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Optimization of baffle’s height in an asymmetric twin-screw extruder using the response surface model

  • Huiwen Yu EMAIL logo , Xuzhang Jie , Tianwen Dong and Baiping Xu EMAIL logo
Published/Copyright: November 29, 2024
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e-Polymers
From the journal e-Polymers Volume 24 Issue 1

Abstract

Dispersive mixing is an important indicator for conventional co-rotating twin-screw extruders. In this work, a new asymmetric twin-screw extruder was developed to improve dispersive mixing. An aqueous solution of sodium carboxymethyl cellulose (CMC-Na) was employed as a matrix fluid, and the red oil-based ink was used as a tracer. A response surface model was constructed to predict the average diameter of droplets in terms of the feed rate, screw speed, and baffle height, and then the corresponding optimal solutions were obtained. Visualization experiments indicated that the gap regions between the screw and the barrel are mainly responsible for the tracers’ breakup. Particle image velocimetry experiments further confirmed that high velocity appeared in these gap regions and resulted in high shear rates, especially for a baffle height of 15.5 mm, where the linked regions of high velocity turned up.

Keywords: asymmetric twin screw; dispersive mixing; droplet; response surface model; particle image velocimetry

1 Introduction

As a type of highly efficient extrusion equipment, co-rotating twin-screw extruders (TSEs) are widely used in the field of polymer, food, and pharmaceutical manufacturing (1–5). Their twin-screw geometries are identical. In other words, they have symmetry, good conveying, and mixing capacity for highly viscous fluids to meet the usual practical applications (6,7). However, the symmetry in screw configurations inhibits further improvement in mixing performance. To break through this deficiency, an asymmetric twin-screw extruder (ATSE) has been self-developed based on the fact that the two screws co-rotate at the same speed as the conventional twin-screw geometry does (8). Due to the periodic change in the height of the screw flights in such an ATSE, the fluid is continuously stretched and retracted as it is conveyed along the screw channels. Whether or not this repetitive action of stretching and retraction is beneficial to dispersive mixing needs to be confirmed by further experimental investigations. In practice, channels are generally partially filled in some sections during extrusion processes under the condition of starvation feed. Therefore, it is important to study the effect of a partially filled state on the dispersive mixing in this ATSE (9–12).

Mixing in TSEs is a crucial process in the field of polymer science and engineering, as it plays a vital role in achieving uniform dispersion of additives (13), fillers (14), and reinforcements (15) within polymer matrices. Ongoing research efforts continue to explore new methods and technologies to enhance dispersion quality and optimize processing parameters for various applications in the polymer industry. In the early stages, Kim and Kwon (16) inserted a baffle into the single-screw channel, which would disturb the flow path of the material differently from the conventional transport path, thus inducing a chaotic effect, which could optimize the dispersion and mixing effect during the extrusion process. This type of screw was termed the chaos screw (CS). Later, based on the CS screw, Hwang et al. (17), Howes et al. (18), and Xu et al. (19) conducted the numerical simulations of chaotic mixing and dispersion in such baffled channels for periodic flows, demonstrating some improvements in mixing capability. Along the line of this idea, a baffle is inserted into one of the co-rotating twin screws while the other screw element is changed accordingly to meet the requirement of full intermeshing. Hence, a symmetry break is introduced into the flow channel of the co-rotating twin screws to enhance the mixing performance.

Studies have focused on optimizing processing parameters and screw configuration to enhance dispersion efficiency (20,21,22). During twin-screw processing, the material is exposed to strong shear and elongation forces, which promotes the breakup of the dispersed-phase droplets. Obviously, the average particle size of the dispersed tracer droplets is one of the main indicators to identify dispersive mixing.

The filling degree of materials in the screw channels significantly influences the dispersion process and particle size distributions. These factors, in turn, are determined by the screw configuration and the corresponding operating conditions, such as the feed rate and the screw speed. In order to obtain the optimal processing parameters or screw configuration, a widely used method, for example, the response surface methodology, is employed (23–28), and it is particularly effective for characterizing mixing.

The objective of this study is to construct a response surface model (RSM) of the average droplet size of the dispersed tracer droplets in terms of the screw speed, feed rate, and screw configurations. The optimal solutions of the aforementioned parameters were obtained by using RSM. A theoretical basis for the regulation of droplets in twin-screw extrusion processes is then provided. Meanwhile, the effect of baffle height on the average droplet diameters in ATSE was also explored.

2 Experiment

2.1 Materials

An aqueous solution of sodium carboxymethyl cellulose (CMC-Na) was used as a matrix fluid. A drop of red oil-based ink was used as a tracer to observe the dispersive mixing process. CMC-Na (fvh 6-7) was provided by Chongqing Lihong Fine Chemicals Co., Ltd. Red oil-based ink was purchased from Dongguan Youmeng Colour Paste Co., Ltd., China.

