Investigation of the Fracture of Resinated Single Wood Fibers in an Environmental Scanning Electron Microscope (Esem)

1998 ◽  
Vol 4 (S2) ◽  
pp. 838-839
Author(s):  
A. Egan ◽  
S. Shaler
Keyword(s):  
Mechanical Properties ◽  
Polymer Composite ◽  
Laser Scanning ◽  
Medium Density Fiberboard ◽  
Wood Fiber ◽  
Image Correlation ◽  
Environmental Scanning ◽  
Wood Fibers ◽  
Wood Polymer ◽  
Scanning Electron

Single fiber fracture is important in understanding the fundamental failure mechanisms in wood/polymer composite products such as medium density fiberboard (MDF). The mechanical properties and fracture behavior of individual wood fibers has only recently been observable using a combination of environmental scanning electron microscopy (ESEM), laser scanning confocal microscopy and digital image correlation (DIC). Previous work has shown that specific areas on the fiber such as microcompressions and pits acted as crack nucelators and induce a brash fracture across the surface of the fiber. Given the development of these procedures it is now possible to observe and measure the mechanical properties and fracture characteristics of the wood fiber/ polymer composite fibers.Individual black spruce wood fibers were coated with diphenylmethane 4-4'diisocyanate resin containing Hostasol Red GG. The addition of the Hostasol Red flurochrome provided the option of quantifying resin coverage by fluorescence microscopy.

scholarly journals Correlation between Mechanical Properties and Processing Conditions in Rubber-Toughened Wood Polymer Composites

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1170 ◽  
Author(s):  
Valentina Mazzanti ◽  
Lorenzo Malagutti ◽  
Andrea Santoni ◽  
Francesca Sbardella ◽  
Andrea Calzolari ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wood Flour ◽  
Wood Fiber ◽  
Sharp Decrease ◽  
Processing Conditions ◽  
Wood Fibers ◽  
Screw Speed ◽  
Feeding Mode ◽  
Wood Polymer ◽  
The Cost

The use of wood fibers is a deeply investigated topic in current scientific research and one of their most common applications is as filler for thermoplastic polymers. The resulting material is a biocomposite, known as a Wood Polymer Composite (WPC). For increasing the sustainability and reducing the cost, it is convenient to increase the wood fiber content as much as possible, so that the polymeric fraction within the composite is thereby reduced. On the other hand, this is often thwarted by a sharp decrease in toughness and processability—a disadvantage that could be overcome by compounding the material with a toughening agent. This work deals with the mechanical properties in tension and impact of polypropylene filled with 50 wt.% wood flour, toughened with different amounts (0%, 10%, and 20%) of a polypropylene-based thermoplastic vulcanizate (TPV). Such properties are also investigated as a function of extrusion processing variables, such as the feeding mode (i.e., starve vs. flood feeding) and screw speed. It is found that the mechanical properties do depend on the processing conditions: the best properties are obtained either in starve feeding conditions, or in flood feeding conditions, but at a low screw speed. The toughening effect of TPV is significant when its content reaches 20 wt.%. For this percentage, the processing conditions are less relevant in governing the final properties of the composites in terms of the stiffness and strength.

Effect of the delignification of wood fibers on the mechanical properties of wood fiber–polypropylene composites

2006 ◽  
Vol 102 (5) ◽  
pp. 4759-4763 ◽  
Author(s):  
Alinaghi Karimi ◽  
Saleh Nazari ◽  
Ismaeil Ghasemi ◽  
Mehdi Tajvidi ◽  
Ghanbar Ebrahimi
Keyword(s):  
Mechanical Properties ◽  
Wood Fiber ◽  
Wood Fibers ◽  
Polypropylene Composites

scholarly journals ADSORPTION OF NANOWOLLASTONITE ON CELLULOSE SURFACE: EFFECTS ON PHYSICAL AND MECHANICAL PROPERTIES OF MEDIUM-DENSITY FIBERBOARD (MDF)

CERNE ◽  
2016 ◽  
Vol 22 (2) ◽  
pp. 215-222 ◽  
Author(s):  
Hamid Reza Taghiyari ◽  
Roya Majidi ◽  
Asghar Jahangiri
Keyword(s):  
Mechanical Properties ◽  
Density Functional ◽  
Medium Density Fiberboard ◽  
Physical And Mechanical Properties ◽  
Mechanical Tests ◽  
National Standard ◽  
Medium Density ◽  
Wood Fibers ◽  
Strong Adsorption ◽  
Cellulose Surface

ABSTRACT Effects of nanowollastonite (NW) adsorption on cellulose surface were studied on physical and mechanical properties of medium-density fiberboard (MDF) panels; properties were then compared with those of MDF panels without NW-content. The size range of NW was 30-110 nm. The interaction between NW and cellulose was investigated using density functional theory (DFT). Physical and mechanical tests were carried out in accordance with the Iranian National Standard ISIRI 9044 PB Type P2 (compatible with ASTM D1037-99) specifications. Results of DFT simulations showed strong adsorption of NW on cellulose surface. Moreover, mechanical properties demonstrated significant improvement. The improvement was attributed to the strong adsorption of NW on cellulose surface predicted by DFT, adding to the strength and integrity between wood fibers in NW-MDF panels. It was concluded that NW would improve mechanical properties in MDF panels as a wood-composite material, as well as being effective in improving its biological and thermal conductivity.

