Çamaşır makinası kapak menteşesi tasarımı
Washing machine door hinge design
Yazar: BURAK KARAÇANLI
Danışman: DOÇ. DR. ALİ GÖKŞENLİ
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Makine Mühendisliği Ana Bilim Dalı / Malzeme ve İmalat Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2024
Konu: Makine Mühendisliği = Mechanical Engineering

Özet:
Her geçen gün teknolojik gelişmelerin yaşandığı ve çevre duyarlılığının arttığı günümüzde, beyaz eşya sektöründe de yüksek rekabet ortamı ve müşteri taleplerinin de etkisiyle yenilikçi çalışmalara ihtiyaç doğmaktadır. Bu doğrultuda ürünlerde kullanılan parçalara daha ucuz, daha hafif ve daha sürdürülebilir alternatifler geliştirilmeye çalışılmaktadır. Çamaşır makinası kapak menteşeleri için şekillenen bu çalışma; malzeme bilimi, yenilikçilik ve sürdürülebilirliğe dayanan yeni bir tasarımının geliştirilmesine yönelik kapsamlı bir araştırma sunmaktadır. Mevcut parçaların incelenmesi, literatür taraması, rakip ürün inceleme çalışmaları, malzeme araştırması, yapısal analiz, yenilenen parça tasarımı, kalıp tasarımı, testler ve sürdürülebilirliği kapsayan bir yaklaşımla; beyaz eşya endüstrisinde yenilikçiliği hedeflerken karbon salınımını da en aza indirmeye yönelik sürdürülebilir bir bakış açısı sunmaktadır. Özellikle kompozit kullanımı tercihi, çevresel zararları azaltırken parçanın dayanımını artırma potansiyelini ortaya koyan bir nokta olarak ortaya çıkmıştır. Çalışmanın merkezinde, geleneksel yaklaşımların sorgulandığı ve zorlayıcı koşullara karşı en uygun şekilde görevini yerine getirebilecek yeni bir tasarım vardır. Buna bağlı olarak kalıp tasarımı ve kalıp akışı analizi, üretim süreçlerine uyum sağlayarak verimliliği en uygun hale getirirken israfı da en aza indirmektedir. Çalışma, yeni menteşe tasarımının bütünlüğünü ve güvenilirliğini sağlayan sıkı bir test ve doğrulama deneyiyle sonuçlanmıştır. Yaşam döngüsü değerlendirme yöntemlerini de içeren sürdürülebilirlik hesaplamaları, önerilen tasarımın çevresel etkisine ilişkin sayısal bilgiler sunarak, karbon salınımını azaltma ve beyaz eşya endüstrisinde çevre bilincine sahip uygulamaları teşvik etme potansiyelinin altını çizmeyi amaçlamıştır. Sonuç olarak bu çalışma, sürdürülebilir üretimin geliştirilmesinde disiplinlerarası iş birliğinin gücünün bir kanıtı olarak hizmet etmektedir. Çalışma; çamaşır makinası kapak menteşesi gibi bir parçayı kompozit malzemeyle yeniden tasarlayarak yalnızca sektördeki zorluklara somut çözümler sunmakla kalmamakta, aynı zamanda beyaz eşya sektörü için daha sürdürülebilir bir geleceğin şekillendirilmesinde çevre bilincinin önemli rolünün altını çizmektedir. Çalışma sonucunda %50 cam elyaf katkılı poliamid kullanak yeniden tasarlanan menteşe; mevcut tasarıma göre %62,5 daha hafif, %55 daha düşük maliyetli ve %60 daha az karbon salınımına sebebiyet verecek şekilde hayata geçmiştir. Hali hazırda Arçelik Global (yeni adıyla Beko Corporate) bünyesindeki fabrikalarda yıllık 5 milyon adet civarında üretilerek 130 farklı ülkeye gönderilecek ürünlerde kullanılmaktadır.

Abstract:
In the present day, we are witnessing rapid technological advancements alongside a significant increase in environmental awareness, and the white goods sector is no exception. The growing level of competition in the industry and evolving customer demands have created an urgent need for innovative solutions. Manufacturers are constantly under pressure to meet these demands while also addressing the pressing issue of environmental impact. As such, the need for more sustainable alternatives for the components used in appliances has become increasingly apparent. The shift towards more cost-effective, lighter, and more sustainable alternatives is gaining momentum, particularly in components that are integral to the functionality of household appliances.
This research, focusing on the washing machine door hinges, offers a thorough and comprehensive study that seeks to develop a new design based on material science, innovation, and sustainability principles. The process includes a detailed examination of the current components, an extensive literature review, competitor product analysis, material research, structural analysis, and a redesigned component. Moreover, the study incorporates mold design, testing procedures, and sustainability measures, all of which aim to contribute to the broader goal of fostering innovation in the white goods industry while reducing carbon emissions. By targeting the reduction of carbon emissions, the study aims to promote more environmentally conscious practices within the sector.
