• 한국염색가공학회지
• /
• 제18권3호
• /
• pp.59-64
• /
• 2006

니팅 공정상의 니팅 요소들 중 편침번수, 실의 공급 각도, 실의 공급 속도 등을 변화시키면서 새로 고안된 실험기구를 이용하여 니팅 존에서의 린트 발생현상을 조사하였다. 편침 번수와 실의 공급 각도는 실의 장력과 린트 발생량에 영향을 미쳤으며 이는 실과 편침 형태에 의한 마찰에 기인한 것으로 사료된다. 그러나 실의 공급 속도는 린트 발생에 큰 영향을 미치지 않았다. 본 실험을 기초로 하여 보다 더 심도 있는 연구를 위해서 좀더 정교한 실험기구의 개발이 필요하며 니팅요소들의 화학적, 기계적 변경에 의해 니팅공정상의 린트 문제를 개선시킬 수 있을 것으로 사료된다.

• Journal of the Korean Wood Science and Technology
• /
• 제47권6호
• /
• pp.700-708
• /
• 2019

To verify the possibility of using resistograph to estimate the age of big old living trees, we selected three Zelkova serrata and seven Pinus densiflora in Goesan. The mean diameters at breast height of Z. serrata and P. densiflora were 102 (92-116) cm and 80 (65-110) cm, respectively. The heights measured from the ground using a resistograph ranged at 1.2-4.3 m and 0.6-1.1 m for Z. serrata and P. Densiflora, respectively. The most appropriate needle speed to determine tree-ring boundaries for measuring ring width was 1500 r/min for both tree species. Alternatively, the suitable feed speeds for Z. serrata and P. densiflora were 50 cm/min and 150 cm/min, respectively. From the measured data, the mean numbers of tree rings of Z. serrata and P. densiflora were 57 (43-68) and 104 (93-124), respectively, and the mean tree-ring widths were 4.27 mm (3.18-5.09 mm) and 2.93 mm (2.32-3.34 mm), respectively. A comparison between the time series of tree-ring widths by resistograph and that from the local master chronologies tallied for the heartwood part. Finally, this study showed that resistograph can be used to estimate tree ages when a local master chronology is available.

• Journal of the Korean Wood Science and Technology
• /
• 제47권1호
• /
• pp.90-100
• /
• 2019

본 연구는 수목의 수령을 조사하는 방법으로 레지스토그래피를 활용하는데 있어서 수종별로 가장 적합한 삽입속도를 찾기 위하여 수행되었다. 회전속도는 1,500 r/min로 고정하였다. 수종은 낙엽송, 더글라스 퍼, 잣나무, 전나무, 느티나무이다. 실험결과 수종에 따른 적합한 삽입속도는 느티나무 75 cm/min, 낙엽송과 더글라스 퍼 100 cm/min, 전나무 150 cm/min, 잣나무 175 cm/min으로 나타났다. 하지만 모든 경우에서 연륜폭이 1 mm이하일 경우 연륜경계 확인이 어려운 것으로 확인되었다. 연륜폭이 1 mm이하인 경우를 제외하고는 연륜폭측정기와 레지스토그래피의 연륜폭그래프는 매우 일치하였다. 향후 연륜폭이 1mm 이하인 미세연륜 확인이 가능한 레지스토그래피가 개발된다면 레지스토그래피가 수령조사를 위해 전통적으로 활용되는 생장편의 연륜관찰방법을 대체할 수 있을 것이다. 또한 레지스토그래피의 연륜폭그래프는 생장량 조사에도 활용할 수 있을 것으로 판단된다.

• 한국생산제조학회지
• /
• 제9권1호
• /
• pp.24-29
• /
• 2000

This paper is experimental study of machining characteristics about martensitic heat resisting steel STR11. Machining characteristics are different according to internal quality(chemical compositions, microscopic structure and nonmetallic inclusion) mechanical properties(tensile strength value impact value and hardness) and dynamic cutting force. Following are the results : 1. In analyzing internal quality test materials have typical martensite structure and a minute needle-shaped structure. 2. Tensile strength and reduction of area and hardness are larger. But values of elongation and impact values are smaller. Fracture surface of tensile specimen is ductile. 3, Cutting force is decreasing with cutting speed increasing 4. Cutting force is increasing with feed speed increasing.

• 패션비즈니스
• /
• 제2권2호
• /
• pp.77-84
• /
• 1998

As a result of surveying the process for sewing, the problems involving the outlook of sewn apparels were error off the standard dimensions and uneven sizes, which verifies the need for urgent technological guidance and development. On the other hand, the majority of the businesses were operating their sewing machines at the speed of 2,000 rpm or higher. Such a conventional working method may not well reflect the properties of the stretch fabrics, causing poorer quality products. Moreover, most of the businesses were using the ball-point needles which should be replaced with appropriate ones for stretch fabric. The types of feed dog which were used most were Drop feed, Union feed, Confound feed, Differential feed in their oder. Anyway, the automatized dog should urgently replace these inefficient ones for stretch fabric. Meanwhile, the types of presser foot which were used most were Plain foot, Teflon foot, Roller foot, Ring foot in their order, which also necessitates their replacement which Teflon foot. 2. As a result of surveying the process for finishing and inspection, while the causes scores less than 3 points, those due to pressers scored more than 3 points. This results suggests that a technological guidance is needed for the pressing work. Lastly, the causes of defect due to poor outlook attributable to such notions as button or zipper and those due to the uneven sizes scored more than 3 points, which suggests that the entire of needle works should be reformed through scientific research and technological guidance.