Wyniki wyszukiwania - Biblioteka Nauki

1

Study on Effects of Mold Temperature on the Injection Molded Article

100%

Han J.-H. , Kim Y.-C.

Archives of Metallurgy and Materials

|

2017

|

tom Vol. 62, iss. 2B

1271--1274

EN

This is a study of the effects of temperature of injection mold on the injection molded article. By supplying water of the proper temperature in the cooling line of mold in the cooling process, the mold was the appropriate temperature, and the deformation of the injection molded article was examined according to the mold temperature. In this study, we conducted simulation analysis and experiments, and the results were analyzed. The minimum deformation of the injection molded article model obtained by supplying 50°C water in the cooling line is 0.003 mm, and the maximum deformation was 0.813 mm. Injection molded article models obtained by supplying 20°C water were found to be a minimum of 0.002 mm, with deformation of up to 0.761 mm. When comparing both conditions, the error rate of injection molded article obtained by supplying 20°C water in the mold cooling line was lower by about 0.18%.

2

Assessment of the resistance to external factors of low-density polyethylene modified with natural fillers

100%

Głogowska K. , Majewski Ł. , Gajdoš I. , Mitaľ G.

Advances in Science and Technology. Research Journal

|

2017

|

tom Vol. 11, no 4

35--40

EN

The study reports the results of investigation of basic processing and thermal properties of low-density polyethylene modified with two types of natural filler: wheat bran and pumpkin seed hulls, their content ranging from 5% to 15% relative to the matrix. In addition, physical properties of the produced granulates are determined, i.e. the relationship between their density and the applied contents of the tested fillers. Furthermore, the study reports the results concerning longitudinal shrinkage, abrasion resistance and cold water absorption of injection molded tensile specimens.

3

Influence of polylactide modification with blowing agents on selected mechanical properties

100%

Tor-Świątek A. , Garbacz T. , Sedlarik V. , Stloukal P. , Kucharczyk P.

Advances in Science and Technology. Research Journal

|

2017

|

tom Vol. 11, no 4

206--214

EN

The article presents research of modification of PLA with four types of blowing agents with a different decomposition characteristic. Modifications were made in both cellular extrusion and injection molding processes. The obtained results show that dosing blowing agents have the influence on mechanical properties and structure morphology. Differences in the obtained results are also visible and significant between cellular processes.

4

Properties of moldings prepared from LDPE-pumpkin seed hulls blend

100%

Głogowska K. , Sikora J. , Dulebova L.

Advances in Science and Technology. Research Journal

|

2017

|

tom Vol. 11, no 4

318--325

EN

In recent decades, standard polymer blends for different applications have been more and more often replaced by blends containing raw materials. The use of natural materials as filler in thermoplastics brings both economic and environmental benefits. The use of a given vegetable filler depends on the geographic location and natural occurrence of the vegetables in a given geographic region. In Poland, for instance, the pumpkin is one of such vegetables. They are used for producing oil which is pressed from pumpkin seeds. Pumpkin seeds are then collected, dried and purified to produce waste material in hull form. Particles of ground pumpkin seed hulls with varying sizes and weight-in-weight concentration ranging from 0% to 20% relative to the matrix are used as filler in low-density polyethylene. Pumpkin seed hulls are ground and sieved. Four fractions of hulls with different particle sizes are produced: <0.2 mm, 0.2-0.4 mm, 0.4-0.6 mm, 0.6-0.8 mm. The paper reports the results of investigation of the mechanical properties, i.e., strength properties determined by static tensile testing and hardness measurement, of injection molds produced at constant processing parameters. In addition, the cross sections of the obtained products are subjected to microscopic examination. Relationships are determined between tensile modulus, maximum tensile stress, tensile stress at yield, maximum tensile strain, tensile strain at yield as well as Shore hardness and weigh-in-weight concentration of the powdered natural filler and its grain sizes. Finally, relevant conclusions are drawn.

