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Huang PW, Peng HS. Fabrication, property characterization, and benefit analysis of mixing mechanism of nitrogen and melt, and its comparison of the porous-foam polypropylene injection molding parts. JOURNAL OF POLYMER ENGINEERING 2023. [DOI: 10.1515/polyeng-2022-0285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Abstract
In this study, an injection molding machine with a mixing mechanism of nitrogen (N2) and melt was designed, and the melt-fill/porous-foaming behavior is observed under the novel barrel design (plasticizing stage) of the gas/melt mixing for the porous injection molded thermoplastic. The thermoplastic employed in this study was polypropylene (PP), and the gas for forming the porous structure is N2. In addition, a thickness of 5 mm and a width of 10 mm paper-clip shape and the mold were constructed for studying the melt-fill-length and fill-length ratio through an experiment. The experimental results showed that the use of an injection molding machine with a mixing mechanism of N2 and melt decreased the melt-fill-length when the N2-output pressure was increased. The reason is that when the gas output, the speed of the screw will be affected. Therefore, during the gas/melt mixing and the plasticization rate will also affect the volume of the foam and the melt. But during plasticizing setting back pressure, can improve its melt volume reduction. When passing through the mixing mechanism and the injected melt, the melt is filled into the mold cavity, and the pressure in the melt is released/porous-foaming grows. At the same time, when the output pressure increases, the amount of melt in the injection barrel will decrease, and its relative porous structure/density distribution will increase. In addition, the mixing/flow direction of the melt impacted the density distribution and dispersion of porous foaming, thus the sample weight/shrinkage of melt-fill-length test sample (Mfl-ts) was improved.
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Affiliation(s)
- Po-Wie Huang
- Ph. D. Program of Mechanical and Aeronautical Engineering , College of Engineering, Feng Chia University , Taichung 40724 , Taiwan
| | - Hsin-Shu Peng
- Mechanical and Computer-Aided Engineering , College of Engineering, Feng Chia University , Taichung 40724 , Taiwan
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Volpe V, Foglia F, Pantani R. Flow-induced crystallization of a Poly(Lactic acid): Effect of the application of low shear rates on the polymorphous crystallization. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Injection moulding is a well-established replication process for the cost-effective manufacture of polymer-based components. The process has different applications in fields such as medical, automotive and aerospace. To expand the use of polymers to meet growing consumer demands for increased functionality, advanced injection moulding processes have been developed that modifies the polymer to create microcellular structures. Through the creation of microcellular materials, additional functionality can be gained through polymer component weight and processing energy reduction. Microcellular injection moulding shows high potential in creating innovation green manufacturing platforms. This review article aims to present the significant developments that have been achieved in different aspects of microcellular injection moulding. Aspects covered include core-back, gas counter pressure, variable thermal tool moulding and other advanced technologies. The resulting characteristics of creating microcellular injection moulding components through both plasticising agents and nucleating agents are presented. In addition, the article highlights potential areas for research exploitation. In particular, acoustic and thermal applications, nano-cellular injection moulding parts and developments of more accurate simulations.
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Affiliation(s)
| | - Andrew Rees
- College of Engineering, Swansea University, Swansea, UK
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Volpe V, Lanzillo S, Affinita G, Villacci B, Macchiarolo I, Pantani R. Lightweight High-Performance Polymer Composite for Automotive Applications. Polymers (Basel) 2019; 11:polym11020326. [PMID: 30960310 PMCID: PMC6419205 DOI: 10.3390/polym11020326] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 01/31/2019] [Accepted: 02/02/2019] [Indexed: 11/29/2022] Open
Abstract
The automotive industry needs to produce plastic products with high dimensional accuracy and reduced weight, and this need drives the research toward less conventional industrial processes. The material that was adopted in this work is a glass-fiber-reinforced polyamide 66 (PA66), a material of great interest for the automotive industry because of its excellent properties, although being limited in application because of its relatively high cost. In order to reduce the cost of the produced parts, still preserving the main properties of the material, the possibility of applying microcellular injection molding process was explored in this work. In particular, the influence of the main processing parameters on morphology and performance of PA66 + 30% glass-fiber foamed parts was investigated. An analysis of variance (ANOVA) was employed to identify the significant factors that influence the morphology of the molded parts. According to ANOVA results, in order to obtain homogeneous foamed parts with good mechanical properties, an injection temperature of 300 °C, a high gas injection pressure, and a large thickness of the parts should be adopted.
