교정용 브라켓에 가해지는 힘의 방향에 따른 결합강도의 비교

이현정,이형순,전영미,김정기 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.5

본 연구는 교정용 금속 브라켓에 다양한 방향에서의 복합적인 응력을 가하여 힘의 방향과 적용점에 따른 교정용 브라켓의 결합강도를 비교하고, 브라켓의 유지력을 평가하는데 기준이 되는 최소결합강도의 특성에 대해 알아보고자 시행되었다. 일정한 표면특성을 갖는 금속봉에 Micro-Loc base, Chessboard base, Non-etched Foil-Mesh base 등 서로다른 기저면 형태를 가지는 3가지 종류의 금속 브라켓을 부착시키고, 0˚, 15˚, 30˚, 45˚, 60˚, 75˚, 90˚의 peel 결합강도(_(0)PBS, _(15)PBS, _(30)PBS, _(45)PBS, _(60)PBS, _(75)PBS, _(90)PBS 및 전단결합강도(SBS)와 인장결합강도(TBS)에 대한 브라켓의 결합강도를 측정하고, 각 브라켓의 기저면 면적을 고려하여 단위면적당 결합강도를 산출하여 비교한 결과 다음과 같은 결론을 얻었다. 1. Micro-Loc base와 Chessboard base 및 Non-etched Foil-Mesh base 브라켓 모두에서 전단결합강도(SBS)가 가장 컸다(p<0.01). 2. Peel 응력의 방향 변화에 따른 peel 결합강도(PBS)의 변화양상은 Micro-Loc base와 Chessboard base, Non-etched Foil-Mesh base 브라켓 모두에서 유사하였으며(p>0.05), peel 응력의 적용 각이 증가할수록 peel 결합강도(PBS)는 감소하였고 60˚에서 최저값을 보였다(p<0.05). 3. Micro-Loc base에서 최저 peel 결합강도(_(60)PBS)는 전단결합강도(SBS)의 29% 수준이었으며, 인장결합강도(TBS)에 대해서는 52% 수준이었고, Chessboard base에서 최저 peel bond strength(_(60)PBS)는 전단결합강도(SBS)의 34% 수준이었으며, 인장결합강도(TBS)에 대해서는 61% 수준이었으며, Non-etched Foil-Mesh base에서 최저 peel 결합강도(_(60)PBS)는 전단결합강도(SBS)의 34% 수준이었으며, 인장결합강도(TBS)에 대해서는 55% 수준이었다. 4. 단위면적당 결합강도에 있어서 전단결합강도(SBS)와 인장결합강도(TBS) 및 75˚와 90˚ peel 결합강도는 Micro-Loc base와 Chessboard base에서 차이가 없었으며 Non-etched Foil-Mesh base에서 가장 작았고(p<0.05), 0˚, 15˚, 30˚, 60˚ peel 응력을 적용한 결과 Chessboard base에서 가장 큰 peel 결합강도를, Non-etched Foil-Mesh base에서 가장 작은 결합강도를 보였다(p<0.05). The purpose of this study was to evaluate the bond strength of orthodontic brackets bonded to metal bar with chemically cured adhesive (Ortho-one, Bisco Co, USA) in various types and directions of force application. Three types of metal bracket with different bracket base configurations; Micro-Loc base(Tomy Co, Japan), Chessboard base(Daesung Co, Korea), Non-etched Foil-Mesh base(Dentaurum, Germany); were used in this study. Peel, shear, tensile bond strengths were measured by universal testing machine and compared each other. The peel force directions applied were 0˚, 15˚, 30˚, 45˚, 60˚, 75˚, 90˚. And then, in consideration of the different surface area of the bracket bases, the bond strength per unit area were calculated and compared. The results obtained were summarized as follows : 1. The bond strengths according to the types and the directions of the forces were greatest at the shear forces in all three bracket base configuration groups(p<0.01). 2. As the peel force direction grew higher in degree, peel bond strength decreased. The patterns of peel bond strength change according to force direction was similar in all three bracket base configurations. The minimum bond strength was 60 degree-peel bond strengths in all three bracket base configurations. 3. In Micro-Loc base group, minimum peel bond strength(_(60)PBS) was in 29% level of shear bond strength and 52% level of tensile bond strength. In Chessboard base group, _(60)PBS was in 34% level of shear bond strength and 61% level of tensile bond strength. In Non-etched Foil-Mesh base group, _(60)PBS was in 34% level of shear bond strength and 55% level of tensile bond strength. 4. The bond strengths per unit area were lowest in Non-etched Foil-Mesh base group and highest in Chessboard base group(p<0.05). However, there were no differences in shear bond strength, tensile bond strength, _(75)PBS and _(90)PBS per unit area between Micro-Loc and Chessboard base groups.

