Process for the production of a wood fiber insulating material board or mat and wood fiber insulating material boards or mats produced by this process

A process for producing wood fiber insulating material boards and mats, which comprises the steps of:

• introducing natural fibers and binder fibers from bale openers uniformly through separate weighing devices disposed downstream of the bale openers into a blow line in a desired mixing ratio and supplied pneumatically through the blow line to a storage container resulting in a fiber mixture, wherein the natural fibers include wood fibers;
• blowing the fiber mixture from the storage container onto a first transport belt with a three-dimensional alignment of the fibers resulting in a fiber fleece;
• scattering thermally activatable synthetic resin granules, obtained during a recycling of plastic parts, onto the fiber fleece and being distributed uniformly over an entire width;
• defibering the fiber fleece at an end of the first transport belt;
• remixing the fiber fleece once again resulting in a remixed fiber mixture;
• blowing the remixed fiber mixture onto a second transport belt with a three-dimensional alignment of the fibers resulting in a mat;
• obtaining a given thickness of the mat by setting a circulating speed of the second transport belt;
• transferring the mat to an oven belt and moving the mat through a heating/cooling oven, for softening of the binder fibers and the synthetic resin granules, resulting in an intimate bonding of the wood fibers, the binder fibers, and the synthetic resin granules;
• and
• setting a final thickness of the wood fiber insulating material boards or mats to a range of 3 to 350 mm by calibration and/or compaction and setting a bulk density of the mat to a range of 20 to 300 kg/m3.