Demolding forces for micron‐sized features during micro‐injection molding

Su, Quanliang; Gilchrist, Michael D.

doi:10.1002/pen.24309

Cited by 22 publications

(24 citation statements)

References 16 publications

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“…In addition to a complete mold filling, high quality replication requires a flawless demolding where all micro-nanostructures withstand demolding forces. Inappropriate design of demolding forces used to remove the manufactured piece from the cavity can lead to irreparable structural deformation or even failure of the molded features on the polymer surface, and also can affect the lifetime of the mold 3,[109][110] .…”

Section: Demoldingmentioning

confidence: 99%

“…Accurate design is needed considering many factors from polymer selection and mold conditions to processing parameters and part design 111 . Applied forces to the polymer surface, difference in the thermal conduction coefficient between the polymer material and mold metal, generated forces due the shrinkage of the polymer during the solidification stage, process parameters, cavity shape and material, molding material and geometry, features shape and aspect ratio-to be name but a few 109 .…”

Section: Demoldingmentioning

confidence: 99%

“…The first uses demolding chemical surface agents named antistiction coatings. The second is a mechanical ejector such as pins, blades, rings, sleeves, and stripper blades 20,109,112 . Both methods have advantages and disadvantages.…”

Section: Demoldingmentioning

confidence: 99%

“…Use of chemical demolding agents is restricted in the medical or some microfluidic applications due to probable harmful effects on human health 57 . Mechanical ejectors can lead to permanent deformation especially when the part geometry is complicated or the distribution of the ejector pins is not appropriate 28,109 . Therefore, a proper design of produced tool and the location of ejector pins is necessary to avoid damage and failure to the polymeric parts 20 .…”

Section: Demoldingmentioning

confidence: 99%

“…Increased holding pressure can reduce the shrinkage and consequently decrease demolding forces. Evidently, longer cooling times lead to higher demolding forces 109 . Moreover, melt temperature and injection pressure also influence demolding forces 109,116 .…”

Section: Fig26 Illustration Of the Demolding Forces 109mentioning

confidence: 99%

See 4 more Smart Citations

Micro-nanostructured polymer surfaces using injection molding: A review

Maghsoudi

Jafari

Momen

et al. 2017

Materials Today Communications

127

110

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Micro injection molding is in great demand due to its efficiency and applicability for industry. Polymer surfaces having micro-nanostructures can be produced using injection molding. However, it is not as straightforward as scaling-up of conventional injection molding. The paper is organized based on three main technical areas: mold inserts, processing parameters, and demolding. An accurate set of processing parameters is required to achieve precise micro injection molding. This review provides a comparative description of the influence of processing parameters on the quality of final parts and the precision of final product dimensions in both thermoplastic polymers and rubber materials. It also highlights the key parameters to attain a high quality micro-nanostructured polymer and addresses the contradictory effects of these parameters on the final result. Moreover, since the produced part should be properly demolded to possess a high quality textured polymer, various demolding techniques are assessed in this review as well.

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Section: Demoldingmentioning

confidence: 99%

Section: Demoldingmentioning

confidence: 99%

Section: Demoldingmentioning

confidence: 99%

Section: Demoldingmentioning

confidence: 99%

Section: Fig26 Illustration Of the Demolding Forces 109mentioning

confidence: 99%

See 3 more Smart Citations

Micro-nanostructured polymer surfaces using injection molding: A review

Maghsoudi

Jafari

Momen

et al. 2017

Materials Today Communications

127

110

View full text Add to dashboard Cite

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Optimization strategy of the multihole products weld lines based on the multi‐objective evaluation system and kriging surrogate model

Wang

Chen

2018

Polymer Engineering & Sci

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The plastic multihole products are widely used in Household Appliance and Automobile industry. The densely distributed weld lines resulting from the multiaperture structure seriously damage the surface appearance and mechanical properties of the products. However, there are relatively few studies on the optimization of weld lines of the plastic multihole products. Therefore, a multihole plate was taken as an example to exploit an optimization strategy for this kind of defects. The multi‐objective evaluation system was established to assess bonding quality of weld lines based on Numerical Simulation. And a multi‐objective optimization methodology was presented to efficiently optimize the process parameters. First, back propagation neural networks and Kriging method were combined to build the surrogate models based on the experiments arranged by Latin hypercube sampling. Second, a systematic test strategy was proposed to ensure high accuracy of the surrogate model. Then, the pareto optimal solution was obtained by integrating the surrogate model and Non‐dominated Sorting Genetic Algorithm II. Finally, the simulated and practical confirmation experiments indicate that bonding quality of weld lines can be effectively characterized and significantly improved by the multi‐objective evaluation system and the multi‐objective optimization methodology, respectively. POLYM. ENG. SCI., 59:781–790, 2019. © 2018 Society of Plastics Engineers

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The generation mechanism of demolding force based on the mold‐part interface contact mode in micro‐injection molding

Zhou

Qiu

2023

Polymer Engineering & Sci

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Demolding is the key step of micro‐injection molding (μIM), which influences the molding quality of polymer parts to a great extent. The essence of demolding is to overcome interface interactions between the mold cavity surface and the part surface, which is closely related to factors such as the cavity surface topography and process parameters. However, a theoretical model predicting the demolding force of μIM is still lacking, resulting in the difficulty of improving the quality of demolding in μIM. Therefore, a comprehensive demolding force model is proposed to clarify the demolding mechanism of μIM. The model focuses on the adhesion behavior and friction behavior in the special contact mode formed by the replication effect of μIM. The theory proof and computation results indicate that the cavity surface topography determines the contact mode of the mold‐part interface (MPI), which in turn changes the real interface contact area, the composition mode of adhesion stress, and the friction forms, thereby affecting the adhesion and friction force during demolding. In addition, the process parameters can also change the contact mode of MPI as the process parameters have a great effect on the filling capacity and the degree of replication, thereby influencing the demolding process.

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Demolding forces for micron‐sized features during micro‐injection molding

Cited by 22 publications

References 16 publications

Micro-nanostructured polymer surfaces using injection molding: A review

Micro-nanostructured polymer surfaces using injection molding: A review

Optimization strategy of the multihole products weld lines based on the multi‐objective evaluation system and kriging surrogate model

The generation mechanism of demolding force based on the mold‐part interface contact mode in micro‐injection molding

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