Oturma Amaçlı Farklı Özellikteki Poliüretan Süngerlerin Sürekli- Yorulma Performansları

Çalışmanın amacı: Bu çalışmanın amacı, Trabzon / Türkiye'de üretilen altı farklı yoğunlukta ve iki farklı kategoride olan poliüretan süngerlere uygulanan sürekli yorulma yüklemesi sonrası IFD sertlik ve kalınlık değerlerinde meydana gelen değişimleri incelemektir. Materyal ve Metod: ASTM D3574 standardı baz alınarak süngerler ilk olarak IFD sertlik testine ve sürekli-yorulma testlerine tabi tutulmuştur. Daha sonra, süngerlerin sürekli yükleme sonrası nihai IFD sertlik değerleri ölçülmüştür. Süngerlerin IFD sertlik değerlerindeki değişimler rapor edilmiştir. Sonuçlar: Normal kategorideki süngerlerin yoğunluğunun arttırılması sünger sertliğini gösteren IFD kayıp oranını azalmasına sebep olmuştur. Ancak, bu durum yumuşak kategorideki süngerler için tam tersidir. Bununla birlikte, normal süngerlerin destek faktörü değerleri, sürekli-yorulma yüklemesinden sonra yoğunluk arttıkça artmış, yumusak süngerler için yoğunluk arttıkça azalmıştır. Bu çalışmada kullanılan tüm süngerler, sürekli-yorulma yüklemesinden sonra, % 10'dan daha az bir kalınlık kaybı göstermiş olup, süngerlerin görünüşlerinde görsel bir bozulma tespit edilmemiştir. Önemli vurgular: Koltuk üretiminde yumuşak bir sünger kullanılacağı zaman, sürekli yorulma yüklemesi altında yumuşak süngerlerin normal süngerlere göre teknik olarak tamamen zıt bir davranış gösterdiğini bilmek önemli olacaktır.

Anahtar Kelimeler:

Sünger, IFD, Sürekli Yorulma, Yükleme, Sertlik, Destek Faktörü

Constant-Fatigue Performance of Different Polyurethane Foams for Sitting Purposes

Aim of study: The target of this study was measuring the changes in IFD firmness and thickness values after constant-fatigue loading on the polyurethane (PUR) foams, with six different densities and two different categories, produced in Trabzon/Turkey. Material and Method: The foams were firstly exposed to indentation force deflection (IFD) and constant-fatigue tests based on ASTM D3574 standard. Then, the final IFD values of the foams were determined after loading and the changes in IFD values were reported. Main results: Results indicated that increasing the density of foam in normal category decreased the IFD loss rate in foam firmness. However, this was vice versa for the soft foams. The support factors of normal foams raised as density increased after constant-fatigue loading, however; the support factors of soft foams decreased as the density increased. All foams used in this study indicated a thickness loss lower than 10% after constant-fatigue loading and, no visual failure was detected on the appearances of foams. Highlights: It is important to note that when using a soft foam in a sofa frame, it technically shows opposite behavior both in IFD loss and support factor values under constant-fatigue loading compared to normal foam.

Keywords:

Foam, IFD, Constant Fatigue, Loading, Firmness, Support Factor,

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ADMET. Announcement dedicated foam testing systems for ASTM D3574. (n.d.) Retrieved from http://www.admet.com/admet-announces-dedicated-foam-testing-systems-for-astm-d3574/
AFPF (Alliance for Flexible Polyurethane Foam) The furniture industry’s guide to today’s flexible foam. (1996). Retrieved from http://polyurethane.americanchemistry.com/Resources-and-Document-Library/3810.pdf
Aliha, M.R.M., Linul, E., Bahmani, A. & Marsavina, L. (2018). Experimental and theoretical fracture toughness investigation of PUR foams under mixed mode I+III loading. Polymer Testing, 67, 75-83.
ASTM D3574 (2011). Standard test methods for flexible cellular materials—Slab, bonded, and molded urethane foams, ASTM International, West Conshohocken, PA A2LA (American Association for Laboratory Accreditation). Huntsman Polyurethanes. (n.d.) Retrieved from http://www.huntsman.com/polyurethanes/Media%20Library/a_MC1CD1F5AB7BB1738E040EBCD2B6B01F1/Customer%20Service_MC1CD1F5B56BE1738E040EBCD2B6B01F1/files/cust_serv_certs_0290.04.pdf
Birlik Sunger. Yoğunluk. (2013a). Retrieved from http://www.birliksunger.com/sayfa.php?kat=5&id=5
Birlik Sunger. Sertlik (ILD, CLD). (2013b). Retrieved from http://www.birliksunger.com/sayfa.php?kat=5&id=4
Cooperative Extension Furniture, Selecting Upholstered Furniture. (n.d.) Retrieved from http://www2.ca.uky.edu/hes/fcs/factshts/hf-lra.130.pdf/, 2015 (accessed 08.05.15). DDL Tested and proven, Independent Testing Laboratory. (n.d.) Retrieved from https://www.testedandproven.com/materials-testing/polyurethane-foam-testing/
De Mello, D., Pezzin, S.H. & Amico, S.C. (2009). The effect of post-consumer PET particles on the performance of flexible polyurethane foams. Polymer Testing, 28(7), 702-708.
Demirel, S. & Ergun Tuna, B. (2019). Evaluation of the cyclic fatigue performance of polyurethane foam in different density and category. Polymer Testing. 76, 146-153.
Eckelman, C.A. (1988a). Performance testing of furniture. Part I. underlying concepts. Forest Products Journal, 38(3), 44-48.
Eckelman, C.A. (1988b). Performance testing of furniture. Part II. A multipurpose universal structural performance test method. Forest Products Journal, 38(4), 13-18.
Gama, N., Silva, R., Carvalho, A. P. O., Ferreira, A. & Barros-Timmons, A. (2017). Sound absorption properties of polyurethane foams derived from crude glycerol and liquefied coffee grounds polyol, Polymer Testing, 62, 13-22.
Gok, A., Yapıcı, F., Gulsoy, S.K., Kurt, S., Altun, S., Kılınç, I. & Korkmaz, M. (2012). Determination of static fatigue performance of upholstery foams. Kastamonu University Journal of Forestry Faculty, 12(2), 285-290.
Hager, S.L. & Craig, T.A. (1992) Fatigue testing of high performance flexible polyurethane foam. J. Cell. Plast., 28(3), 284-303.
Hu, L., Tackett, B., Tor, O. & Zhang, J. (2016). Analysis of sitting forces on stationary chairs for daily activities. Ergonomics. 59(4), 556-567.
IDM instruments, MiniFlx CLD. (n.d.) Retrieved from http://www.idminstruments.com.au/products/miniflexcld/
Kumar, M. & Kaur, R. (2017). Glass fiber reinforced rigid polyurethane foam: synthesis and characterization, e-Polymers, 17(6), 517.
Knight, J.E. (1987). SPI study-Flexible foam in-use fatigue testing for chairs. Journal of Cellular. Plastics, 23(2), 135-157.
Lal, J.A. & Raman, J. (1992). Polyurethane furniture, toxic gases. Retrieved from http://ir.canterbury.ac.nz/bitstream/10092/8477/1/lal_raman_report.pdf
Li, A., Yang, D.D., Li, H.N., Jiang, C.L. & Liang, J.Z. (2018). Flame-retardant and mechanical properties of rigid polyurethane foam/MRP/mg(OH)2/GF/HGB composites. Journal of Applied Polymer Science, 135(31), 1-8.
Marsavina, L., Constantinescu, D. M., Linul, E., Voiconi, T. & Apostol, D. A. (2015). Shear and mode II fracture of PUR foams. Engineering Failure Analysis, 58, 465-476.
PFA (Polyurethane Foam Association). In touch: Flexible polyurethane foam: A primer. (2016). Retrieved from http://pfa.org/intouch/new_pdf/IntouchV1.1a.pdf
PFA (Polyurethane Foam Association). In touch: How foam firmness affects performance. (1994). Retrieved from http://www.pfa.org/intouch/new_pdf/lr_IntouchV4.3.pdf
PFA (Polyurethane Foam Association). In touch: Compression modulus (support factor). (1993). http://pfa.org/intouch/new_pdf/lr_IntouchV3.1.pdf
Saha, M.C., Mahfuz, H., Chakravarty, U.K., Uddin, M., Kabir, Md. E. & Jeelani, S. (2005). Effect of density, microstructure, and strain rate on compression behavior of polymeric foams. Material Science and Engineering, 406, 328-336.
Standard Council of Canada, Insulating materials. (n.d.) Retrieved from http://palcan.scc.ca/specs/pdf/360_e.pdf
Testresources, ASTM D3574 Testing equipment for flexible cellular urethane foams. (n.d.) retrieved from http://www.testresources.net/applications/standards/astm/astm-d3574-testing-for-slab-bonded-and-molded-flexible-cellular-urethane-foams/ Todd, B.A., Smith, S.L. & Vongpaseuth, T. (1998). Polyurethane foams: Effects of specimen size when determining cushioning stiffness. J. Rehabil. Res. Dev., 35(2), 219-224.
Zwick Roel, Soft foam material tests. (n.d.) Retrieved from http://www.zwick.com.tr/tr/uygulamalar/plastikler/suengerler.html