The powder of CMC-Na was used to prepare a matrix fluid. Its aqueous solution was prepared as follows: first, the CMC-Na powder was placed in the drying equipment at a set temperature of 40°C for 8 h. Then, it was added to water at 50°C with a CMC-Na/water mass ratio of 1.5/98.5. After stably stirring for 2 h, the CMC-Na solution was left undisturbed for at least 24 h to allow air bubbles to escape. Both the CMC-Na solution and the tracer are shear-thinning non-Newtonian fluids.

In this work, two tracers were used in the experiments, one of which was an oil-based ink which pulsed into an aqueous solution of CMC-Na to explore the dispersive mixing properties. Except for considering the rheology behaviors of the tracers, the choice of tracers is mainly based on their detectability by analytical instruments or visual tools (18). The shear rate-dependent apparent viscosity of this aqueous solution and the tracer are provided elsewhere (29). The viscosity of CMC-Na and the oil-based ink decreases with increasing shear rate, showing obvious shear thinning properties consistent with those of commonly used polymer melts. Meanwhile, the storage modulus of CMC-Na is greater than the loss modulus, showing obvious elasticity. The tracer loss modulus is greater than the storage modulus, showing obvious viscosity. In contrast, for commonly used biomass materials polylactic acid, the rheological curves showed similar behaviors, and the storage modulus and loss modulus increased with increasing frequency (30).

Another type of tracer is the fluorescent particles (Beijing MicroVec, LTD) used in particle image velocimetry (PIV) experiments, whose average size is 50 μm. The tracer particles are thoroughly mixed with CMC-Na solution in a mass ratio of 1:5,002.5 prior to the PIV experiment.

2.2 Screw geometries of ATSE

In this study, TSE and ATSE are presented, and their cross-sections are shown in Figure 1. The outer diameter of the screw is defined as D, the inner diameter as d, and the centerline distance between the two screws as C. The cross-sectional outlines consist of circular arcs, as shown in Figure 1(a) for the TSE. Additionally, the newly developed ATSE screw geometries are also depicted in Figure 1(b) for comparison. Both screw A and screw B of ATSE also consist of eight arcs, where the eight arcs M1M2, M2M3, M3M4, M4M5, M5M6, M6M7, M7M8, and M8M1 of screw A are engaged with the eight arcs N1N2, N2N3, N3N4, N4N5, N5N6, N6N7, N7N8, and N8N1 of screw B. Regardless of TSE or ATSE, the arc M1M2 is centered at point O1 with a radius of D/2 and the arc M5M6 is also centered at point O1. In contrast, M5M6 in TSE has a radius of D/2, while the arc M5M6 in ATSE has a radius of h, where h is defined as the height of the lower flight. The arcs M3M4 and M7M8 are centered at point O1 with a radius of d/2. In TSE, the arcs N1N2 and N5N6 are centered at point O2 and have the same radius of d/2. In ATSE, the arcs N1N2 and N5N6 are still centered at point O2, but the radius of arc N5N6 becomes C-h instead of the radius d/2 of arc N1N2 in order to meet the need for the intermeshing function. The arcs N3N4 and N7N8 have radius D/2 and are centered at point O2. Consistent with TSE, ATSE generates the arc M2M3 with a radius of C and a center of point O3, as highlighted in red. The point O3 is obtained by extending the line M3O1 to intersect with the outer circle at the point O3 (Figure 1(a) and (b)). Obviously, the arc M2M3 is tangent to the arc M3M4 at point M3. It follows that the arcs M4M5, M6M7, M8M1, N2N3, N4N5, N6N7, and N8N1 can be obtained in the same way. In addition to TSE, in ATSE, in this work, the central angle of the arcs M1M2 and M5M6 in screw A and the arcs N1N2 and N5N6 in screw B are α. The central angles of the bellies of the arcs M2M3 and M8M1 in screw A and the arcs N2N3 and N8N1 in screw B are equal to β , which can be written as

(1) β = 2 arccos C D

and the central angles of the bellies of the arcs M4M5 and M6M7 in screw A and the arcs N4N5 and N6N7 in screw B are equal to γ , which is defined as

(2) γ = π − arccos d 2 + 4 h 2 − 4 Cd 4 ( 2 C − d ) h

Figure 1 Geometries of (a) TSE 17.5, (b) ATSE13.5, (c) ATSE 14.5, (d) ATSE 15.5, and (e) ATSE 16.5.
Figure 1

Geometries of (a) TSE 17.5, (b) ATSE13.5, (c) ATSE 14.5, (d) ATSE 15.5, and (e) ATSE 16.5.