Waterproofing performance of waterstop with adhesive bonding used at joints of underground concrete structures

Cho, Byoung Hooi,Nam, Boo Hyun,Seo, Sangyeon,Kim, Jungil,An, Jinwoo,Youn, Heejung Elsevier 2019 Construction and Building Materials Vol.221 No.-

<P><B>Abstract</B></P> <P>Waterstop is a typically used waterproofing material to prevent water leakage through the joints where consecutive concrete casting is not possible during the construction of underground concrete structures. A conventional waterstop, however, frequently allows for water passage through the interface between a waterstop and concrete under a high water-pressure environment owing to a deep excavation depth and high groundwater table. An alternative solution proposed in this study is to use artificial adhesive bonding between the waterstop and concrete using double-sided adhesive tape to actively prohibit water leakage through joints under a high hydrostatic pressure. The performance of the proposed waterproofing system was experimentally evaluated and compared with the control system (without adhesive). The results indicated that the adhesive bonding type resisted water migration under the pressure head of 30 <I>m</I>, whereas the conventional waterstop could not effectively waterproof even at the pressure head of 10 <I>m</I> in the soundly constructed cementitious composite structures. In addition, the peel strength, which is the bonding strength between the adhesive tape and cementitious composite, was measured to quantify the effect of surface contamination of the waterstop on the interface bonding strength. The adhesive tape on the surface of the waterstop was “contaminated” by either or both sand and bentonite slurry for the peel strength test. The results indicate that the surface contamination of the waterstop does not induce a meaningful reduction in the bonding strength for the tested conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Introducing newly designed waterstop to prevent water leakage at the joints. </LI> <LI> Introducing a testing device to evaluate the waterproofing performance at the joints. </LI> <LI> Providing the waterproofing level of conventional waterstop and the newly designed one. </LI> <LI> Proving the peeling strength between adhesive tape and cementitious composite for different contamination conditions. </LI> </UL> </P>

고강력 직물의 열융착 라미네이팅을 통한 충격 완화용 에어쿠션 소재로의 적용 가능성 검토 연구

김지연,김훈민,민문홍 한국염색가공학회 2020 韓國染色加工學會誌 Vol.32 No.3

In order to study wearable air cushion materials capable of responding to massive impact in high-altitude fall situation, high tenacity woven fabrics were bonded by heat only depending on various type of thermoplastic films and then mechanical properties were measured. Tensile strength, elongation, and 100% modulus measurement results for 4 types of films show that TPU-2 has higher impact resistance and easier expansion than PET-1. After thermal bonding, the combination with the highest tensile strength was a material with a TPU-2 film for nylon and a PET-2 film for PET, so there was a difference by type of fabric. The tear strength of the bonded materials were increased compared to the fabric alone, which shows that durability against damage such as tearing can be obtained through film adhesion. All of the peel strengths exceeded the values r e quired by automobile airbags by about 5 times, and the TPU-2 bonded fabric showed the highest value. The air permeability was 0 L/dm2/min. For both the film and the bonded material, which means tightness between the fabric and the film through thermal bonding. It is expected to be applied as a wearable air cushion material by achieving a level of mechanical properties similar to or superior to that of automobile airbags through the method of bonding film and fabric by thermal bonding.

