An adhesive product particularly suitable for use in the manufacture of wood particle board comprises from 50-90 parts by weight urea formaldehyde resin and from 10-50 parts by weight spent liquor from the acid sulfite pulping of lignocellulose, the adhesive product containing from 0.2 to 4.0% by weight ammonium ion (expressed as NH.sub.3) based on the spent liquor solids. The sulfite spent liquor component of the mixture prior to mixing has a pH of from 3-9; the urea formaldehye resin prior to mixing, a pH of from 6 to 8. The urea formaldehye resin is further characterized by a molar ratio of formaldehyde to urea of from 1. 0 to 1.8, and a methylol content corresponding to a Witte number of from 1.0 to 1.8.PPGlued wood products such as wood particle board are made using the herein described adhesive by applying to the surfaces of wood particles a bonding quantity of the foregoing adhesive, assembling the adhesive-coated pieces, and hot pressing the resulting assembly to cure the adhesive and bond the pieces together.
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