5

Analysis of fiber orientation in the wood-polymer composites (WPC) on selected examples

100%

Frącz W. , Janowski G.

Advances in Science and Technology. Research Journal

|

2017

|

tom Vol. 11, no 3

122--129

EN

The fibers orientation in the polymer matrix is an important factor determining mechanical properties of products made of composites by means of an injection molding process. The fibers arrangement has an effect on shrinkage of the composite and the dimensional accuracy of molded piece. The knowledge of fiber orientation can determine the proper dimensions and design of the molding cavities and then correct some of physical and mechanical properties of the molded piece. The orientation of fillers depends on many factors, among which the important role play processing parameters including the injection speed. The aim of this study was to assess the orientation of the fibers in wood-polymer composite on the selected examples. The knowledge and proper use of micromechanical models allow to evaluate the fibers flow and their orientation in polymer matrix. The research was performed both for numerical simulations and experimental studies for results verification.

6

Modeling of flow phenomena associated with polymer injection into a mold

100%

Przybylski W. , Dzionk S.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2003

|

tom Vol. 7, No 2

233-241

EN

The process of plastic injection, although of extensive industrial use, is still relatively poorly researched. In building a finite element model for the injection process, the emphasis was laid on the modeling of phenomena occurring at the polymer-mold interface. With this purpose in mind, the mesh was refined in the vicinity of mold walls. The influence of the air present in the mold during the injection process was also taken into account. As the outcome of solving the problem so formulated, a model of polymer behavior at the mold wall interface has been obtained. Numerical simulations were carried out with the aid of a FIDAP flow-modeling program, and their results were partly verified by experimental means.

7

Select technical aspect of energy using and management in injection molding process

100%

Pepliński K.

Journal of Polish CIMAC

|

2011

|

tom Vol. 6, no 3

227-234

EN

Technical aspect of energy using and management in Poland industry of injection molding plant are not well known. Energy management is assignment of increasing importance to plastics processors. However there is no wellknown structure for measurement, estimation and prediction. Many technical workers sometimes are trying to measure something, but don’t know techniques how to do it in a good way. Next then get the bad answers. This paper describes and illustrates some basic techniques and aspect of easurement, estimation and prediction. This engineering element can be used for most plastics processing companies. More importantly, the paper looks at how this information can be used to get better both operations and performance in injection molding industry and per analog in other plastics industry.

8

Modelowanie numeryczne procesu wtryskiwania kompozytów polimerowych - wybrany przykład wypraski

100%

Nabiałek J. , Kwiatkowski D. , Gnatowski A.

Kompozyty

|

2008

|

tom R. 8, nr 4

419-422

PL

Przedstawiono wyniki komputerowych symulacji procesu wtryskiwania wybranego kompozytu polimerowego. Autorzy podjęli próbę modelowania wtryskiwania wypraski nastręczającej trudności technologiczne. Po analizie wyników poprawiono błędy konstrukcyjne i ponownie przeprowadzono symulację komputerową. W pracy wykorzystano pakiet oprogramowania inżynierskiego CAD/CAM/CAE - I-DEAS NX ver. 11 oraz program symulacyjny Moldflow Plastics Insight ver. 6.1. Do symulacji zastosowano wypraskę o kształcie prostopadłościennej obudowy urządzenia elektronicznego. Przeprowadzano symulacje komputerowe dla różnych warunków wtryskiwania. Materiał, dla którego przeprowadzono badania, to kompozyt polipropylenu z 20% dodatkiem kredy. Wyniki symulacji procesu wtryskiwania przedstawiono w postaci graficznej. Stwierdzono, iż możliwe jest wykluczenie błędów konstrukcyjnych na etapie projektowania wyprasek na podstawie wyników symulacji komputerowych procesu wtryskiwania.

