scholarly journals EFFECT OF NATURAL AND ACCELERATED AGING ON THE PROPERTIES OF WOOD-PLASTIC COMPOSITES

Wood Research ◽  
2021 ◽  
Vol 66 (5) ◽  
pp. 700-710
Author(s):  
LIYUAN ZHAO ◽  
BIN LV ◽  
XIAORUI PENG ◽  
YUEJIN FU
Keyword(s):  
Low Temperature ◽  
Recovery Rate ◽  
Wood Fiber ◽  
Accelerated Aging ◽  
Fiber Content ◽  
Creep Recovery ◽  
Wood Plastic Composites ◽  
Freeze Thaw ◽  
Temperature Cycles ◽  
Plastic Composites

The correspondence of natural and laboratory-accelerated aging of WPC has long beenahighly important problem discussed by many scholars. In this work, the changes in moisture content (MC), modulus of rupture (MOR), modulus of elasticity (MOE), screw holding force and creep recovery rates of two groups of wood-plastic composites (WPC) after natural and accelerated aging (high-low temperature cycles and freeze-thaw cycles) were studied to provide guidance for the use of WPC in outdoor applications. The results showed that, after the natural aging and freeze-thaw cycles treatments, MC increased significantly with both 167% of the untreated value of wood-HDPE composites with 30% wood fiber content and a thickness of 25 mm (W25), while 67% and 133% of the wood-HDPE composites with 30% wood fiber content and a thickness of 20 mm (W20), but is almost unchanged after the treatment with high-low temperature cycles. The mechanical strength, including MOR, MOE, screw holding force and creep recovery rate, decreased after natural and accelerated aging. The greatest decreases of MOR, MOE, screw holding force and creep recovery rate were 14%, 13%, 21%, and 7% for W25, while 5%, 8%, 8%, and 14% for W20 respectively. Environmental aging can reduce the strength of WPC, but the bending strength retention rate is more than 85%, showing that performance of WPC is relatively stable compared to wood materials, which is oneof thereasons for the widely use of WPC in outdoor applications.

scholarly journals Thermal Properties of Wood-Plastic Composites with Different Compositions

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 881 ◽  
Author(s):  
Yong Guo ◽  
Shiliu Zhu ◽  
Yuxia Chen ◽  
Dagang Li
Keyword(s):  
Low Temperature ◽  
Melting Temperature ◽  
Dimensional Stability ◽  
Crystallization Temperature ◽  
Wood Fiber ◽  
Linear Thermal Expansion ◽  
Fiber Content ◽  
Wood Plastic Composites ◽  
Degradation Temperature ◽  
Plastic Composites

The thermal performance of wood–plastic composites (WPCs) with different fiber, different fiber contents, and different lubricants were investigated in this paper. The results show that the thermal degradation temperature, melting temperature, crystallization temperature, crystallinity, and viscosity of WPCs with wood fiber were slightly higher than those of WPCs with floor sanding powder and rice husk. As the wood fiber content increased, the melting temperature and crystallinity of WPCs decreased while the crystallization temperature, viscosity, and pseudoplasticity increased. When the wood fiber content was increased to 60%, the dimensional stability of WPCs tended to be constant, and a higher wood fiber content was not conducive for processing of WPCs. WPCs had a small coefficient of linear thermal expansion at low temperature and demonstrated a good dimensional stability. The presence of lubricant reduced the viscosity and increased the pseudoplasticity of the WPCs, which is advantageous for the dimensional stability of WPCs at low temperature while making it worse for high temperatures.

scholarly journals Rheological Properties of Wood–Plastic Composites by 3D Numerical Simulations: Different Components

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 417
Author(s):  
Xingcong Lv ◽  
Xiaolong Hao ◽  
Rongxian Ou ◽  
Tao Liu ◽  
Chuigen Guo ◽  
...  
Keyword(s):  
Flow Field ◽  
Rheological Properties ◽  
Wood Fiber ◽  
Velocity Shear ◽  
Wood Plastic Composites ◽  
Shear Rates ◽  
Plastic Composites ◽  
Power Law Fluids ◽  
Field Information ◽  
Computational Fluid Dynamics Cfd

