged in specific directions in each layer. MDF and particleboard are different products made from bonded wood fibers or particles.

Key advantages over metal include easier machining, lower weight, and straightforward replacement. However, designers must account for moisture absorption and warping, directional strength differences, creep, flammability, dust generation, and limited durability under repeated screw fastening. For permanent equipment requiring high precision or high load capacity, comparisons with aluminum, steel, and engineering plastics are essential.

Chemical and Physical Properties | Weight, Heat, Moisture, Chemical Resistance, and Electrical Properties

Weight and Density

As general reference ranges, conventional plywood has a density of approximately 0.4–0.75 g/cm³, depending on wood species and moisture content; LVL is approximately 0.45–0.7 g/cm³, and OSB approximately 0.55–0.7 g/cm³. A 900 × 600 × 18 mm panel with a density of 0.60 g/cm³ weighs approximately 5.83 kg. Dimensions and thickness alone are not enough to determine weight; check the density of the actual product.

Heat Resistance, Weather Resistance, and Moisture-Related Dimensional Changes

Wood has lower thermal conductivity than metals, but exposure to high temperatures can cause drying, thermal degradation, charring, and combustion. Even when phenolic resin is used, the product is not necessarily noncombustible or fire-resistant. Wood absorbs and releases moisture as ambient humidity changes, affecting panel thickness, in-plane dimensions, and warpage. Allow the material to acclimate to its service environment before final machining and dimensional inspection, and apply coatings or edge sealing consistently to both faces and all edges.

Resistance to Solvents, Oils, and Cleaning Agents

Wood can absorb liquids. Assess compatibility with cutting oils, coolants, alcohols, and detergents not only for the wood itself but also for adhesives, coatings, and bonded rubber or urethane layers. For equipment that requires repeated cleaning with chemicals, compare plastic sheets and metals as priority alternatives.

Electrical Properties and Static Dissipation

The electrical resistance of wood varies greatly with moisture content, contamination, and surface finish, so it cannot always be regarded as an insulating material. For antistatic or conductive plywood, verify surface resistance, resistance to ground, grounding paths, and resistance after wear against the product specifications. In electrostatic discharge (ESD) protected areas, combine a control program based on standards such as IEC 61340-5-1 with personnel grounding and periodic inspections.

Mechanical Properties | Strength, Toughness, Creep, Wear, and Cost

Flexural Strength and Anisotropy

The flexural strength and flexural modulus of plywood vary with wood species, thickness, veneer layup, bond quality, and loading direction. Pay particular attention to the strong and weak axes of LVL and OSB. For safety-related components, use manufacturers’ guaranteed values, JAS classifications, and test results.

Localized Compression, Splitting, and Toughness

Wood is useful for fixture supports that distribute loads over an area, but splitting, delamination, and localized crushing can occur around holes, at edges, under bolt bearing surfaces, and in narrow battens. Consider through-bolts with large-diameter washers, backing plates, and metal sleeves.

Creep, Friction, and Wear

Deflection can increase under sustained loads or repeated humidity changes. Friction and wear during conveying depend on surface roughness, wood species, films, counterface materials, and contact pressure. Some phenolic film-faced plywood products offer excellent cleanability and wear resistance, although their slip characteristics vary by specification. Rubber- or urethane-faced panels help prevent damage to products, but the bonded layer must be monitored for peeling, contamination, and foreign-particle generation.

Material and Processing Costs

Standard plywood is generally economical for prototypes, fixtures, and packaging, but specialty finishes such as surface films and conductive, flame-retardant, or wear-resistant specifications increase material and processing costs. Evaluate replacement frequency, cleaning time, and local availability in addition to purchase price.

Wood-Based Material Types and Performance Comparison

High-Performance and Durable Plywood

Shina (basswood-faced) plywood is valued for its attractive surface and ease of machining and finishing, while lauan plywood is used for general-purpose applications. However, the face veneer species alone does not determine core construction or bond strength. Concrete formwork plywood (commonly called ‘conpane’ in Japan) is available with or without a surface film; phenolic resin may be used in either the adhesive or the surface film. The informal name ‘conpane’ does not itself indicate any particular strength or water-resistance grade.

Specially Processed Wood Products

For conductive and antistatic plywood, verify product-specific resistance values and grounding requirements. Rubber- and urethane-faced plywood can provide slip resistance, workpiece protection, and impact absorption, but friction, compression set, oil resistance, delamination, and static electricity must be evaluated for the specific facing material.

Materials for Logistics and Packaging

LVL is a candidate for longitudinal battens, beams, and crate members, while OSB is suitable for consideration as crate panels or sheet material. For wood packaging used in international shipments, check whether each material is covered by or exempt from ISPM 15, and take care when combining engineered wood with solid-wood battens or feet.

* This table summarizes general trends and does not guarantee the performance of any specific product. As with other wood-based materials, heat exposure and combustion must be considered; flame-retardant or noncombustible performance requires separate testing and certification.