For simplicity, the aforementioned lower screw flight was defined as the baffle because this flight looks like a baffle wounding around the flow channel of screw A. Obviously, when the baffle is increased to the same height as TSE17.5, which is equal to the screw’s outer size, the ATSE geometry naturally evolves into the conventional TSE. To investigate the effect of baffle’s height on dispersive mixing, five screw geometries were selected for this study. The flight height of the TSE was 17.5 mm, referred to as TSE17.5 (Figure 1(a)). The baffle’s height h was used to identify the different ATSE geometries, and the four baffle’s heights of 13.5, 14.5, 15.5, and 16.5 mm were selected in this study, as shown in Figure 1(b)–(e), denoted as ATSE 13.5, ATSE14.5, ATSE15.5, and ATSE16.5, respectively. From the lateral view, it is apparent that the smaller the baffle’s height of screw A, the wider the opposite matched flight of screw B.

In order to make sure that screws A and B can be meshed at all times during rotation, the cross-sectional profiles of the two screws in any axial positions must be satisfied with the intermeshing conditions. As shown in Figure 2(a), when screw A is fixed, i.e., a reversal rotation at a speed of the screw A about its rotation center is applied, screw B will finish a translation in the opposite direction also around the screw A’s center with the result that the complete touch between the two screws always remains. The cross-sectional structure is formed into a three-dimensional structure, as shown in Figure 2(b).

Figure 2 Validation of the intermeshing relationship of the asymmetric twin-screw pair. (a) Profiles of relative motion examined under reversal rotation. (b) 3D geometries of the intermeshed screw pair.
Figure 2

Validation of the intermeshing relationship of the asymmetric twin-screw pair. (a) Profiles of relative motion examined under reversal rotation. (b) 3D geometries of the intermeshed screw pair.

Each screw of the TSE has double identical flights with the same height and width, resulting in the existence of symmetry. In contrast, two screws of the ATSE (Figure 2b) lose their symmetry completely. More exactly, screw A consists of alternating high flight and lower baffles. The baffle’s height on the right side is h, while the corresponding floor of screw B is a segment of the circular curve with a radius of C − h (Figure 1(b)). Similarly, the two screws of the TSE and ATSE are engaged with each other at all times. Correspondingly, screw B, the other screw of ATSE, also consists of two identical screw flights with the same height and width equal to the screw diameter, as shown in Figure 2(b).

2.3 Experiment equipment

An ATSE of the SJ35×12 type was self-developed in Jiangmen Key Laboratory of Intelligent Manufacturing of Polymer Materials (Figure 3). The TSE consisted of 17 screw element pairs (a lead of 48 mm with a pitch of 24 mm). The gap between the screw flight and the inner wall of the barrel (δ) was about 0.1 mm. The TSE and the ATSE had the same central distance (C = 30 mm), the same total screw length (L = 490 mm), the same screw outer diameter (D = 35 mm), and the same inner diameter (d = 25 mm). The barrel is totally transparent so that the flow pattern and mixing process of the matrix fluid containing the tracers inside the barrel can be captured by charge-coupled device (CCD) cameras.

Figure 3 Schematic diagram of the visualization experiment.
Figure 3

Schematic diagram of the visualization experiment.

The average sizes of the tracer droplets were estimated using a visualization experiment method. A puling film device was mounted downstream of the ATSE, where a thin transparent film could be pulled forward at a certain constant speed to collect the extruded matrix fluid containing the dispersed tracer droplets through the die slit for further statistics calculations.

2.4 Experimental procedure

Characterization of dispersive mixing: the sketch diagram of the experimental setup is shown in Figure 3. The screw speed (n, in rpm) and feed rate (q, in kg·h−1) were adjusted to the required values of RSM. Here quadratic approximation was employed; hence, three points for each variable were designed. Once the extrusion process reached a steady state, the ATSE was shut down suddenly, and a drop of red oil-based ink tracer (approximately 0.02 ml) was immediately injected into the location of the barrel (X = 15 mm, Y = 5 mm, and Z = 292 mm), as shown in Figure 3. After the injection was completed, the ATSE was restarted, and the film-pulling device was activated simultaneously to drive the transparent thin film (approximately 0.2 mm) to move forward at a constant speed. A light source was placed underneath the moving film. The distribution of the tracer droplets, immersed in the matrix fluid within the film, was recorded online using a top view CCD camera. The CCD camera captured images at a rate of 0.5 fps, resulting in a time interval ∆ t of 2 s.

An image analysis software (Image-Pro Plus) was used to calculate the mean length ( l ) and width ( w ) of the tracer droplet on the film (Figure 3). In this work, the average droplets’ diameters ( L ¯ = ( l + w ) / 2 ) and their coefficients of variation were used to evaluate the dispersive mixing results. The detailed process is described in a previous study (29).

