scholarly journals An Analysis of the Casting Polymer Mold Wear Manufactured Using PolyJet Method Based on the Measurement of the Surface Topography

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3029
Author(s):  
Paweł Turek ◽  
Grzegorz Budzik ◽  
Jarosław Sęp ◽  
Mariusz Oleksy ◽  
Jerzy Józwik ◽  
...  
Keyword(s):  
Surface Topography ◽  
Surface Condition ◽  
Dynamic Change ◽  
Growth Dynamics ◽  
Peak Height ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Maximum Height ◽  
Mold Wear ◽  
Polymer Mold

An important factor having an impact on the condition of machine parts is their surface topography. For instance, in the production of a molded element in casting or injection molding processes, the surface topography of the molding cavity has a significant impact on the surface condition of the product. An analysis of the wear of a mold made with the PolyJet technique was performed in this work, and we examined the surface topography using the stylus method after casting a wax model of the turbine blade. The surface topographies showed a gradual degradation of the mold cavity surface. After the manufacture of 40 castings, there was a significant deformation of the microstructure of the mold cavity. The maximum height value (Sz) parameter had the most dynamic change from 18.980 to 27.920 μm. Its growth dynamics are mainly influenced by maximum peak height (Sp) rather than the maximum pit height (Sv) parameter. In the case of the root mean square height (Sq) and arithmetic mean height (Sa), their gradual increases can be seen from 2.578 to 3.599 μm and from 2.038 to 2.746 μm. In the case of the value of the skewness (Ssk) parameter, a small positive skew was observed. As for the kurtosis (Sku) values, the distributions are clearly leptokurtic.

Effects of process conditions on the heat transfer coefficient at the polymer-mold interface and tensile strength of thin-wall injection molding parts

2019 ◽  
Vol 39 (5) ◽  
pp. 493-500
Author(s):  
Laiyu Zhu ◽  
Liping Min ◽  
Xianglin Li ◽  
Zhanyu Zhai ◽  
Dietmar Drummer ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Weld Line ◽  
Polymer Melt ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Thin Wall ◽  
Wall Injection ◽  
The Heat Transfer Coefficient

Abstract Generally, the strength at the weld line of the injection molded part is very weak. The heat transfer coefficient (HTC) between the polymer melt and the mold cavity surface was analyzed to solve this problem. The surface roughness of the mold cavity and the material of the mold insert were changed to adjust the interface environment between the polymer melt and the mold cavity surface. HTC was obtained by combing the experimental measurement with the theoretical calculation. In the current study, the influence of HTC on the tensile strength of the weld line of the molded specimen was investigated. The results show that the weld line strength of the molded specimen increases with the decrease in HTC between the polymer and the mold cavity surface. Meanwhile, the decrease in the surface roughness of the mold cavity or replacing the mold material with lower thermal conductivity can reduce the value of the HTC between the polymer and the mold effectively and can delay the cooling rate of the hot polymer melt. This provides a new idea to solve thin-wall injection molding weld line defects.

The Effective Measures of Preventing Collapse Angle Problem in Polishing Plastic Mould

2012 ◽  
Vol 538-541 ◽  
pp. 1720-1723
Author(s):  
Yi Lei Ren ◽  
Hong Qi Lin
Keyword(s):  
Preventive Measures ◽  
Dimensional Accuracy ◽  
Machining Process ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Plastic Model ◽  
Plastic Parts ◽  
Surface Angle ◽  
Plastic Mold

Plastic mold polished, in the mold cavity parting collapsed throwing angle appear, which seriously affect the dimensional accuracy and surface quality of the plastic parts, this article proposed two effective preventive measures: (1) cutting the model which having a same size as plastic model of the cavity at the parting surface, sticking the model and cavity parting with 502 glue together, within the required type of alignment, and then thrown together, polished finish will be a model to out; (2) in the plastic model cavity machining process, type in the mold cavity surface set aside allowance 0.5 ~ 1mm, polished until the cavity is completed, the surface of the cavity type 0.5 ~ 1mm rubbed off with a grinding allowance, it will ensure the cavity size and cavity to prevent the collapse of sub-surface angle at the phenomenon.

scholarly journals Proposition of a Solution for the Setting of the Abrasive Waterjet Cutting Technology

2013 ◽  
Vol 13 (5) ◽  
pp. 279-285 ◽  
Author(s):  
J. Valíček ◽  
M. Harničárová ◽  
M. Kušnerová ◽  
R. Grznárik ◽  
J. Zavadil
Keyword(s):  
Surface Topography ◽  
Surface Condition ◽  
Tool Material ◽  
Point Of View ◽  
Abrasive Waterjet ◽  
Depth Of Cut ◽  
Technological Parameters ◽  
Final Surface ◽  
Analytical Processing ◽  
The Subject

