• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.324-329
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• 2014

Purpose: The finite element method (FEM) is advantageous because it can save time and cost by reducing the number of samples and experiments in the effort to identify design factors. In computational problem-solving it is necessary that the exact material properties are input for achieving a reliable analysis. However, in the case of fiber boards, it is difficult to measure their cross-directional material properties because of their small thickness. In previous research studies, the Poisson's ratio was measured by analyzing ultrasonic wave velocities. Recently, the Poisson's ratio was measured using a high-speed digital camera. In this study, we measured the transverse strain of a fiber board and calculated its Poisson's ratio using a high-speed digital camera in order to apply these estimates to a FEM analysis of a fiber board, a corrugated board, and a corrugated box. Methods: Three different fiber board samples were used in a uniaxial tensile test. The longitudinal strain was measured using the Universal Testing Machine. The transverse strain was measured using an image processing method. To calculate the transverse strain, we acquired images of the fiber board before the test onset and before the fracture occurred. Acquired images were processed using the image processing program MATLAB. After the images were converted from color to binary, we calculated the width of the fiber board. Results: The calculated Poisson's ratio ranged between 0.2968-0.4425 (Machine direction, MD) and 0.1619-0.1751 (Cross machine direction, CD). Conclusions: This study demonstrates that measurement of the transverse properties of a fiber board is possible using image processing methods. Correspondingly, these processing methods could be used to measure material properties that are difficult to measure using conventional measuring methodologies that employ strain gauge extensometers.

• Journal of the Korean Wood Science and Technology
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• v.15 no.3
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• pp.44-55
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• 1987

In order to study the effect of sawdustboard combined with plastic chips, 0.5mm($T_1$), 1mm($T_2$), 1.4mm($T_3$) thick nylon fiber. polypropylene rope fiber(RP), and 0.23mm thick moth-proof polypropylene net fiber(NP) were cut into 0.5, 1, 2cm long plastic chips. Thereafter, sawdustboard combined with plastic chips prepared as the above and plastic non-combined sawdustboard(control) were manufactured into 3 types of one-, two-, and three layer with 5 or 10% combination level. By the discussions and results at this study, the significant conclusions of mechanical and physical properties were summarized as follows: 1. The MORs were shown in the order of 3 layer> 2 layer> 1 layer among plastic non-combined boards, and $T_3$ < $T_2$ < $T_1$ < RP (NP(5%) < NP(l0%) among plastic combined boards. In 2cm long plastic chip in 1 layer board, the highest strength through all the composition was recognized. 1 layer board showing the lower strength with 0.5cm plastic chip rendered to the bending strength improvement by 2 or 3 layer board composition. On the other hand, 2 or 3 layer combined with 1, 2cm long polypropylene net fiber chips incurred MOR's conspicuous decrease requiring optimum plastic chip combined level and consideration to combined type. 2. MOE in plastic non-combined 3 layer board exhibited sandwich construction effect by higher resin content application to surface layer in the order of 3layer>1layer>2layer with the highest stiffness of the board combined with polypropylene chip, while nylon chip-combined board had little difference from plastic non-combined board. In relevant to length and layer effect, 3 layer board combined with the 0.5cm long polypropylene net fiber chip in 5% and 10% combined level presented 34-43% and 44-76% stiffness increase against plastic non-combined board(control), respectively. Moreover, in 1 layer board, 30% stiffness increase with 10% against 5% combined level in the 1 and 2cm long polypropylene net fiber chip was obtained. 3. Stress at proportional limit(Spl) showing the fiber relationship (r: 0.81-0.97) between MOR presented in the order of 1 layer<2 layer<3 layer in plastic non-combined board. Correspondingly, combined effect by layer and plastic chip length was similar to MOR's. 4. Differently from previous properties(MOR, MOE, Spl). work to maximum load(Wml) of 2 layer board approached to that of 3 layer board. Conforming the above phenomenon. 2 layer combined with 0.5cm long polypropylene net fiber chip kept the greater work than 1 layer. The polypropylene combined board superior to nylon -and plastic non - combined board seemed to have greater anti - failing capacity. 5. Internal bond strength(IB), in contrast to MOR's tendency. showed in the order of T1