The rheological properties of wood–plastic composites (WPCs) with different wood fiber contents were investigated using a rotational rheometer under low shear rates. The flow field information was analyzed and simulated by Ansys Polyflow software. The results showed that the WPCs with different wood fiber contents behaved as typical power-law fluids. A higher wood fiber content increased the shear thinning ability and pseudoplasticity of the WPCs. The pressure, velocity, shear rate, and viscosity distributions of the WPC during extrusion could be predicted by computational fluid dynamics (CFD) Ansys Polyflow software to explore the effects of different components on the flow field of WPCs.

scholarly journals Hot water extracted wood fiber for production of wood plastic composites (WPCs)

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Manuel Raul Pelaez-Samaniego ◽  
Vikram Yadama ◽  
Eini Lowell ◽  
Thomas E. Amidon ◽  
Timothy L. Chaffee
Keyword(s):  
Ponderosa Pine ◽  
Degradation Products ◽  
Wood Flour ◽  
Wood Fiber ◽  
Diffusion Constant ◽  
Hot Water ◽  
Thickness Swelling ◽  
Wood Plastic Composites ◽  
Hot Water Extraction ◽  
Plastic Composites

Abstract Undebarked ponderosa pine chips were treated by hot water extraction to modify the chemical composition. In the treated pine (TP), the mass was reduced by approximately 20%, and the extract was composed mainly of degradation products of hemicelluloses. Wood flour produced from TP and unextracted chips (untreated pine, UP) was blended with high-density polyethylene (HDPE) and polypropylene (PP) and was extruded into wood plastic composites (WPCs). Formulations for WPCs consisted of 58% pine, 32% plastic, and 10% other additives. WPC based on HDPE+TP and PP+TP absorbed 46–45% less water than did WPC based on HDPE+UP and PP+UP, respectively. Thickness swelling was reduced by 45–59%, respectively, after 2520 h of immersion. The diffusion constant decreased by approximately 36%. Evaluation of mechanical properties in flexure and tension mode indicated improvements in TP-WPC properties, although the data were not statistically significant in all cases. Results showed that debarking of ponderosa pine is not required for WPC production.

Fungal Degradation of Wood Plastic Composites Made with Thermally Modified Wood Residues

2016 ◽  
Vol 721 ◽  
pp. 8-12 ◽  
Author(s):  
Edgars Kuka ◽  
Dace Cirule ◽  
Janis Kajaks ◽  
Anna Janberga ◽  
Ingeborga Andersone ◽  
...  
Keyword(s):  
Wood Fiber ◽  
Fungal Growth ◽  
Fungal Resistance ◽  
Wood Fibers ◽  
Wood Plastic Composites ◽  
Fungal Degradation ◽  
Plastic Composites ◽  
Thermally Modified Wood ◽  
Modified Wood

Wood plastic composites (WPC) are mainly used as an outdoor material, so durability against fungal decay is one of the factors that should be analyzed and if necessary improved. WPC are susceptible to biodegradation, although these materials have limited water absorption because of the wood fiber encapsulation in polymer matrix. In the study two different water pretreatment methods (short-term and long-term) were used to ensure appropriate water content for fungal growth. Also in the paper thermally modified wood (different regimes) fiber influence on WPC fungal resistance is investigated. The results showed that long-term water pretreated WPC specimens had more suitable conditions for fungal degradation that led to higher weight loss. The results which were related to thermally modified wood fibers showed, that WPC with thermally modified wood fibers had improved resistance against fungi. Thermal modification regimes had an effect on WPC durability as well.

