The effect of pressure and temperature on microthermoforming thermoplastic films integrated in the injection moulding process

2016 ◽  
Vol 36 (6) ◽  
pp. 597-605 ◽  
Author(s):  
Ariane Jungmeier

Abstract Injection moulding is a widespread large-scale production technology for the manufacturing of thermoplastic parts, with small wall thicknesses limiting the feasible flow length. Introducing microthermoforming into the injection moulding process with dynamic mould temperature control enables the production of film-based, plane microstructured parts with further three-dimensional functional structures (e.g. for handling or for fitting in devices/assembly groups). Investigations show that considerable forming is possible with pressures up to 140 bar and forming temperatures far below the glass transition temperature of 50-μm-thick polycarbonate films in cycle times of <3 min. Generally speaking, the novel technology is expected to allow for multifunctional, thin-walled microstructured parts at large scales with short cycle times.

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1940
Author(s):  
Muhammad Usman Naseer ◽  
Ants Kallaste ◽  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anton Rassõlkin

This paper presents current research trends and prospects of utilizing additive manufacturing (AM) techniques to manufacture electrical machines. Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. AM offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques. AM has a lot to offer in every aspect of machine fabrication, such that from size/weight reduction to the realization of complex geometric designs. However, some practical limitations of existing AM techniques restrict their utilization in large scale production industry. The introduction of three-dimensional asymmetry in machine design is an aspect that can be exploited most with the prevalent level of research in AM. In order to take one step further towards the enablement of large-scale production of AM-built electrical machines, this paper also discusses some machine types which can best utilize existing developments in the field of AM.


2020 ◽  
Author(s):  
Filip Bošković ◽  
Alexander Ohmann ◽  
Ulrich F. Keyser ◽  
Kaikai Chen

AbstractThree-dimensional (3D) DNA nanostructures built via DNA self-assembly have established recent applications in multiplexed biosensing and storing digital information. However, a key challenge is that 3D DNA structures are not easily copied which is of vital importance for their large-scale production and for access to desired molecules by target-specific amplification. Here, we build 3D DNA structural barcodes and demonstrate the copying and random access of the barcodes from a library of molecules using a modified polymerase chain reaction (PCR). The 3D barcodes were assembled by annealing a single-stranded DNA scaffold with complementary short oligonucleotides containing 3D protrusions at defined locations. DNA nicks in these structures are ligated to facilitate barcode copying using PCR. To randomly access a target from a library of barcodes, we employ a non-complementary end in the DNA construct that serves as a barcode-specific primer template. Readout of the 3D DNA structural barcodes was performed with nanopore measurements. Our study provides a roadmap for convenient production of large quantities of self-assembled 3D DNA nanostructures. In addition, this strategy offers access to specific targets, a crucial capability for multiplexed single-molecule sensing and for DNA data storage.


2019 ◽  
Vol 809 ◽  
pp. 140-147 ◽  
Author(s):  
Maike Böttcher ◽  
Daisy Nestler ◽  
Jonas Stiller ◽  
Lothar Kroll

Ceramic materials are suitable for use in the high temperature range. Oxide ceramics, in particular, have a high potential for long-term applications under thermal cycling and oxidising atmosphere. However, monolithic oxide ceramics are unsuitable for use in high-temperature technical applications because of their brittleness. Thin-walled, oxidation resistant, and high-temperature resistant materials can be developed by reinforcing oxide ceramics with ceramic fibres such as alumina fibres. The increase of the mechanical stability of the composites in comparison to the non-fibre reinforced material is of outstanding importance. Possible stresses or cracks can be derived along the fibre under mechanical stress or deformation. Components made of fibre-reinforced ceramic composites with oxide ceramic matrix (OCMC) are currently produced in manual and price-intensive processes for small series. Therefore, the manufacturing should be improved. The ceramic injection moulding (CIM) process is established in the production of monolithic oxide ceramics. This process is characterised by its excellent automation capability. In order to realise large scale production, the CIM-process should be transferred to the production of fibre-reinforced oxide ceramics. The CIM-process enables the production of complicated component shapes and contours without the need for complex mechanical post-treatment. This means that components with complex geometries can be manufactured in large quantities.To investigate the suitability of the injection moulding process for the production of OCMCs, two different feedstocks and alumina fibres (Nextel 610) were compounded in a laboratory-scale compounder. The fibre volume fractions were varied. In a laboratory-scale injection moulding device, microbending specimens were produced from the compounds obtained in this way. To characterise the test specimens, microstructure examinations and mechanical-static tests were done. It is shown that the injection moulding process is suitable for the production of fibre-reinforced oxide ceramics. The investigations show that the feedstocks used have potential for further research work and for future applications as material components for high-temperature applications in oxidising atmospheres.