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Affiliation(s)
- Valentina Volpe
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II 132, Fisciano, 84084 Salerno, Italy.
| | - Sofia Lanzillo
- SAPA s.r.l. Via Appia Est, 1 82011 Arpaia, 82011 Benevento, Italy.
| | | | | | | | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, via Giovanni Paolo II 132, Fisciano, 84084 Salerno, Italy.
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D'Urso L, Acocella MR, Guerra G, Iozzino V, De Santis F, Pantani R. PLA Melt Stabilization by High-Surface-Area Graphite and Carbon Black. Polymers (Basel) 2018; 10:E139. [PMID: 30966175 PMCID: PMC6415102 DOI: 10.3390/polym10020139] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 01/24/2018] [Accepted: 01/30/2018] [Indexed: 11/17/2022] Open
Abstract
Small amounts of carbon nanofillers, specifically high-surface-area graphite (HSAG) and more effectively carbon black (CB), are able to solve the well-known problem of degradation (molecular weight reduction) during melt processing, for the most relevant biodegradable polymer, namely poly(lactic acid), PLA. This behavior is shown by rheological measurements (melt viscosity during extrusion experiments and time sweep-complex viscosity) combined with gel permeation chromatography (GPC) experiments. PLA's molecular weight, which is heavily reduced during melt extrusion of the neat polymer, can remain essentially unaltered by simple compounding with only 0.1 wt % of CB. At temperatures close to polymer melting by compounding with graphitic fillers, the observed stabilization of PLA melt could be rationalized by scavenging traces of water, which reduces hydrolysis of polyester bonds. Thermogravimetric analyses (TGA) indicate that the same carbon fillers, on the contrary, slightly destabilize PLA toward decomposition reactions, leading to the loss of volatile byproducts, which occur at temperatures higher than 300 °C, i.e., far from melt processing conditions.
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Affiliation(s)
- Luciana D'Urso
- Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Maria Rosaria Acocella
- Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Gaetano Guerra
- Department of Chemistry and Biology, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Valentina Iozzino
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Felice De Santis
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy.
| | - Roberto Pantani
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (SA), Italy.
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Volpe V, De Filitto M, Klofacova V, De Santis F, Pantani R. Effect of mold opening on the properties of PLA samples obtained by foam injection molding. POLYM ENG SCI 2017. [DOI: 10.1002/pen.24730] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Valentina Volpe
- Department of Industrial Engineering; University of Salerno; Via Giovanni Paolo II 132, Fisciano 84084 Salerno Italy
| | - Martina De Filitto
- Department of Industrial Engineering; University of Salerno; Via Giovanni Paolo II 132, Fisciano 84084 Salerno Italy
| | - Vera Klofacova
- Centre of Polymer Systems; Tomas Bata University in Zlin; Trida Tomase Bati 5678, Zlin 760 01 Czech Republic
| | - Felice De Santis
- Department of Industrial Engineering; University of Salerno; Via Giovanni Paolo II 132, Fisciano 84084 Salerno Italy
| | - Roberto Pantani
- Department of Industrial Engineering; University of Salerno; Via Giovanni Paolo II 132, Fisciano 84084 Salerno Italy
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Micromechanical Characterization of Complex Polypropylene Morphologies by HarmoniX AFM. INT J POLYM SCI 2017. [DOI: 10.1155/2017/9037127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
This paper examines the capability of the HarmoniX Atomic Force Microscopy (AFM) technique to draw accurate and reliable micromechanical characterization of complex polymer morphologies generally found in conventional thermoplastic polymers. To that purpose, injection molded polypropylene samples, containing representative morphologies, have been characterized by HarmoniX AFM. Mapping and distributions of mechanical properties of the samples surface are determined and analyzed. Effects of sample preparation and test conditions are also analyzed. Finally, the AFM determination of surface elastic moduli has been compared with that obtained by indentation tests, finding good agreement among the results.
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