• Journal of the Korean Recycled Construction Resources Institute
• /
• v.3 no.4
• /
• pp.328-334
• /
• 2015

Building insulation materials use for the purpose of energy saving. Insulation materials can be classified inorganic and organic insulation materials. Inorganic insulation is used for fire resistive performance parts and organic insulation is used for thermal performance parts. Meanwhile, organic insulation is due to toxic gas emission in fire. Inorganic insulation is too heavy and low thermal performance than organic materials. This study is focused on evaluation of the physical properties of inorganic foam material using industrial by-products such as waste glass powder and fly ash. From the test result, inorganic foam materials for the applicability of fire-resistance and insulation light-weight materials.

• Resources Recycling
• /
• v.26 no.1
• /
• pp.16-21
• /
• 2017

This paper relates to the synthesis of a source powder for SiC crystal growth. ${\beta}-SiC$ powders are synthesized at high temperatures (>$1400^{\circ}C$) by a reaction between silicon powder and carbon powder. The reaction is carried out in a graphite crucible operating in a vacuum ambient (or Ar gas) over a period of time sufficient to cause the Si+C mixture to react and form poly-crystalline SiC powder. End-product characterizations are pursued with X-ray diffraction analysis, SEM/EDS, particle size analyzer and ICP-OES. The purity of the end-product was analyzed with the Korean Standard KS L 1612.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.9 no.3
• /
• pp.397-404
• /
• 2021

In this study, it was reviewed that the effect of solid capsules on the quality of surface repair materials and the healing properties of long-term aging, as part of a study to utilize self-healing surface repair materials using solid capsules as repair materials. As a result of evaluation of the rheological properties of self-healing surface repair materials according to the mixing of solid capsules, plastic viscosity, yield stress, and table flow tended to decrease. In the case of compressive strength, 1MPa per 1% of the solid capsule decreased proportionally. As a result of evaluating the long-term healing properties, when 10% of solid capsules were mixed, a healing rate of 90% was shown at 28 days of healing, because the solid capsule was preserved even after 91 days of age had elapsed. after 91 days of healing, even in the case of 5% of solid capsules, a healing rate of 90% was shown.

• Resources Recycling
• /
• v.33 no.4
• /
• pp.29-35
• /
• 2024

The recycling of waste resources, such as spent catalysts, primarily involves leaching and extracting metal components via smelting. These metal components are then recovered as salts, such as sulfates and nitrates. When crystallization occurs during the calcination of the recovered salts, the salts are converted into oxides, which are then reduced to form metals or ceramic materials. Common reducing agents used in oxide reduction include hydrogen and carbon, and metal powders are obtained upon reduction. Carbide synthesis can occur if the recycled element is a transition metal and carbon is used as the reducing agent. Despite being ceramic materials, transition metal carbides exhibit excellent conductivity owing to their metallic bonding. Recently, MXene, a two-dimensional transition metal carbide, has gained attention for electromagnetic wave shielding, secondary battery electrodes, and water purification owing to its electrical conductivity and large surface area. This study developed a process for synthesizing high-value MXene materials from waste resources. The properties of these MXenes were evaluated to confirm the potential of using waste resources as raw materials for MXenes.

• Archives of design research
• /
• v.19 no.3 s.65
• /
• pp.105-116
• /
• 2006

In product manufacturing industries, a recent issue is the green concept. The green concept is a complicated area. If the green concept is for products, its serious issues have to be criticized. Although the importance of the green concept has overflowed, its influences have not been disputed vigorously. So this study is to critic the serious issues of the green concept in aesthetics in product design, manufacturing, and products' prices. The green environment has four representative elements: systems, policies, minds, and technologies, but they are not in the field of design. An element of the green concept, green design is also a sub concept for design, so it should be based on aesthetics. It is green aesthetics. But since green design first appeared, it has never approached by aesthetics because it has mostly had social meanings and expectations. So for green aesthetics, to think about what makes a product, and what can be aesthetic issues among them are important. Products consist of form, structure, material, and technology. Form means different shapes in a structure, but there cannot be any specific directions for a green concept. Structure has two kinds: interior and exterior structure. While interior structure has a technological character, exterior structure is deeply related with aesthetics, but it has also no chance for green concept. Material can be divided as two also: aesthetic and technological. Aesthetics materials mean the colors, opacity, and tactile sense of materials, but they are not aesthetic issues. Technological materials are recycled materials or non-recycled materials. Even if recycled materials are used today, they are close to systems or policies rather than aesthetics. With this result, green aesthetics is a very difficult concept. Second, green products are usually 30% more expensive than general products. But every consumer has his or her own economical conditions, and nobody can coerce consumers into buying expensive green products for green environments. And green products without good quality cannot satisfy consumers. This means that green concept is not accomplished by just manufacturing green products. Third, although a lot of proposals have appeared as green design in exhibitions, most of them are close to craft because they are so hard to be manufactured. Manufacturing is the first consideration for products. These three issues are enough to explain why green concept is complicated in manufacturing products. If they are not solved, the green concept is just a fiction. So if this study proposes a turning point against blind green-oriented atmosphere, it will be meaningful enough.