EN

In the paper results of computer simulations of the injection molding process of selected polymer composite were presented. Authors made an attempt at modeling of injection molding of the polymer molded part technologically not correct. After analyzing the results structural errors were improved and the computer simulation was carried out again. At work the package of providing the engineering software CAD/CAM/CAE - I DEAS NX ver. 11 and simulation software Moldflow Plastics Insight ver. 6.1 were used. A molded part was used to the simulation about the shape of the rectangular prism casing of electronic device. Computer simulations ware performed for different conditions of process. The material for which investigations were performed is the polypropylene composite with 20% percentage of chalk. The results of the injection molding simulation were presented in the graphical way. It was found, that it is possible to exclude structural errors in the mold part designing phase on the grounds of injection molding computer simulations results.

9

Interpretation of warpage simulation results in AMSI

100%

Gajdoš I. , Jachowicz T. , Slota J. , Krasynskyi V.

Applied Computer Science

|

2015

|

tom Vol. 11, no 2

5--16

EN

The article describes the problematic of interpretation of warpage simulation results in Autodesk Simulation Moldflow Insight. Warpage results are relatively easy to obtain from injection molding analysis, but the result interpretation demands higher skilled user. For detailed warpage evaluation based on specific dimensions is application of anchor plane necessary. Theory of anchor plane creation is described and anchor planes were applied for inspection of critical dimension on molding “terminal box”.

10

The Impact of Selected Injection Conditions on the Properties and Structure of Molded Parts Made of HDPE with Chemical Blowing Agent

100%

Palutkiewicz P. , Postawa P. , Wawrzyniak J.

Archives of Metallurgy and Materials

|

2021

|

tom Vol. 66, iss. 2

497--502

EN

In this work, the influence of plastic injection molding conditions, mainly plasticizing conditions: plasticizing pressure (back pressure) and decompression (suck-back) after dosing on weight, thickness, mechanical properties and structure of HDPE parts obtained by injection molding with the addition of chemical blowing agent was done. In order to enable the manufacturing of correctly made molded parts under given plasticizing conditions, other parameters (hold time and hold pressure, injection velocity and injection time) were also changed. It was found that making correct molded parts using decompression requires increased hold pressure and hold time. The share of the porous structure in the parts is inversely proportional to the decompression as well as the hold pressure and hold time, while the plasticizing pressure has little effect on thickness, mass, tensile strength and elongation at maximum force, however, it affects the structure of the molded parts to some extent.

11

Research on the content and filler type on injection shrinkage

88%

Jachowicz T. , Gajdoš I. , Krasinskyi V.

Advances in Science and Technology. Research Journal

|

2014

|

tom Vol. 8, nr 23

6--13

EN

The paper presents the phenomenon of injection shrinkage. The definition of shrinkage and shrinkage types are presented. The main factors affecting shrinkage value of injection-molded part are discussed. Based on the experimental tests conducted using injection-molded parts made from polypropylene filled with glass fiber and talc, the dependence of injection-molded part shrinkage on filler content and selected parameters of the injection molding process has been determined.

12

A numerical simulation study of mold filling in the injection molding process

88%

Baum M. , Anders D.

Computer Methods in Materials Science

|

2021

|

tom Vol. 21, No. 1

25--34

EN

Injection molding can undoubtedly be regarded as one of the most widely used manufacturing processes for polymers (Guevara-Morales & Figueroa-Lopez, 2014). Furthermore, injection molding has found its way into various branches of industry (Fernandez et al., 2018) since it has several essential advantages over other processing techniques in terms of good surface finish, the ability to process complex parts without the need for secondary operations, and low cost for mass production. In order to find optimal process settings, it is necessary to gain a deeper insight into the filling process and the underlying physical phenomena, as well as a thorough understanding of the complex material behavior. In this context, the numerical simulation of the injection molding process is increasingly important. Therefore, the current contribution is dedicated to present a thorough comparative numerical study for the mold filling of an exemplary thin-walled mold geometry, including a realistic non-Newtonian viscosity model for the polymer melt. For the numerical simulation, the authors employ the commercial CFD software packages Cadmould 3D-F and ANSYS CFX. While ANSYS CFX is a well-established CFD software for numerical modelling of multiphysical phenomena, Cadmould 3D-F is a highly specialized and computationally efficient alternative suitable for certain geometric configurations in the context of injection molding. The present study is new in the sense that it demonstrates the equivalence of the considered software packages for the simulation of the injection molding process in thin-walled mold geometries.

