Numerical simulation of flow characteristics in new co-rotating triangle arrayed triple screw extruders

Zhu, X.Z.; Yuan, Hui; Wang, W.Q.

doi:10.1016/j.jmatprotec.2008.07.045

Cited by 18 publications

(8 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The materials firstly flow through the high shear region composed of three meshing zones to achieve distributive mixing, then enter the central area where melt stretching and dispersive mixing will be achieved. The whole process formed alternating shearing and extensional flow field, contributing to the efficient dispersion and mixing of the materials . However, the flow field in the twin screw extruder is usually dominated by the shear flow .…”

Section: Introductionmentioning

confidence: 99%

Effect of dispersed phase on the morphology of in situ microfibrils and the viscoelastic properties of its composite via direct extrusion

Xin

Huang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

A triangle arrayed triple-screw extruder was used to prepare in situ polypropylene (PP) microfibrillar composites (MFCs) by direct extrusion, in which polyamide 6,6 (PA66) and poly(butylene terephthalate) (PBT) were used as dispersed phases while PP as matrix phase. The morphological evolution of the dispersed phase were investigated by SEM through taking samples along the extruder from different positions. The results showed that the fibrillating mechanism of PA66 was entirely different from that of PBT. Dynamic oscillatory shear rheological properties were used to analyze the effect of different types of in situ microfibrils on the rheological properties of MFCs. The obtained results showed that the storage modulus and complex viscosity of both PP/PA66 and PP/PBT MFCs were improved with increasing fibrillar aspect ratios. The loss tangent tan d at low frequencies decreased with the increase of fibrillar aspect ratio. Moreover, the gel point concentration of PP/PA66 composite was lower than that of PP/PBT composite.attributed the increase in the viscosity to the formation of a physical PET fibrillar network which hinder the relaxation of the PP phase, as indicated from the frequency-independent tan d curve.Generally, Winter-Chambon analysis 15,16 is used to determine the gel point, 5 which is the critical fibril content at which a rheologically percolated network forms. The formation of such a network is a typical characteristic of the composites with deformable and long (means high aspect ratio) fibrils. 10,17 Rizvi and Park 10 and Kakroodi et al. 17 applied this method and found out that 3.0 wt % polyamide (PA) and 4.5 wt % PP were needed for the poly(lactic acid) and polyethylene (PE) systems, respectively, to form rheologically percolated network. The strain-hardening behavior of polymer blends with fibrillar morphology has been reported, and the dramatic improvement in strain-hardening response of PE was observed through the in situ fibrillation of 1 wt % PP. 17The preparation process of in situ MFCs is quite complex. There are many factors, including the viscosity, compatibility, and interfacial tension of the fibrillar phase and matrix, die structure, draw ratio, processing temperature, and so on, which influence fibrillation. 18,19 It can be summarized as two aspects: the first is the thermoplastic system, the second is the processing conditions. Currently, most of the MFCs are prepared by V C 2018 Wiley Periodicals, Inc.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of dispersed phase on the morphology of in situ microfibrils and the viscoelastic properties of its composite via direct extrusion

Xin

Huang

et al. 2018

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Therefore, triple-screw extruders are suitable for processing of high viscosity polymers or polymers with higher content of fillers [33]. Additionally, published data indicate that in triplescrew extruders the power consumption is 1.5 times higher than in co-rotating twin-screw extruders, while simultaneously their productivity increase around 1.3 times [34]. However, despite of above mentioned advantages of triple screw extrusion the research works about its application in polymer technology are still very limited [35][36][37], while its using during reactive processing is practically unknown.…”

Section: Extruders As Chemical Reactors -Basic Conceptsmentioning

confidence: 99%

Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments

Formela¹,

Zedler²,

Hejna³

et al. 2018

Express Polym. Lett.

112

View full text Add to dashboard Cite

Abstract.Reactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application for processing of bio-based polymer blends and composites is a relatively new direction of scientific research. This work presents a literature review on recent advances in the processing of bio-based polymer blends and composites via reactive extrusion. We described compatibilization mechanisms for different types of biodegradable polymeric materials based on: (i) aliphatic polyesters, (ii) aliphatic polyesters/starch and (iii) aliphatic polyester/natural rubber systems. A special attention was focused on conventional and dynamic cross-linking of bio-based polymer blends and composites as an effective way to prepare new materials with unique properties e.g. biodegradable thermoplastic elastomers or shape-memory materials. Advantages and limitations affecting future trends in development of biodegradable polymer blends and composites reactive extrusion are also discussed.

show abstract

“…The materials in TTSE would experience a shear‐extensional alternating effect. Furthermore, the good melt conveying properties of TTSE could shorten the thermal processing duration and improve blending performance . These characteristics indicate that the TTSE with an extensional effect is more efficient in blending immiscible polymers at a high viscosity ratio.…”

Section: Introductionmentioning

confidence: 99%

Effects of extensional flow on properties of polyamide‐66/poly(2,6‐dimethyl‐1,4‐phenylene oxide) blends: A study of morphology, mechanical properties, and rheology

Yang

Xin

Huang

et al. 2016

Polymer Engineering & Sci

View full text Add to dashboard Cite

In this study, polyamide-66/poly(2,6-dimethyl-1,4-phenylene oxide) (PA66/PPO) blends with high viscosity ratio were processed by a self-designed triangle-arrayed triple-screw extruder (TTSE, which simulates extensional flow) and a commercial twin-screw extruder (TSE), respectively. Furthermore, in order to improve the mechanical properties of the immiscible PA66/PPO blends, PPO-grafted maleic anhydride (PPO-g-MA) and styrene-ethylene-butylene-styrene (SEBS) block copolymer were used. The mechanical properties, phase morphology, and rheological properties of both binary PA66/PPO blends and toughened PA66/PPO/ PPO-g-MA blends were comprehensively investigated to compare the above mentioned two processing method. Samples processed with TTSE exhibited better mechanical properties than the TSE-processed blends. The morphologies of the blends were examined by scanning electron microscopy, exhibiting smaller particles sizes and narrower particle size distributions, which were attributed to the significant effects of extensional flow in TTSE. The toughening mechanism of compatibilized blends was investigated through morphology analysis, dynamic mechanical, and rhelogical analysis. Thus, TTSE with an extensional effect was proved to be efficient in the blending of high viscosity ratio polymers.

show abstract

Numerical simulation of flow characteristics in new co-rotating triangle arrayed triple screw extruders

Cited by 18 publications

References 11 publications

Effect of dispersed phase on the morphology of in situ microfibrils and the viscoelastic properties of its composite via direct extrusion

Effect of dispersed phase on the morphology of in situ microfibrils and the viscoelastic properties of its composite via direct extrusion

Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments

Effects of extensional flow on properties of polyamide‐66/poly(2,6‐dimethyl‐1,4‐phenylene oxide) blends: A study of morphology, mechanical properties, and rheology

Contact Info

Product

Resources

About