plastics processing
Recently Published Documents


TOTAL DOCUMENTS

201
(FIVE YEARS 20)

H-INDEX

13
(FIVE YEARS 0)

2022 ◽  
pp. 1-30
Author(s):  
Wei Zheng ◽  
Adam Kramschuster ◽  
Alex Jordan

Abstract This article discusses technologies focused on processing plastic materials or producing direct tools used in plastics processing. The article focuses on extrusion and injection molding, covering applications, materials and their properties, equipment, processing details, part design guidelines, and special processes. It also covers the functions of the extruder, webline handling, mixing and compounding operations, and process troubleshooting. Thermoforming and mold design are covered. Various other technologies for polymer processing covered in this article are blow molding, rotational molding, compression molding, transfer molding, hand lay-up process, casting, and additive manufacturing.


2021 ◽  
Vol 11 (24) ◽  
pp. 11805
Author(s):  
Fátima de Almeida ◽  
Vitor F. C. Sousa ◽  
Francisco J. G. Silva ◽  
Raúl D. S. G. Campilho ◽  
Luís P. Ferreira

Plastics injection molding is a sector that is becoming increasingly competitive due to the environmental issues it entails, pressuring consumers to reduce its use. Thus, plastics processing companies attempt to minimize costs, with the aim of increasing competitiveness. This pressure is transmitted to the mold manufacturers, as the mold conditions the equipment that it is used for, which may have significantly different amortization costs. The present work aimed to design a novel mechanism able to deal with the necessary movements in 2K injection molding in a more compact way. A novel hybrid mechanical and hydraulic movement was developed. More compact movements lead to smaller molds, which can be used on smaller injection machines, leading to reduced costs. This methodology consists of multiplying a disproportionate movement to the mold through several movements, which results in a slightly more complex, but much more compact, system for molds devoted to multi-material injected parts.


TAPPI Journal ◽  
2021 ◽  
Vol 20 (9) ◽  
pp. 599-604
Author(s):  
CHINMAY SATAM ◽  
ASHOK GHOSH ◽  
PETER W. HART

Starches have recently regained attention as ecofriendly barrier materials due to the increased demand for sustainable packaging. They are easily processable by conventional plastics processing equipment and have been utilized for oil and grease barrier applications. While starches have excellent oxygen barrier properties and decent water barrier properties at low relative humidity (RH), they are moisture sensitive, as demonstrated by the deterioration of the barrier properties at higher RH values. Starch esters are chemically modified starches where the hydroxyl group of the starch has been substituted by other moieties such as acetates. This imparts hydrophobicity to starches and has been claimed as a good way of retaining water vapor barrier properties of starches, even at high RH conditions. We studied the water vapor barrier properties of one class of starch esters, i.e., high amylose starch acetates that were assumed to have good water vapor barrier properties. Our investigations found that with a high degree of substitution of hydroxyl groups, the modified starches did indeed show improvements in water vapor response as compared to pure high amylose starch films; however, the barrier properties were orders of magnitude lower than commercially used water vapor barriers like polyethylene. Even though these materials had improved water vapor barrier response, high amylose starch acetates are likely unsuitable as water vapor barriers by themselves, as implied by previous literature studies and patents.


2021 ◽  
Vol 5 (1) ◽  
pp. 7-14
Author(s):  
Tomasz Chaciński ◽  
Paweł Sutowski

The article deals with issues related to quality management and quality assessment in production of plastic articles in injection moulding. Expert knowledge collected in textbooks and literature allows to get acquainted with the characteristics of plastic article production and product quality defects arising in such processes. The characteristics and technology of plastics processing are discussed, the most frequent quality defects occurring in the production of articles made of plastics by injection molding are listed. On the basis of expert knowledge collected in the literature, a series of actions leading to the elimination of each of the mentioned quality defects has also been proposed.


