Density and Oil Content of Keruing Wood: Key Traits and Marine Plywood Suitability
In wood processing and foreign trade, wood selection depends on how its physical properties fit application needs. Keruing, a hardwood for industrial use, stands out for its density and oil content. Unlike rubberwood or eucalyptus, it has unique density differences and contains oleo-resin—bringing both processing challenges and application strengths. This article explores Keruing’s density and oil traits, explains why it fails as a substrate for birch veneer lamination and paint finishing, and confirms its ideal use in marine plywood.
Density: Keruing vs. Rubberwood Density shapes wood strength and durability. Keruing’s air-dried density is 20–30% higher than rubberwood’s, even higher than eucalyptus' . This comes from tight fiber arrangement, thick cell walls, and small cavities—giving Keruing better compressive/flexural strength and hardness. Plywood made from it resists deformation and cracking, suiting scenarios needing long-term stability. Yet high density brings challenges: heavier Keruing raises transport costs; it wears tools faster during processing, requiring sharper equipment; pre-drilling is needed to avoid cracking when nailing. Still, these issues are manageable with optimized techniques, and its structural advantages remain irreplaceable in specific uses.
Oil Content: Why Keruing Fails for Veneer and Panit Keruing’s oleo-resin (a mix of resin acids, fatty acids, and neutral substances) is its defining chemical trait—and the main reason it’s unsuitable for birch veneer lamination or paint finishing.
2.1 No Good for Birch Veneer Lamination Birch veneer needs strong adhesion to the substrate. Keruing’s oleo-resin seeps out when heated or sanded, forming a sticky film that blocks adhesive bonding. Over time, veneer delaminate easily; temperature changes worsen this. And the oil from keruing wood may penetrate the surface of birch veneer. Also, Keruing’s high density causes uneven surface tension, leading to bubbles or warping in thin birch veneer—ruining quality. 2.2 Poor for Paint Finishing Paint requires even adhesion and drying. Keruing’s resin contaminates sandpaper during pre-painting sanding, leaving a sticky, uneven surface that causes brush marks or orange peel texture. The resin weakens paint adhesion, leading to peeling or blistering. Even after painting, resin seepage causes discoloration. Pre-treatments (e.g., solvent cleaning) only temporarily reduce seepage, making Keruing risky for painted products like furniture. 2.3 Managing Oil-Related Issues For other uses (not veneer/paint), industries use pre-drying (to reduce resin seepage) or solvent soaking. Cooling cutting (e.g., water spraying) during processing prevents resin softening. But these work only for industrial applications like marine plywood—not for laminate birch veneer or paint.
- Keruing: Ideal for Marine Plywood Keruing’s density and oil content, flaws for veneer/paint, make it perfect for marine plywood—used in ships, docks, and offshore structures, which demand strength, water resistance, and anti-microbial properties. First, high density gives marine plywood needed stability. Ships face waves and currents; Keruing’s strength resists deformation and impacts, unlike weak rubber/eucalyptus. Second, oleo-resin boosts water and corrosion resistance. It forms a protective film, blocking moisture and salt—preventing swelling, rotting, and aging. Third, the resin fights microbes. Marine bacteria and fungi decompose wood, but Keruing’s resin has natural anti-bacterial compounds, reducing decay and maintenance costs. Finally, resin enhances wear and weather resistance. It lowers friction for ship decks and resists UV rays/rain, keeping plywood durable. In short, Keruing’s density ensures stability, while its oleo-resin—though bad for birch veneer lamination and finishing —gives water, corrosion, and anti-microbial protection. These match marine environment needs, making it ideal for marine plywood.
As a professional manufacturers, we must leverage its strengths (marine use) and avoid its weaknesses (veneer/finishing) to maximize value.
Having a deep grasp of the properties of raw materials like Keruing and rubberwood/eucalyptus wood, we avoid unsuitable options (such as Keruing for birch veneer substrates) and select the right materials to create high-quality birch plywood that meets customer expectations!