• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1008-1013
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• 1999

Mechanical properties and morphology of pectin/starch blend films depending upon the composition and plasticizer ratio were studied. Blends were prepared continuously in a twin-screw extruder. Films were prepared using a single-screw extruder with slit die. Most of the blends showed a good thermoplastic behavior, while the blends with very high ratio of pectin/starch had a poor thermoplasticity. Tensile properties of blend films were changed significantly by the amount of glycerol and relatively little by the ratio of pectin/starch. Differential scanning calorimetry(DSC) curves of wet blends showed a transition similar to glass transition temperature(Tg) at about $125^{\circ}C$. It was found by Scanning electron microscopy(SEM) study that there exists a good interfacial adhesion between pectin and starch.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2003.04a
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• pp.162-166
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• 2003

탄성체는 크게 열경화성 탄성체(thermosetting elastomer)와 열가소성 탄성체(thermoplastic elastomer)로 분류할 수 있다. 이러한 탄성체들 가운데 대표적인 소재로 반복하여 재사용이 가능하여 경제적인 소재이며 환경친화적인 소재인 열가소성 폴리우레탄에 대한 관심이 높아져 왔고 그에 따른 연구도 활발히 진행되어 왔다. 이러한 열가소성 폴리우레탄(TPU)은 가공의 용이성과 양호한 물리적 ㆍ화학적 성질 때문에 섬유용 소재에서 엔지니어링 플라스틱에 이르기까지 광범위한 산업용 소재로의 개발을 통하여 사용량이 지속적으로 증가를 보이고 있다. (중략)

• Journal of the Korean Wood Science and Technology
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• v.45 no.5
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• pp.559-571
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• 2017

This study was conducted to determine the adhesive performances of plywoods affected by layering direction and the amounts of thermoplastic films. The face and back layers of veneer were hardwood species (Mixed light hardwood) and core layer veneer was radiata pine (Pinus radiata D. Don). Thermoplastic film used as adhesive were polypropylene (PP) film and polyethylene (PE) film. Thermal analysis and tensile strength were investigated on each films. As a result, the melting temperature of PP and PE films were $163.4^{\circ}C$ and $109.7^{\circ}C$, respectively, and the crystallization temperature were $98.9^{\circ}C$ and $93.6^{\circ}C$, respectively. Tensile strength and elongation of each films appeared higher on the width direction than length direction. Considering the characteristics of the thermoplastic films, the test for the amount of film used was carried out by layering film to the target thickness on veneer. The effecting of layering direction of film on plywood manufacturing was conducted by laminating in the length and width directions of the film according to the grain direction of veneer. Tensile-shear strength of plywood in wet condition was satisfied with the quality standard (0.7 MPa) of KS F 3101 when the film was used over 0.05 mm of PP film and over 0.10 mm of PE film. Tensile-shear strength of plywood after cyclic boiling exceeded the KS standard when PP film was used 0.20 mm thickness. Furthermore, higher bonding strength was observed on a plywood made with width direction of film according to grain direction of veneer than that of length direction of film. Based on microscopic analysis of the surface and bonding line of plywood, interlocking between veneers by penetration of a thermoplastic film into inner and cracks were observed.

• Tribology and Lubricants
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• v.25 no.2
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• pp.86-95
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• 2009

Adhesion tests were carried out in order to investigate the effect of temperature on the adhesion behavior between a PMMA film and a fused silica lens in the micro scale. For the tests, a microtribometer system was specially designed and constructed. The pull-off forces on the PMMA film were measured under atmospheric condition as the temperature of the PMMA film was increased from 300 K to 443 K and decreased to 300 K. The contact area between the PMMA film and the lens was observed during the test. The adhesion behavior was changed with the change of the PMMA surface state as the temperature increased. In glassy state below 363 K, the pull-off force did not change with the increase of temperature. In rubbery state from 383 K to 413 K, the pull-off force increased greatly as the temperature increased. In addition, the area of contact was enlarged. In viscous state above 423 K, the fingering instability was observed in the area of contact when the PMMA film contacted with the lens. It was also found that the adhesion behavior can be varied with the thermal history of the PMMA film. The residual solvent in the PMMA film could emerge to the PMMA surface due to the heating and reduced the pull-off force.