Moreover, the velocity field of the matrix fluid was measured using PIV, revealing the difference in mixing among different screw configurations (31,32). The velocity field measurement by PIV is as follows: the experiment device was set up as shown in Figure 3. The CMC-Na aqueous solution containing fluorescent tracer particles was fed into the screw channel from the side port. A high-speed video camera was connected to a computer to record the flow velocity field over a range of Z values from 324 to 385 mm.

3 Results and discussion

3.1 RSM

To the best of our knowledge, h (Figure 1) is perhaps the key factor in determining the dispersive mixing. Therefore, an RSM with three independent variables of screw speed n, feed rate q, and screw geometry h was developed using the Box−Behnken design (BBD) for analysis of the effects among screw speed, feed rate, and screw geometry on the average droplet size L ¯ (30,33,34). BBD is a 3-level second-order experimental design method that uses a multivariate quadratic equation (Eq. 3) to describe the relationship between the variables and the response:

(3) Y = f ( X 1 , X 2 , … , X n ) ± Er

where Y is the response, X i is an independent y-coded variable, and Er is the model error.

The values and levels of three independent actual variables are shown in Table 1.

Table 1

Values and levels of three independent actual variables

Actual variable Level
Low (−1) Mean (0) High (1)
Screw speed n (rpm) 30 60 90
Feed rate q (kg·h−1) 6.54 13.08 19.62
Screw configuration h (mm) 13.5 15.5 17.5

X 1 , X 2 , and X 3 are the coded variables, while n , q, and h are the actual variables. The relationships among them are shown after the dimensionless treatment (Eqs. 4–6):

(4) X 1 = n − 60 30

(5) X 2 = q − 13.08 6.54

(6) X 3 = h − 15.5 2

When Eq. 3 is applied to this model, we have Eq. 7:

(7) f ( X 1 , X 2 , X 3 ) = a 0 + ∑ i = 1 3 a i X i + ∑ i = 1 3 ∑ j = 1 3 a ij X i X j + ∑ i = 1 3 a ii X i 2 ± Er

where a 0 , a i , a ij , and a ii are the coefficients to be determined, with i = 1, 2, or 3 and j = 1, 2, or 3.

The corresponding working conditions and the results of the 17 groups of experiments designed by BBD are shown in Table 2.

Table 2

Experimental results of the BBD

No. n (rpm) q (kg·h−1) h (mm) Experimental L ̅ E (mm) Predicted L ̅ RSM (mm)
1 30 19.62 15.5 0.2531 0.2535
2 90 6.54 15.5 0.2216 0.2251
3 30 13.08 17.5 0.2516 0.2504
4 60 19.62 13.5 0.2198 0.2202
5 90 13.08 13.5 0.2024 0.2073
6 90 13.08 17.5 0.2183 0.2203
7 60 6.54 17.5 0.2322 0.2349
8 60 13.08 15.5 0.2131 0.2117
9 60 13.08 15.5 0.2126 0.2117
10 60 13.08 15.5 0.2110 0.2117
11 30 6.54 15.5 0.2423 0.2434
12 60 6.54 13.5 0.2306 0.2302
13 90 19.62 15.5 0.1980 0.2006
14 30 13.08 13.5 0.2467 0.2484
15 60 13.08 15.5 0.2131 0.2117
16 60 13.08 15.5 0.2068 0.2117
17 60 19.62 17.5 0.2270 0.2305

The fit of Eq. 7 to the experimental data yields Eq. 8:

L ̅ = 0.8784 − 2.171 × 10 − 3 × n − 4.54 × 10 − 3 × q − 7.2902 × 10 − 2 × h − 4.4 × 10 − 5 × n × q + 4.6 × 10 − 5 × n × h + 1.07 × 10 − 4 × q × h + 1.2 × 10 − 5 × n 2 + 1.9 × 10 − 4 × q 2 + 2.278 × 10 − 3 × h 2

(8) ( R 2 = 0.9837 )

The main objective of this study is to compare the dispersive mixing differences between TSE and ATSE and to analyze the factor’s contributions to these differences. This study serves as a guide for the choice of screw geometry.

To validate the accuracy of Eq. 8, nine sets of experiments were conducted under different operating conditions other than the data listed in Table 2. With regard to the average droplet diameter, the predicted value was denoted as L ̅ RSM , while the experimental value was denoted as L ̅ E . The experimental and predicted values of the average diameter are shown in Figure 4. The prediction error of Eq. 6 is less than 0.94%, indicating that the predictive model is reliable.

Figure 4 Comparison of the predicted and experimental values.
Figure 4

Comparison of the predicted and experimental values.

