An insulating material based on used raw materials is disclosed, as well as a process for producing the same. Such insulating materials are useful as fillers, heat insulating, construction and/or insulating materials in construction and packaging, as parts shaped in insulating material, as in-situ molded cellular plastic and as packaging material. This insulating material is essentially composed of 50-70 % crushed wood and/or defibrated used paper and/or defibrated cardboard with 0-30 % textile, vegetable or inorganic fibres and 20-50 % alkali silicate, with respect to the total mass of the insulating material. The rest is composed if required of 0-30 % additives, with respect to the total mass of the insulating material.
