Electron microscopy studies of ?- and?-form spherulites in weld lines of injection moulded polypropylene parts

Singh, Divya; Moslé, H. G.; Kunz, Martin; Wenig, W.

doi:10.1007/bf01129928

Cited by 7 publications

(2 citation statements)

References 6 publications

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“…A skin layer was homogeneously formed at the weld as well as at at other positions, but the amount of β‐form spherulites at the weld line was smaller than those in the other positions. A decrease in the number of β‐form spherulites was detected at the cold weld line [13], and the generation of β‐form spherulites increased at the mold temperature of 100°C as compared with that at 40°C [14]. At the lower mold temperature, α‐form crystals form because the crystallization rate of α‐form crystals is faster than β‐form crystals at temperatures below 90°C and above 133°C [15].…”

Section: Resultsmentioning

confidence: 99%

The unique flow of polypropylene at the weld line behind an obstacle in injection molding

Kobayashi

Teramoto²,

Kanai

2010

Polymer Engineering & Sci

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In this article, a weld line placed behind an obstacle in an injection‐molded plaque made of metallic mold‐in‐color polypropylene (PP) was investigated. A broad uneven glossy section was visually observed along the weld line after the v‐notch weld disappeared. Although disk‐shaped metallic pigments were oriented parallel to the wall according to laminar flow, the pigment particles at the weld behind the obstacle were ordered vertically at the center of the depth direction. In PP molded without pigment, a black line was observed at the same position in the metallic weld. Based on a measurement of the crystal structure, the black line was caused by the rapid cooling of molten PP. Elongational flow occurred along the weld line after the diminishing v‐notch weld. The unique flow ordered the pigments obliquely at the advancing flow front and disturbed the subsequent flow of hot PP which transferred heat to the crystallizing mass. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

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Section: Resultsmentioning

confidence: 99%

The unique flow of polypropylene at the weld line behind an obstacle in injection molding

Kobayashi

Teramoto²,

Kanai

2010

Polymer Engineering & Sci

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“…In accordance with the guidelines provided by ISO 50001, the procedures and instruments were categorized into three primary areas, and the particular results important to each category were then synthesized. In its concluding section, the article discusses problems and topics that still need to be addressed and offers proposals for new lines of inquiry [11][12][13][14][15][16].…”

Section: Introductionmentioning

confidence: 99%

Energy-Efficient Manufacturing: Opportunities and Challenges

Singh,

Sharma,

Dubey

et al. 2024

E3S Web Conf.

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The industrial manufacturing sector is the biggest final usage sector when speaking of both final energy consumption and emission of greenhouse gases (accounting for over 30% of the total); the industry's expansion is fast modifying the climate of the whole globe. Energy conservation is one of the key components of success for sustainable production because of the pressing need to reduce the negative effects that industrial operations have on the surrounding environment. As a direct consequence of this, the scientific community's involvement in energy management has significantly increased, which has resulted in a number of literature evaluations being conducted on methodologies. However, there is a dearth of both a detailed study of the techniques and tools that attempt to improve energy awareness as well as an assessment of the impact that these methods and tools have on energy efficiency. To try to fill this void, the author of this work conducts an extensive literature study on the various energy assessment methodologies and tools with their microstructures. After examining the databases of scientific literature, a total of 1366 publications were retrieved; however, it might be of use to industry practitioners in the field of energy management. In accordance with the guidelines provided by ISO 50001, the procedures and instruments were categorized into three primary areas (namely, AAM which means analysis, assessment, and saving measures), and the particular results important to each category were then synthesized as the outcome of study. In its concluding section, the article discusses problems and topics that still need to be addressed and offers proposals for new lines of inquiry.

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Weldlines in injection‐molded parts: A review

et al. 1995

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It is a well-known fact that weldlines are unavoidable in most injection-molded products of even moderate complexity. While there are many situations where they are barely perceptible, weldlines represent a potential source of weakness in molded parts. In injection molding weldlines are generated when two separate melt streams join either in multigated molds or as a consequence of flow around obstacles. The development of many interesting materials has been hampered by poor weldline strength. Among such materials are plastics reinforced with fibers or platelets, liquid crystal polymers, and a number of multiphase polymer blends. Weldlines have ever been called the "Achilles' heel" of these multiphase materials. This article is a review of the literature published on weldlines in injected parts. It deals primarily with the aspects related to the mechanical behavior of weldline-containing parts. It begins with a brief description of the phenomena important for the part formation in the mold, including those leading to weldlines, in addition to the techniques used to characterize weldline-containing parts. The following three sections consider the structure and properties of weldlines in neat amorphous and semicrystalline polymers, filled and reinforced plastics, and finally in polymer blends and alloys. In the last section methods developed for increasing the weldline strength are discussed.

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Electron microscopy studies of ?- and?-form spherulites in weld lines of injection moulded polypropylene parts

Cited by 7 publications

References 6 publications

The unique flow of polypropylene at the weld line behind an obstacle in injection molding

The unique flow of polypropylene at the weld line behind an obstacle in injection molding

Energy-Efficient Manufacturing: Opportunities and Challenges

Weldlines in injection‐molded parts: A review

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