조선 초 금속활자 인쇄기술의 선택과 활성화 - 세종대까지의 금속활자 인쇄본 서적 분석을 중심으로 -

김화선 한국서지학회 2023 서지학연구 Vol.95 No.-

이 연구는 조선이 건국 초기에 금속활자 인쇄기술을 선택하게 된 계기와 활성화된 사항을 「조선왕조실록」의 기사와 조선 초기에 인출된 금속활자 인쇄본들의 분석을 통해 살펴보는 것을 목적으로 한다. 활자 인쇄의 개념을 처음으로 시작한 것은 중국이었지만, 활자 인쇄를 활성화시켰던 것은 조선이었다는 점은 부인할 수 없는 사실이다. 우리나라에서 활자 인쇄는 대체로 약 13세기 초부터 성행하였던 것으로 보이며, 고려에서는 중앙과 지방에서 활자 인쇄를 실행한 여러 기록들이 남아 있다. 그러나 왜 활자 인쇄를 선택하였는가에 대해서는 관련 기록이 남아 있지 않다. 특히 금속활자 인쇄가 가장 활성화되었다고 평가받는 조선 역시 활자 인쇄를 왜 선택하였는가에 대한 기록은 찾아볼 수 없다. 그렇다 보니, 후대의 연구에서는 조선이 금속활자 인쇄를 선택한 계기에 대해 활자는 목판에 비해 다품종 소량 인쇄에 적합한 방법이라고 여겼다던가, 활자로 인쇄하면 신속하게 서적을 인쇄해 낼 수 있기 때문이라는 등으로 보면서 조선 건국 초기에 직면했던 시대적 상황과 연관지어 조선의 금속활자 선택을 이해해온 면이 없지 않다. 조선왕조실록에서 드러나고 있는 조선 초기의 금속활자 인쇄 기사들과 현재 전하고 있는 조선 초 금속활자 인쇄본들은 당시 금속활자 인쇄가 그 어느 시기보다 활성화되었는지를 여실히 보여준다. 또한 금속활자 인쇄 기록과 현전본들은 당시의 위정자들이 금속활자 인쇄를 어떠한 기술로 인식하고 있었는지를 보여주는 근거들이라고 볼 수 있다. 이에 따라 금속활자 인쇄 관련 기록들과 현재 전하는 금속활자 인쇄본을 분석하여 얼마나 활성화되었는지를 보여주고, 이로써 조선이 금속활자 인쇄기술을 바라보는 기술 인식과 그 특징들을 살피고자 하였다. 이 글을 통해 필자는 조선의 위정자들은 금속활자는 인쇄하고자 하는 모든 것을 찍어낼 수 있는 기술이라 인식하고 있었다는 점을 밝히고자 하였다. 금속활자 인쇄 기술을 선택하는 과정에서 서적의 분량이나 성격과 같은 요소들은 주요하게 영향을 미치는 요소가 되지 않았고, 목판인쇄처럼 다량 인쇄도 가능하다고 인식하였다. 위정자들만을 위한 서적뿐 아니라 관청에서 필요한 실무서들을 관원들의 요청에 의해 인쇄하여 반사되었으며, 백성들을 훈계할 목적의 문서들마저도 금속활자로 인쇄된 모습을 확인할 수 있었다. 이로써 적어도 조선 초기의 금속활자는 필요한 것은 무엇이든지 찍어낼 수 있는 기술이었다는 점을 밝히고자 하였다. This study aims to examine the factors that led to the choice and activation of metal type printing technology in the early Joseon Dynasty. To do so, I analyzed articles from the Annals of the Joseon Dynasty and metal type print books in the early Joseon period. Although it was China that first started letterpress printing, it is undeniable that Joseon revitalized metal type printing. In Korea, letterpress printing generally seems to have been around since the beginning of the 13th century, and there are several records of letterpress printing in Goryeo, both in the center and in the provinces. However, there is no record of why they chose letterpress printing. Even in Joseon, which is considered to have been the most active in metal type printing, there is no record of why they chose metal type printing. As a result, later studies have tried to understand the reasons for Joseon’s choice of metal type by relating it to the conditions they faced in the early years of the Joseon Dynasty, such as the fact that metal type was a more suitable method for printing small quantities of various items compared to woodblocks, or that printing with metal type allowed them to print books quickly. Records of metal type printing in the Annals of the Joseon Dynasty of the early Joseon Dynasty and surviving metal type print books show that metal type printing was more active than ever. This provides evidence of how the rulers of the time perceived metal type printing as a technology. Therefore, I analyzed the records of metal type printing and the surviving metal type print books to show how active it was. Through this, I examined the technological perceptions and characteristics of Joseon’s view of metal type printing technology. Joseon rulers recognized that metal type was a technology that could print anything they wanted to print. In the process of choosing metal type printing technology, factors such as the volume and nature of the book were not the main influencing factors, and it was recognized that it was possible to print large quantities like woodblock printing. And even documents intended to admonish the people can be found printed with metal type. In conclusion, at least in the early Joseon Dynasty, metal type was a technology that could be used to print whatever was needed.