13

The Impact of Selected Injection Conditions on the Properties and Structure of Molded Parts Made of HDPE with Chemical Blowing Agent

88%

Palutkiewicz P. , Postawa P. , Wawrzyniak J. , Palutkiewicz P. , Postawa P. , Wawrzyniak J.

|

14

Experimental study on mechanical properties of PE/CNT composites

88%

Najipour A. , Fattahi A. M.

Journal of Theoretical and Applied Mechanics

|

2017

|

tom Vol. 55 nr 2

719--726

EN

High density polyethylene/carbon nanotube composites have been produced for investigations. Four CNT volume fractions and two injection pressures were considered. According to the Taguchi approach, eight experiments were designed. The effect of the carbon nanotubes weight fraction and injection pressure on hardness and impact strength of nanocomposite samples were investigated. The results showed that the effect of the carbon nanotube weight fraction on hardness and impact strength of nanocomposite samples was much higher than the effect of injection pressure. By adding 1%wt (weight) carbon nanotube into the polymer, the impact strength and hardness of the samples improved by 74% and 47%, respectively

15

Application of Moldflow Simulation in Injection Molding of Plastic Tank

88%

Tutak P.

Journal of Applied Computer Science Methods

|

2017

|

tom Vol. 9 No. 1

79--88

EN

This article presents an application of moldflow simulation to optimize the injection molding process of charge air cooler plastic tank. The work shows the advantages of this kind of simulation software and information that it can provide. It also explains how big role today play simulation softwares and how they can improve product and reduce development cost.

16

The Optimization of PHBV-hemp Fiber Biocomposite Manufacturing Process on the Selected Example

88%

Frącz W. J. , Janowski G. , Bąk Ł.

Advances in Science and Technology. Research Journal

|

2021

|

tom Vol. 15, no 2

127--137

EN

In this work, a modern biocomposite on the base of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) matrix commonly known as PHBV was produced in the extrusion process, containing 30% by weight of hemp fibers. The use of the above-mentioned filler allowed to reduce the producing costs of the composite material compared to pure PHBV, improving, among others, some mechanical properties of products made of this biocomposite while maintaining full biodegradation. The obtained biocomposite can be successfully used for the production of injection molded products, but its processing properties are not yet fully known and consequently it is difficult to obtain the optimal performance properties of the products. As part of this study, the process of optimization of the production process of products from the PHBV-hemp fiber biocomposite was carried out on the example of samples intended for testing in the uniaxial tensile test. By using orthogonal planes, widely used in optimization process, the required number of injection molding tests was reduced. Input data values were determined by the factorial planning method that is commonly used in designing experiments. The calculations were carried out in the Minitab 18 software. Six controlling factors were used in the analyzes, each of which was subject to changes on three levels. When selecting the range of controlling factors, it was initially assumed that for all assumed levels of variability it must be possible to fill the mold cavity completely. The orthogonal plan of the L27 type was used in the research. For the purposes of the method, an orthogonal table was built containing 27 combinations of parameters subject to optimization. Optimization was undertaken for two main criteria: shrinkage of the ,,dog-bone” samples (primary and secondary volumetric shrinkage), mechanical properties (Young's modulus, tensile strength, elongation at break). By means of Taguchi method, a significant improvement of some product mechanical properties made of biocomposite was noted and the effective reduction of the processing shrinkage was observed.

17

Characteristics of injection molded parts with the areas of weld lines

75%

Bociąga E. , Skoneczny W.