• Tribology and Lubricants
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• v.25 no.4
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• pp.207-216
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• 2009

Friction tests were carried out in order to investigate the effects of temperature on the friction and wear behaviors between a PMMA film and a fused silica lens using a microtribometer. The friction forces on the PMMA film were measured under atmospheric condition as the temperature of the film was increased from 300 K to 443 K. The contact area between the film and the lens was observed. The tribological characteristics of the film were significantly changed as the temperature increased. The changes were discussed with the change of the film state from glassy to viscous flow. In addition, the results showed that the friction behavior can be varied with the thermal history of the PMMA film. Residual solvent in the PMMA film could emerge to the PMMA surface due to an additional heating and the solvent on the film surface decreased the friction force.

• Composites Research
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• v.31 no.6
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• pp.317-322
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• 2018

In various industry, the composite is tried to be applied to products and thermoplastic based composite is in the spotlight because this composite can be recycled. The use of continuous fiber thermoplastic (CFT) method increased gradually than long fiber thermoplastic (LFT). In this study, tensile, flexural, and impact test of different array types of glass fiber (GF)/thermoplastic composites were performed to compare with GF array. Impregnation property between GF mat and thermoplastic was determined using computed tomography (CT). At CFT method, thermoplastic film is not wet into GF roving and many voids are appeared into composite. This phenomenon affects to decrease mechanical properties. Plain pattern GF mat was the best mechanical and impregnation properties that distance between two roving was set closely to $100{\mu}m$.

• Composites Research
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• v.30 no.3
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• pp.181-187
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• 2017

The effect of nanoscopic and microscopic Fe, $Fe_3O_4$, and Ni particles and their shapes and substrate materials on the heating behavior of thermoplastic polyurethane (TPU) adhesive films was investigated via induction heating. The heat generation tendency of $Fe_3O_4$ particles was higher than that shown by Fe and Ni particles in the TPU adhesive films. When the Fe and Ni particle size was larger than the penetration skin depth, the initial heating rate and maximum temperature increased with an increase in the particle size. This is attributed to the eddy current heat loss. The heating behavior of the TPU films with Ni particles of different shapes was examined, and different hysteresis heat losses were observed depending on the particle shape. Consequently, the flake-shaped Ni particles showed the most favorable heat generation because of the largest hysteresis loss. The substrate materials also affected the heating behavior of the TPU adhesive films in an induction heating system, and the thermal conductivity of the substrate materials was determined to be the main factor affecting the heating behavior.

• Composites Research
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• v.35 no.2
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• pp.75-79
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• 2022

In this study, the effect of mechanical and chemical properties of glass fiber reinforced thermoplastic (GFRTPs) according to the number of recycling was confirmed. The composite materials were manufactured through a hot press compression molding process using an E-glass chopped strand mat and a polypropylene film. Four specimens were named according to the number of recycled test repeat: First manufacture, 1st Recycle, 2nd Recycle, and 3rd Recycle. To investigate the mechanical properties of the prepared specimen, tensile test, flexural test, drop-weight impact test, differential scanning calorimetry (DSC), and field emission electron gun-scanning electron microscope (FE-SEM) was performed. As a result, as the number of recycling steps repeat, the degree of crystallization, tensile strength, elastic modulus, and flexural strength were increased, but the impact properties were greatly reduced.

• Polymer(Korea)
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• v.25 no.1
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• pp.122-132
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• 2001

Thermoplastic film infusion process was investigated by using a rubber tool, which intrinsically contains a thermally-expandable characteristic and effectively compensates for the pressure loss caused by thermoplastic polymer infusion. Increasing temperature up to the melting temperature of matrix, the polymer melt subsequently infused into the dry fabric, but the pressure was successfully sustained by the rubber tool. Even with the decreased resin volume, the rubber tool produced sufficiently high elastic force for continuous resin infusion. Combining D'Arcy's law with the compressibility of rubber tool and elastic fiber bed, a film infusion model was developed to predict the resin infusion rate and pressure change as a function of time. In addition, the film infusion process without the rubber tool was viewed and analyzed by a compression process of the elastic fiber bed and viscous resin melt. The compressibility of fiber bed was experimentally measured and the multiple-step resin infusion was well described by the developed model equations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.458-461
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• 2002

This study presents development of a machine for shrink wrapping of cans or drink bottles with thermoplastic films. The accurate position-control, the safety factor of chains, the reduction-ratio of the chain and gear, the appropriate heating temperature for banding vinyl are discussed for the optimum shrink wrapping M/C design.