인사동 출토 금속유물 발굴 성과와 금속활자의 유형

오경택,이승철,남권희,옥영정 한국서지학회 2023 서지학연구 Vol.93 No.-

The excavation of the historic site in Insadong (within the urban environment improvement project site of the 15th and 16th zones of Gongpyeong-dong, Seoul) is one of the important achievements of the excavation conducted in 2021. The building sites and metal artifacts discovered from the cultural layer of the 16th century are important materials that shed light on the cultural aspects of the early Joseon Dynasty. Metal artifacts that reveal the scientific and technological knowledge of the early Joseon Dynasty, which were previously only known through documents, were excavated, and among them, the over 1,600 metal printing blocks have significant bibliographic value because they clarify the reality of metal printing blocks during the early Joseon Dynasty. The types of metal printing blocks excavated are broadly divided into Chinese characters and Korean, and are further classified into large, medium, and small sizes according to their respective dimensions. They can also be categorized by the shape on the back of the printing block, including the low ‘∧’ shape, deep ‘∩’ shape, square groove shape, long tunnel shape, divided leg shape, and flat base shape. If we examine them by type of printing block, they can be further divided into Gyongja-ja (estimated), Gapin-ja, Eulhae-ja, Eulyu-ja, and Hangul-ja. This article provides a general overview of the significant content from a bibliographic perspective based on the preliminary review of the types of metal printing blocks. The excavated printing blocks are mixed with various types of printing blocks, and further detailed research may reveal new types of printing blocks. Moreover, a comparative study with the existing metal printing blocks through scientific analysis and precise investigation of human culture and history is necessary. Continuous research is also needed to evaluate the value of artifacts that can provide insight into daily life, such as the metallic artifacts that were previously only known through records, such as Ilseongjeongsi (the astronomical clock) and Jujun (the military arrow). 인사동 유적(서울 공평구역 제15․16지구 도시환경정비사업부지 내 유적 발굴조사)은 2021년에 조사된 유적 중 중요한 발굴 성과 중에 하나다. 16세기 문화층에서 조사된 건물지와 금속유물은 조선 전기의 문화 양상을 밝히는데 중요한 자료다. 문헌으로만 알려진 조선 전기의 과학 기술을 알 수 있는 금속유물들이 출토되어 이 시기의 과학기술을 확인할 수 있으며, 그 중에서도 1600여점에 이르는 금속활자는 조선전기 금속활자의 실체를 규명할 수 있어서 서지학적 가치가 매우 크다. 출토된 금속활자의 유형은 한자와 한글로 크게 나뉘며 각 크기에 따라 대, 중, 소로 구분된다. 또한 활자 뒷면의 모양에 따라 낮은 ‘∧’형, 깊은 ‘∩’형, 사각홈형, 긴터널형, 네다리형(분할형), 평저형 등으로 분류할 수 있다. 이를 활자 유형별로 살펴보면 경자자(추정), 갑인자, 을해자, 을유자, 그리고 한글활자 등으로 다시 구분할 수 있다. 이 글에서는 1차 검토된 내용을 바탕으로 서지학적으로 의미있는 내용을 개괄적으로 살펴보기 위하여 유형을 크게 구분해본 것이다. 출토 활자에는 여러 종류의 활자들이 혼합되어 있으며, 앞으로 좀 더 상세한 연구를 통해서 새로운 유형의 활자가 등장할 수도 있다. 또한, 활자에 대한 과학적 분석과 인본 등에 대한 정밀한 조사를 통해 현재 전해지고 있는 금속활자들과의 비교연구가 진행되어야 할 것이다. 그리고 일성정시의(日星定時儀), 자격루 장치인 주전(籌箭) 등 기록으로만 존재를 알 수 있던 금속 유물에 대한 지속적인 연구와 생활상을 살펴볼 수 있는 유물에 대한 가치 검토가 필요하다.