• Composites Research
• /
• v.28 no.4
• /
• pp.168-175
• /
• 2015

Recently, the applications of carbon fiber reinforced plastics (CFRPs) have become broader than ever when it comes to such industries as automotive, ships, aerospace and military because of their lightweight-ness and high mechanical properties. Thermosetting plastics like epoxy are frequently used as the binding matrix in CFRPs due to their high hardness, wetting characteristics and low viscosity. However, they cannot melted and remolded. For this reason, thermosetting plastic wastes have caused serious environmental problems with the production of fiber reinforced plastics. Thus, many studies have focused on the carbon fiber reinforced thermoplastics (CFRTPs) and recycling carbon fiber. In this study, recycled carbon fiber (RCF) was prepared from CFRPs using a pyrolysis method, which was employed to separate resin and carbon fiber. The degree of decomposition for epoxy resin was confirmed from thermal gravimetric analysis (TGA) and scanning electron microscope (SEM). The RCF was cut and ground to prepare a carbon fiber composite sheet (CFCS). CFCS was manufactured by applying recycled carbon fibers and various thermoplastic fibers. Various characterizations were performed, including morphological analyses of surface and cross-section, mechanical properties, and crystallization enthalpy of CFCS at different cooling conditions.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.1
• /
• pp.26-32
• /
• 2020

Concrete recycling is becoming mandatory rather selective due to depletion of constructional materials and increase of concrete waste. Studies on recycling concrete are conducted in various point of view for long time. However, standard or guideline of many countries for the application of recycled aggregate concrete(RAC) has restrictions such as low replacement rate of coarse aggregate and no fine aggregate allowed due to inferior material properties of recycled aggregate. This study intends to figure out the feasibility of casting natural aggregate concrete(NAC) and RAC separately in a structural member. In making RAC, replacement rate of coarse aggregate was 50, 100% in RAC and treatment of interface of two concretes is introduced. RAC treatment of recycled aggregate or inclusion of additives was not done as it can increase embodied energy of concrete work. Double-shear test with uniformly distributed loading was adopted to evaluate shear strength at the interface of two concretes. After curing it was hard to distinguish interface of two concretes. Experimental result revealed that specimen with higher replacement rate showed higher shear-to-compressive strength ratio, which is possibly attributed to coarse aggregate size and roughness of sheared section. Further study on the effect of various parameters is required and subsequent research activity is on-going.

• Science of Emotion and Sensibility
• /
• v.26 no.1
• /
• pp.79-86
• /
• 2023

This study aims to create a highly conductive E-textile made by recycling PET with a Dip-coating process. PET fiber with hydrophobic properties is characterized by the difficulty in imparting great conductivity when both Virgin and Recycled are made of electronic fibers through a Dip-coating process. To advance the effectiveness of the Dip-coating process, a sample made of recycled PET was surface modified for 50 w 5 minutes and 10 minutes employing a Covance-2mprfq model from FEMTO SCIENCE. After that, the sample was immersed in an SWCNT dispersion (.1 wt%, Carbon Co., Ltd.) for 5 minutes, and then dip coating was conducted to allow the solution to permeate well into the sample through a padder (DAELIM lab). After the procedure was completed, the resistance measurement was measured with a multimeter at both ends and then accurately remeasured with a wider electrode. As a result of this contemplation, it was affirmed that great conductivity might be given through an impregnation process through the plasma surface modification. When the surface modification was performed for 10 minutes, the resistance was reduced by up to 2.880 times. Dependent on the results of this research, E-fibers employed in the smart wearable sector can also be made of recycled materials, improving smart wearable products that can save oil resources and reduce carbon emissions.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.21 no.1
• /
• pp.19-26
• /
• 2015

The carton for liquid products are divided into 'gable top carton' and 'aseptic carton'. Currently, these packages are being recycled in the toilet tissue manufacturing process. The recycling of the carton aluminium laminate is the most important problem facing the recycling procedure of the carton packages due to the reduction in quality of recycled materials. The polymer structure with synthetic resins being used mainly in beverage packaging is also one of the important factors for the procedure for its recycling. The objective of this study was to investigate the package material and structure of the carton for liquid products through marketing research and suggest the supplementation in the work processes of production, use, and recycling. The results represent to improve the recycling profit and the quality of recycled materials when a laminated aluminium of carton for liquid products is replaced to the transparent polymer film. The improvement of the sorting and recycling process may help their recycling efficiencies. In addition, the limited use of synthetic resin molded packaging and increase of wood-pulp collection rate will provide the improvement of the recycling profit and the quality of recycled materials.

• Resources Recycling
• /
• v.28 no.6
• /
• pp.9-17
• /
• 2019

The use of rare metals in increasing along with the growth of the Fourth industrials revolution and new energy industries, and the recycling of rare metals becomes more important as the used of rare metals increase. In this paper, the domestic and international quality standards of tin metal, one of the rare metals, and the performance test of recycled tin were investigated. As a results of the performance test, it was analyzed that there is no difference in performance between the natural and recycled tin.