Abstract The submitted paper aims to clarify the abrasive waterjet technology, particularly from the point of view of produced surface topography. It provides a new insight into the deformation process caused by the effect of abrasive waterjet and into the possibilities of using the surface topography for solving the issues of optimization of the process. The subject of study is a system of cutting tool, material and final surface topography and optimization of their parameters. The cutting or disintegrating tool of abrasive waterjet technology is flexible. The trajectory of its cut traces is strictly determined here by disintegration resistance at critical moments of tool-material interaction. The physico-mechanical character of the interaction within the cut will manifest itself in the final surface condition. This process can be re-analysed by measuring the selected elements of topography and roughness on the final surface, namely depending on the depth of the cut, technological parameters of the tool and mechanical parameters of the material. The mentioned principle is the basis of the presented solution. It lies in the analytical processing and description of correlation interrelations between set technological and measured topographical quantities in relation to the depth of cut and the type of material.

Research on the Surface Topography Model of Galvanized Steels in Sheet Metal Forming

2014 ◽  
Vol 665 ◽  
pp. 102-106
Author(s):  
Lei Gang Wang ◽  
Ya Ting Xu ◽  
Jian Fen Zhou ◽  
Yao Huang
Keyword(s):  
Surface Topography ◽  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Zinc Coating ◽  
Peak Height ◽  
Contact Friction ◽  
Galvanized Steels ◽  
Erichsen Cupping Test ◽  
Optical Profilometer

Due to the induced effect of plastic deformation and markedly influence of contact friction, the surface topography of galvanized steels has changed along with time and space during the sheet metal forming. WykoNT1100 non-contact optical profilometer was used to measure the surface topographies of different deformation zones in Erichsen cupping test. And the surface topography models of different deformation zones were established based on the statistical method. The results indicated that the surface topography was roughened with the increase of deformation and the degrees of roughening in different deformation zones were different. The function curve of micro-peak height in punch fillet zone which had serious deformation was relatively flat. It indicated that the data distributions were scattered, the roughness values were large and the zinc coating was severely exfoliated. However, the function curve in vertex zone was lanky with centralized data, small roughness values and intact zinc coating. Moreover, the surface topography was also affected by the contact friction.

Multi-Objective Optimization of the Heating Rods Layout for Rapid Electrical Heating Cycle Injection Mold

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Guoqun Zhao ◽  
Xiping Li ◽  
Yanjin Guan
Keyword(s):  
Temperature Distribution ◽  
Injection Molding ◽  
Mold Cavity ◽  
Electrical Heating ◽  
Cavity Surface ◽  
Heating Cycle ◽  
Multi Objective Optimization ◽  
Heating Efficiency ◽  
Multi Objective ◽  
Distribution Uniformity

Rapid electrical heating cycle injection molding (ERHCM) technology is a promising green manufacturing technology for plastic parts. By using this technology, the defects that usually appear on the surface of conventionally injected parts, such as weld and flow marks, can be avoided effectively. This paper studies rapid electrical heating cycle injection molding technology and its mold structure design techniques. Temperature distribution uniformity and heating efficiency on the mold cavity surface are considered as the major influencing factors on product quality and production efficiency. A multi-objective optimization model for the heating rods layout in the mold cavity plate is formulated to optimize temperature distribution uniformity and heating efficiency with respect to the heating rods layout. An application to a liquid crystal display TV panel is implemented successfully using a genetic algorithm.

The Synergistic Effect of Tool Geometry and Hard Turning vs. Grinding Processes on 3D Surface Micro Topography

2007 ◽  
Author(s):  
R. A. Waikar ◽  
Y. B. Guo
Keyword(s):  
Surface Topography ◽  
Synergistic Effects ◽  
Ground Surface ◽  
Tool Geometry ◽  
Maximum Height ◽  
Machining Processes ◽  
3 Dimensional ◽  
3D Surface ◽  
Valley Side ◽  
3D Surface Topography

