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1

Analysis of the Influence of the Mould Temperature in the Weld Line Areas on Strength of the Injection Mouldings

100%

Humienny R. , Postawa P. , Kalwik A.

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tom Vol. 67, iss. 1

325--331

EN

The weld lines that occur in injection mouldings are critical areas on which depends on the strength of the mouldings. The flow of the material in the injection mould takes place through the gate and then gradually in the mould cavity. Depending on the shape of the formed object, the weld line may or may not occur. In the case of spreading of plastic streams or bypassing obstacles in the form of cores in the mould, the joining lines run down. Most often, the strength of the moulded part is the lowest in these areas and the resulting lines can cause cracking. The aim of the research presented in the publication was to evaluate the properties of particular parts of mouldings obtained from an experimental injection mould equipped with 4 weld line areas. The tests were performed using the method of thermal analysis by Dynamic Mechanical Analysis DMA. Tensile tests were performed on the parts with weld areas and the maximum crack force was determined. The morphology of the obtained fractures was observed using an optical microscope.

2

Odkształcenia wyprasek z polipropylenu wywołane różnicą temperatury formy wtryskowej

75%

Bociąga E. , Jaruga T. , Mazik K.

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tom [R.] 16, nr 5

244-248

PL

Osiągnięcie odpowiednich wymiarów i kształtu wyprasek wtryskowych zależy od wielu czynników. Jednym z nich jest temperatura formy. Jej odpowiednia wartość umożliwia uformowanie korzystnej struktury materiału, natomiast odpowiedni rozkład temperatury w formie warunkuje równomierne ochładzanie tworzywa w gnieździe formującym i zapobieganie powstawaniu odkształceń po usunięciu wypraski z formy. W artykule przedstawiono analizę wpływu różnicy temperatury formy na przeciwległych ściankach na strukturę i odkształcenia wyprasek z polipropylenu. Czynnikami zmiennymi były: temperatura formy oraz grubość ścianki wypraski.

EN

Obtaining of proper dimensions and shape of injection mouldings depends on many factors. One of them is the temperature of mould. A proper value of this temperature enables forming of advantageous structure of material. An appropriate distribution of temperature in the mould is responsible for uniform cooling of plastic material in the mould form and prevents the deformations after removing the moulding from the mould. The analyses of the influence of temperature difference of the opposite walls of the mould on the structure and deformation of polypropylene mouldings was presented in the article. Variable factors were: mould temperature and wall thickness of moulding.

3

The Influence of Wall Thickness and Mould Temperature on Structure and Properties of Thin Wall Ductile Iron Castings

51%

Górny M. , Kawalec M. , Witek G. , Rejek A.

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2019

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tom iss. 2

55--59

EN

The excellent property combination of thin wall ductile iron castings (TWDI), including thin wall alloyed cast iron (e.g. austenitic TWDI) has opened new horizons for cast iron to replace steel castings and forgings in many engineering applications with considerable cost benefits. TWDI is considered as a potential material for the preparation of light castings with good mechanical and utility properties, the cost of which is relatively low. In this study, unalloyed and high Ni-alloyed (25% Ni) spheroidal graphite cast iron, with an austenitic metallic matrix were investigated. The research was conducted for thin-walled iron castings with 2, 3 and 5mm wall thickness, using different mould temperature (20°C, and 160°C) to achieve various cooling rates. The metallographic examinations i.e. characteristic of graphite nodules, metallic matrix, and primary grains of austenite dendrites (in high-nickel NTWDI) and mechanical properties were investigated. The study shows that homogeneity of the casting structure of thin-walled castings varies when changing the wall thickness and mould temperature. Finally, mechanical properties of thin-walled ductile iron castings with ferritic-pearlitic and austenitic metallic matrix have been shown.

4

Możliwości badawcze stanowiska eksperymentalnej formy wtryskowej z ośmioma niezależnymi obiegami termostatowania

51%

Postawa P. , Grzesiczak D.

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2015

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tom T. 21, Nr 1 (163)

42--45

PL

W artykule przedstawiono możliwości badawcze eksperymentalnej formy wtryskowej wyposażonej w osiem niezależnych układów chłodzenia. Forma została wyposażona również w cztery termopary umieszczone bezpośrednio pod gniazdem formującym. Głównym celem wykonania formy była analiza wpływu pola temperatury formy na przepływ tworzywa w formie oraz właściwości otrzymanych wyprasek. Na rysunkach zamieszczonych w artykule przedstawiono schemat stanowiska badawczego wyposażonego w eksperymentalną formę wtryskową, termostat dwuobiegowy Wittmann, dwa rotametry wodne czterodrogowe oraz tor pomiarowy i rejestrujący temperaturę podczas procesu wtryskiwania.

EN

The research capabilities of experimental mould with eight independent cooling circuits were presented in the article. The main aim of the research was to determine the effect of the normal process of injection moulding on the temperature change in different areas of the mould and obtained moulding. Four thermocouples were placed under the cavity and connected to a recorder, thus giving the possibility of uploading data during the injection process. Diagrams showing the research stand equiped with experimental mould, injection moulding machine, thermo controler Wittman, two 4-way rotameters and on-line temperature monitoring system.