What is film faced plywood?

The building film faced plywood is an amorphous substance with a branched structure and composed of two or more sugar groups. The main chain and side chain contain hydrophilic groups, so it is the most hygroscopic component in wood. One of the factors that cause the building template to absorb moisture, expand, deform and crack. In addition, during the heat treatment of wood, certain polysaccharides in hemicellulose are easily broken into cleavage products of aldehydes and certain sugars. Under the action of heat, these substances can polymerize to form water-insoluble polymers, which can reduce the moisture absorption of the building template and reduce the expansion and contraction of the building template.
https://www.chantawood.com/film_faced_plywood/list_1.html