Surface topography induced by precision machining is critical for component performance. This paper is to study the synergistic effects of work materials, machining processes, and tool geometry on the geometrical surface quality. Four representative surface topographies of turned and ground surfaces were prepared at “extreme” machining conditions (gentle and abusive) and compared in terms of 3-dimensional (3D) surface features of amplitude, area and volume, spatial, and hybrid parameters. The 3D surface topography maps revealed the anisotropic and repeatable nature of a turned surface which was in sharp contrast with the random and isotropic nature of a ground surface. In general, a gentle turned surface has higher values of amplitude parameters (arithmetic mean, root mean square, maximum height of summits, maximum depth of valleys, and ten-point height) than an abusively turned surface, whereas the opposite was true for the ground counterparts. Only the gentle ground surface has a negative skewness which means that the topography distribution is more biased towards the valley side. The larger kurtosis value of the abusively ground surface implies a more peaked surface topography. The gentle ground and abusively turned surfaces have a much larger bearing area ratio and therefore better bearing capacity than the gentle turned and abusively ground ones. The abusively ground surface has higher fluid retainability than other surfaces in terms of mean void volume.

scholarly journals Numerical Simulation of Temperature and Pressure Changes due to Partial Discharges in Spherical Cavities Within Solid Dielectrics at Different Ageing Conditions

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4771 ◽  
Author(s):  
Johnatan M. Rodríguez-Serna ◽  
Ricardo Albarracín-Sánchez
Keyword(s):  
Dielectric Material ◽  
Surface Condition ◽  
Partial Discharges ◽  
Cavity Surface ◽  
Element Analysis ◽  
Finite Element Analysis Simulation ◽  
Insulation Systems ◽  
Temperature And Pressure ◽  
Solid Dielectrics ◽  
Pressure Changes

Partial Discharges (PD) behavior during ageing of the insulation systems exhibits variations that depend on changes in gas filling characteristics and surface condition. In this article, numerical simulations of temperature and pressure behavior in an air-filled spherical cavity within a homogenous solid dielectric material due to PD activity are presented. An Analytical-Finite Element Analysis simulation approach was implemented in MATLAB and results exhibit reasonable agreement with experimental measurements reported by other authors. Simulation results allow concluding that pressure changes are directly related to variations in the PD behavior. In addition, affectations to cavity surface due to temperature increments can be discarded.

FABRICATION OF CARBON THIN FILMS BY PULSED LASER DEPOSITION IN DIFFERENT AMBIENT ENVIRONMENTS

2016 ◽  
Vol 78 (3) ◽  
Author(s):  
Mohamad Helmi Abd Mubin ◽  
Muhammad Sufi Roslan ◽  
Syed Zuhaib Haider Rizvi ◽  
Kashif Chaudhary ◽  
Suzairi Daud ◽  
...  
Keyword(s):  
Thin Films ◽  
Peak Height ◽  
Maximum Height ◽  
Ambient Conditions ◽  
Graphite Target ◽  
Force Microscopy ◽  
Atomic Force ◽  
Average Maximum ◽  
Spacing Ratio ◽  
Carbon Thin Films

In this work, carbon thin films are grown in different background environments (Air, Helium and Argon) at different pressures (60, 160, 500 and 1000 mbar) by ablating the graphite target with Nd:YAG laser of wavelength of 1064 nm, pulse energy of 740 mJ and pulse rate of 6 ns. 10,000 laser shots are used to ablate graphite target under different ambient conditions. Grown thin films are analyzed by Atomic Force Microscopy (AFM) to measure thickness, roughness average, maximum profile peak height, average maximum height of profile and spacing ratio of the surface. The obtained results show that the roughness average, thickness of film, maximum profile peak height, average maximum height of profile and spacing ratio of thin films decreases with increase in ambient pressuresand shows highest value at low pressure (160 mbar) in helium environment as compared with air and argon.

Mold Cavity Surface Subdivision Method Based on Fuzzy Clustering for Edge Detection

2012 ◽  
Vol 430-432 ◽  
pp. 808-811
Author(s):  
Zhi Xin Feng ◽  
Yi Shu Zhai ◽  
De Hua Miao
Keyword(s):  
High Efficiency ◽  
Boundary Detection ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Surface Boundary ◽  
Detection Technology ◽  
Surface Subdivision ◽  
Fuzzy C Means Clustering ◽  
System Of Parameters ◽  
Cutting Direction

This paper presents a mold cavity surface subdivision method by using image boundary detection technology to realize high efficiency NC machining. From the new perspective of image processing, the method constructed an optimal cutting direction angle field image in the u-v system of parameters according to the relationship between maximum cutting bandwidth and cutting direction in the theory of iso-scallop height firstly, and then fuzzy c - means clustering method was applied for subdivision surface boundary detection. Experimental results demonstrate good performance of the proposed method in distinguishing and extracting boundary points of surface subdivision.

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