METHOD AND APPARATUS FOR PREPARATION OF MINERAL FIBRE BASED GROWTH MEDIUM, A PLANT GROWTH MEDIUM AND USE OF IT

摘要

A process for the preparation of a plant growth medium having a density gradient, comprising the steps of providing a primary web comprising mineral fibre material and a curable binding agent, compressing the primary web in at least one longitudinally extending zone in such a manner that the applied pressure increases substantially continuously in the latitudinal direction of the zone, forming a secondary web by bringing the primary web overlap itself, optionally compressing said secondary web and curing the binding agent.