수종의 밴드 접착 시멘트의 물성에 대한 비교 연구

양규호,김기백,김선미,최남기 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.3

본 연구의 목적은 시중에 유통되고 있는 밴드 시멘트들을 종류별로 이용하여 교정용 밴드의 결합강도를 비교하고, 각 시멘트의 파절 양상을 비교하여 교정용 밴드에 대한 사용지침을 마련하는데 도움이 되고자 하였다. 100개의 발거된 인간의 제 3대구치를 이용해 실험군은 총 5개의 군으로 하였으며, 각 군당 시편수가 20개가 되도록 임의적으로 분류하였다. 실험에 사용한 밴드 시멘트는 다음과 같다; Ormco gold, Ultra Band-Lo™, Fuji Ortho™ LC, 3M Unitek™ Multi-Cure Glass Ionomer, Ketac-Cem™. Universal testing machine(Instron Corp., Canton, MA, USA)를 사용하여 최대하중값을 측정하였고, 전단결합강도 값을 계산하였다. 밴드가 탈락한 후, 탈락부위를 평가하여 법랑질과 시멘트, 시멘트와 밴드 사이로 구분하였다. 밴드의 전단강도는 One-way ANOVA를 이용하여 통계처리 하였으며 Tukey test를 이용하여 검정하였다. 또한 탈락 부위는 Chi-squre analysis를 이용하여 통계 처리하였고, Fisher's exact test로 군간 유의성을 검정하였다. 실험 결과 평균 파절 강도는 Ormco군이 가장 높았고(2.44±0.57), Fuji Ortho™군(2.24±0.50), Ketac-Cem™군(2.10±0.57), 3M Unitek™군(1.82±0.43), Band-Lok™군(1.73±0.28) 순이었으며, Ormco군은 Band-Lok™군과 3M Unitek™군, Fuji Ortho™군은 Band Lok™군과만 통계적으로 유의할만한 차이를 보였다(p<0.05). 파절 양상에서 Ormco군과 Band-Lok™군은 서로뿐만 아니라 다른 군과 유의할만한 차이를 보였으며, Fuji Ortho™, 3M Unitek™, Ketac-Cem™군 간에는 유의한 차이가 없었다. The aim of this study was to compare the shear-peel strength and the fracture site of 5 commercially available orthodontic band cements. One hundred molar bands were cemented to extracted human 3rd molars. The specimens were prepared in accordance with the manufacturer's instructions for each cement. After storage in a humidor at 37℃ for 24 hours. the shear debonding force was assessed for each specimen using an universal testing machine with crosshead speed of 2 mm/minute. Maximal failure stress was converted to mean shear-peel strength. MPa. The predominant site of band failure was recorded visually for all specimens as either at the band/cement or cement/enamel interface. Mean shear-peel strength of Ormco was the highest(2.44±0.57). followed by Fuji Ortho™(2.24±0.50), Ketac-Cem™(2.10±0.57). 3M Unitek™(1.82±0.43). Band-Lok™(1.73±0.28). There were statistically significant differences between Ormco and Band-Lok™. Ormco and 3M Unitek™. and Fuji Ortho™ and Band-Lok™(p<0.05). The predominant site of bonding failure for bands cemented with the Ormco was at the band/cement interface. whereas bands cemented with Ultra Band-Lok™ failed predominantly at the enamel/cement interface. There was no significant difference among the other cements(Fuji Ortho™. 3M Unitek™. Ketac-Cem™).

Quadrant Analysis in Correlation between Mechanical and Electrical Properties of Low-Temperature Conductive Film Bonded Crystalline Silicon Solar Cells

Baek, Su-Wung,Choi, Kwang-Il,Lee, Woo-Hyoung,Lee, Suk-Ho,Cheon, Chan-Hyuk,Hong, Seung-Min,Lee, Kil-Song,Shin, Hyun-Woo,Yan, Yeon-Won,Lim, Cheolhyun Korea Photovoltaic Society 2015 Current Photovoltaic Research Vol.3 No.1

In this study, we analyzed the correlation between mechanical and electrical properties of low-temperature conductive film (LT-CF) bonded silicon solar cells by a quadrant analysis (horizontal axis (peeling strength), vertical axis (power loss)). We found that a series of points with various bonding parameters such as bonding temperature, pressure and time were distributed in the different three regimes; weak regime (Q2: weak bonding strength and high power loss), moderate regime (Q4 : strong bonding strength and low power loss) and hard regime (Q3 : weak bonding strength and low power loss). Using this analogous technique, it was possible to fabricate the LT-CF bonded silicon solar cells with the various conditions displayed in Q3 of the quadrant plots, possessing the peeling strength of ~ 1N/mm and power loss of 2~3%.

