The use of co-polyesters with a low MELTing point in the textile industry has received much attention in order to use the ability of STRENGTH by MELTing in different forms, including fibers, yarns, fabrics and non-wovens. One of the important indicators of molecular weight and flowability of fibrous polymers before their processing is to evaluate the MELT flow index. With this simple method, the flow behavior of fibrous polymers can be investigated at low cost and in a short period of time before the MELT-spinning process. In this research, the value of MELT flow index of four different grades of copolyester with a temperature of 198 °C was determined. Therefore, checking the flow behavior by using the MELT flow index measuring device, temperature changes, residence time and load weights are used. The results showed that intrinsic viscosity is one of the influencing factors on the value of MELT flow index and flow stability in different test conditions, and changes in temperature and residence time have the greatest effect on the change of MELT flow index. As the temperature and residence time increase, the viscosity decreases. Also, by carefully examining their MELT flow behavior, it was observed that among the four different grades of copolyester examined, the grade with intrinsic viscosity of 0. 66 and 0. 69 dl/g is the most suitable option for the MELT spinning process.

MELT STRENGTH of polymer is one of the main primaries for the success in producing low-density extrusion foam and thermoforming process. Polypropylene (PP) as a linear polyolefin has low MELT STRENGTH for bubble stabilization and sagging. Large molecules and long chain branches of PP cause higher molecular entanglements and increase elongational STRENGTH of PP MELT. In this paper rheological behavior, MELT elasticity, mechanical properties, and crystallinity of linear PP blends are studied and compared with blends containing a long chain branched PP resins. It is found that ternary blends of Linear PP improve the MELT elasticity in a certain composition, comparing to binary blends. Branched PP resins increase molecular entanglements, which leads to higher MELT elasticity. The results of this study help to understand the effects of chain size and chain architecture in increasing the MELT STRENGTH and MELT drawability of PP blends. These are the most important factors for producing low density PP foam and high quality thermoformed products.

Background and Aim: ZOE has been used in different fields of dentistry for many years. A locally produced component (Zoliran) has been recently introduced to the marketwith similar characteristic to the original Zonalin. Because of a lower cost involved to use Zoliran cement and its availability, confirm reliability of its physical properties. This investigation was designed to assess the Compressive STRENGTH of Zoliran cement in comparison to Zonalin cement as the standard material. Materials and Methods: Five samples with dimension of 4mmx6mm of each cement were provided and stored in distilled water in 370C±10C for a period of 24 hours. The lowest load of force was registered as the reference to which the sample could be broken by(according to the criteria No: 30 of ANSIIADA). The value of compressive STRENGTH was then calculated using the following formula (K =4F/πD2 ). Results: The mean compressive STRENGTH of five samples was measuredas: 14.33 Mpa for Zoliran cement and 31.83 Mpa for Zonalin cement. The mean compressive STRENGTH of Zonalincement was significantly higher than the mean suggested in ANSl/ADA Specification No.30. The mean compressiveSTRENGTH of Zoliran cement was also lower than the mean value registered in ANSI/ADA SpecificationNo.30. Conclusion: Compressive STRENGTH of Zoliran cement was significantlylower than that of Zonalin cement. Further tests are required to compare the other physical properties of this material before it can be clinically recommended.

Several full porcelain systems are available in the market, among which In - Ceram (Vita Zahnfabrik, Bad Sackingen, Germany), has been introduced to show unique properties including: fine esthetic and high quality STRENGTH. In this investigation Flexural STRENGTH of In - Ceram core material has been evaluated by four - point bending test with Instron (Model 1195) machine. Samples were provided in form of ten bars of core material with the dimension of 30 × 6 × 2.5 mm.Results obtained show that the mean value of 538 ± 42 (MPa), of force is required to hit its resistance limit which is higher than similar values in other dental ceramics, within acceptable clinical range.

Polypropylene filament yarns, when compared with polyethylene terephthalate and polyamide yarns have lower stretchability after being false twist textured. To overcome this deficiency, other researchers have tried to lower the degree of crystallinity of this fibre by either tension annealing or blending it with polyethylene terephthalate and polystyrene. These physical or chemical modifications have not yet achieved a satisfactory level of enhancement of the texture ability of polypropylene. Considering the importance of BCF polypropylene yarns, in this research, the effect of blending polypropylene with12.5 and 25% of polyamide 6 on the bulk of the final BCF yarn has been investigated. The results show that although both crimp contraction and crimp modulus increases with the temperature and pressure of hot air during texturing, but blending polypropylene with even 25% of polyamide 6 does not enhance the texture ability of BCF yarns. Also, the reduction in the crystallinity of the yarns does not lead to any improvement in the texture ability of the polypropylene BCF yarns.

STRENGTH measurement of rock requires testing that must be carried out on test specimens with particular sizes in order to fulfill testing standards or suggested methods. Often, the coring process breaks up the weaker core pieces, and they are too small to be used in either index tests or conventional STRENGTH tests such as point load index (Is) and Brazilian tensile STRENGTH (BTS). One of the index tests to indirectly determine the rock STRENGTH is the block punch index (BPI) test, which requires flat disc specimens without special treatment. This study aimed to evaluate the applicability of the BPI test for predicting the uniaxial compressive STRENGTH (UCS), BTS and IS of the sandstones by empirical equations. Also, we have compared the performance of the BPI and IS for predicting the UCS and BTS. It was experimentally shown that BPI is a reliable method for predicting the UCS, BTS and Is of the sandstones under study. Moreover, the results indicate that BPI could be utilized with same importance as Is for predicting the UCS, while predicting the BTS by Is appears to be more reliable than BPI.

Stress relaxation behavior of milled newsprint/HDPE composite containing coupling agent was studied. Composites containing 25 and 50% filler in weight were produced, and were compared to neat polymer. MELT blending followed by injection molding was the manufacturing process. Results showed that incorporating filler to polymer increases the flexural STRENGTH and modulus. It was observed that higher stress is needed to maintain higher strain levels. Furthermore, comparing the stress ratio patterns revealed that the difference among relaxation of different samples develops over time. Power law computed parameters showed that higher strain level results in higher stress relaxation amplitude (A) and lower time exponent (t). It was also found that, almost complete linear relationship could be established between strain level and parameter A, and the effect of strain level on parameter A is more pronounced at higher filler contents.

The first step in the manufacturing of long and high fibre volume fraction of thermoplatic composite is the prepreg production with a MELT impregnation process. During this process a polymeric matrix is introduced into the fibre tow. In this research an extruder equipped with a specially designed cross- head die was used for producing long and high fibre volume fraction of thermoplastic prepregs and to study the continuous MELT impregnation of glass fibre roving with a polypropylene MELT. A suitable relation determined from the cross-sectional area of the bundles and prepreg was selected as a proper indication of the impregnation quality. Our study shows that process and material parameters such as MELT temperature and MELT flow index have positive effect on the impregnation and those like line speed and MELT pressure inside the cross-head die having a negative effect on fibre wetting.

Hot-MELT extrusion is one of the most widely applied processing technologies in the plastic, rubber and food industry. Today this technology has found its place in the array of pharmaceutical manufacturing operations. MELT extrusion process are currently applied in the pharmaceutical field for the manufacture of a variety of dosage forms and formulations such as granules, pellets, tablets, suppositories, implants, stents, transdermal systems and ophthalmic inserts. This review article in detail describes the MELT extrusion equipment and process. Industrial application of this process along with specific areas on pharmaceutical industry is illustrated. This article concludes with the overview of published examples of the MELT extrusion process.