Micropatterning of metal oxide nanofibers by electrohydrodynamic (EHD) printing towards highly integrated and multiplexed gas sensor applications

Kang, Kyungnam,Yang, Daejong,Park, Jaeho,Kim, Sanghyeok,Cho, Incheol,Yang, Hyun-Ho,Cho, Minkyu,Mousavi, Saeb,Choi, Kyung Hyun,Park, Inkyu Elsevier 2017 Sensors and actuators. B Chemical Vol.250 No.-

<P><B>Abstract</B></P> <P>Integration of heterogeneous sensing materials in microelectronic devices is essential to accomplish compact and highly integrated environmental sensors. For this purpose, a micro-patterning method of electrospun metal oxide nanofibers based on electrohydrodynamic (EHD) printing process was developed in this work. Several types of metal oxide (SnO<SUB>2</SUB>, In<SUB>2</SUB>O<SUB>3</SUB>, WO<SUB>3</SUB> and NiO) nanofibers that were produced by electrospinning, fragmented into smaller pieces by ultrasonication, and dissolved in organic solvents were utilized as inks for the printing. Constant or pulsed wave bias consisting of base and jetting voltages were applied between a nozzle and a substrate to generate a jetting of nanofiber solutions. Several parameters for EHD printing such as pulse width, inner diameter of the nozzle, distance from the nozzle to the substrate, and stage speed, were optimized for accurate micro-patterning of electrospun nanofibers. By using optimized printing parameters, microscale patterns of electrospun nanofibers with a minimum diameter less than 50μm could be realized. Gas sensors were fabricated by EHD printing on the microelectrodes and then used for the detection of toxic gases such as NO<SUB>2</SUB>, CO and H<SUB>2</SUB>S. Four kinds of metal oxides could detect down to 0.1ppm of NO<SUB>2</SUB>, 1ppm of H<SUB>2</SUB>S and 20ppm of CO gases. Also, heterogeneous nanofiber gas sensor array was fabricated by the same printing method and could detect NO<SUB>2</SUB> using the sensor array platform with microheaters. Furthermore, microscale patterns of nanofibers by EHD printing could be applied to the suspended MEMS platform without any structural damage and this sensor array could detect NO<SUB>2</SUB> and H<SUB>2</SUB>S gases with 20mW power consumption.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A new method for the microscale patterning of 1D metal oxide for integrated and low-power gas sensor array is proposed. </LI> <LI> Electrohydrodynamic (EHD) printing enables finer patterning of 1D metal oxide nanomaterials than other methods. </LI> <LI> Highly integrated and low-power MEMS gas sensor array has been realized by EHD printing of heterogeneous nanomaterials. </LI> </UL> </P>