2021 ◽  
Vol 1042 ◽  
pp. 17-22
Author(s):  
Sibele Piedade Cestari ◽  
Peter Martin ◽  
Paul Hanna ◽  
Mark Kearns ◽  
Luis Claudio Mendes

Throughout the combination of unique approaches on innovative polymer composites and rotational moulding plastics processing technique, we developed a building block using a mix of recycled and virgin plastic. This block was a technical case study from a multidisciplinary approach - comprising materials science, polymers processing and design - to reinsert recycled plastics in the Circular Economy. The aim was to produce a three-dimensional interlockable block, combining unique design and unconventional materials to create an emblematic building element. We investigated the composition and availability of local plastic waste, as well as other waste-stream materials – concrete waste, red mud, hemp fibre, sugarcane bagasse. We prepared a range of composites and blends to test their prospective aspect and processability. To simulate the end-result of a rotationally-moulded part, we prepared samples of the blends in an oven. The thermal analysis showed that all materials were thermally stable at the processing temperature of the virgin polymer in rotomoulding, around 200 °C. There were an evident LLDPE continuous-phase and a recyclate dispersed-phase. We also explored the aesthetic effect of scattering particles of colour in the mixes. The impact test showed better results for the polyethylene-based recyclates if compared to polypropylene and poly (ethylene terephthalate) ones. We concluded that waste materials could be revalued into something practical and reproducible, produced by rotational moulding plastics processing. And we developed a viable and innovative potential product for the Circular Economy, requiring minimal fixing and no further external finishing.


Author(s):  
Michael Heinrich ◽  
Ricardo Decker ◽  
Paul Reindel ◽  
Katja Böttcher ◽  
Isabelle Roth-Panke ◽  
...  

AbstractThe paper describes a novel technological approach to influencing the rheological properties of thermoplastic materials exposed to acoustic energy. The flow behavior of polypropylene with different mass percentages of glass fibers is investigated in a parallel plate rheometer under high-frequency longitudinal excitation. The influence of oscillation frequency on the melt viscosity is explained by means of shear thinning criteria. The dependence of the oscillation shape using sinusoidal excitation on shear thinning as a function of different fiber reinforcement percentages is also investigated. A phenomenological view describes the mutually influencing parameters with regard to different material compositions and different excitation frequencies over the time course of the rheometric measurement. Interacting relationships are analyzed and discussed and the potential of the actuator system to influence the plastic melt is worked out. Based on this, a technological approach follows which describes the transfer of an oscillating mold surface to plastics processing methods, which, especially in the case of energy-intensive injection molding technology, leads to the expectation of possible resource efficiency in energy and material.


Author(s):  
Fatih Selim Yildizhan

Plastics are synthetic or semi-synthetic meltable substances that can be modeled in solid objects. In the modern world, it seems impossible today to live without plastic or synthetic polymers, which production and usage only go back to 1950. While plastics play a central role in modern society, the production of safer and cleaner products for potential use is required for decreasing the negative environmental effects. The purpose of this article is to analyze the plastic industry, the role of plastics in our social life, the situation in the plastics market, plastic recycling, and masterbatch compound production. For the purpose of this article, the main markets which have been analyzed are; Europe, Asia, and North America. There is a specific part focusing on Turkey who ranks 6th in terms of plastics processing capacity in Europe and has a huge plastic waste mismanagement problem. Finally, there is an analysis of the financial and operational side of global plastics trading, contract terms, and payment methods, which are being used today by the companies who are operating in the petrochemical industry and commodity trade financing generally.


2021 ◽  
Vol 112 (11-12) ◽  
pp. 3501-3513
Author(s):  
Yannik Lockner ◽  
Christian Hopmann

AbstractThe necessity of an abundance of training data commonly hinders the broad use of machine learning in the plastics processing industry. Induced network-based transfer learning is used to reduce the necessary amount of injection molding process data for the training of an artificial neural network in order to conduct a data-driven machine parameter optimization for injection molding processes. As base learners, source models for the injection molding process of 59 different parts are fitted to process data. A different process for another part is chosen as the target process on which transfer learning is applied. The models learn the relationship between 6 machine setting parameters and the part weight as quality parameter. The considered machine parameters are the injection flow rate, holding pressure time, holding pressure, cooling time, melt temperature, and cavity wall temperature. For the right source domain, only 4 sample points of the new process need to be generated to train a model of the injection molding process with a degree of determination R2 of 0.9 or and higher. Significant differences in the transferability of the source models can be seen between different part geometries: The source models of injection molding processes for similar parts to the part of the target process achieve the best results. The transfer learning technique has the potential to raise the relevance of AI methods for process optimization in the plastics processing industry significantly.


Sign in / Sign up

Export Citation Format

Share Document