scholarly journals A New Conformal Cooling System for Plastic Collimators Based on the Use of Complex Geometries and Optimization of Temperature Profiles

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2744
Author(s):  
Jorge Manuel Mercado-Colmenero ◽  
Abelardo Torres-Alba ◽  
Javier Catalan-Requena ◽  
Cristina Martin-Doñate
Keyword(s):  
Thermal Performance ◽  
Cycle Time ◽  
Cooling System ◽  
Plastic Material ◽  
Dynamic Performance ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Optical Part ◽  
Part Surface ◽  
Plastic Parts

The paper presents a new design of conformal cooling channels, for application in collimator-type optical plastic parts. The conformal channels that are presented exceed the thermal and dynamic performance of traditional and standard conformal channels, since they implement new sections of complex topology, capable of meeting the high geometric and functional specifications of the optical part, as well as the technological requirements of the additive manufacturing of the mold cavities. In order to evaluate the improvement and efficiency of the thermal performance of the solution presented, a transient numerical analysis of the cooling phase has been carried out, comparing the traditional cooling with the new geometry that is proposed. The evolution of the temperature profile versus the thickness of the part in the collimating core with greater thickness and temperature, has been evaluated in a transient mode. The analysis of the thermal profiles, the calculation of the integral mean ejection temperature at each time of the transient analysis, and the use of the Fourier formula, show great improvement in the cycle time in comparison with the traditional cooling. The application of the new conformal design reduces the manufacturing cycle time of the collimator part by 10 s, with this value being 13% of the total manufacturing cycle of the plastic part. As a further improvement, the use of the new cooling system reduces the amount of thickness in the collimator core, which is above the ejection temperature of the plastic material. The improvement in the thermal performance of the design of the parametric cooling channels that are presented not only has a significant reduction in the cycle time, but also improves the uniformity in the temperature map of the collimating part surface, the displacement field, and the stresses that are associated with the temperature gradient on the surface of the optical part.

scholarly journals Application of New Triple Hook-Shaped Conformal Cooling Channels for Cores and Sliders in Injection Molding to Reduce Residual Stress and Warping in Complex Plastic Optical Parts

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2944
Author(s):  
Abelardo Torres-Alba ◽  
Jorge Manuel Mercado-Colmenero ◽  
Juan de Dios Caballero-Garcia ◽  
Cristina Martin-Doñate
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Cooling System ◽  
Plastic Part ◽  
Correct Operation ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Geometric Conditions ◽  
Optical Part ◽  
Conformal Cooling Channels

The paper presents a new design of a triple hook-shaped conformal cooling channels for application in optical parts of great thickness, deep cores, and high dimensional and optical requirements. In these cases, the small dimensions of the core and the high requirements regarding warping and residual stresses prevent the use of traditional and standard conformal cooling channels. The research combines the use of a new triple hook-shaped conformal cooling system with the use of three independent conformal cooling sub-systems adapted to the complex geometric conditions of the sliders that completely surround the optical part under study. Finally, the new proposed conformal cooling design is complemented with a small insert manufactured with a new Fastcool material located in the internal area of the optical part beside the optical facets. A transient numerical analysis validates the set of improvements of the new proposed conformal cooling system presented. The results show an upgrade in thermal efficiency of 267.10% in comparison with the traditional solution. The increase in uniformity in the temperature gradient of the surface of the plastic part causes an enhancement in the field of displacement and in the map of residual stresses reducing the total maximum displacements by 36.343% and the Von—Mises maximum residual stress by 69.280% in comparison with the results obtained for the traditional cooling system. Additionally, the new design of cooling presented in this paper reduces the cycle time of the plastic part under study by 32.61%, compared to the traditional cooling geometry. This fact causes a very high economic and energy saving in line with the sustainability of a green mold. The improvement obtained in the technological parameters will make it possible to achieve the optical and functional requirements established for the correct operation of complex optical parts, where it is not possible to use traditional cooling channels or standard conformal cooling layouts.

scholarly journals Experimental Investigation and Comparison of the Thermal Performance of Additively and Conventionally Manufactured Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 574
Author(s):  
Ana Vafadar ◽  
Ferdinando Guzzomi ◽  
Kevin Hayward
Keyword(s):  
Surface Roughness ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Manufacturing Method ◽  
Industrial Sectors

Air heat exchangers (HXs) are applicable in many industrial sectors because they offer a simple, reliable, and cost-effective cooling system. Additive manufacturing (AM) systems have significant potential in the construction of high-efficiency, lightweight HXs; however, HXs still mainly rely on conventional manufacturing (CM) systems such as milling, and brazing. This is due to the fact that little is known regarding the effects of AM on the performance of AM fabricated HXs. In this research, three air HXs comprising of a single fin fabricated from stainless steel 316 L using AM and CM methods—i.e., the HXs were fabricated by both direct metal printing and milling. To evaluate the fabricated HXs, microstructure images of the HXs were investigated, and the surface roughness of the samples was measured. Furthermore, an experimental test rig was designed and manufactured to conduct the experimental studies, and the thermal performance was investigated using four characteristics: heat transfer coefficient, Nusselt number, thermal fluid dynamic performance, and friction factor. The results showed that the manufacturing method has a considerable effect on the HX thermal performance. Furthermore, the surface roughness and distribution, and quantity of internal voids, which might be created during and after the printing process, affect the performance of HXs.