In the analysis of variance, the sum of squares SS L ¯ , the percentage of contributions PC, and the total PC, denoted as TPC, for each individual model component can be calculated using Eqs. 9–13, and the values are shown in Table 3.

(9) SS L ¯ = ∑ n = 1 n = 17 ( L ¯ n − L ¯ ¯ ) 2

where L ¯ ¯ = ∑ n = 1 n = 17 L ¯ / 17 , n is the number of experiments in Table 2, and L ¯ n can be obtained from Table 2:

(10) PC = SS × 100 / ∑ SS

(11) TPC i = ∑ i = 1 i = 3 SS i ∑ i = 1 i = 3 ∑ j = 1 j = 3 ( SS i + SS ii + SS ij )

(12) TPC ii = ∑ i = 1 i = 3 SS ii ∑ i = 1 i = 3 ∑ j = 1 j = 3 ( SS i + SS ii + SS ij )

(13) TPC ij = ∑ i = 1 i = 3 SS ij ∑ i = 1 i = 3 ∑ j = 1 j = 3 ( SS i + SS ii + SS ij )

Table 3

Multiple regression results and the percentage of contributions

Source SS PC TPC
X 1 2.941 × 10−3 64.29
X 2 1.04 × 10−4 2.27 68.95
X 3 1.10 × 10−4 2.39
X 1 X 2 2.96 × 10−4 6.46
X 1 X 3 3.03 × 10−5 0.66 7.29
X 2 X 3 7.84 × 10−6 0.17
X 12 4.61 × 10−4 10.07
X 22 2.77 × 10−4 6.05 23.76
X 32 3.49 × 10−4 7.64

According to the TPC values, the effects of the coded variables on L ¯ follow the order: first-order variables ( X 1 , X 2 , X 3 ) > quadratic ( X 1 2 , X 2 2 , X 2 3 ) > interactions ( X 1 X 2 , X 1 X 3 , X 2 X 3 ). According to PC, the effect of the actual variables on L ¯ follows the order: n > h > q .

The effect of the screw speed, feed rate, and screw configuration on the average droplet diameter L ¯ are shown in Figure 5(a–e). The contribution percentages of PC and TPC are shown in Figure 5f. It is found that the screw speed plays an important role during the extrusion process, contributing the largest effect on L ¯ . Generally, increasing the screw speed from 30 to 90 rpm results in a decrease in L ¯ . For instance, for ATSE13.5 at a feed rate of 13.08 kg·h−1, increasing the screw speed from 30 to 90 rpm leads to a reduction in the average droplet diameter by approximately 14.82%. Depending on the feed rate and screw configuration, the average droplet diameter decreases from 0.24 to 0.19 mm, as the screw speed increases from 30 to 90 rpm (Figure 5(c)) (35,36).

Figure 5 Effects of screw speed ( n n ) and feed rate ( q q ) on the average droplet diameter ( L ¯ \bar{L} ) for different screw configurations: (a) ATSE13.5, (b) ATSE14.5, (c) ATSE15.5, (d) ATSE16I.5, and (e) TSE17.5, and (f) the percentage of contributions of PC and TPC.
Figure 5

Effects of screw speed ( n ) and feed rate ( q ) on the average droplet diameter ( L ¯ ) for different screw configurations: (a) ATSE13.5, (b) ATSE14.5, (c) ATSE15.5, (d) ATSE16I.5, and (e) TSE17.5, and (f) the percentage of contributions of PC and TPC.

For the case of ATSE15.5 at a screw speed of 60 rpm, when the feed rate was increased from 6.54 to 19.62 kg·h−1, the average droplet diameter decreased first and then increased. When the feed rate was increased from 6.54 to 14.73 kg·h−1, the average droplet diameter decreased by about 5.43%. However, as the feed rate continued to increase from 14.73 to 19.62 kg·h−1, the average droplet diameter increased by about 2.33% (Figure 5(c)) (37).

Similarly, for a feed rate of 13.08 kg·h−1 at a screw speed of 60 rpm, changing the screw configuration from 13.5 to 17.5 mm, the average droplet diameter showed a trend of decreasing first and then increasing. More exactly, the average droplet diameter decreased by approximately 2.47% as the screw configuration increased from 13.5 to 15.5 mm (Figure 5(a–c)). However, as the screw configuration further increased from 15.5 to 17.5 mm, the average droplet diameter increased by about 5.73% (Figure 5(c–e)).

According to Eq. 6, the minimum droplet diameter can be achieved when the n , q , and h values are within the ranges of 30 rpm < n < 90 rpm, 6.54 kg·h−1 < q < 19.62 kg·h−1, and 13.5 mm < h < 17.5 mm, respectively. The corresponding minimum value is L ̅ = 0.196 mm, which occurs at N = 89.79 rpm, Q = 16.33 kg·h−1, and h = 14.86 mm (Figure 6).

