Constant-Fatigue Performance of Different Polyurethane Foams for Sitting Purposes

Year 2019, Volume: 19 Issue: 2, 225 - 234, 30.09.2019

Samet Demirel , Busra Ergun Tuna

https://doi.org/10.17475/kastorman.626277

Cited By: 5

Abstract

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

Supporting Institution

TÜBİTAK

Project Number

TOVAG-215O254

Thanks

We would like to thank the Scientific and Technological Research Council of Turkey (TÜBİTAK) who financially supported this study with the grant number of TOVAG-215O254 and Gündoğdu Furniture Factory who provided PUR foams to be tested

Oturma Amaçlı Farklı Özellikteki Poliüretan Süngerlerin Sürekli- Yorulma Performansları

Abstract

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.

Keywords

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

Project Number

TOVAG-215O254

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