The Antimicrobial Effect of Different Antimicrobial Agents on Wood-Plastic Composites

2013 ◽  
Vol 377 ◽  
pp. 191-196
Author(s):  
Wang Wang Yu ◽  
Dong Xue ◽  
Bing Liu ◽  
Wen Lei ◽  
Ming Yan Wang ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Mass Loss ◽  
Antimicrobial Agents ◽  
Color Change ◽  
Wood Fiber ◽  
Antimicrobial Effect ◽  
Molding Process ◽  
Corrosion Properties ◽  
Wood Plastic Composites ◽  
Plastic Composites

Wood-plastic composites (WPC) were prepared by compression molding process using high density polyethylene and wood fiber as the main raw materials. The influence of nanozinc oxide, nanosilver antimicrobial powder and rosin amid treatment on WPC was investigated respectively by testing the mass loss, flexural strength, color change, surface tension, as well as surface images of the composites before and after the corrosion test. The results indicate that nanozinc oxide has little antimicrobial effect on WPC. While nanosilver antimicrobial powder and rosin amid both have effects on the anti-corrosion properties of WPC. It is also suggested that the WPC with the mass fraction of 6% rosin amid is the most antimicrobial, and its mass loss and flexural strength only decrease by 0.0788% and 2.24% respectively. These cost-efficient WPC can be practical to industrial application.

Research on Technology of Wood-Plastic Composites

2012 ◽  
Vol 630 ◽  
pp. 75-79
Author(s):  
Hua Yong Zhang ◽  
Xiao Jian Liu ◽  
Hai Yan Sun
Keyword(s):  
Raw Materials ◽  
Wood Fiber ◽  
Thermoplastic Resin ◽  
Excellent Performance ◽  
Wood Plastic Composites ◽  
Plastic Composites ◽  
Recycled Plastics

Wood-plastic composites were produced by heating, blending and extruding with recycled plastics and wood fiber as chief raw materials and some thermoplastic resin as the additive. The compounding formula and producing craft were researched and optimized. The influence of the ratio of wood fiber and additives was examined. Wood-plastics composites with excellent performance were produced.

Effects of wood fiber surface chemistry on strength of wood–plastic composites

2015 ◽  
Vol 343 ◽  
pp. 11-18 ◽  
Author(s):  
Sébastien Migneault ◽  
Ahmed Koubaa ◽  
Patrick Perré ◽  
Bernard Riedl
Keyword(s):  
Surface Chemistry ◽  
Wood Fiber ◽  
Fiber Surface ◽  
Wood Plastic Composites ◽  
Plastic Composites

scholarly journals A Computer Model of Starve Fed Single Screw Extrusion of Wood Plastic Composites

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1252
Author(s):  
Krzysztof J. Wilczyński ◽  
Kamila Buziak
Keyword(s):  
Computer Model ◽  
Wood Fiber ◽  
Experimental Studies ◽  
Melt Temperature ◽  
Wood Plastic Composites ◽  
Single Screw ◽  
Single Screw Extrusion ◽  
Plastic Composites ◽  
Screw Extrusion ◽  
Melting Mechanism

In this study, we present a computer model of starve fed single screw extrusion of wood plastic composites (WPC). Experimental studies have been performed on the extrusion of the polypropylene (PP) based composites with various wood fiber contents (WF). The melting mechanisms of the composites in the extruder have been observed, and melting models have been proposed for partially and fully filled sections of the screw. It was observed that in the partially filled section the material is melted by conduction, as in the case of extrusion of neat polymers. On the other hand, in the fully filled section, the Tadmor melting mechanism appears, which is different compared to the melting mechanism of neat polymers at starve fed extrusion, where dispersed melting is observed. Using the melting models, the global computer model of the process has been developed which makes it possible to predict the process flow, i.e., the polymer melt temperature and pressure, the polymer melting rate, and the degree of screw filling. To build the model, the specific forward/backward procedure was developed, which consists in determining “forward” the melting profile, and “backward” the pressure and screw filling profile. The temperature profile in the melting section is computed “forward”, while “backward” in the metering section. This procedure makes it possible to solve the crucial problem of modeling of the starve fed extrusion process, which is to find the location of the point where the screw is fully filled, and the pressure is developed. The model has been tested by pressure measurements in the extruder.

Effects of wood fiber esterification on properties, weatherability and biodurability of wood plastic composites

2013 ◽  
Vol 98 (7) ◽  
pp. 1348-1361 ◽  
Author(s):  
Liqing Wei ◽  
Armando G. McDonald ◽  
Camille Freitag ◽  
Jeffrey J. Morrell
Keyword(s):  
Wood Fiber ◽  
Wood Plastic Composites ◽  
Plastic Composites
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