LOW TOXIC CHIPBOARD BOARDS

摘要

The low toxic boards are used in the furniture industry and in civil engineering. They have low formaldehyde emission - under 10 mg/100 g (class E-1) and improved physicomechanical characteristics in comparison with the chipboards plates produced with adhesive carbamideformaldehyde oligomer (resin). The chipboards include the following components in wt. pts: chipboards chips from 85 to 92, carbamideformaldehyde oligomer 7-9, tannin or tannin oligomer 0.5-3.5. The tannin was extracted from the Acacia subspecies: Acacia nilotica and Acacia meransii, and the tannin oligomer was produced from tannin, formaldehyde and phenol or carbamide under low-temperature condensation. The boards are produced by pressing under p = 2.4 0.2 MPa and temperature T = 180 5°C. They have formaldehyde emission under 10 mg/10 g, bending strength over 20 MPa, unstricking strength over 0.4 MPa, expansion along the thickness up to 11% and density of 750 kg/m3./!