Figure 6 The optimal parameter according to RSM.
Figure 6

The optimal parameter according to RSM.

3.2 Effect of screw configurations

From the RSM, it is evident that the average droplet diameter undergoes significant changes with the change in screw configurations. However, the optimal configuration also varies with the feed rate and the screw speed. To assess the impact of screw configuration on mixing, a fixed feed rate ( q = 13.08 kg·h−1) and screw speed ( n = 60 rpm) were employed. According to Eq. 6, the optimal solution of the baffle’s height was h = 15.098 mm, resulting in an average droplet diameter of L = 0.21 mm (Figure 7).

Figure 7 The optimal screw configuration at n = 60 rpm and q q = 13.08 kg·h−1.
Figure 7

The optimal screw configuration at n = 60 rpm and q = 13.08 kg·h−1.

While maintaining a fixed feed rate of q = 13.08 kg·h−1 and a screw speed of n = 60 rpm, the average diameter of droplets under different screw configurations was experimentally obtained (Figure 8a). The smallest droplet scale was observed for ATSE15.5, followed by ATSE14.5. It is speculated that the baffle’s height, corresponding to the smallest droplet size, lies between 14.5 and 15.5 mm.

Figure 8 Particle size distributions of droplets on a segment of pulling film: (a) experiment results of average droplet diameters and coefficients of variation for q q = 13.92 kg·h−1 and n n = 60 rpm, (b) ATSE13.5, t = 40 s, (c) ATSE14.5, t = 44 s, (d) ATSE15.5, t = 44 s, (e) ATSE16.5, t = 46 s, and (f) ATSE17.5, t = 48 s.
Figure 8

Particle size distributions of droplets on a segment of pulling film: (a) experiment results of average droplet diameters and coefficients of variation for q = 13.92 kg·h−1 and n = 60 rpm, (b) ATSE13.5, t = 40 s, (c) ATSE14.5, t = 44 s, (d) ATSE15.5, t = 44 s, (e) ATSE16.5, t = 46 s, and (f) ATSE17.5, t = 48 s.

The droplet distributions spread on the pulling film by ATSE13.5, ATSE14.5, ATSE15.5, ATSE16.5, and TSE17.5 are shown in Figure 8(b)–(f), respectively. As marked by the dashed-line circles, it can be seen that there is obviously a lumpy droplet in ATSE13.5, while small lumpy droplets are also present in ATSE14.5 and TSE17.5. On the other hand, the droplets are better dispersed, and no obvious lumpy droplets exist in ATSE15.5.

As shown in Figure 9(a) for ATSE and Figure 9(b) for TSE, seen from the upper intermeshing region, the tracers’ breakup was viewed in the same window with a z range of 292–310 mm at the successive time moments. The partially filled zones are highlighted in a green dashed line. It was found that when the screw flight was pushed forward, the tracers seemed slower in the z direction than the screw flight and almost circumferentially penetrated the gap regions between the screw and barrel. These gap regions were mainly responsible for the most breakup of the tracers. Both screw configurations generate the multi-scale breakup where the tracers are stretched into many thin filaments and further experience irregular breakup through the necking action. It seems that there is a high-velocity zone in the circumferential direction in such gap regions, through which the tracers have more opportunities to pass.

Figure 9 Morphological distribution of irregular droplets and their breakup behaviors in the gap regions from top view: (a) ATSE and (b) TSE.
Figure 9

Morphological distribution of irregular droplets and their breakup behaviors in the gap regions from top view: (a) ATSE and (b) TSE.

To analyze the reason for the differences in dispersive mixing among the above five screw geometries, i.e., TSE17.5, ATSE13.5, ATSE14.5, ATSE15.5, and ATSE16.5, PIV experiments were further conducted to understand the flow patterns. Due to the complexity of the intermeshed screws, the velocity measured by PIV is mainly focused on the barrel surface. When the baffle’s heights are 13.5 and 14.5 mm, the fluid pushed by the baffle hardly touches the surface of the barrel so that the speed can scarcely be measured by PIV. It seems that there are some blank areas in the flow channels, indicating the PIV failed to capture the velocity distributions in these regions. However, as the baffle’s height increases, the fluid gradually touches the barrel wall, and then the fluid velocity is gradually identified. The fluid distribution in the flow channels of screw A and screw B is asymmetric, and so is the fluid in the front and rear channels of screw B. This phenomenon also changes gradually with the increase of the baffle’s heights, as shown in Figure 10(a)–(e).

