• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.85-90
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• 2006

Increasing the filler content of sheet improves the optical properties and printability of paper and provides an opportunity for saving production cost through fiber replacement with relatively low-priced filler. But increasing the filler content tends to decrease the strength of paper and filler retention. It also tends to deteriorate drainage on the paper machine. To overcome these problems, preflocculation technology of fillers may be employed. Many research efforts have been made on the properties of preflocculated filler, namely prefloc, whose size and size distribution were influenced by polymer type and shear level. But there is much to be investigated about the effect of the prefloc characteristics on the physical properties of paper. To evaluate the effect cationic polymers on the size and size distribution of preflocculated GCC and their shear stability, cationic PAM and cationic starch were used. The influence of the preflocculation on filler retention and its surface distribution, and the changes of physical and optical properties of handsheets affected by the characteristics of preflocs were examined. Filler distribution on sheet surface was also analyzed by EPMA. Results showed that cationic PAM formed large preflocs at low dosage. Cationic starch was required to add 15 times as much as cationic PAM to obtain the preflocs with similar size. But preflocs formed with cationic starch was superior in shear stability to those formed with cationic PAM. Filler preflocculation technology could provide an opportunity of increasing filler content significantly without loss in tensile strength. And increased filler contents could compensate brightness loss which often accompanies filler preflocculation. When excessively large preflocs were used, however, brightness loss rather than the improvement in tensile strength was predominant. Therefore it is of great importance to produce preflocs with proper size and shear stability for maximizing the improvement of physical properties of papers.

• Fashion & Textile Research Journal
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• v.14 no.4
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• pp.629-634
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• 2012

Knitted fabric using acrylic/wool blended yarn (A/W) is increasingly used in the knit industry; subsequently, research on knitted fabric using A/W has increased. This study presents an scientific database from evaluating physical properties of $1{\times}1$ rib stitch using A/W. In this study,$1{\times}1$ rib stitch using A/W were made at various knitting tensions (dial no. 2-6) and the number (4-6) of ply yarn. The physical properties of $1{\times}1$ rib stitch using A/W were measured and analyzed. The density was in the range 5.5-6.4 wales/cm and 4.0-5.6 courses/cm, respectively. The density increased when less plying yarns and more knitting tension were added during knitting. The thickness was in the range of 1.592-2.362 mm and the tensile strength was in the range 32.75-53.63 Kgf/mm. The burst strength was in the range 107.8-139.2 $N/cm^2$. Thickness, tensile strength, and burst strength increased as the number of ply yarn and the knitting tension increased. The elongation and the recovery extension rate were in the range 102.29-112.13% and 96.4-97.7%, respectively. The heat retention rate was in the range 59.3-65.1%. There was no difference of the elongation and the recovery extension rate and the heat retention rate by the knitting tension and the number of the ply yarn. The permeability was in the range 170.5-396.3 $cm^3/cm^2/sec$. Air permeability decreased as the number of ply yarn and the knitting tension increased. The pilling properties were excellent for all $1{\times}1$ rib stitches.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10c
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• pp.7-12
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• 1998

The waste sludge is by-produced about 20-30% of total production and arised to the severe problems of this mine's surrounding environmnet. This study was invested the composition of component, particle of size of the waste sludge by Chemical Analysis, X, R, D, Particle Size Analyzer and the physical properties (air content, slump, strength, etc) of concrete when the waste sludge is added into concrete. so, It's recomended the proper content of the waste sludge to be added into concrete. and then, is verified to be applied at batch plant in field. Above the results, the recomeded content of the waste sludge is about 2-4% (about 4-8% in cement) in aggregates and when it's added the recomended content, they are detected to be more or less changed the physical properties of concrete, ( equally strength and durability, little less air con tent, little increased shinkage, etc). but the application of the recomended content don't arise the problem of the basic quality control of concrete and physical properties.

• Elastomers and Composites
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• v.7 no.1
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• pp.38-44
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• 1972

As a series of the studies of EPDM-polymer blonds, the experiments are concentrated to the investigation of the physical properties of the EPDM-BR blends. The results are shown as follows: 1. In blending, tensile strength and elongation decreased with increase in EPDM contents. 2. The resistance for aging and ozone were much improved after blending. It was effective more :han the ratio of EPDM/BR is 50/50. 3. Tear strength is less influenced after blending and rebound character decreased with increase in EPDM contents.

• Elastomers and Composites
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• v.6 no.2
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• pp.65-72
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• 1971

The purpose of this study is to establish an effective way to utilize the application of EPDM-Polymer blends. First of all, the physical properties for EPDM/NR blends and compounding agents were studied. The results are shown as follows: 1. In blending, tensile strength and tear strength decreased with increase in EPDM contents. It was not effective more than the ratio of EPDM/NR is 50/50. 2. Elongation is influenced by blending, especially the ratio of EPDM/NR is 50/50. 3. It was found that both the resistance for ozone and aging were much improved after blending.