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.1
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• pp.1-13
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• 2006

The recent environmental protection issue has diminished the supply of sand for soft ground improvements so much that the prices of sand have shown a sudden rise. Plastic material is one of substitutes for sand material, but plastic is nonperishable and doubtable if it has potential environmental hormone disrupting substances. Moderate-priced natural fiber drain board made with coconut coir and jute filter are in the spotlight recently as an alternative material for sand and plastic drain board etc. Natural fiber drain has not only competitive price but also a characteristic of assimilation into the soils after finishing of its own function. Discharge capacity of the fiber drain board evaluated by triaxial type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of the fiber drain board and the plastic drain board which were installed in the clayey soil during the composite discharge capacity test were almost similar. It was also found that biodegradation of the fiber drain board was in progress until 18 month after installation in the clayey soil, but they had still enough engineering properties to use at field.

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.47-58
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• 2001

For finding both ways of recycling the wood and plastic wastes and solving the problem of free formaldehyde gas emission through manufacturing wood particle-polypropylene fiber composite board without addition of formaldehyde-based thermosetting resin adhesive, control particleboards and nonwoven web composite boards from wood particle and polypropylene fiber formulation of 50 : 50, 60 : 40, and 70 : 30 were manufactured at density levels of 0.5, 0.6, 0.7, and 0.8 g/$cm^3$, and were tested both in the physical and mechanical properties according to ASTM D 1037-93. In the physical properties, control particleboard had significantly higher moisture content than composite board. In composite board, moisture content decreased with the increase of target density only in the board with higher content of polypropylene fiber and also appeared to increase with the increase of wood particle content at a given target density. Control particleboard showed significantly greater water absorption than composite board and its water absorption decreased with the increase of target density. In composite board, water absorption decreased with the increase of target density at a given formulation but increased with the increase of wood particle content at a given target density. After 2 and 24 hours immersion, control particleboard was significantly higher in thickness swelling than composite board and its thickness swelling increased with the increase of target density. In composite board, thickness swelling did not vary significantly with the target density at a given formulation but its thickness swelling increased as wood particle content increased at a given target density. Static bending MOR and MOE under dry and wet conditions increased with the increase of target density at a given formulation of wood particle and polypropylene fiber. Especially, the MOR and MOE under wet condition were considerably larger in composite board than in control particleboard. In general, composite board showed superior bending strength properties to control particleboard, And the composite board made from wood particle and polypropylene fiber formulation of 50 : 50 at target density of 0.8 g/$cm^3$ exhibited the greatest bending strength properties. Though problems in uniform mixing and strong binding of wood particle with polypropylene fiber are unavoidable due to their extremely different shape and polarity, wood particle-polypropylene fiber composite boards with higher performance, as a potential substitute for the commercial particleboards, could be made just by controlling processing variables.

• Journal of the Korean Wood Science and Technology
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• v.31 no.3
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• pp.1-10
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• 2003

Shredded waste newspapers, waste acrylic raw fibers, and urea-formaldehyde (UF) adhesives, at 10% by weight on raw material, were used to produce recycled waste paper-waste acrylic raw fiber composite boards in laboratory scale experiments. The physical and mechanical properties of fire retardant treated recycled waste paper-waste acrylic raw fiber composite boards were examined to investigate the possibility of using the composites as internal finishing materials with specific gravities of 0.8 and 1.0, containing 5, 10, 20, and 30(wt.%) of waste acrylic raw fiber and 10, 15, 20, and 25(wt.%) of fire retardant (inorganic chemical, FR-7^®) using the fabricating method used by commercial fiberboard manufacturers. The bending modulus of rupture increased as board density increased, decreased as waste acrylic raw fiber content increased, and also decreased as the fire retardant content increased. Mechanical properties were a little inferior to medium density fiberboard (MDF) or hardboard (HB), but significantly superior to gypsum board (GB) and insulation board (IB). The incombustibility of the fire retardant treated composite board increased on increasing the fire retardant content. The study shows that there is a possibility that composites made of recycled waste paper and waste acrylic raw fiber can be use as fire retardant internal finishing materials.

