Air-Assisted Spinning System for Industrial Sealing Applications

Abstract

Sealing activity that prevents leakage formation by operating in accordance with variable pressure conditions is known as sealing. Although sealing elements are known in industrial applications by different names such as rotating shaft felt, O-Ring, snap ring, and bellows seal, they are defined as elements that prevent the passage of any substance between moving or stationary machine parts. In this study, polymeric matrix composite materials were applied using zeolite, hydroxyapatite, meerschaum, activated charcoal as additives and polystyrene (PS)-polylactic acid (PLA) as the main matrix material via air-assisted spinning system, and coating was applied in circular form by spraying onto the application area to bring it to a specific layer. The layer thickness of this process varies depending on the variability of the leakage condition and the area of application. Given the appropriate cost of the obtained product(s), ease of production through environmental waste recycling, and potential for multipurpose use in sealing applications, it is considered that this material will serve as a multipurpose material.

1. Introduction

Sealing materials are generally applied in the control of fluid flow in an area with two pressures. They are used to prevent passage of liquid or air. Through pumps, compressors and similar equipment, a force is created as a pressurized fluid affects an area. As a result of this force, if the barrier material—which is referred to as a sealing element—is absent in that area, leakage will occur from the opposite side. For this reason, in industrial applications, sealing is provided by installing gaskets, foam, film and similar materials [1]. Cost increases in particular, expansion of leakage areas, and inability to provide adequate sealing performance have supported the search for new materials. While zeolite, hydroxyapatite, meerschaum, and activated charcoal were used as natural materials in this study, polystyrene (PS)-polylactic acid (PLA) was selected as environmental waste, and materials suitable for air spinning were chosen. Zeolite is a hydrated aluminum silicate in crystalline form. It is a material with high absorption capacity [2]. [caption id="attachment_150548" align="aligncenter"] Figure 1.5. PS granule image [11][/caption] Polylactic acid (PLA) is a starch-based bioplastic. It is frequently used in industrial applications and is a polymer that, unlike petroleum-based products, will continue to be preferred in the future. In particular, our team produced activated charcoal-based PLA composite membranes for filtration during the COVID-19 pandemic, preventing the passage of viruses and bacteria. They provided adequate oxygen permeability [12]. [caption id="attachment_150549" align="aligncenter"] Figure 1.6. PLA granule image [13][/caption] Air-assisted spinning system is a nanotechnological system. Air at a specific pressure from a compressor is supplied through a specific beam and is brought into contact with a polymer solution. The material that begins to spray is collected in the collection area through a circular dispersal system, thereby creating a specific layer. What is important in this system is the appropriate viscosity of the polymer solution and the controlled supply of air at a specific pressure. Appropriate distance, feed rate, collector material and area are very important. They seriously affect the coating condition. In this study, zeolite, hydroxyapatite, meerschaum, and activated charcoal as additives, and polystyrene (PS)-polylactic acid (PLA) as the main matrix material were used to obtain sealing material using an air-assisted spinning system.

2. Material and Method—Materials Used

For zeolite, hydroxyapatite, meerschaum, and activated charcoal additives, and polystyrene (PS) and polylactic acid (PLA) materials, our team purchased zeolite and meerschaum themselves. Our team synthesized hydroxyapatite from eggshells and obtained activated charcoal from walnut shells via pyrolysis. PS and PLA were sourced as environmental waste.