Design and Optimization of Conformal Cooling System of an Injection Molding Chimney

2016 ◽  
Vol 850 ◽  
pp. 679-686
Author(s):  
He Li ◽  
Yi Mei ◽  
Bo Lin ◽  
Hua Qiang Xiao
Keyword(s):  
Temperature Field ◽  
Cooling System ◽  
Transfer Model ◽  
Analysis Method ◽  
Range Analysis ◽  
Straight Pipe ◽  
Cooling Systems ◽  
Conformal Cooling ◽  
Design And Optimization ◽  
Plastic Parts

Cooling system is important in the quality and the efficiency of forming plastic parts. The heat transfer model for conformal chimney cavity and straight pipe cooling system was developed employing thermal analysis module of UG software. The temperature field distributions of two cavities were analyzed. The differences in chimney forming warping deformations, shrinkage and freeze times for the two types of cooling systems were analyzed quantitatively by Moldflow software. The results showed that the temperature field distribution of the conformal cooling system was more homogeneous and the forming quality and efficiency of molding for the plastic parts was better. Finally, the cooling system parameters were optimized through orthogonal test and range analysis method.

An Investigation on Warpage Analysis in Plastic Injection Moulding

2011 ◽  
Vol 264-265 ◽  
pp. 433-438 ◽  
Author(s):  
Abul B.M. Saifullah ◽  
Syed H. Masood
Keyword(s):  
Cycle Time ◽  
Injection Moulding ◽  
Cooling System ◽  
New Technology ◽  
Simulation Software ◽  
Plastic Part ◽  
Moulding Process ◽  
Cooling Channels ◽  
Cooling Design ◽  
Mould Design

In an injection moulded part, warpage is the distortion caused by non-uniform shrinkage within the plastic part. When looking critically at the causes of warpage, it is found that several key parameters of the moulding process have some effect on the warpage. However, the two major categories that contribute to warpage include the part design and the mould design. In mould design, the gate location, runner/gate system and cooling system design are the major factors affecting not only the warpage and part quality but also the injection moulding cycle time. This paper presents an investigation of using different cooling system configuration on warpage and shrinkage of an industrial plastic part with the aim of determining which cooling configuration will provide minimum warpage and cycle time. As conventional injection mould cooling design is based on straight drilling, it limits the geometric complexity of the cooling design, especially curved shape cooling channels. Nowadays, new technology of advanced rapid tooling based on solid freeform fabrications can be been used to provide conformal cooling channels in injection moulds. In this paper, several type of cooling channels are analysed to compare the performance in terms of warpage and shrinkage and to determine which configuration is suitable for minimizing warpage. Autodesk Moldflow Insight (AMI) simulation software is applied to examine the results of the cooling performances and warpage analysis.

scholarly journals Use of Maraging Steel 1.2709 for Implementing Parts of Pressure Mold Devices with Conformal Cooling System

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5533
Author(s):  
Jarosław Piekło ◽  
Aldona Garbacz-Klempka
Keyword(s):  
Cooling System ◽  
Casting Machine ◽  
Steel Powder ◽  
Experimental Tests ◽  
Test Material ◽  
Conformal Cooling ◽  
Temperature Changes ◽  
Cooling Channels ◽  
Conformal Cooling Channels ◽  
Conventional Solution

In this paper, we present the results of experimental tests and numerical calculations for parts of foundry mold devices made by selective laser melting (SLM). The main aim of this research was to compare the heat conduction efficiency of the conformal and the traditional channel arrangement. The infusion spreader with a conformal channel arrangement and the test material were made with an M2 Concept Laser Cusing machine using 1.2709 steel powder. Temperature changes in the spreaders were compared between conventional and conformal cooling channels using finite element method (FEM) calculations. The position of the so-called “thermal equilibrium isotherm” was determined for both sprue spreaders, which separate the area of the mold with a constant temperature from the zone of cyclic temperature changes. The components of the sprue spreaders in a stress state caused by temperature changes during the operation of the pressure machine were determined using the FEM model. It was found that the cooling system shortened the time of solidification and cooling of the alloy. Based on the analysis of the strength test results and the fracture surface of the samples, the relationship between heat treatment parameters and the strength, hardness, and elongation of the tested material was determined. The sprue spreaders were installed under a pressure machine and tested under production conditions. The use of a sprue spreader with a conformal cooling system shortened the time of a single cycle of the casting machine compared to the conventional solution.

