On the penetrability of various glues in chips from pine sapwood and heartwood

Investigation of the penetrability of various glues [urea-formaldehyde resi n (UF-resin), phenol-formaldehyde resin (PF-resin), melamine-urea-phenol-fo rmaldehyd made of pine sapwood and heartwood revealed: the various glues pe netrate chips from pine sapwood regardless of tree age, height of the sampl e studied and surface structure deeper than in those made of heartwood. The various glues more deeply penetrate chips from sapwood and heartwood of th e 48-year-old pine than chips from sapwood and heartwood of the 124-year-ol d pine. The penetrability of various glues in chips from sapwood and heartw ood of the 124-year-old pine increases with increasing height of the sample studied. Moreover, glues penetrate sanded surfaces of chips from sapwood a nd heartwood of the 48- und the 124-year-old pine to a lesser extent than u nsanded chip surfaces.