Author(s):  
Jaho Seo ◽  
Amir Khajepour ◽  
Jan P. Huissoon ◽  
Young-Jun Park

Thermal control is a key issue for injection moulding process due to its effects on production quality and rate. In this study, an on-line thermal control strategy is provided for effective thermal management in plastic injection moulding process. The strategy covers for methods in determining sensor locations as a prerequisite step for modeling and control, identifying a thermal dynamic model of a mould with uncertainties and designing a cavity wall temperature controller. A verification of the designed controller’s performance is carried out from the viewpoints of accuracy in on-line temperature tacking and response time under different injection moulding process with various cycle-times.


2020 ◽  
Author(s):  
Matthew Limpert ◽  
Terrill B. Atwater ◽  
Ashley L. Ruth

Lithium manganese oxide spinels are attractive materials for lithium-ion battery cathodes due to their capability for high voltage application paired with a three-dimensional conductive pathway that can allow for improved lithium insertion and deinsertion kinetics. However, this material suffers from limited cyclability as a result of the energy barriers for removing lithium from the octahedral sites and capacity fading as a result of manganese dissociation. This work incorporates a multiple doping strategy for selecting capacity distribution across various voltage regimes. The resulting electrochemical cells are able to produce useful capacity at 5.2 V, 4.7 V, 4.1 V, and 2.75 V. Additionally, materials synthesized in a laboratory setting and via large scale production via licensing with no cobalt content has resulted in capacities exceeding 200 mAh/g. These materials achieve 75% capacity retention at 3C vs. C/10 discharge down to 2.75 V.


2019 ◽  
Vol 116 (48) ◽  
pp. 23909-23914 ◽  
Author(s):  
Wanbo Li ◽  
Miao Yu ◽  
Jing Sun ◽  
Kentaro Mochizuki ◽  
Siyu Chen ◽  
...  

Three-dimensional hierarchical morphologies widely exist in natural and biomimetic materials, which impart preferential functions including liquid and mass transport, energy conversion, and signal transmission for various applications. While notable progress has been made in the design and manufacturing of various hierarchical materials, the state-of-the-art approaches suffer from limited materials selection, high costs, as well as low processing throughput. Herein, by harnessing the configurable elastic crack engineering—controlled formation and configuration of cracks in elastic materials—an effect normally avoided in various industrial processes, we report the development of a facile and powerful technique that enables the faithful transfer of arbitrary hierarchical structures with broad material compatibility and structural and functional integrity. Our work paves the way for the cost-effective, large-scale production of a variety of flexible, inexpensive, and transparent 3D hierarchical and biomimetic materials.


Carbon ◽  
2014 ◽  
Vol 78 ◽  
pp. 147-155 ◽  
Author(s):  
Reema Kamaliya ◽  
Bhanu Pratap Singh ◽  
Bipin Kumar Gupta ◽  
Vidya Nand Singh ◽  
Tejendra Kumar Gupta ◽  
...  

Author(s):  
Rossella Surace ◽  
Gianluca Trotta ◽  
Alessandro Bongiorno ◽  
Vincenzo Bellantone ◽  
Claudia Pagano ◽  
...  

Due to its high efficiency for the large scale production of polymeric parts, micro injection moulding is one of the key technologies of the new millennium. Although a lot of researches have been conducted to identify the most effective processing conditions for micro injection moulding, the comprehension of the influence of all parameters on the quality, the properties and the reliability of the moulded parts is still an issue. In this context, this study aims to evaluate the effects of the micro injection moulding process conditions on the tensile properties of micro parts, investigating the influence of three main process parameters: the injection speed, the mould temperature and the melt temperature. A full factorial plan has been applied to study the contributions of these parameters and a second study has been performed to understand the synergic interaction between the two temperatures on the tensile strength. Due to its high level of potential crystallinity, a typical semi-crystalline thermoplastic resin was used in the experiments. The results of the analysis showed a great influence of the mould temperature (Tmould) on the ultimate tensile strength and of the melt temperature (Tmelt) on the deformation at the point of breaking; whereas the injection speed was significant on the overall mechanical performance. A new studied factor (Tmelt-Tmould) could affect the resulting molecular structure and consequently the mechanical behaviour, but itself is not sufficient to thoroughly explain the observed behaviour. Moreover, the visual inspection of the deformation mechanism at break shows three distinctive trends demonstrating the great variability of the mechanical properties of micro-injected specimens due to process conditions.


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