scholarly journals Production injection moulds with additive technology by the HP MJF 4200 printer

2021 ◽  
Vol 1199 (1) ◽  
pp. 012072
Author(s):  
Z Chval ◽  
K Raz ◽  
M Stepanek
Keyword(s):  
Cost Reduction ◽  
Injection Moulding ◽  
Universal Design ◽  
Plastic Material ◽  
Additive Technologies ◽  
Thermal Resistivity ◽  
Fusion Technology ◽  
Additive Technology ◽  
Cooling Channels ◽  
Plastic Parts

Abstract This paper is focused on the production plastic parts. It is describing two technologies-injection moulding and additive technology. The production process of the metal mould for the new parts takes about ten weeks. It is necessary to make some reductions after the mould is produced. It is increasing the time which is necessary for the prototype of products. This time (from the initial design of mould to the prototype of product) can take about six months. Additive technologies can be used for decreasing this time and for cost reduction. Moulds produced by the additive technology are mostly special inserts which can be implemented in the universal design of mould. It is also possible to produce whole moulds from plastic material. These moulds can have integrated cooling channels. There are high demands on the material of the mould with respect to the thermal resistivity, toughness and surface quality. There are really often used SLA technologies, which are considering the High Temp Resin and Material Jetting Digital ABS. Other options used in the factories are Somos PerFORM and Digital ABS Plus. This paper deals with the possibility of usage of the HP Jet Fusion technology with the material PA12 GB for the production of mould inserts and it is evaluating this process and repeatability of process.

scholarly journals Use of a Holistic Design and Manufacturing Approach to Implement Optimized Additively Manufactured Mould Inserts for the Production of Injection-Moulded Thermoplastics

2020 ◽  
Vol 4 (4) ◽  
pp. 100
Author(s):  
Loucas Papadakis ◽  
Stelios Avraam ◽  
Demetris Photiou ◽  
Simona Masurtschak ◽  
Juan Carlos Pereira Falcón
Keyword(s):  
Cycle Time ◽  
Injection Moulding ◽  
Mould Insert ◽  
Conformal Cooling ◽  
Moulding Process ◽  
Cooling Channels ◽  
Injection Process ◽  
Conformal Cooling Channels ◽  
Injection Moulding Process ◽  
Design And Manufacture

Injection moulding is one the most familiar processes for manufacturing of plastic parts by injecting molten thermoplastic polymers into a metallic mould. The cycle time of this process consists of the phases of injection, packing, cooling, and ejection of the final product. Shortening of cycle time is a key consideration to increase productivity. Therefore, in this manuscript the adoption of additively manufactured mould inserts with conformal cooling channels by means of selective laser melting (SLM) with the aim to reduce process cycles is presented. The design and manufacture of a mould insert with conformal cooling channels for producing pressure fitting thermoplastic parts is described. Numerical analysis of the injection process and simulation of shape distortions after SLM were conducted providing useful results for the design and manufacture of the mould insert. The results of the numerical analyses are compared with experimental 3D geometrical data of the additively manufactured mould insert. Temperature measurements during the real injection moulding process demonstrating promising findings. The adoption of the introduced method for the series production of injection moulded thermoplastics proves a shortening of cycle times of up to 32% and a final product shape quality improvement of up to 77% when using mould inserts with conformal cooling channels over the conventional mould inserts.

Spray Cooling for Time Resolved Emission Measurements of ICs

2004 ◽  
Author(s):  
Rama R. Goruganthu ◽  
David Bethke ◽  
Shawn McBride ◽  
Tom Crawford ◽  
Jonathan Frank ◽  
...  
Keyword(s):  
Heat Flux ◽  
Thermal Performance ◽  
Flip Chip ◽  
Cooling System ◽  
Spray Cooling ◽  
Junction Temperature ◽  
Maximum Temperature ◽  
Uniform Heat Flux ◽  
High Heat Flux ◽  
Time Resolved

Abstract Spray cooling is implemented on an engineering tool for Time Resolved Emission measurements using a silicon solid immersion lens to achieve high spatial resolution and for probing high heat flux devices. Thermal performance is characterized using a thermal test vehicle consisting of a 4x3 array of cells each with a heater element and a thermal diode to monitor the temperature within the cell. The flip-chip packaged TTV is operated to achieve uniform heat flux across the die. The temperature distribution across the die is measured on the 4x3 grid of the die for various heat loads up to 180 W with corresponding heat flux of 204 W/cm2. Using water as coolant the maximum temperature differential across the die was about 30 °C while keeping the maximum junction temperature below 95 °C and at a heat flux of 200 W/cm2. Details of the thermal performance of spray cooling system as a function of flow rate, coolant

Sign in / Sign up

Export Citation Format

Share Document