Change in injection moulded parts shrinkage and weight as a function of processing conditions

Postawa, P.; Koszkul, J.

doi:10.1016/j.jmatprotec.2005.02.241

Cited by 52 publications

(30 citation statements)

References 8 publications

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“…This is both costly and time consuming. Therefore, design of experiments (DOE) is usually adopted to schedule the injection experiment [37,38]. DOE commonly uses the method invented by Taguchi [39].…”

Section: Introductionmentioning

confidence: 99%

Taguchi analysis of shrinkage and warpage of injection-moulded polypropylene/multiwall carbon nanotubes nanocomposites

Prashantha¹,

Soulestin²,

Lacrampe³

et al. 2009

Express Polym. Lett.

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Abstract. This paper focuses on the effect of multi-walled carbon nanotube (MWNT) addition on shrinkage and warpage properties of polypropylene (PP) injection mouldings before and after annealing. A Taguchi design of experiments has been implemented to highlight the influence and optimise processing conditions such as injection flow rate, holding pressure, back pressure and screw speed. The addition of 2 wt% of carbon nanotubes into PP significantly reduces the shrinkage and warpage of injection-moulded parts as compared to the neat PP. Skrinkage reduction up to 48% (respectively 33%) is noticed in the flow direction before (respectively after) annealing, whereas warpage reduction exceeds 55%. The sensitivity of the injection-mouldings dimensional properties to processing parameters remains roughly the same in case of neat PP and PP/MWNT nanocomposites when shrinkage is considered. It is even significantly reduced by carbon nanotubes addition when warpage is considered. Furthermore, the Taguchi method provides an efficient and effective tool to study the effects of process parameters on the warpage and shrinkage of injection moulded parts. The additive model used works well for predicting the warpage and shrinkage behaviour of PP and PP/MWNT composites.

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Section: Introductionmentioning

confidence: 99%

Taguchi analysis of shrinkage and warpage of injection-moulded polypropylene/multiwall carbon nanotubes nanocomposites

Prashantha¹,

Soulestin²,

Lacrampe³

et al. 2009

Express Polym. Lett.

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show abstract

“…One reason is that we assume the intimate contact of surface between the polymer and the mold wall, but in fact the polymer will shrink in solidification. 21 The realistic coefficient of thermal conductivity is lower than the theoretical one. Another reason is that the polymer will crystallize for t > t 2e .…”

Section: Theoretical Results Of Temperature Distributionmentioning

confidence: 94%

Heat transfer in injection molding of crystalline plastics

Bai

Yin

et al. 2006

J of Applied Polymer Sci

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A theoretical mathematical model is presented to describe the temperature distribution and the rate of phase change in the injection molding process of crystalline plastics. Under some assumptions, an exact closed form is solved with the use of an internal technique. The model was tested by measuring the temperature profile in a slab mold instrumented with thermocouples. Measurements of temperature profiles in the center of the polymer slab compare well to model prediction.

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“…Injection moulded parts Range, min-max is shown in the parenthesis (n=3) are prone to suffer from shrinkage, which results in imperfections in the device airflow path that may affect entrained particles and thereby drug product performance (26). Hence, this may be an important element to inspect and control from a product development and manufacturing perspective, since small differences may have a significant bearing on interdevice variability.…”

Section: Discussionmentioning

confidence: 99%

Effect of Device Design and Formulation on the In Vitro Comparability for Multi-Unit Dose Dry Powder Inhalers

Shur

Saluja

Lee

et al. 2015

AAPS J

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Abstract. The focus of this investigation was to understand the design space to achieve comparable in vitro performance of two multi-unit dose dry powder inhalers (DPIs)-Flixotide® Accuhaler® (reference product) and MultiHaler® (test product). Flow field, pressure drop and particle trajectories within the test and reference DPI devices were modelled via computational fluid dynamics (CFD). Micronized fluticasone propionate (FP) was characterized to determine particle size distribution (PSD), specific surface area (SSA) and surface interfacial properties using cohesive-adhesive balance (CAB). CFD simulations suggested that the pressure drop and airflow velocity in the MultiHaler® were greater than Accuhaler®. Two modified test devices (MOD MH 1 and MOD MH 2) were manufactured with the introduction of by-pass channels in the airflow path, which achieved comparable specific resistance and airflow path between the test and reference devices. Assessment of reference product formulation in modified test devices suggested that MOD MH 2 achieved comparable in vitro performance to the reference product. CAB analysis suggested that adhesion of all FP batches to lactose was different, with batch D showing greatest and batch A least adhesion to lactose. Test DPI formulations were manufactured using four different batches of FP with milled or sieved lactose, and showed that batch A FP formulated with sieved lactose in MOD MH 2 device demonstrated the highest degree of similarity to the Accuhaler® in vitro deposition. Application of CFD modelling and material characterization of formulation raw materials enabled the modification of device and formulation critical material attributes to create an in vitro comparable device/formulation system to the reference product.KEY WORDS: aerosolization; computational fluid dynamics; device design; dry powder inhaler; in vitro comparability; in vitro performance.

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Change in injection moulded parts shrinkage and weight as a function of processing conditions

Cited by 52 publications

References 8 publications

Taguchi analysis of shrinkage and warpage of injection-moulded polypropylene/multiwall carbon nanotubes nanocomposites

Taguchi analysis of shrinkage and warpage of injection-moulded polypropylene/multiwall carbon nanotubes nanocomposites

Heat transfer in injection molding of crystalline plastics

Effect of Device Design and Formulation on the In Vitro Comparability for Multi-Unit Dose Dry Powder Inhalers

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