『고려사』 판본과 그 간행 시기

김광철 동아대학교 석당학술원 2014 石堂論叢 Vol.0 No.59

There are 80 editions of 『Goryosa(高麗史)』 in domestic and abroad library these days. Among them, 5 kinds of the book were printed with Eulhae metal type(乙亥字) and the rest of them were printed with woodblock printing(木板本). The woodblock printing『Goryosa』 was recarved based on Eulhae metal type 『Goryosa』. 『Goryosa』 whose compilation had been finished in the first year of King Moonjong(文宗) was firstly published with 『Goryeosa-Jeolyo(高麗史節要)』 around April in the first year of King Danjong(端宗). Considering the printing methods since the age of King SeJong(世宗), we can assume that the first edition of 『Goryosa』 was published with Gapin metal type(甲寅字). And it’s lines and letters are form of 10 lines with 17 letters. The first edition of 『Goryosa』 was printed a small quantity. And It was housed inside palace only, which caused a request of its additional printing and publicizing. By these request of proclamation, King Seongjong(成宗) promised to print and distribute 『Goryosa』 as soon as possible. These pledges was carried into effect, Eulhae metal type 『Goryosa』 was published in the late sixth year and early seventh year of King Seongjong. 『Goryosa』 had been a wide circulation in the society of bureaucrats and intellectuals after print it using the Eulhae metal type. It had been adopted as a reference text for contests since the age of King Seongjong and frequently used in the discussion of current issues. While suffering Japanese invasion of Korea in 1592(壬辰倭亂), so many precious books were burnt or scattered. Even the printed books of 『Goryosa』 was not immune. After the war, King Kwang- Hae(光海君) has done various works to promote literature and book acquisition. The work was cut on blocks and published based on the metal movable type prints. The woodblock printing 『Goryosa』 was printed in the fourth year of King Gwanghae. 현재 국내외 도서관 등에 소장되어 있는 『고려사』 판본은 모두 80여 종 정도이다. 그 판종(版種)은 활자본인 을해자(乙亥字)본과 목판본 두 종류인데, 목판본 『고려사』는 을해자본을 저본으로 하여 복각한 것이다. 문종 1년 8월에 편찬을 완료한 『고려사』는 『고려사절요』와 함께 단종 1년 4월에 처음으로 간행되었다. 이 때 『고려사』의 인쇄는 소량에 그쳤고, 그것도 궁궐에만 보관하도록 하여 반포되지 않았다. 『고려사』 초간본의 형태는 다만 세종대 이후 인쇄 경향과 『고려사절요』와 동시기에 간행된 점을 감안하면, 갑인자(甲寅字)본이었을 가능성이 높다. 그 판식은 을해자본 『고려사』와는 달리 10행 17자의 행격을 유지했을 것으로 추정된다. 『고려사』는 간행되었지만, 반포되지 않음으로써 간행 직후부터 반포를 요구하는 목소리가 계속 이어졌다. 이 같은 반포 요구에 따라 성종은 각종 사서(史書)를 을해자로 인쇄하는 과정에서 『고려사』의 인쇄와 반포를 약속했다. 이는 곧 실행에 옮겨져 성종 6년 말에서 7년 초에는 을해자본 『고려사』가 빛을 보게 되었다. 을해자본 『고려사』가 간행됨으로써 경연 과목으로 널리 활용되고 민간 유통도 활성화되어 지식인 사회에서 고려사에 대한 인식을 심화시키는 계기가 되었다. 그런데 임진왜란을 겪으면서 전쟁으로 수많은 서적들이 소실되거나 흩어지는 가운데 『고려사』 또한 그 피해를 면치 못했다. 전쟁이 끝난 후 광해군은 서적의 수집과 간행 등 문예 진흥책을 펼쳤는데, 서적의 간행은 주로 남아 있는 주자본을 저본으로 하여 목판본으로 복각하는 방안이 채택되었다. 『고려사』의 목판본 복각은 『용비어천가』, 『신증동국여지승람』 등과 함께 광해군 2년 말부터 시작되어 5년 9월 이전에 완료되었다.

