Definition and Characteristics of OSB

1. Definition

OSB (Oriented Strand Board, also known as OSB) is a high-strength structural board made from fresh wood (such as pine, poplar, etc.), which is peeled, sliced into 40-120mm long, 5-20mm wide, and 0.3-0.7mm thick wooden pieces, dried, glued, and oriented (surface longitudinal, core transverse), and then hot pressed into shape.

2. Main features

High strength: Directional paving makes the board have bending and shear strength close to plywood, far higher than ordinary particleboard.

Good stability: The criss crossing wood chip structure reduces expansion and deformation, making it suitable for environments with large temperature and humidity changes.

Excellent moisture resistance: Some OSB (such as OSB-3, OSB-4) use waterproof adhesives, which can be used in humid environments.

High environmental friendliness: High quality OSB uses formaldehyde free MDI adhesive (isocyanate adhesive), with extremely low formaldehyde emissions (ENF grade).

Good processing performance: Strong nail grip, can be sawed, drilled, and milled, suitable for use in furniture and building structures.

Production process

The production process of OSB mainly includes wood processing → planing → drying → gluing → paving → hot pressing → post-processing, as follows:

(1) Wood processing

Select small-diameter materials with a diameter of 8cm or more (such as pine and poplar).

Peeling (rotary or drum type peeling machine), bark can be used for fuel 10.

(2) Slices

Use a disc or ring planer to cut the wood into thin slices of 40-120mm in length and 5-20mm in width.

(3) Drying and screening

The wood chips are dried by hot flue gas, and the moisture content is reduced to 2% -4%.

Filter and remove fine particles (5% -15% fine particles used as fuel) 10.

(4) Glue application

Use MDI adhesive (environmentally friendly) or phenolic resin adhesive (waterproof) 4.

The adhesive dosage is about 5% -8%.

(5) Directional paving

The surface wood chips are arranged vertically, and the core layer is arranged horizontally, forming a three-layer cross structure.

The paving machine ensures even distribution of wood chips and increases the strength of the board by 5.

(6) Hot pressing

Using a continuous press (ContiPress) ™） Or multi-layer hot press machine, temperature 180-220 ℃, pressure 3-5 MPa.

The density of the board after hot pressing is about 600-700kg/m ³ 3.

(7) Post processing

Cooling, trimming, sanding (some OSB do not require sanding) 10.

Some products are veneered (such as melamine veneer).

Development Trends

Environmental upgrade: The market share of formaldehyde free OSB (MDI adhesive) has increased by 7.

High performance OSB: such as moisture-proof OSB-4 and high-density OSB used for load-bearing structures.

Alternative plywood: OSB has extensively replaced plywood in Europe and America, and the domestic market is also growing rapidly.