Assembly Line Balancing In A Clothing Company

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2005Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2005Bu çalışmada, bir konfeksiyon işletmesinde beş farklı model kullanılarak, çok modelli hat dengeleme probleminin çözümü için iki adet sezgisel yöntem, Helgeson ve Birnie tarafından geliştirilen “Konum Ağırlıklı Dengeleme Yöntemi” ve El-Sayed ve Boucher tarafından geliştirilen “Probabilistik Hat Dengeleme Yöntemi”, kullanılmıştır. Montaj hattı dengeleme problemi ile ilgili tanımlar ve çözüm yöntemleri hakkında bilgi verilmiş ve 1954-2004 yılları arasında yapılmış çalışmaları içeren literatur araştırması detaylı bir şekilde sunulmuştur. Vaka çalışmasının amacı, sabit bir çevrim süresi için, optimum iş gücü ve makine adedi kullanarak maksimum hat etkinliğine ulaşmaktır. Her iki metod kullanılarak, farklı kısıtlar göz önüne alınmış ve iki farklı hat dengeleme sonucu elde edilmiştir. Dengeleme sonuçları birbirleri ile karşılaştırılmıştır.In this study two heuristic assembly line balancing techniques known as “Ranked Positional Weight Technique” developed by Helgeson and Birnie and “ Probabilistic Line Balancing Technique” developed by El-Sayed and Boucher are applied to solve multi-model assembly line balancing problem in a clothing company for five different models. Information about definitions and solution methods related to the assembly line balancing problems is given and a literature research between 1954-2004 is introduced in detail. The aim of the case study is to reach maximum line efficiency by using optimum machine and worker amount for a constant cycle time. By using both methods, different restrictions are taken into consideration and two different line balancing results are reached. The balancing results are compared with each other.Yüksek LisansM.Sc

Seam properties of ultrasonic welded multilayered textile materials

This study examined the effects of ultrasonic welding parameters on bond strength, seam thickness and seam stiffness, as well as water permeability. For study purpose, two types of four-layered fabrics with same compositions and different areal densities suitable for inner part of sport shoes were used. Two different types of seams, lapped and superimposed, were applied for ultrasonic welding and also compared by traditional seam applied by shoe manufacturer. The morphology of different type of seams was also analyzed to observe the influence of welding parameters on the layers during the ultrasonic welding process. Bonding strength was found to depend on the seam type and composition of the joined fabric layers. It was confirmed by the shoe manufacturer that all the produced welded seams provided the requested minimum bond strength to be suitable for the use of the shoes. The traditional seams applied by the shoe manufacturer were thicker but had lower stiffness in comparison to all welded seams. It was also found out that ultrasonic welding damaged the membrane, which was confirmed by no water resistance of welded seams. Statistical analysis showed that ultrasonic welding parameters, such as welding frequency and velocity, influence the bond strength, thickness, and bending stiffness of welded seams, but the obtained results were statistically insignificant. © 2015, © The Author(s) 2015