『고려사』 판본과 그 간행 시기

김광철 ( Kim Gwang Cheol ) 東亞大學校附設 石堂傳統文化硏究院 2014 石堂論叢 Vol.0 No.59

현재 국내외 도서관 등에 소장되어 있는 『고려사』 판본은 모두 80여 종 정도이다. 그 판종(版種)은 활자본인 을해자(乙亥字)본과 목판본 두 종류인데, 목판본 『고려사』는 을해자본을 저본으로 하여 복각한 것이다. 문종 1년 8월에 편찬을 완료한 『고려사』는 『고려사절요』와 함께 단종 1년 4월에 처음으로 간행되었다. 이 때 『고려사』의 인쇄는 소량에 그쳤고, 그것도 궁궐에만 보관하도록 하여 반포되지 않았다. 『고려사』초간본의 형태는 다만 세종대 이후 인쇄 경향과 『고려사절요』와 동시기에 간행된 점을 감안하면, 갑인자(甲寅字)본이었을 가능성이 높다. 그 판식은 을해자본 『고려사』와는 달리 10행 17자의 행격을 유지했을 것으로 추정된다. 『고려사』는 간행되었지만, 반포되지 않음으로써 간행 직후부터 반포를 요구하는 목소리가 계속 이어졌다. 이 같은 반포 요구에 따라 성종은 각종 사서(史書)를 을해자로 인쇄하는 과정에서 『고려사』의 인쇄와 반포를 약속했다. 이는 곧 실행에 옮겨져 성종 6년 말에서 7년초에는 을해자본 『고려사』가 빛을 보게 되었다. 을해자본 『고려사』가 간행됨으로써 경연 과목으로 널리 활용되고 민간 유통도 활성화되어 지식인 사회에서 고려사에 대한 인식을 심화시키는 계기가 되었다. 그런데 임진왜란을 겪으면서 전쟁으로 수많은 서적들이 소실되거나 흩어지는 가운데 『고려사』 또한 그 피해를 면치못했다. 전쟁이 끝난 후 광해군은 서적의 수집과 간행 등 문예 진흥책을 펼쳤는데, 서적의 간행은 주로 남아 있는 주자본을 저본으로 하여 목판본으로 복각하는 방안이 채택되었다. 『고려사』의 목판본 복각은 『용비어천가』, 『신증동국여지승람』 등과 함께 광해군 2년 말부터 시작되어 5년 9월 이전에 완료되었다. There are 80 editions of 『Goryosa(高麗史)』 in domestic and abroad library these days. Among them, 5 kinds of the book were printed with Eulhae metal type(乙亥字) and the rest of them were printed with woodblock printing(木板本). The woodblock printing 『Goryosa』 was recarved based on Eulhae metal type 『Goryosa』. 『Goryosa』 whose compilation had been finished in the first year of King Moonjong(文宗) was firstly published with 『Goryeosa- Jeolyo(高麗史節要)』 around April in the first year of King Danjong (端宗). Considering the printing methods since the age of King SeJong(世宗), we can assume that the first edition of 『Goryosa』 was published with Gapin metal type(甲寅字). And it`s lines and letters are form of 10 lines with 17 letters. The first edition of 『Goryosa』 was printed a small quantity. And It was housed inside palace only, which caused a request of its additional printing and publicizing. By these request of proclamation, King Seongjong(成宗) promised to print and distribute 『Goryosa』 as soon as possible. These pledges was carried into effect, Eulhae metal type 『Goryosa』 was published in the late sixth year and early seventh year of King Seongjong. 『Goryosa』 had been a wide circulation in the society of bureaucrats and intellectuals after print it using the Eulhae metal type. It had been adopted as a reference text for contests since the age of King Seongjong and frequently used in the discussion of current issues. While suffering Japanese invasion of Korea in 1592(壬辰倭亂), so many precious books were burnt or scattered. Even the printed books of 『Goryosa』 was not immune. After the war, King Kwang- Hae(光海君) has done various works to promote literature and book acquisition. The work was cut on blocks and published based on the metal movable type prints. The woodblock printing 『Goryosa』 was printed in the fourth year of King Gwanghae.

Comparison of Fitness of Metal Copings Manufactured by Wax Milling and 3D Printing

nam joong Kim,Seung-Min Park 대한예방치과학회 2023 International Journal of Clinical Preventive Denti Vol.19 No.4