Polimery

|

2020

|

tom T. 65, nr 5

337--345

EN

The weld lines in injection molded parts arise as a result of the collision of two fronts of the flowing material, which fills the mold cavity and are sometimes unavoidable. They decrease the mechanical properties and surface state of the moldings, due to insufficient connection of the fronts of melted polymer streams. The paper discusses the reasons for the occurrence of weld lines in molded parts, which have been divided into ones related to the design of the injection molded part, properties of the injected material, injection mold construction and injection parameters. The design of the molded parts should ensure even, smooth flow of the material in the cavity, but in the case of parts with many injection points, holes, varied wall thickness, complicated and irregular structure the weld lines can not be avoided. The type of material processed significantly influences the strength of the weld line area. Too high viscosity of the material, fillers and large particles of the coloring agent highly oriented in the weld line area, are the factors lowering properties of the molded part. Considering the design of the injection mold, the most important aspects in forming proper parts with weld lines are correct venting of the mold, small differences in the material temperature in all cavity areas, correctly selected injection points, avoiding jet filling of the cavity. The quality of such parts can be improved by changing the injection conditions, mainly by increasing the mold and melt temperature, also increasing the holding pressure and the injection speed. The possibilities of preventing the weld lines creation or reducing the negative effects of their occurrence have been presented, e.g. by changing the design and location of gates in injection molds, changing processing conditions or using unconventional methods of injection molding, like cascade cavity filling, push-pull and multiple live-feed injection molding, vibration process. Further examinations in the range of cyclic heating/cooling of the injection mold are suggested as the most promising regarding the quality of parts in the area of weld line, their strength and surface state.

PL

Obszary łączenia strumieni tworzywa w wypraskach wtryskowych powstają w wyniku zderzenia się ze sobą dwóch frontów przepływającego tworzywa, wypełniającego gniazdo formujące, i są niekiedy zjawiskiem nieuniknionym. Z powodu niedostatecznego połączenia ze sobą frontów strumieni uplastycznionego tworzywa pogarszają się właściwości mechaniczne oraz stan powierzchni wyprasek. Omówiono przyczyny występowania obszarów łączenia strumieni tworzywa w wypraskach związane z: budową wypraski, właściwościami wtryskiwanego tworzywa, konstrukcją formy wtryskowej oraz warunkami wtryskiwania. Budowa wyprasek powinna zapewniać równomierny przepływ materiału w gnieździe formującym, jednak w wypadku wyprasek z wieloma punktami wtrysku, otworami, zróżnicowaną grubością ścianek, skomplikowanym kształtem nie można uniknąć powstawania linii łączenia strumieni tworzywa. Rodzaj przetwarzanego materiału ma istotny wpływ na wytrzymałość obszaru łączenia strumieni tworzywa. Zbyt duża lepkość tworzywa, obecność napełniaczy i dużych cząstek środka barwiącego silnie zorientowanych w obszarze linii łączenia są czynnikami pogarszającymi właściwości formowanych wyprasek. Do najważniejszych czynników, uwzględnianych podczas projektowania formy wtryskowej, decydujących o wytwarzaniu poprawnych wyprasek z liniami łączenia strumieni tworzywa zalicza się: prawidłowe odpowietrzanie formy, niewielkie różnice w temperaturze materiału we wszystkich obszarach gniazda formującego, odpowiednio dobrane punkty wtrysku oraz unikanie strumieniowego wypełniania gniazda. Jakość takich wyprasek można także poprawić w wyniku zmiany warunków wtryskiwania, głównie zwiększenia temperatury formy i tworzywa wtryskiwanego, a także zwiększenia ciśnienia docisku i prędkości wtrysku. Przedstawiono możliwości zapobiegania powstawaniu obszarów łączenia strumieni tworzywa lub ograniczania negatywnych skutków ich występowania, np. w wyniku zmiany budowy i usytuowania przewężek w formach wtryskowych, zmiany warunków przetwarzania lub zastosowania niekonwencjonalnych metod wtryskiwania, takich jak: wtryskiwanie kaskadowe, pulsacyjne liniowe i rozdzielcze lub wibracyjne. Dalsze badania w zakresie wtryskiwania z cyklicznym nagrzewaniem/ochładzaniem formy wtryskowej są sugerowane jako najbardziej obiecujące pod względem otrzymywania dobrych jakościowo wyprasek w obszarze łączenia strumieni tworzywa, o dużej wytrzymałości i dobrym stanie powierzchni.