The research conducted as part of this study is built upon a vast array of existing publications and case studies within the white goods sector. However, the scope was not limited solely to the white goods industry; other industries, such as automotive and defense, were also examined for comparative insight. The chosen focus on the door hinge is critical, as it is a key component in the washing machine's functionality and durability. Additionally, the hinge plays a significant role in the overall sustainability of the product, and its redesign offers the potential for reducing environmental impact. This study has taken environmental factors into account while ensuring that the new design also meets the necessary functional performance requirements.
As the material alternatives for the door hinge were explored, particular attention is intended project objectives. The material chosen needed to exhibit lower density compared to metals, higher yield strength, superior impact resistance, and durability. It was also critical that the selected material be widely available in the white goods industry and its suppliers. Based on these criteria, material options were evaluated and selected. The material properties used throughout the study were sourced from Matweb, an international material database that compiles data from hundreds of manufacturers. This approach allowed for a more comprehensive selection process, avoiding the limitations of using reports from a single manufacturer and ensuring a broader and more reliable dataset for material choice.
At the heart of this study lies the questioning of traditional approaches, along with the development of a new design capable of performing optimally under a range of challenging conditions. The goal was to achieve reductions in part costs, weight, and carbon emissions while ensuring the new design could pass all necessary production approval tests. Additionally, maintaining high product quality and meeting reliability standards was a key objective. The cost reduction will help maintain the company's competitive edge in the market, while a decrease in part weight will result in lower logistical costs. Reducing carbon emissions contributes to the company's broader sustainability goals, and passing the required tests is essential to maintain the high-quality standards set by the industry.
The decision to focus on the washing machine door hinge was influenced by the fact that it will be used in approximately 96.4% of the products manufactured starting in 2024. The project adhered to the design constraints set forth by the company, ensuring compatibility with existing designs. The new hinge was designed to be manufactured using plastic injection molding, which led to changes in both the design and production processes. Key dimensions, such as arm length, arm thickness, distance from bushing center to screw center, hinge arm gap, and screw center spacing, were maintained to ensure compatibility with existing designs and structures.
One of the most notable changes in the production process involved changing from aluminum injection molding to plastic injection molding. This change required a revision of the design, mold creation, and production processes. Additionally, composite materials were considered as a possible alternative. The potential impact of composite materials on the production process was thoroughly assessed. To accommodate these changes, mold design and mold flow analysis were optimized, ensuring high production efficiency while minimizing waste. The first samples produced using PA66GF50 were tested for dimensional accuracy using advanced 3D scanning equipment, which verified that the dimensions were consistent with the technical specifications. In the case of parts taken from the mold cavities, each was evaluated separately, and dimensional accuracy was found to be within the tolerances.
However, some minor deformations were observed in the hinge arm area. This was noted as an area for further development, and it was agreed that additional work would be required to improve this issue. The study concluded with a series of stringent testing and validation procedures to ensure that the new hinge design was both reliable and met all required standards. Before any washing machines can enter mass production, they must undergo a series of tests that ensure they meet performance and safety standards. These tests include strength, durability, and transport tests, and they are conducted in accordance with international legal regulations as well as the company's own specific testing protocols. In this study, only the tests affecting the door hinge were considered, with numerical details being withheld for confidentiality reasons.
Strength tests were conducted both experimentally and through digital simulations using strain analysis, which helped inform the final material choice and design. The transport and durability tests were conducted experimentally on the prototypes, as digital simulations of these tests had previously proven to be unreliable and labor-intensive. The results showed that the samples made from PA6GF50 failed the hinge strength test and open-close durability test in the gray version, while the black version only failed the hinge strength test. Given that the hinge strength test is one of the most demanding tests, these results were in line with expectations. On the other hand, samples made from PA66GF50, both in the gray and black versions, successfully passed all the required tests.
Sustainability calculations, including life cycle assessment (LCA), were performed to assess the environmental impact of the new design. These calculations offered concrete data that emphasized the significant reduction in carbon emissions, providing evidence that the redesigned hinge has the potential to contribute positively toward more sustainable practices within the white goods industry. The findings showed that the new hinge design results in a 60% reduction in carbon emissions, with a per-part reduction of approximately 0.43 kgCO₂. This reduction is primarily attributed to several factors: the use of a new material that generates 50% lower carbon emissions, the fact that the production process consumes less energy, the absence of waste and wastewater in production, and the proximity of the new manufacturing facility to the previous one (only 30 km away).
This research demonstrates that by redesigning components like the washing machine door hinge using composite materials, the white goods industry can not only overcome certain challenges but also make significant strides toward sustainability. The new design, using 50% glass-fiber-reinforced polyamide, is 62.5% lighter, 55% cheaper, and produces 60% less carbon emissions than the original design. The redesigned hinge is already in production at Arçelik Global (now Beko Corporate) factories, with an annual production of approximately 5 million units to be distributed to 130 countries worldwide.
Further research may focus on improving perceived quality. Despite the fact that the new design has passed all necessary tests, it shows more displacement under the same force compared to the original design. This increased displacement can negatively affect the perceived quality of the product. Research has shown that customers' perceptions of quality can be affected by increased displacement, even if the product performs effectively. Therefore, potential design updates could be explored to reduce displacement, ensuring that costs remain low while maintaining the project's original goals.