본 연구의 목적은 3D 프린터를 활용하여 맞춤형 중창을 디자인 할 때에 필요한 발길이, 발너비, 아치 측정법과 측정결과를 활용한 맞춤형 라운드토 중창 모델링 프로세스를 제안하는 것이다.
연구의 목적을 달성하기 위해 기존 문헌연구를 통해 맞춤형 중창 모델링에 필요한 발의 요소를 알아보았고 이를 측정하기 위해 소비자가 자신의 발 크기(발길이, 발너비)와 아치를 측정할 수 있는 측정 도구를 제작하였으며, 이를 적용하여 라운드토 맞춤형 중창을 제작할 수 있는 모델링 프로세스를 제안하였다.
모델링 프로세스를 검증하기 위해 피험자 3명을 대상으로 착화감 평가를 2회 진행하였다. 제안한 프로세스를 적용하여 4개의 중창(A, B, C, D)모델링 하였으며, 적합한 아치 모델링의 곡률 차이를 알아보기 위해 2mm씩 높이 차이를 두어 아치를 모델링 하였다.
실험을 위해 Zebris FDM Treadmill과 Vista Medical사의 인솔형 족저압력기를 사용하여 4개의 중창에 대한 평균압력을 측정하였고, 전체 중창에 대한 압력 비교와 전·중·후족부 영역별 평균압력을 비교·분석하였다. 비교 결과 가장 적합한 라운드토 중창 모델링 프로세스를 알 수 있었다.
착화감 평가 결과 A, B, C, D 증창 전체에 해당하는 평균 압력값은 피험자1 에서는 B(3.8442)<D(3.8448)<C<A 순서로 B중창의 압력이 가장 낮게 나타났고, 피험자2의 경우에는 B<A<D<C순으로 B중창이 가장 낮게 나타났다. 피험자3에서는 A<B<C<D 순서로 A중창의 압력값이 가장 낮게 나타나면서, 3명의 피험자 중 2명에게서 B중창의 평균 압력값이 제일 낮게 나타났다. 전족부·중족부·후족부로 영역을 분할하여 압력을 살펴본 결과 피험자 모두 B중창일 때 후족부에 집중된 압력이 낮아지는 양상을 보였다.
B중창은 다른 중창에 비해 중창의 압력을 분산시켜줄 수 있으며, 특정부위에 집중된 압력을 감소시켜 평균 압력을 감소시킨다고 판단할 수 있다.
이러한 결과를 바탕으로 맞춤형 라운드토 중창을 모델링 할 때에는 본 연구에서 제시한 모델링 과정을 거치는 것이 적합하며, 아치를 모델링 할 때에는 B중창 아치 모델링 방법을 적용한 모델링 프로세스를 사용하는 것이 가장 적합하다고 할 수 있겠다.
With recent personalization trends, ‘customized order’ has become more popular in conventional ready-made market as well. In fact, the number of active consumers who look for a perfect product for them by making best use of their options has been on the rise. This new trend was detected In shoe industry as well. Since the early 2000s, shoe manufacturers have had consumers participate in the design of new products and provided personalized and tailored shoes and services.
However, it is costly and burdensome for businesses to provide different products and services to each customer. In most customized shoes, therefore, consumers have been given an option to select few things such as color and material. In fact, foot shape and dimensions which are the most important parts in tailored shoes have not even been considered. To reflect these aspects, expensive methods such as shoe master’s craftsmanship and 3D scanner have been used.
Foot shape and size vary by gender, age and race. In terms of foot length, for example, feet can be classified into three categories: Egyptian Type, Square Type and Greek Type. Depending on the foot shape and type, the factors and parts causing inconvenience and differ. However, the current ready-made production system has not been able to produce shoes in diverse sizes to meet each consumer’s needs and demand. However, this kind of stance ignores the fact that feet have own independent dimensions. After all, it appears that shoes have been manufactured provided that people have the same feet in terms of foot length, width and shape regardless of indigenous and environmental factors.
The Additive Manufacturing(AM) has a lot of advantages in customized midsole design by simplifying complicated gluing process and significantly reducing the use of parts. Regarding the design of customized midsole, in particular, the 3D-printing technology enables small batch production and all-in-one printing. Furthermore, it is suitable in a printing customized midsole which reflects diverse foot sizes, ball width and arch shape. In addition, the 3D printer-based tailored midsole design is advantageous to manufacturers, consumers and designers. After all, the 3D printer-based customized midsole design has a great growth potential. However, there have been few studies on this matter. Especially, it’s been almost impossible to find a study on a customized midsole design-modeling method using a 3D printer.
This study aimed to suggest a foot length, width, and arch measuring method needed in designing customized midsole using a 3D printer and modeling process for customized round toe midsole based on the measurement results. For this, the foot factors needed for customized midsole modeling were examined through analysis on conventional literature studies and expert advices. For measurement, a foot measuring tookit has been fabricated to allow consumers to measure their foot length, width and arch.
In addition, the add-subtract rate which adds ten millimeter to the toe and three millimeter to the heel point and subtracts eight percent from the foot width after foot measurement was applied.
Then, a modeling process which can fabricate customized round toe midsole was proposed. To verify the modeling process, three testees were participated in foot pressure measurement test twice After applying the proposed process, four midsoles (A, B, C and D) were modeled. To find out differences in the curvature of suitable arch modeling, the arch was modeled with a height interval of two millimeter.
For a test, the average pressure on the four midsoles was measured using Zebris FDM and insole foot pressure measuring system. Then, it was comparatively analyzed by fore foot, mid foot and rear foot. According to the analysis, the best round toe midsole modeling process was obtained.
According to a foot pressure test, ‘B (3.8442 psi.)’ was the lowest, followed by ‘D (3.8448 psi.),’ ‘C’ and ‘A’ in terms of average pressure in the testee #1. In the testee #2, in contrast, ‘B’ was the lowest, followed by ‘A,’ ‘D’ and ‘C.’ In the testee #3, ‘A’ was the lowest, followed by ‘B,’ ‘C’ and ‘D.’ In conclusion, ‘B’ revealed the lowest average pressure in two of three testees. According to analysis on the pressure by fore foot, mid foot and rear foot, the pressure on the rear foot decreased when the midsole was ‘B’ in all testees. Unlike other midsoles,
‘B’ can reduce average pressure by scattering midsole pressure and reducing it on a particular part. Based on these results, the modeling process proposed in this study needs to be gone through when modeling customized round toe midsoles. In modeling foot arch, it would be desirable to use the arch modeling method of ‘B’ midsole which was raised by two millimeter from the highest arch point and by one millimeter from the rest art points among the three points between the start and end points in the side line which directly reflected a consumer’s feet.