• Journal of the Korean Geosynthetics Society
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• v.4 no.1
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• pp.27-36
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• 2005

Discharge capacity of the fiber mat and the fiber drain made with natural fibers abstracted from plant source was evaluated by permeability test for fiber mat and Delft type test and composite discharge capacity test using disturbed clayey soils for fiber drain. The permeability test results for environmentally friendly coconut fiber mat prove that fiber mat has outstanding permeability in substituting permeable sand. However, discharge capacity of fiber drain evaluated by conventional Delft type discharge capacity test was relatively lower than that of plastic drain board. Nevertheless, settlement and pore pressure dissipation behaviors of fiber drain and plastic drain board installed clay soil during the composite discharge capacity test were almost similar to that of plastic drain board. It is found that the natural fiber drain satisfies requiring minimum discharge capacity in substituting the conventional plastic drain board.

• Journal of the Korean Ceramic Society
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• v.40 no.8
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• pp.735-738
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• 2003

The PTFE composites for the microwave printed circuit board were prepared using woven glass fiber. The dielectric constant of the PTFE composites with oven glass fiber tended to decrease with an increase of immersion time, and was saturated at 3 times immersion. It resulted from the fact that fine powders of PTFE filled up at the pore and bend of woven glass fiber sufficiently. As the immersion time increased, the propagation velocity increased due to the reduction of dielectric constant.

• Journal of the Korea Institute of Building Construction
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• v.12 no.4
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• pp.442-450
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• 2012

In this study, fire resistance and residual strength were examined after the addition of PF fiber and bonding fireproofing gypsum board to a high strength concrete-model column of 50 MPa grade. At the beginning of the experiment, all the properties of base concrete appeared to satisfy the target range. In terms of the internal temperature record, a trend of slightly high temperature was shown when the fireproofing gypsum board was not bonding, and when the fireproofing gypsum board was bonding, as PF content increased gradually, the temperature was gradually lowered. In terms of the relationship, as time elapsed a low temperature was shown when fiber was mixed, and when the board was bonding, the trend of lower temperature could be confirmed. Meanwhile, in terms of spalling property, a severe explosive fracture was generated at PF 0%, and falling off was prevented as the fiber content was increased; however, discoloration and a multitude of cracks were discovered, and when the board was bonding, the trend in which the exterior became satisfactory when the content was increased emerged. In terms of the residual compressive strength, measuring of strength could not be performed at PF 0% without bonding of board, and the strength was increased as the fiber content was increased; however, there was a decrease in strength of about 30 ~ 40%, and in the case of PF 0% with the bonding of board, the strength could be measured; however, about an 80% decrease in strength was shown, and only about a 10 ~ 20% decline in strength was displayed, as the range of decrease was reduced as the fiber content was increased. Considering all of these factors, it was determined that a more efficient enhancement of fire resistance was obtained when two methods are applied in combination rather than when the PF fiber content and bonding of fireproofing gypsum board are utilized individually.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.11a
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• pp.163-164
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• 2018

In this study, the adhesion performance of the adhesive between the concrete base and the fiber panel was verified through experiments. Attachment to all three types by applying adhesive to panel and attaching to CRC board surface, method of applying adhesive to CRC board surface by panel, method of applying adhesive on panel and CRC board surface respectively, As a result of the performance test, the adhesive strength of the panel attached to the panel on the CRC board after the application of the adhesive was highest on both the back surface of the panel and the surface of the CRC board.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.55-60
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• 2003

Case that long-fiber reinforced polymeric composites of fiber orientation situation of a direction state is J=1 that is direction of tensile strength of another state appeared highest. And theoretical tensile strength value of long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state appeared similarly with tensile strength value that long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state. Also, than case that efficiency of fiber orientation situation of long-fiber reinforced polymeric composites is J=1 in it is J=0.1 of fiber orientation situation effect of long-fiber reinforced polymeric composites about 60% high appear.