For a more detailed introduction to wood species and their properties, see this reference book.Revised Full-Color Encyclopedia of 200 Wood Species: A Comprehensive Guide to Wood Available in Japan (Japanese-language book)

Standards | JAS, JIS, and ISPM 15

Understanding JAS Classifications

Check the applicable Japanese Agricultural Standards (JAS) for general-purpose plywood, structural plywood, concrete formwork plywood, specially processed decorative plywood, laminated veneer lumber (LVL), and structural panels such as OSB. Do not assume water resistance or strength from the material name alone. Specify bond performance, strong/weak axis orientation, moisture content, formaldehyde emission class, thickness, and dimensional tolerances.

What to Specify on Engineering Drawings

Rather than specifying only ‘plywood t18’, include the product name, manufacturer’s part number or JAS classification, panel thickness and tolerances, grain direction, moisture content, face and edge treatments, hardware and fastening methods, replaceable components, and inspection requirements. For ESD-control materials, also state resistance limits, grounding methods, and measurement conditions.

Manufacturing Processes | Plywood, LVL, and OSB

Plywood Manufacturing

A typical process is: (1) log selection → (2) heating or steaming → (3) veneer production using a rotary lathe or other equipment → (4) veneer drying → (5) grading and repair → (6) adhesive application → (7) layup with generally perpendicular grain directions → (8) cold and hot pressing → (9) trimming, sanding, and inspection. Adhesive type, veneer thickness, and pressing conditions affect performance.

LVL

Dried veneers are stacked with their grain mainly parallel, bonded, and hot-pressed, making LVL well suited to longitudinal structural members. Confirm direction-dependent properties and performance under changing humidity.

OSB

Long, thin wood strands are produced from logs, then dried, mixed with resin, oriented, layered, hot-pressed, and trimmed. Different strand orientations in the face and core layers create strong and weak axes.

Surface Finishing

For phenolic film-faced, decorative, conductive-sheet-faced, rubber-faced, and urethane-faced plywood, quality depends not only on the base panel but also on the facing and adhesive layers: evaluate chemical resistance, wear, delamination, and sealing of machined edges.

How to Select Materials | Practical Examples for FA Equipment and Process Design

Application-Based Selection

Design Tips | Deflection, Fastening, Temperature, and Humidity

For a simplified beam model with a concentrated load at midspan, deflection is δ = PL³/(48EI). Reducing the support span L and adding reinforcing battens are effective ways to control deflection. Use an elastic modulus E appropriate to the panel’s grain direction and moisture content. Because screw holes and edges are prone to splitting, consider pilot holes, sufficient edge distances, large-diameter washers, through-bolts, and metal inserts. Seal both faces and edges consistently to reduce warping, and verify dimensions after acclimatization to the humidity at the installation site.

Machining and Processing Precautions

When cutting and drilling, use backing boards, clamps, and sharp woodworking tools to minimize splintering and delamination. Dust extraction, prevention of dust explosions and fires, personal protective equipment, ventilation, and review of safety data sheets (SDS) for paints and adhesives are important. Inspect repeated sliding-contact areas for wear debris and detached fragments, and design them for easy replacement.

This is a useful introductory book on the fundamentals of wood.Illustrated Introduction: Understanding the Latest Fundamentals and Structure of Wood (How-nual Visual Guide Book; Japanese-language book)

Frequently Asked Questions (FAQ)

Are Concrete Formwork Plywood and Structural Plywood the Same?

No. ‘Conpane’ is a common Japanese term for concrete formwork plywood, while structural plywood belongs to a separate JAS category. Check the intended use, applicable standards, and strength requirements.

Is Phenolic Resin Plywood Waterproof and Noncombustible?

No. The use of phenolic resin in the adhesive or surface film does not guarantee complete waterproofing or noncombustibility.

Is Antistatic Plywood Alone Enough for ESD Protection?

No. Resistance measurements, grounding, personnel and equipment controls, and periodic inspection are also necessary.

What Is the Difference Between LVL and OSB?

LVL consists mainly of veneers laminated with their grain aligned in the same direction. OSB is a panel made from oriented and bonded wood strands. Consider the longitudinal or strong-axis properties of each material.

Conclusion

Wood and plywood offer advantages in machinability, availability, low weight, and replaceability when used for fixtures, temporary components, and packaging in FA equipment. However, limitations such as directional strength differences, moisture absorption and warping, creep, flammability, dust, solvent resistance, and static electricity control must be considered. Select products suited to the application and operating environment, and consider hybrid designs that combine wood-based components with metal structures.

References and Related Articles

• Ministry of Agriculture, Forestry and Fisheries (MAFF) | JAS Standards
• JISC
• IPPC (ISPM 15)
• Mechanical Design 7 | Plastics and Engineering Plastics

Numerical values are representative examples. For engineering specifications, prioritize product-specific JAS conformity, manufacturers’ documentation, and testing under actual loads and operating conditions.