سوسن ضياء احمد شبر

human communities grow larger and larger, the problem of waste management becomes one of urgent need that should be solved. Recycling and reusing of the waste materials is an efficient measure in management of the waste materials, which in addition to preventing the pollution, it conserves natural resources. Plastic bottles made of polyethylene terephthalate (PET), constitutes a major fraction of household wastes. They are classified as non-biodegradable waste materials which are harmful for public health. So making use of PET in concrete production can be useful method to get rid of plastics solid waste damage on environment. In this research, effect of using waste PET that was converted to granules in concrete has been studied experimentally. Different proportion of sand ranging from 1% to 8%, were replaced by granulated plastic. The resulting concrete was compared with normal concrete without any addition of granulated plastic. Then the specimen were tested after 7, 28 days after curing, and some engineering properties of the mixtures including slump test, fresh and dry density, compressive, and slip strength have been investigated. Analyzing experimental results of this work indicated that optimum dosage of waste bottles replacement is 2% as fine aggregate-substitution aggregate to get maximum compressive strength and slip strength.

This study was undertaken to provide more insight on the optimum injection temperature used for the production of PE crates, thereby saving time and money, and improving part quality. The work included processing trails of HDPE crates in an injection molding machine at five temperatures ranged from 220 to 300°C. Both Rheological and mechanical characterization was conducted in order to understand the effect of injection temperature on the properties of crates. Oven aging was also applied for (4 weeks) to evaluate the long-term thermal stability. The results revealed that producing the crates at a temperature range of (260-280 °C) gives the best rheological and mechanical result. The lowest drop in thermal stability has been observed for the crates produced at this temperature range.

The rheological and fusion behavior of polyvinyl chloride (PVC) compounds plays a dominant role in the processing operations and in the development of physical properties in the processed material. A comprehensive study was made in this work to evaluate the effect of shear and thermal history on stability, mechanical and rheological properties of rigid PVC compounds. Different samples of Rigid Poly vinyl chloride including dry blend powder, granules, and bottles molded from both were examined. A study was also made on recycled RPVC where 25% of reclaimed material was continuously blended with fresh dry blend and processed for 15 cycles. Results showed that compaction of the PVC material took place in the brabender plastograph at constant temperature and shear stress. Correlations were given to explain results concerning residual stability and rheological behavior. Furthermore, it was seen that elongation and tensile impact are dependent on shear history.

High impact polystyrene (HIPS) was subjected to repeated thermal and shear stresses by different methods, using a high pressure capillary Rheometer, a laboratory extruder and a Brabender plasticorder. The results showed that the recycling of HIPS caused a decrease in the shear stresses and consequently in the viscosity at constant shear rate. The high pressure capillary Rheometer gave a greater decrease than with the Brabender plasticorder. Tensile strength values were progressively decreased with the laboratory extruder, but increased in the case of Brabender mixer; the elongation was decreased in both cases. This work was then applied in a local plant to compare experimental and actual results.

Pyrolysis of high density polyethylene (HDPE) was carried out in a 750 cm3 stainless steel autoclave reactor, with temperature ranging from 470 to 495° C and reaction times up to 90 minute. The influence of the operating conditions on the component yields was studied. It was found that the optimum cracking condition for HDPE that maximized the oil yield to 70 wt. % was 480°C and 20 minutes. The results show that for higher cracking temperature, and longer reaction times there was higher production of gas and coke. Furthermore, higher temperature increases the aromatics and produce lighter oil with lower viscosity.

إن إعادة تدو رٌ الفضلات البلاست كٌ ةٌ بطر قٌة التكس رٌ الحراري ف جو خامل Pyrolysis تمثل من وجهة النظر الاقتصاد ةٌ مصدرا مهما لإنتاج بد لٌ للوقود السائل ، وكذلك فإنها تمثل طر قٌة مهمة لتخلصٌ الب ئٌة من الملوثات البلاست كٌ ةٌ. و عٌد البول اثل نٌ واحدا من اكبر واهم مكونات الفضلات البلاست كٌ ةٌ. علما إن هذه الطر قٌة غ رٌ مستعملة أو مستثمرة محل اٌ وتطب قٌها مف دٌ ب ئٌ اٌ، كما انه وٌفر مصدرا رخ صٌا للوقود الذي مٌكن أن سٌتعمل مباشرة كبد لٌ عن النفط الخام ف المراجل و المولدات والمصاف ،ً أو مٌكن أن تجرى عل هٌ بعض العمل اٌت الثانو ةٌ مثل الازمرة أو الهدرجة لإنتاج مقاطع مشابهة للكازول نٌ أو ز تٌ الغاز. تتم عمل ةٌ اللتكس رٌ من خلال تعرضٌ الفضلات الى حراره تتراوح من 480 °C - 500 وذلك ف مفاعل مغلق ذو نظام الدفعات وبحجم 750 سم 3 ولفترات زمن هٌ تتراوح من 90 5 دق قٌه لغرض دراسة افضل الظروف لانتاج اعلى وافضل انتاج - من بد لٌ الوقود السائل.