Preparation and characterization of wood-plastic plywood bonded with high density polyethylene film

To blaze new trails for utilizing forestry processing residue, higher plant content biocomposites were proposed based on a combination of moso bamboo flour/silane KH550/high density polyethylene (HDPE), and the materials were characterized by diffractometry, spectroscopy, microscopy, and calorimetry. During surface modification, reactions between bamboo and silane occurred on the lignin aldehyde group. After 6 wt% KH550 treatment, crystallinity of bamboo was increased by 1.11 %, and melting temperature and enthalpy of the composite rose by 2.37 °C and 5.27 J/g, agreeing with improved interface morphology. Increasing in thickness from 3 to 9 mm, the physical and mechanical properties of composite were improved overall. Bamboo content caused the biggest influence, while thickness swelling exhibited the greatest susceptibility. Increasing the bamboo ratio boosted flexural and tensile properties, but it compromised toughness and water resistance, while silane and moulding parameters featured complicated relationships regarding performances. Combining an artificial neural network (ANN), KH550 3 wt%, moulding temperature of 180 °C, and a time of 8 min endowed 9 mm composites of 70 wt% bamboo with performance comparable to load bearing MDF in GB/T 11718.

Section: Effect Of Process On Composite Physical and Mechanical Propesupporting

confidence: 78%

Section: Effect Of Materials and Moulding Parametersmentioning

confidence: 69%

Interfacial Characterization and Optimal Preparation of Novel Bamboo Plastic Composite Engineering Materials

Song¹,

Zhao

et al. 2015

“…Because formaldehyde is classified as a human carcinogen, formaldehyde emission during manufacture and use of wood-based composites poses a threat to human health (Song et al 2015a). Although adjusting the adhesive formulation or developing a bio-based adhesive have been attempted to control formaldehyde emission, their effect is limited due to reasons such as higher cost or lower water-resistance of the novel adhesive (Fang et al 2013b).…”

Section: Introductionmentioning

confidence: 99%

Utilization of Polypropylene Film as an Adhesive to Prepare Formaldehyde-free, Weather-resistant Plywood-like Composites: Process Optimization, Performance Evaluation, and Interface Modification

Song¹,

Wei²,

Li³

et al. 2016

To develop formaldehyde-free wood-based composites, plywood-like composites (WV/PPF) were prepared using wood veneer (WV) with polypropylene film (PPF) as a novel formaldehyde-free, water-resistant adhesive. To prepare WV/PPF, the effects of hot-pressing conditions (temperature, 165 to 195 °C; pressure, 0.9 to 1.3 MPa; duration, 40 to 70 s/mm; and adhesive dosage between adjacent WVs, 100 to 200 g/m 2 ) were investigated. Results showed that conditions at 180 °C, 0.9 MPa, 70 s/mm, and 150 g/m 2 gave WV/PPF desirable physical-mechanical properties. Then, WV/PPF was compared with plywood-like composites using, respectively, polyethylene film (PEF), urea-formaldehyde resin (UFR), and phenol-formaldehyde resin (PFR) as adhesives. Results showed that the physical-mechanical properties of WV/PPF were favored over WV/PEF and WV/UFR, and were comparable to those of WV/PFR. Maleic anhydride grafted polypropylene (MAPP) or γ-aminopropyltriethoxysilane (APTES) surface modification of WV was performed to enhance the interface compatibility of WV/PPF. Results showed that the physical-mechanical properties of modified WV/PPF were favored over those of WV/PFR; MAPP modification was better for shear properties, while APTES modification was better for dimensional stability and flexural properties. Overall, the environmental and technological benefits demonstrated the potential of WV/PPF as a novel construction and building material.

“…Particularly, the hot-pressing temperature has a notable effect on the formation of adhesive bonded joints between porous veneers and molten films, where the wood plastic interface is formed through the mechanical interlocking (Fang et al 2013a). When the polyethylene-film dosage between every two veneers increases from 61.6 g/m 2 to 246 g/m 2 , various properties of poplar/polyethylene plywoods are positively affected (Fang et al 2013b). Compared to poplar/UF resin plywoods, poplar/polyethylene plywoods present the lower 7-day water adsorption (by 23.5 %), thickness swelling (by 5.10 %), and almost the same dynamic mechanical properties under 100 °C; therefore poplar/polyethylene plywoods are applicable for the higher moisture and geothermal floors (Fang et al 2013b).…”

Section: Introductionmentioning

confidence: 99%

“…When the polyethylene-film dosage between every two veneers increases from 61.6 g/m 2 to 246 g/m 2 , various properties of poplar/polyethylene plywoods are positively affected (Fang et al 2013b). Compared to poplar/UF resin plywoods, poplar/polyethylene plywoods present the lower 7-day water adsorption (by 23.5 %), thickness swelling (by 5.10 %), and almost the same dynamic mechanical properties under 100 °C; therefore poplar/polyethylene plywoods are applicable for the higher moisture and geothermal floors (Fang et al 2013b). Moreover, the silane A-171 has been used to modify veneer surfaces, thus enhancing the affinity of hydrophilic poplar veneers with hydrophobic polyethylene films .…”

Section: Introductionmentioning

confidence: 99%

Developing and Evaluating Composites Based on Plantation Eucalyptus Rotary-cut Veneer and High-density Polyethylene Film as Novel Building Materials

Song¹,

Wei²,

Ren³

et al. 2016

To achieve value-added utilizations of plantation timbers, eucalyptus veneer/high-density polyethylene film composites were prepared, with process-factors (PF) (hot-pressing temperature, HT; hot-pressing duration, HD; hot-pressing pressure, HP; HDPE-film content, HC) and composite-properties (CP) (water-resistant bonding-strength, BS; modulus of rupture, MOR; modulus of elasticity, MOE) investigated. According to thermal analyses, 140 to 180 °C was appropriate for HT. Based on statistical analyses, HD was easier to affect CP, while MOE was easier to be affected by PF. Quantitative relationships between PF and CP were determined by the neural-network (ANN) modeling. In ANN simulation surveys, CP displayed Gaussian distributions (R 2 > 0.9) when PF changed in current ranges, with positive correlations between BS and MOR (R 2 ≈ 0.5). Combining ANN and the genetic-algorithm, optimal processes (HT, 160 °C; HD, 50 s/mm; HP, 1.3 MPa; HC, 6 layers) were found, and optimal results (BS, 1.30 MPa; MOR, 86.94 MPa; MOE, 8.33 GPa) were comparable to various reported poplar-plywoods. Microscopic images demonstrated that composite interfaces were formed by the mechanical interlocking. The optimal BS attained Chinese standards for water-resistant plywoods, so proposed composites can serve as waterresistant and formaldehyde-free building materials for furniture and interior design.