Effects of processing conditions on cavity pressure during injection-compression molding

Lee, Ho-Sang; Yoo, Young-Gil

doi:10.1007/s12541-012-0286-x

Cited by 12 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The clamping stroke allows detailed reproduction of surface geometries and improved dimensional stability of the component. Injection‐compression molding processes exist as low‐pressure processes to avoid damage to inserts. Pre‐encapsulation of electronic components close to the contour before encapsulation with high‐performance thermoplastics is conceivable from a process engineering point of view and ties in with the approach of the interlayer (see further “Polymer Materials” section).…”

Section: Resultsmentioning

confidence: 99%

Thermoplastic encapsulations of a sensor platform by high‐temperature injection molding up to 360°C

Werner

Krumpholz

Rehekampff

et al. 2019

Polymer Engineering & Sci

View full text Add to dashboard Cite

For bioprotective encapsulated Internet of Things (IoT) electronics for the medical market, especially for cost‐effective, single or multiple use, injection molding will be of major importance. The stresses from the production process pose special challenges for electronics. The aim of the study was the simulative and experimental characterization of the load spectrum from the injection molding process and its effects on electronics. General recommendations for the encapsulation of IoT electronics in polymer matrices were derived. A microcontroller‐controlled temperature sensor board and a suitable injection mold were developed. Eight circumferential NTC‐sensors measured the prevailing thermal load directly on the component during overmolding. A simulation model allowed statements on the loads to be made about individual components, validated in experimental tests. In addition to PP and PMMA, PSU with a melt temperature of 360°C was tested. The temperature influence of the melt could be described as a function of the component position. The loss of adhesion, shrinkage, distortion, cavities, and delamination were analyzed using micrograph analysis. Complete functionality of the electronics was ensured after encapsulation. Optimization strategies were developed for the design of both IoT electronics and the injection mold. Novel concepts such as interlayer or backfill vias could be derived for future research approaches. POLYM. ENG. SCI., 59:1315–1331 2019. © 2019 Society of Plastics Engineers

show abstract

Section: Resultsmentioning

confidence: 99%

Thermoplastic encapsulations of a sensor platform by high‐temperature injection molding up to 360°C

Werner

Krumpholz

Rehekampff

et al. 2019

Polymer Engineering & Sci

View full text Add to dashboard Cite

show abstract

“…Future work should also focus on the combination of insert moulding and injection compression moulding to minimize the blister formation in FIM parts. Compression moulding has seen successfully used for the FIM process in several studies [29,30] and forms a strong basis for future research both for experimental and numerical activities.…”

Section: Discussionmentioning

confidence: 99%

Blister Formation in Film Insert Moulding

et al. 2020

View full text Add to dashboard Cite

The formation of blister in the injection moulded parts, especially in the film insert moulded parts, is one of most significant causes of part rejection due to cosmetic requirements or functionality issues. The mechanism and physics of blister formation for molded parts are not well-understood by the state-of-the-art literature. The current paper increases the fundamental understanding of the causes for blister formation. In the experiment, a membrane strip of 5 mm in width was overmoulded with Polypropylene (PP), which formed a disc-shaped part with a diameter of 17.25 mm and a thickness of 500 µm. To investigate the influence of the processing parameters, a full factorial design of experiments (DoE) setup was conducted, including mould temperature (Tm), barrel temperature (Tb), injection speed (Vi) and packing pressure (Pp) as variables. The degree of blistering at the surface was characterized by the areal surface roughness parameters Spk and Smr1, measured with a confocal laser microscope. The measurements were taken on the 10 mm long section of the membrane surface in the centre of the moulded part across the entire width of the film. In addition, the film insert moulding (FIM)-process was simulated and the average shrinkage of the substrate material under the membrane was investigated. Eventually, a method and processing window could be defined that could produce blister-free parts.

show abstract

“…Thus, for optical components, such as plastic lens arrays (PLAs), an appropriate setting of the ICM processing parameters is essential in improving the imaging qualities of the final product. [5][6][7] The melt flow process of plastic molding is highly complex, and involves the interaction between many non-linear, non-stable, and time-or temperature-dependent properties. 8 Hence, determining the optimal processing parameters using conventional experimental trial-and-error methods is time-consuming, expensive, and offers no guarantee of determining the optimal outcome.…”

Section: Introductionmentioning

confidence: 99%

“…However, residual stress is easily accumulated within the molded component during the compression and packing stages, and this often leads to the warpage of the component as it undergoes cooling following ejection from the mold. Thus, for optical components, such as plastic lens arrays (PLAs), an appropriate setting of the ICM processing parameters is essential in improving the imaging qualities of the final product 5–7 …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Injection‐compression molding process on optical quality optimization of plastic lens array

Lin,

Lin

2023

Polymers for Advanced Techs

View full text Add to dashboard Cite

Plastic lens arrays (PLAs) have the advantages of a light weight and a compact size. However, their optical performance is often degraded by warpage, caused by the accumulation of residual stress during the injection molding process. Accordingly, the present study employs mold flow analysis simulations and a Taguchi‐Gray relational analysis (GRA) framework to optimize the processing parameters of the injection compression molding (ICM) process. The analyses focus specifically on the effects of the mold temperature, melt temperature, injection velocity, packing pressure, packing time, and compression gap on the optical path difference (OPD) and lens center displacement (LCD) of the fabricated lens array. The results confirm that the optimized processing parameters significantly improve the OPD, LCD, birefringence, and imaging properties of the PLA compared to those of a PLA fabricated using standard molding conditions.

show abstract

Effects of processing conditions on cavity pressure during injection-compression molding

Cited by 12 publications

References 12 publications

Thermoplastic encapsulations of a sensor platform by high‐temperature injection molding up to 360°C

Thermoplastic encapsulations of a sensor platform by high‐temperature injection molding up to 360°C

Blister Formation in Film Insert Moulding

Injection‐compression molding process on optical quality optimization of plastic lens array

Contact Info

Product

Resources

About