Plywood QC Inspection Checklist : Part 31 Quality Control in Plywood Manufacturing Physical Properties of Commercial Plywood
Each plywood plant has resident quality control personnel to help ensure that the finished panel will meet the requirements stipulated in the manufacturing standard . Veneer thickness, moisture control for veneer drying, panel grading, and glue bonding are examples of stages of manufacture that are continuously monitored in quality control.
Quality control in plywood manufacture is complex, once there are many elements that affect panel performance, including: options for hardwood or softwood , pressing and temperature cycles applied ,and the kind of adhesive used……….
Plywood offers all the inherent advantages of the parent wood plus enhanced properties in its laminated structure.
High impact resistance
Being a wood based material, plywood has the ability to accommodate the occasional short-term overload; up to twice the design load. This is useful where seismic activity or cyclonic winds can occur. This property is also effective when used as construction flooring or as concrete formwork. Plywood’s laminated structure distributes loads from impact over a larger area on the opposite face, which effectively reduces the tensile stress.
Surface dimensional stability
The cross laminated construction of plywood ensures that plywood sheets remain relatively stable under changes of temperature and moisture. This is especially important in flooring and formwork construction where moisture exposure is very likely.
High strength to weight ratio
With high strength and stiffness to weight ratios, plywood is very cost effective to use in structural applications such as flooring, shearwalls, formwork and webbed beams.
The panel shear of plywood is nearly double that of solid timber due its cross laminated structure. This makes plywood a highly effective material to use in gussets for portal frames, webs of fabricated beams and as bracing panels.
Plywood does not corrode and can be used in chemical works and cooling towers as a cost-effective, durable material when preservative treated.
Plywood can be manufactured to fit every requirement. The veneer thickness varies from a few millimeters to inches. The number of veneers used also ranges from three to several, increasing the thickness of the sheet. The extra layers add more plywood strength. Thin veneers are used to increase flexibility for use in ceilings and paneling.