• Journal of the Korean Wood Science and Technology
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• v.39 no.5
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• pp.429-436
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• 2011

The selected physical and mechanical properties of non-certificated LVL circulated in domestic lumber market were investigated and compared to relevant standards. The tested LVL passed the moisture content and the soaking delamination rate limit as per domestic (KS) and Japanese standard (JAS). The evaluated mechanical properties were flatwise/edgewise bending strength, modulus of elasticity (MOE), horizontal shear and compressive strength. The 30 mm-thick LVL showed significantly higher bending strength than that of the 25 mm-thick LVL. The modulus of elasticity (MOE) showed same tendency in the results of bending strength. The edgewise bending strength and MOE were higher than that of flatwise bending strength and MOE. The horizontal shear strength values were also showed similar results to bending strength values. The tested results were compared each other and each products were graded according to JAS 701 grade specification. The failure mode of LVL in bending test showed the similar failure mode of solidwood that failed in a simple tension manner (splintery tension). The glue line failure was severe in 25 mm-thick specimens due to concentration of shear stress in layer discontinuity containing small voids and starved glue lines. In horizontal shear strength test, failure mode of LVL showed the typical horizontal shear failure. Compressive specimens failed with fiber crushing in company with apparent delamination that splitted along the length of the specimens. From the results, the complete bonding between lamination and consistency in thin veneer layer were considered as a critical factor in the mechanical properties of LVL. Moreover, the standard test procedure and specification for non-certificated LVL should be required to check the performance of uncertificated materials.

• Elastomers and Composites
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• v.7 no.2
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• pp.183-192
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• 1972

As a series of tile studies of EPDM-Polymer blends, tile experiment are concentrated to the investigation of the physical properties of tile EPDM-NR-SBR blends. The results are shown as follows: 1. In blending, tensile strength decreased with increase in EPDM contents, especially the ratio of EPDM/NR-SBR is 75/25. 2. Elongation and tear strength were much influenced by blending, especially the ratio of EPDM/NR-SBR is 50/50. 3. Ozone resistance is much improved after blending. It was effective more than tile ratio of EPDM/NR-SBR is 25/75. 4. Aging resistance is much improved after blending. It was effective more than the ratio of EPDM/NR-SBR is 50/50. 5. Hardness increased with increase in EPDM contents and on the other hand, abrasion resistance decreased.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.4
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• pp.86-91
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• 1999

This study is performed to evaluate the physical and meanical properties of oyster shell concrete. The result shows that the unit weights of concrete with oyster shell are less by 15 ~2% than that of the normla cement concrete. The highest strengths are achieved by 2.5% oyster shell concrete , with increased compressive strength by 4% , tensile strength by 6% and bending strength by 7% than that of the normal cement concrete, respectively. The static modulusof elasticity is in the range of 290$\times$10$^3$~314 $\times$10$^3$kgf/㎤ for 2.5~7.0% oyster shell concrete,which has showed about the same compared to that of the normal cement concrete. The Poisson's number of oyster shell concrete is less than that of the normal cement concrete. Accordingly, oyster shell concrete will improve the properties of concrete.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.5
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• pp.433-437
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• 2004

The MmSH is a process of injecting ABS to produce innovated physical properties compared to the conventional injection process. Physical properties such as thickness and adhesion strength of Ni plate electrolessly coated on a conventional and a MmSH injected ABS have been studied in the pH range 4~8. Thickness of the plate on the MmSH and the conventionally injected ABS appeared to be directly proportional to pH. The ABS processed by the conventional injection showed adhesion strength corresponded to ASTM 4B above pH 5. On the other hand, the ABS processed by the MmSH injection showed a superior adhesion strength corresponded to ASTM 5B above pH 6. It was calculated the shielding effectiveness of above 50 dB in all conditions.

• Journal of the Korean Graphic Arts Communication Society
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• v.18 no.1
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• pp.95-102
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• 2000

This paper presents the second part of a study of deinking using wort. Physical properties of deinked pulps such as tensile strength, bursting strength and tearing resistance were investigated. In order to analyze the properties, the fiber length and coarseness of deinked pulp was also measured. Results of deinking experiments showed that the deinking efficiency of enzyme treatments was higher than that of chemical treatments in strength properties such as tensile strength, bursting strength and tearing resistance on the the whole. we think that the reason why is that the fiber length and coarseness of deinked pulp with wort are more increased and decreased than those of deinked pulp with chemicals individually.