Performance of Wood-Polymer Composite Prepared by In Situ Synthesis of Terpolymer within Wood

2010 ◽  
Vol 34-35 ◽  
pp. 1165-1169 ◽  
Author(s):  
Yong Feng Li ◽  
Bao Gang Wang ◽  
Qi Liang Fu ◽  
Yi Xing Liu ◽  
Xiao Ying Dong
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Polymer Composite ◽  
Value Added ◽  
Untreated Wood ◽  
Modulus Of Rupture ◽  
Hydroxyl Group ◽  
Wood Polymer ◽  
Wood Polymer Composite

In order to improve the value-added applications of low-quality wood, a novel composite, wood-polymer composite, was fabricated by in-situ terpolymerization of MMA, VAc and St within wood porous structure. The structure of the composite and the reaction of monomers within wood were both analyzed by SEM and FTIR, and the mechanical properties were also evaluated. The SEM observation showed that the polymer mainly filled up wood pores, suggesting good polymerizating crafts. The FTIR results indicated that under the employed crafts, three monomers terpolymerized in wood porous structure, and grafted onto wood matrix through reaction of ester group from monomers and hydroxyl group from wood components, suggesting chemical combination between the two phases. The mechanical properties of the wood-polymer composite involving modulus of rupture, compressive strength, wearability and hardness were improved 69%, 68%, 36% and 210% over those of untreated wood, respectively. Such method seems to be an effective way to converting low-quality wood to high-quality wood.

A preliminary study of green production of fiberboard bonded with tannin and laccase in a wet process

Holzforschung ◽  
2009 ◽  
Vol 63 (5) ◽  
Author(s):  
Petri Widsten ◽  
Alfred Hummer ◽  
Carol Heathcote ◽  
Andreas Kandelbauer
Keyword(s):  
Mechanical Properties ◽  
Tannic Acid ◽  
Negative Impact ◽  
Medium Density Fiberboard ◽  
Wood Fibers ◽  
Dry Process ◽  
Wet Process ◽  
Positive Effects ◽  
Green Production ◽  
Industrial Standards

Abstract A gluing method for fiberboard based on laccase-activated tannin and wood fibers was investigated on a laboratory scale. Oxygen consumption measurements showed that hydrolyzable tannins (tannic acid and chestnut tannin) were more reactive toward laccase than condensed tannins from mimosa and quebracho. Wet-process hardboard prepared with laccase and the most reactive tannin, tannic acid, had superior mechanical strength compared to controls and boards made with laccase alone or laccase and other tannins. The other tannins did not improve mechanical properties more than laccase treatment alone. The addition of wax to the tannic acid-laccase formulation improved the dimensional stability of the boards enough for them to comply with industrial standards, although wax had a negative impact on the mechanical properties. The results cannot be directly applied to dry-process medium-density fiberboard (MDF) production; however, the positive effects of tannin and laccase on hardboard properties also warrant investigations on the green chemistry of MDF production.

Effects of Nano-ZrO2 on the Microstructure and Mechanical Properties of Ti(C,N)-Based Cermet Die Materials

2010 ◽  
Vol 154-155 ◽  
pp. 1319-1323 ◽  
Author(s):  
Xing Hai Wang ◽  
Chong Hai Xu ◽  
Ming Dong Yi ◽  
Hui Fa Zhang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Flexural Strength ◽  
Weight Percent ◽  
Environmental Scanning ◽  
Microstructure And Mechanical Properties ◽  
Vacuum Atmosphere ◽  
Die Materials ◽  
Scanning Electron

In recent, the development of new die materials is one of the important topics in the field of die research. In this paper, effects of nano-ZrO2 addition on the microstructure and mechanical properties of Ti(C,N)-based cermets were studied. The newly developed Ti(C,N)-based cermet die materials with different contents of nano-ZrO2 of 0~25wt% were prepared by hot pressing technique under vacuum atmosphere at 1450°C for 30min. Moreover, the microstructure of this Ti(C,N)-based cermet die materials was observed by environmental scanning electron microscope. It indicates that the comprehensive mechanical properties can reach the optimum when the weight percent of the nano-ZrO2 is 10%. The corresponding flexural strength and fracture toughness is 967 MPa and 13.62 MPa•m1/2, respectively which is approximately 65% and 110% higher than that of the cermet without nano-ZrO2 addition. It suggests that the addition of nano-ZrO2 can improve the mechanical properties especially the fracture toughness and flexural strength of Ti(C,N)-based cermet die materials.

Sign in / Sign up

Export Citation Format

Share Document