Wyniki wyszukiwania - BazTech

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Miejscowe opory przepływu polimeru

Polaczek P.

Zeszyty Naukowe. Mechanika / Politechnika Opolska

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2013

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z. 102

123-126

EN

This article show the method for calculating the pressure drop is closely linked with rheological properties. In the present study attempts to assess the impact of non- Newtonian fluid properties (polymer solutions) to the value of their local pressure drop.

2

Głowica wytłaczarska do rur polimerowych

Baranowski W., Palutkiewicz P.

Przetwórstwo Tworzyw

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2012

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[R.] 18, nr 5

404-408

PL

W artykule przedstawiono nowe rozwiązanie konstrukcyjne głowicy wytłaczarskiej do wytwarzania rur z polietylenu. Cechą znamienną głowicy jest to, że część stożkowa rdzenia od strony dyszy oraz część stożkowa dyszy od strony rdzenia mają na swych powierzchniach zwoje rozmieszczone po linii śrubowej, które są przesunięte względem siebie. Tworzą one kanał, w którym tworzywo przepływające przez niego zostaje skręcone po linii śrubowej. Tak ukształtowana rura ma większą wytrzymałość mechaniczną.

EN

A new design for extrusion head for manufacturing of polyethylene pipes was presented in this article. A significant feature of the head is a part of the conical core of the conical nozzle and the nozzle port of the core are on their surfaces spaced ribs in helical path, which are shifted relative to each other. They form a channel in which the flowing plastic is twisted in a helix. That shaped pipe has a higher mechanical strength.

3

Selected methods of modelling of polymer during the injection moulding process

Koszkul J., Nabiałek J.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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Vol. 24, nr 1

253-259

EN

Purpose: The purpose of present paper was presenting chosen results of investigations on polymer flow during mould cavity filling phase of injection process. Advancement in the simulation software make possible to model more phenomena occurring during polymer flow in injection molding process. Design/methodology/approach: The results of computer simulations of injection process have been compared with the results of video recording for the plastic flow during filling phase. For the simulating investigations a professional computer software Moldflow Plastics Insight ver. 6.1. has been employed. A specialized injection mould which enables observation and registration of the plastic flow during processing has been employed. The mould enables direct monitoring of the course of phenomena inside the mould cavity in two planes. To record the flow, a digital video camera has been employed. As an example the issue of stream flow (jeting) have been described. Findings: The results of the investigations enabled documenting of specific phenomena which occur during plastics or their composites injection process. The registered video sequences have been compared with the results of numerical calculations and then it was estimated to what degree the computer simulation of injection process may be useful in practice. Research limitations/implications: The camera enabled to register the flows with the rate of 25 fps. This reduced the scope of the investigations, since at higher plastic flow speeds the registered image became less clear. The investigations were performed on a wide scale, however, only chosen results have been presented. Practical implications: Deep understanding of the phenomena which occur during filling the injection mould may lead to more effective design of the processing tools and shortening of the time for implementation and production time. Originality/value: The transparent sight-glasses have been used, made of a material called ZerodurŽ which is characterized by the coefficient of thermal expansion close to zero.

4

Investigations of the plastics flow during the injection molding process - selected results

Nabialek J., Kwiatkowski D.

Journal of Achievements in Materials and Manufacturing Engineering

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2006

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Vol. 17, nr 1-2

225--228

EN

Purpose: The purpose of present paper was presenting chosen results of investigations on polymer flow during mould cavity filling phase of injection process. Deep understanding of the phenomena which occur during filling the injection mould may lead to more effective design of the processing tools and shortening of the time for implementation and production time. Design/methodology/approach: The results of computer simulations of injection process have been compared with the results of video recording for the plastic flow during filling phase. For the simulation investigations a professional computer software Moldflow Plastics Insight ver. 4.1. has been employed. A specialized injection mould which enables observation and registration of the plastic flow during processing has been employed. The mould enables direct monitoring of the course of phenomena inside the mould cavity in two planes. To record the flow, a digital video camera has been employed. As an example the issue of flowing around the rectangular obstacle of the plastic stream and flowing through the throat have been described. Findings: The results of the investigations enabled documenting of specific phenomena which occur during plastics or their composites injection process. The registered video sequences have been compared with the results of numerical calculations and then it was estimated to what degree the computer simulation of injection process may be useful in practice. Research limitations/implications: The camera enabled to register the flows with the rate of 25 fps. This reduced the scope of the investigations, since at higher plastic flow speeds the registered image became less clear. The investigations were performed on a wide scale, however, only chosen results have been presented. Originality/value: The transparent sight-glasses have been used, made of a material called Zerodur® which is characterized by the coefficient of thermal expansion close to zero.

5

Analytic models of polymer flow in extrusion head channels

Chwarścianek F.

Archiwum Nauki o Materiałach

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2004

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T. 25, nr 2

133-160

EN

This study presents an analysis of non-Newtonian fluid flow modeled on general rheological power-law equation (The Shulman model and the like). The flow moves through axi-symmetric slot extrusion head channels of any geometric profile curvature. The formulated equations of motion were solved by the method of integral approximations. The applicability of optimum solutions is also presented.

PL

W opracowaniu przedstawiono analizę przepływu płynu nienewtonowskiego modelowanego ogólnym reologicznym równaniem typu potęgowego (model Szulmana i pochodne) przez osiowo-symetryczne szczelinowe kanały o dowolnej krzywiźnie profilu geometrycznego, spotykane w głowicach wytłaczarskich. Sformułowane równania ruchu rozwiązano metodą przybliżeń całkowych i określono możliwość aplikacyjnego wykorzystania optymalnych rozwiązań.