Explanatory notes
… either : (1) With an added binding substance (e.g., unvulcanised rubber, glue, plastics, tar, gelatin), or (2) … substance at a temperature of about 300 °C. In this latter case the natural gum in the cork acts as a binder. … is an excellent heat‑ or sound‑insulating material. In many cases, however, the addition of the binders required for the …