18

Przygotowanie procesu produkcyjnego formy wtryskowej

75%

Michalczuk H. , Tubielewicz K. , Chmielik I. P.

Mechanik

|

2016

|

tom R. 89, nr 7

764--765

PL

Omówiono sposób przygotowania procesu produkcyjnego formy wtryskowej na element wchodzący w skład mechanizmu, jakim jest wózek dziecięcy. Przedstawiono strategię opracowania planu obróbczego oraz przygotowania kodu sterującego na obrabiarki sterowane numerycznie. Zaprezentowano metodę obróbki elementów kształtujących, z których złożona jest forma, na 5-osiowym centrum frezerskim Matsuura MX-520.

EN

Describes a process for the preparation of the production process of the injection mold for the component of the mechanism, which is the stroller. It outlines the strategy for the development of a processing plan and prepare the control code for numerically controlled machines. Presented method of processing elements shaping, which is a form of complex 5-axis center of a milling Matsuura MX-520.

19

Optimization of injection molding process by DOE

75%

Gajdos I. , Duleba B. , Spisak E. , Greskovic F. , Dulebova L.

Hutnik, Wiadomości Hutnicze

|

2014

|

tom Vol. 81, nr 7

470--475

EN

This paper deals with determination of optimal injection molding process parameters by DOE technique. Taguchi’s orthogonal table was applied to plan the simulation and the experiments. For this study plastic simulation of injection molding for specimens made of fiber glass filled PBT was performed . Determination of the optimal process parameters was based on RSM surface with goal of minimization moldings warpage. Five controlling factors of melt temperature, coolant inlet temperature, injection and packing and cooling time, packing pressure and packing time with three levels for each factor were selected. According to the results, melt temperature is the most important parameter for both moldings. Injection time and coolant inlet temperature had no significant effect on the shrinkage of either moldings.

PL

Artykuł skupia się na określeniu za pomocą metody DOE optymalnych parametrów procesu formowania wtryskowego. Do planowania symulacji i eksperymentu zastosowano ortogonalną tablicę Tagucjiego. Symulację wykonano dla procesu formowania wtryskowego włókna szklanego wypełnionego tworzywem PBT. Optymalne parametry procesu zostały przedstawione za pomocą tzw. „powierzchni odpowiedzi” (RSM) w celu określenia minimalnego zwichrowania wyprasek. W badaniach uwzględniono pięć parametrów sterowalnych: temperaturę wtrysku, temperatura chłodziwa, czas wtrysku-docisku-studzenia oraz ciśnienie i czas docisku. Wartości tych parametrów podzielono na trzy poziomy. W odniesieniu do wyników, temperatura wtrysku jest najważniejszym parametrem. Natomiast czas wtrysku oraz temperatura chłodziwa nie mają istotnego znaczenia na skurcz wypraski.

20

Study on filling patterns of engineering polymers In geometrically balanced injection molds

75%

Narowski P. , Wilczyński K.

Challenges of Modern Technology

|

2015

|

tom Vol. 6, no. 2

15--18

EN

Filling patterns and imbalances which occur during injection molding of engineering plastics, e.g. Polyoxymethylene (POM), have been studied. Four different geometries of runner systems have been applied for experimentation. Autodesk Moldflow software has been used for finite element method (FEM) simulations of imbalance phenomenon. Evolution strategies have been suggested for optimization of runner systems in multi-cavity injection molds.