Figure 10 PIV measurements of the velocity vector distributions in the upper intermeshing regions of different screw channels: (a) ATSE13.5, (b) ATSE14.5, (c) ATSE15.5, (d) ATSE16.5, and (e) TSE17.5, and (f) the average axial velocity and the resultant velocity.
Figure 10

PIV measurements of the velocity vector distributions in the upper intermeshing regions of different screw channels: (a) ATSE13.5, (b) ATSE14.5, (c) ATSE15.5, (d) ATSE16.5, and (e) TSE17.5, and (f) the average axial velocity and the resultant velocity.

As shown in Figure 10(d) and (e), similar velocity vector distributions were found, indicating that the ATSE16.5 shares a similar mixing mechanism with the conventional co-rotating twin-screw geometry. Surprisingly, the ATSE15.5 looks somewhat different; more exactly, there are linked gap regions of high velocity along the axial direction, implying the tracers will have more opportunities to pass through these gap regions so that they will be subjected to the high shear rates. Perhaps this is one of the main reasons why the ATSE15.5 produces smaller droplets.

To explore the differences in the overall speed of several screws, here we chose two variables to reveal the flow behavior in the barrel, including the mean axial velocity V z and the mean resultant velocity V ( V = V x 2 + V z 2 ) , as shown in Figure 10(f). The results show that the average axial velocity of the matrix fluid in the ATSE was lower than that of TSE, indicating that ATSE will generate a longer mean residence time. As the mean residence time increases, the axial mixing improves. However, despite a low average axial velocity, ATSE15.5, in turn, exhibited the highest mean resultant velocity among all the screw geometries, implying the existence of the largest x-directional velocity and there was perhaps more circumferential flow of the matrix fluid in the barrel. An increase in the circumferential flow gives rise to an increase in the shear rate to improve mixing in these regions.

4 Conclusions

This work aims to compare dispersive mixing and flow patterns between a conventional TSE and four ATSEs using the same set of experimental devices we developed. A visualization method was applied to observe the breakup process of the dispersed tracers in the matrix fluid under a partially filled condition in the barrel, and the final mixing results were collected by a moving pulling film. In order to further optimize the screw geometry as well as the operating parameters, an RSM was developed to quantify the effects of the aforementioned parameters on the average diameter of the dispersed tracer droplets. The flow velocity field was analyzed using the PIV technique.

The main conclusion can be reached that the baffle’s height of an ATSE plays a significant role in dispersive mixing. The BB design can successfully predict the average droplet size. The effect of the geometrical and operating parameters follows the order: screw speed > baffle’s height > feed rate. As the flight’s height increases, the average droplets’ diameter initially decreases and then increases. The visualization results showed that the droplet breakup mainly occurred in the gap region between the screw and barrel, where the tracers were stretched into thin filaments, and then irregular multi-scale breakup occurred. The PIV observation results revealed that the optimal screw configuration had significantly linked gap regions of high speed between the screw and the barrel in the axial direction. The circumferential high-speed flow increased the chances for the tracers to pass through these gap regions, thereby increasing the shear rate to achieve more efficient dispersive mixing.

  1. Funding information: This study was supported by the National Natural Science Foundation of China (No.12102306, 52363006) and the Special Project in Key Area of the Guangdong Provincial Department of Education (2023ZDZX3039 and 2020ZDZX2051). This project was also supported by the Opening Project of the Key Laboratory of Materials Processing and Mold (Zhengzhou University) Ministry of Education. Supported by the Opening Project of Key Laboratory of Polymer Processing Engineering (South China University of Technology) Ministry of Education (KFKT1906).

  2. Author contributions: Huiwen Yu: writing – original draft, conceptualization, methodology, and writing – review and editing; Xuzhang Jie: writing – original draft; Tianwen Dong: supervision; Baiping Xu: writing – conceptualization, review, and editing.

  3. Conflict of interest: Authors state no conflict of interest.

  4. Data availability statement: The data sets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

References

(1) Martín-Diana AB, Espeso BB, Pulido IJJ, Martínez PJA, Rico D. Twin-screw extrusion as hydrothermal technology for the development of gluten-free teff flours: effect on antioxidant, glycaemic index and techno-functional properties. Foods. 2022;11(22):3610. 10.3390/foods11223610.Search in Google Scholar PubMed PubMed Central

(2) Ren A, Spahn JE, Smyth H. Twin-screw continuous mixing can produce dry powder inhalation mixtures for pulmonary delivery. J Pharm Sci. 2022;112(1):272–81. 10.1016/j.powtec.2023.118519.Search in Google Scholar

(3) Zhou CY, Wu M, Sun DY, Wei WG, Yu HZ, Zhang T. Twin-screw extrusion of oat: evolutions of rheological behavior, thermal properties and structures of extruded oat in different extrusion zones. Foods (Basel, Switz). 2022;11(15):2206. 10.3390/foods11152206.Search in Google Scholar PubMed PubMed Central