Method—Sealing Material Production via Air-Assisted Spinning System

10 grams of PS and 10 grams of PLA were separately dissolved in acetone-toluene (50%-50%) solvent system using a heated magnetic stirrer. 0.70% zeolite, 1.45% hydroxyapatite, 1.27% meerschaum, and 0.98% activated charcoal were added to the half-filled PS-PLA mixture container and stirred overnight using a heated magnetic stirrer. This mixture was filled into a spray gun and applied onto a plate with controlled air supply at a specific pressure to obtain polymeric matrix composite sealing material. This process was supported using an air-assisted system with a circular nozzle. In materials science, spherical form is desired. With tightly packed and circular fibers, a broad surface area and an environment to prevent leakage passage would be created. Three different coating durations of 15 minutes, 30 minutes, and 45 minutes were applied to obtain three different composite-coated plates. [caption id="attachment_150550" align="aligncenter"] Figure 1.1. Zeolite material image [3][/caption] Hydroxyapatite is an inorganic material based on calcium phosphate. Although generally produced through synthesis as a result of chemical processing, it can also be obtained from animal sources, seashells, and eggshells through chemical precipitation methods. Our research group has conducted numerous studies on this material, which is in our area of expertise. Our reason for using eggshells is both that it is a food waste and that it is reliable. Because marine products contain heavy metals, and sourcing from other animal sources carries risks of avian flu and other diseases. As a material with high absorption capacity, it has sectoral use [4]. [caption id="attachment_150552" align="aligncenter"] Figure 1.2. Hydroxyapatite material image [5][/caption] Meerschaum is a porous, slightly adhesive mineral that is generally white in color and rarely lead-colored. In particular, its use as an absorption material in sectoral applications is noteworthy [6]. [caption id="attachment_150553" align="aligncenter"] Figure 1.3. Meerschaum image [7][/caption] Activated charcoal, also known as activated carbon or amorphous carbon, is an allotrope of the carbon element. It is a fine black powder organic substance that is exposed to heat and moisture effects to retain color and odor compounds in dissolved materials. Our research team produced activated charcoal from walnut shells or hazelnut shells via pyrolysis and used it as a filtration material [8]. [caption id="attachment_150554" align="aligncenter"] Figure 1.4. Activated charcoal image [9][/caption] Polystyrene (PS) is obtained through polymerization of styrene in monomer form. It is derived from petroleum and is more commonly abbreviated as PS in the plastics industry. In addition to its use in foam form for insulation and support purposes, it is also used in absorption applications. In this study, recycling was achieved through the use of environmental waste products, and a cost-effective sealing application was realized [10]. [caption id="attachment_150555" align="aligncenter"] Figure 2.1. Air-assisted spinning production stages at three different durations[/caption]

3. Results

In this study, air-assisted spinning was successfully carried out at three different coating durations using natural and environmental waste materials. Three different coating durations were selected to enable them to provide sealing function. It is therefore considered that this material will be used as a multipurpose material in sealing applications.   References 1. Kerküklü, Y. (2008). Dönel Sızdırmazlık Elemanlarının Performansına Yüzey Pürüzlülüğünün Etkileri (Doctoral dissertation, Fen Bilimleri Enstitüsü). 2. Mesci, B. (2007). Bakır endüstrisi flotasyon atıkları ve zeolitlerin beton üretiminde kullanılabilirliğinin araştırılması. 3. https://www.enerjiportali.com/zeolit-nedir-nerelerde-kullanilir/ 4. Buluş, E., Buluş, G. S., Akkaş, M., Cetin, T., Yaman, E., & Altındal, T. (2020). Production and Characterization of Natural Sourced Hydroxyapatite Added Polystyrene Tissue Scaffolds by Electrospinning. JOURNAL OF MATERIALS AND ELECTRONIC DEVICES, 6(1), 12-18. 5. https://www.nanokar.com.tr/blog/nano-hidroksiapatit-iceren-dis-macunlari 6. Korkmaz, Ş. (2014). Doğal Ve Preslenmiş İületaşının bazı Fiziksel Özelliklerinin Karşılaştırılması (Doctoral dissertation, Anadolu University (Turkey)). 7. https://bilgihanem.com/luletasi-nedir/ 8. Buluş, E., Buluş, G. S., & Yakuphanoglu, F. (2020). Production of polylactic acid-activated charcoal nanofiber membranes for COVID-19 pandemic by electrospinning technique and determination of filtration efficiency. Journal of Materials and Electronic Devices, 4(1), 21-26. 9. https://tr.wikipedia.org/wiki/Aktif_karbon 10. Akinay, Y. Radar soğurucu kompozit malzeme üretimi. 11. https://www.seyirplastik.com/polistiren-gpps-hips/ 12. Bulus, E., Ismık, D., Mansuroğlu, D. S., Fındıkoğlu, M. S., Bozkurt, B., Şahin, Y. M., ... & Sakarya, G. (2019, April). Electrohydrodynamic atomization (EHDA) technique for the health sector of polylactic acid (PLA) nanoparticles. In 2019 Scientific Meeting on Electrical-Electronics & Biomedical Engineering and Computer Science (EBBT) (pp. 1-4). IEEE. 13. https://turkish.alibaba.com/g/polylactic-acid-price.html     Erdi Buluş Instructor / Materials Technology Specialist Istanbul Arel University ArelPOTKAM (Polymer Technologies and Composite Application and Research Center) Department of Transportation Services Civil Aviation Cabin Services Program, Vocational School   Gülseren Sakarya Buluş Specialist Istanbul Provincial Health Directorate Bahçeşehir University Department of Engineering Management Graduate Education Institute