Rippling
Rippling appears when dry plywood absorbs water through some small damage on the phenolic film or edges in short time.
Water moves along a vessel. Wood around the vessel gets wet.
Rippling steps:
Dry plywood absorb water through a small damage or edges in film face.
Water is transported by a vessel along grain direction.
Wood around vessel gets wet and swells. Rippling appears.
Later moisture is balanced in the plywood and rippling goes down.
Edge Rippling
Edge rippling appears when dry plywood absorbs water from edges. Areas around vessels swell first. Later moisture is balanced in plywood and edge rippling goes down.
How to minimize the “rippling” effect?
As we know the rippling is caused because of the low moisture content of plywood. So in order to reduce the rippling effect, the phenolic film should be treated prior to first use.
How to do it?
Formwork workers will need to apply a wet cement slurry or grout wash on the plywood surface. The plywood edge swelling on the film will become less noticeable.