Objective: In this study, the coping was manufactured using wax milling and additive manufacturing using 3D printing (DLP) for a design with internal values set in a CAD program. Metal copings were manufactured through burial, recall, and casting of the processed copings using conventional methods, and the internal suitability was compared and evaluated. Methods: The maxillary first molar was selected as an abutment test specimen model, and 35 abutment test specimens were produced with cemented carbide plaster. Wax coping was produced by cutting a wax block using a milling machine, and a castable resin pattern was produced using a printer. Burial, casting, and fitting were carried out according to traditionalmethods. Citing the silicon replica technique, the soft silicone thickness of the four cusps and the buccal and lingual margins was measured using the ‘2D cross-section’ function of the design program. Results: Margin fitness was measured from 0.027 mm to 0.037 mm for the metal coping of wax milling and 0.025 mm to 0.034 mm for the metal coping of 3D printing. The inner spacing was measured from 0.095 mm to 0.239 mm for the metal coping of wax milling and 0.013 mm to 0.241 mm for the metal coping of 3D printing. Conclusion: The spacing at the margins was less than 50 micrometers for both of metal copings using wax milling and 3D printing respectively. For the four cusp points, the inner spacing of the metal coping of 3D printing was narrower than the metal coping of wax milling.

正祖 綸音의 印出과 對民 보급

권기석 서울대학교 규장각한국학연구원 2018 한국문화 Vol.0 No.83

This is a study on how Chŏngjo’s yunŭm(綸音, king’s message) was effectively published and distributed to the people based on the cooperation system between the central government and the local government in the late Chosŏn period. The cooperation system of the central and foreign government offices in the 18th century had already been established since the early Chosŏn period. The central government entrusted local officials with the management of the printing woodblocks in their workplace and proceeded with book publishing by using local manpower and materials. To effectively utilize this central-local cooperation system, a comprehensive list of woodblocks around the country was compiled, and printing capacities from all over the country were utilized to meet central demand or to spread knowledge to local areas. Movable metal types were suitable for rapid low-volume printing, whereas woodblocks enabled long-term high-volume printing. The central government chose the printing method according to the characteristic of the book to be published considering the advantages and disadvantages of the two printing means. Local authorities tried to reprint the central publications and quickly distribute them to subordinate county and local residents. King Chŏngjo published and distributed the king's message, yunŭm to the common people in the form of a booklet. He used this messages to proactively promote national policies such as saving the hungry people by famine and reducing taxes. In order for the his messages to be transmitted quickly nationwide, he made effective use of the cooperation system of central and local publishing, and translated them into Hangeul so that the lower classes could read it easily. In many cases, the first edition of yunŭm was printed in metal types by the central government. Then the provincial government reprinted the central government's editions, using woodblocks. Finally, each county received the books printed in the provincial office and copied it to the people of each village or read it verbally. The role of the local government was especially great for the nationwide distribution of yunŭm. The central government office, such as Kyosŏgwan(校書館) and Kyujanggak(奎章閣), had only printed hundreds of copies at most. However, when local authorities were working together at the same time, it was possible to print more than a thousand copies quickly. King Chŏngjo always tried to confirm that yunŭm was released without any troubles, and he also paid attention to the reaction of the people who read it. He pursued an aggressive method of governance, seeking consent and empathy with bureaucrats and people through the distribution and publishing of yunŭm, which could then be carried out by the integrated management of the government-led printing system at that time.

3D printing으로 제작된 금속 코어와 치과용 도재 간의 전단결합강도 평가

정재관(Jung, Jae-Kwan),이수옥(Lee, Su-Ok),김기백(Kim, Ki-Baek) 한국산학기술학회 2015 한국산학기술학회논문지 Vol.16 No.4

