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Chemical treatment with sodium hydroxide, formamide and ethyl acetate is shown to affect certain properties of paper made from recovered fibres. Sodium hydroxide treatment improves the brightness of sheets by approx. 0.12-17.2% under similar recycling conditions. All chemical treatments usually improve the tensile and burst strengths of sheets to some degree. The highest tensile and burst strength values of 42.09 Nm/g and 2.60 kPa m(2)/g were obtained at the first recycling stage with 10% ethyl acetate treatment (O10Et(1)), and these represent approximately 142.2% and 100% improvement of tensile and burst strength respectively. In contrast, although the results revealed that certain chemical treatments markedly improved both tensile and burst strengths, there is some variation observed for tear strengths. The largest improvement in tear strength (72.9%) was found at the third recycling stage with 5.0% formamide treatment (O5Fa(3)), followed by O10Et(3) (33.9%) and O10Na(3) (29.2%). It is important to note that the highest tear strength value of 9.09 Nm(2)/g was found at the second recycling stage of the control samples. The results clearly show that the tensile and burst strengths of sheets can be improved by certain chemical treatments, but there is no correlation with tear strengths.

The recycling of paper is an important issue and requires a systematic and investigative approach. However; it is necessary to scrutinize alternative methods on the strength of the development of recycled fibres to explore the impact of recycling on properties of recycled fibres. In this study, it was found that repeated treatments of recovered fibres with all three chemicals usually enhance their ability to re-swell and improve bonding potential in fibre networks. This is evidenced by higher water retention values (WRV) and improved strength properties. The highest WRV value of 2.65 g/g was observed with a 10.0% ethyl acetate treatment in the third recycling stage, which indicates approximately 660% higher WRV compared with control samples (0.34 g/g). Measurements also showed that the optical properties of lightness and the brightness properties of the sheets show variations. However; the highest brightness improvement of 3.8% was observed at 5.0% ethyl acetate treatment at the second recycling stage. This level of treatment has also given the highest lightness value of 73.97, which indicates only 0.54% improvement. The maximum tensile strength value of 23.89 N.m/g was observed at the third recycling stage with 10.0% formamide charge. However; this level of treatment also gave the highest burst at 1.50 kPa.m(2)/g and tear value of 2.88 N.m(2)/g, which indicates a 128.2% higher burst and 176.9% higher tear strengths, compared with control samples, respectively.

Aim of study: It was our aim to produce fireproof papers from Turkish Red Pine (Pinus brutia Ten.) using eco-friendly pulping method and fire retardant chemicals (FR).

In this study, bleached sulfate pulps used as raw material and the effects of polymers used with bentonite in paper industry on retention and paper properties were investigated. Retention has influence on paper properties like smoothness, physical and optical properties, on the cost of paper produced and the mill effluent treatment. For minimized to fine loss anionic and cationic polymer (percol 156, percol 3030, basf luredur, poli-datmac and cartaretin) with bentonite were used. The maximum retention was detrmined in usage 0.2% bentonite and 0.2% polymer. Since bentonite and polymer values added above 0.2% in furnish retention were decreased. In general, polymers used with bentonite were increased the strength and decreased the optical properties., Bu çalışmada, ağartılmışsülfat kağıt hamurları kullanılmış ve bentonit ile birlikte kullanılan polimerlerintutunma ve kağıt özellikleri üzerine etkisi araştırılmıştır. Tutunma, kağıdınyüzey düzgünlüğü, fiziksel ve optik özelliklerini, kağıt maliyetini ve atık suarıtma tesislerinin yükünü etkilemektedir. Kırıntı lif kaybını minimumaindirmek için bentonit ile birlikteanyonik ve katyonik polimerleri (percol 156, percol 3030, basf luredur, poli-dadmac vekartaretin) kullanılmıştır. %0.2 oranında bentonit ve %0.2 polimer kullanımındamaksimum tutunma olduğu bu oranın yükseltilmesi durumunda tutunma oranınazaldığı tespit edilmiştir. Bentonit ile birlikte kullanılan polimerler genelolarak kağıdın fiziksel direnç özelliklerini artırmış, optik özelliklerini iseazaltmıştır.

Objective: Primary fibromyalgia syndrome (PFS) is a nonarticular rheumatological syndrome characterized by disturbances in the hypothalamo-pituitary-adrenal (HPA) axis. The site of the defect in the HPA axis is a matter of debate. Our aim was to evaluate the HPA axis by the insulin-tolerance test (ITT), standard dose (250 mug) ACTH test (SDT) and low dose (1 mug) ACTH test (LDT) in patients with PFS.