Quadrant Analysis in Correlation between Mechanical and Electrical Properties of Low-Temperature Conductive Film Bonded Crystalline Silicon Solar Cells

Su-Wung Baek,Kwang-Il Choi,Woo-Hyoung Lee,Suk-Ho Lee,Chan-Hyuk Cheon,Seung-Min Hong,Kil-Song Lee,Hyun-Woo Shin,Yeon-Won Yan,Cheolhyun Lim 한국태양광발전학회 2015 Current Photovoltaic Research Vol.3 No.1

In this study, we analyzed the correlation between mechanical and electrical properties of low-temperature conductive film (LT-CF) bonded silicon solar cells by a quadrant analysis (horizontal axis (peeling strength), vertical axis (power loss)). We found that a series of points with various bonding parameters such as bonding temperature, pressure and time were distributed in the different three regimes; weak regime (Q2: weak bonding strength and high power loss), moderate regime (Q4 : strong bonding strength and low power loss) and hard regime (Q3 : weak bonding strength and low power loss). Using this analogous technique, it was possible to fabricate the LT-CF bonded silicon solar cells with the various conditions displayed in Q3 of the quadrant plots, possessing the peeling strength of ~ 1N/mm and power loss of 2~3%.

Investigation of bonding properties of Al/Cu bimetallic laminates fabricated by the asymmetric roll bonding techniques

Vini, Mohamad Heydari,Daneshmand, Saeed Techno-Press 2019 Advances in computational design Vol.4 No.1

In this study, 2-mm Al/Cu bimetallic laminates were produced using asymmetric roll bonding (RB) process. The asymmetric RB process was carried out with thickness reduction ratios of 10%, 20% and 30% and mismatch rolling speeds 1:1, 1:1.1 and 1:1.2, separately. For various experimental conditions, finite element simulation was used to model the deformation of bimetallic Al/Cu laminates. Specific attention was focused on the bonding strength and bonding quality of the interface between Al and Cu layers in the simulation and experiment. The optimization of mismatch rolling speed ratios was obtained for the improvement of the bond strength of bimetallic laminates during the asymmetric RB process. During the finite element simulation, the plastic strain of samples was found to reach the maximum value with a high quality bond for the samples produced with mismatch rolling speed 1:1.2. Moreover, the peeling surfaces of samples around the interface of laminates after the peeling test were studied to investigate the bonding quality by scanning electron microscopy.

기계안전분야 : 접착 및 기계적 프레스 접합부에서의 인장-박리 피로강도 평가

정강 ( Kang Jung ),김호경 ( Ho Kyung Kim ) 한국안전학회(구-한국산업안전학회) 2009 한국안전학회지 Vol.24 No.3

The effect of hydrogen bonding by varied amine compound on the properties of UV-curable PSAs

장세정,백승석,황석호 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

투명함이 요구되는 터치패널용 Pressure Sensitive Adhesives 제조를 위해 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), Isobornyl acrylate (IBOA)를 포함하는 사원공중합체를 제조하였다. 아민그룹을 갖는 서로 다른 네 종류의 모노머 2-(Dimethylamino)ethyl acrylate (DMAEA),N,N-Dimethylacrylamide (DMAAm), N-Acrylpiperidine (APPE), 4-Acryloylmorpholine (ACMO) 를 각각 제 4의 모노머로 사용하여 광중합하였다. 수소결합의 세기와 linear component의 유무에 따라 서로 다른 adhesion properties와 굴절률 변화를 보였다. 이를 확인하기 위해 peel strength, probe tack, rheological behavior, prism coupler, FT-IR 등을 측정하였다.

Ti/Fe 클래드 판재의 접착력 측정

김지훈(J. H. Kim),김대용(D. Kim),김낙현(N. H. Kim),이영선(Y. S. Lee) 한국정밀공학회 2011 한국정밀공학회 학술발표대회 논문집 Vol.2011 No.6월