Features of wood composite materials with a violation of the continuity of the synthetic polymer phase

The features of the formation of composite materials from crushed wood particles with minimal application of synthetic oligomeric compounds (glue) in relation to chipboard (chipboard) are considered. The process of forming adhesive compounds from wood particles was studied, in which, during tarring, glue droplets are applied with an incomplete coating of the particle surface. The degree of tarring was determined. Various types of adhesive joints were analyzed, dividing them into normal ones when the glue is on the microparticles of both surfaces to be glued, and weakened joints when the glue is only on one of them, as well as defects in the structure of the material that occur when microparticles contact without glue. Variants of the formation of types of adhesive joints when applying contacting particles were evaluated and it was found that Hc is only about 15%, and weakened ones – almost 50% of the total area of the contacted particles. The study showed that the tear strength of normal adhesive joints is 1,3…1,7 times higher than weakened ones, and that applying an excess of glue can increase the strength of weakened joints. The process of the behavior of a drop of glue on a substrate as a result of wetting of the substrate and absorption into the wood structure was studied. It is suggested to improve the quality by such techniques as heating the applied glue, modifying the nozzle design, reducing the interval between tarring and hot pressing operations.

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