Constant-Fatigue Performance of Different Polyurethane Foams for Sitting Purposes

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.

Influence of spacer filament fineness on indentation characterizations of warp-knitted spacer fabrics for mattresses

“…Both surface layers of the fabric are the small diamond-shaped mesh structure, knitted with 300D/96F Polyester FDY; the middle layer consists of polyester monofilaments arranged as spacer filaments arranged in X-shaped structure, which is stable and produces good resistance to inversion derivatives. 19 In addition, the spacer filament fineness was chosen from four kinds of mattress materials commonly used and different, 0.12, 0.15, 0.18, and 0.25 mm.…”

Power unit design of industrial sponge crushing machine and vibration analysis by finite element method

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“…Ezme makinesi sisteminin hidrolik şeması Fluid-Sim Hidrolik Paket Programı yardımıyla oluşturulmuştur (Şekil 3). Devre esas olarak bir basınç ünitesi (1), bir yağ filtresi (2), bir basınç sıralama valfi (3), iki 4 yollu 3 konumlu (4/3) yön kontrol valfi (4), bir çift yönlü akıştan kontrol valfi(5), iki çift etkili hidrolik silindir ϕ50mmx400mm(6), bir çift etkili hidrolik silindir ϕ100mmx1200mm(7) ve bir hidrolik akümülatörden (8) oluşmaktadır. Sistem, basınçlı yağı basınç ünitesi ve filtre vasıtasıyla basınç sıralama valfine gönderir.…”

Block Sponge Compression and Packaging System Design and Analysis with Finite Element Method

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