3D 프린팅 기술은 최근 치과용 보철물 제작 기술로 도입이 되었다. 본 연구의 목적은 3D 프린팅 기술에 의해 제작된 금속 코어와 상부 도재와의 전단결합강도를 평가하는 것이다. 본 연구를 위해 30개의 금속 코어를 제작하였다(cast 15개, 3D printing 15개). 금속 코어에 치과용 도재를 축성하여 시편 제작을 완료하였다. 완성된 시편의 전단결합강도는 crosshead speed 1mm/min으로 하중을 가하여 측정하였으며, 두 그룹의 전단결합강도 값 사이에는 통계적으로 유의한지 알아보기 위하여 Mann-Whitney test를 이용하였다(유의수준 0.05). 측정이 끝난 후 시편을 대상으로 파절양상을 분석하였다. 본 연구를 위한 실험 설계, 금속 코어 제작, 도재 축성 등의 시편 제작부터 실험 수행과 수행 후 실험 데이터 분석과 통계 분석 그리고 파절된 시편을 대상으로 한 파절 양상 분석까지 총 6개월이 소요되었다. 실험 결과 cast 50.14, 3D printing 54.36 MPa를 갖는 것으로 조사되었고, 통계적으로도 유의하였다. 파절양상은 두 집단 모두 시편의 대부분이 혼합형 파절양상을 보였다. 이와 같은 결과 들로 미루어볼 때 3D 프린팅에 의해 제작된 금속도재관 제작을 위한 금속 코어는 임상적으로 허용이 가능할 것으로 사료된다. The purpose of this study was to evaluate the shear bond strength between metal core fabricated by 3D printing and dental porcelain. Thirty metal cores were fabricated(cast 15ea, 3D printing 15ea). The porcelain for each group was builded to the metal core. Sample was loaded to shear force(crosshead speed 1mm/min) in a universal material testing machine. The fracture samples were analyzed failure aspect. The means were statistical analyzed using by Mann-whitney test(α=0.05). The period of experimental(metal cores fabrication, dental porcelain build up, data analysis, statistical analysis, failure aspect analysis and others) for this study took six months. The mean±SDs of shear bond strength was 50.14±1.60MPa for the cast group, and 54.36±3.18MPa for the 3D printing group(p=0.035). The failure aspect showed mixed failure. As a results, metal cores fabricated by 3D printing method were clinically acceptable range.

3D프린팅 산업 및 금속소재 사용시 유해인자 노출 연구 현황

박해동,허이준 대한안전경영과학회 2023 대한안전경영과학회지 Vol.25 No.1

We attempted to provide an overview of the laws and current state of the 3D printing industry in South Korea and around the world, using the annual industry surveys and the Wohler report. Additionally, we reviewed articles relating to the potential exposure to hazards associated with 3D printing using metal materials. In South Korea, there were 406 3D printing-related businesses, employing 2,365 workers, and the market size was estimated at 455.9 billion won in 2021. Globally, the average growth rate of the 3D printing industry market over the past 10 years was 27.4%, and the market size was estimated at $11.8 billion in 2019. The United States had the highest cumulative installation ratio of industrial 3D printers, followed by China, Japan, Germany, and South Korea. A total of 6,168 patents related to 3D printing were registered in the US between 2010 and 2019. Harmful factors during metal 3D printing was mainly evaluated in the powder bed fusion and direct energy deposition printing types, and there is a case of material extrusion type with metal additive filaments. The number, mass, size distribution, and chemical composition of particles were mainly evaluated. Particle concentration increases during the opening of the chamber or post-processing. However, operating the 3D printer in a ventilated chamber can reduce particle concentration to the background level. In order to have a safe and healthy environment for 3D printing, it is necessary to accumulate and apply knowledge through various studies.

금속 마스크 스크린이 금속 재결합 전류와 태양전지 특성에 미치는 영향

이욱철(Uk Chul Lee),정명상(Myeong Sang Jeong),이준성(Joon Sung Lee),송희은(Hee-eun Song),강민구(Min Gu Kang),박성은(Sungeun Park),장효식(Hyo Sik Chang),이상희(Sang Hee Lee) 한국태양광발전학회 2021 Current Photovoltaic Research Vol.9 No.1

The mesh mask screen, which is generally used for screen printing metallization of silicon solar cell, requires high squeegee pressure and low printing speed. These requirements are acting as a limiting factor in production yield in photovoltaic industries. In order to improve the productivity, a metal mask, which has high durability and high printing speed, has been researched. In this paper, the characteristics of each solar cell, in which electrodes were formed by using a metal mask and a mesh mask, were analyzed through recombination current density. In particular, the metal-induced recombination current density (Jom) representing the recombination of the emitter-metal interface was calculated using the shading method, and the resulting efficiency and open-circuit voltage were analyzed through the diode equation. As a result of analyzing the proportion of the metal-induced recombination current density to the total emitter recombination current density, it was analyzed that the reduction of the metal-induced recombination current density through the metal mask is an important factor in reducing the total recombination current density of the solar cell.