(4) Albert TKM, Sami PJB. Twin-screw extrusion for the production of nanocellulose-PVA gels with a high solid content. Carbohydr Polym. 2022;286:119308. 10.1016/j.carbpol.2021.119308.Search in Google Scholar

(5) Adrian L, Krzysztof W. Modeling of twin screw extrusion of polymeric materials. Polymers. 2022;14(2):274. 10.3390/polym14020274.Search in Google Scholar PubMed PubMed Central

(6) Zhang XM, Feng LF, Chen WX. Numerical simulation and experimental validation of mixing performance of kneading discs in a twin screw extruder. Polym Eng Sci. 2009;49(9):1772–83. 10.1002/pen.21446.Search in Google Scholar

(7) Bauer H, Khinast J. Detecting mixing barriers in Twin-Screw extruder elements via Lagrangian Coherent Structures. Chem Eng Sci. 2022;263:118069. 10.1016/j.ces.2022.117029.Search in Google Scholar

(8) Xu BP, Yu HW, Kong PA. Co-rotating self-cleaning two screw extruder with an internal baffle. E.P. Patent 3122532 A1; September 29, 2021.Search in Google Scholar

(9) Orefice L, Khinast J. DEM study of granular transport in partially filled horizontal screw conveyors. Powder Technol. 2017;305:347–56. 10.1016/j.powtec.2016.10.057.Search in Google Scholar

(10) Yu H, Xu B, Wu H, Wang LTM. A visualization of flow patterns of viscoelastic fluid partially filled in a co‐rotating nontwin screw extruder. Polym Eng Sci. 2019;59:E24–32. 10.1002/pen.25082.Search in Google Scholar

(11) Yu H, Xu B, Liu B, Du Y, Feng JSY. A conveying model of fluid partially filled in a nontwin screw extruder allowing for a positive displacement. Polym Eng Sci. 2020;60(1):151–60. 10.1002/pen.25464.Search in Google Scholar

(12) Dong T, Wu J. Simulation of non‐Newtonian flows in a partially filled twin‐screw extruder by smoothed particle hydrodynamics. Polym Eng Sci. 2022;62(3):802–14. 10.1002/pen.25648.Search in Google Scholar

(13) Chen HL, Cao Q, Ye ZW, Lai BB, Zhang YC, Dong H, et al. Making 2-D materials mechanochemically by Twin-Screw extrusion: continuous exfoliation of graphite to multi-layered graphene. Adv Mater Technol. 2024;9:2301780. 10.1002/admt.202301780.Search in Google Scholar

(14) Megarry A, Taylor A, Gholami A, Wikström H, Tajarobi P. Twin-screw granulation and high-shear granulation: The influence of mannitol grade on granule and tablet properties. Int J Pharm. 2020;590(2020):119890. 10.1016/j.ijpharm.2020.119890.Search in Google Scholar

(15) Thyashan N, Perera YS, Xiao RM, Abeykoon C. Investigation of the effect of materials and processing conditions in twin-screw extrusion. Int J Lightweight Mater Manuf. 2024;7(3):353–61. 10.1016/j.polymertesting.2024.111178.Search in Google Scholar

(16) Kim SJ, Kwon TH. Enhancement of mixing performance of single: crew extrusion processes via chaotic flows: Part I. Basic concepts and experimental study. Adv Polym Technol. 1996;15(1):41–54. 10.1002/(SICI)1098-2329(199621)15:1<41:AID-ADV4>3.0.CO;2-K.Search in Google Scholar

(17) Hwang WR, Jun HS, Kwon TH. Experiments on chaotic mixing in a screw channel flow. AIChE J. 2002;48(8):1621–30. 10.1002/aic.690480805.Search in Google Scholar

(18) Howes T, Mackley MR, Roberts EPL. The simulation of chaotic mixing and dispersion for periodic flows in baffled channels. Chem Eng Sci. 1991;46(7):1669–77. 10.1016/0009-2509(91)87014-4.Search in Google Scholar

(19) Xu BP, He L, Wang MG, Tan SZ, Yu HW, Turng L-S. Numerical simulation of chaotic mixingin single screw extruders with different baffle heights. Intern Polym Process. 2016;31(1):108–18. 10.3139/217.3167.Search in Google Scholar

(20) Yu HW, Zhao ZW, Xu BP, Hu GH, Lemaitre C, Feng Y. Residence time distribution in an asymmetrical twin-screw extruder. Ind Eng Chem Res. 2023;62(43):17997–8008. 10.1021/acs.iecr.3c01234.Search in Google Scholar

(21) Bauer H, Matić J, Evans RC, Gryczke A, Ketterhagen W, Sinha K, et al. Determining local residence time distributions in twin-screw extruder elements via smoothed particle hydrodynamics. Chem Eng Sci. 2022;247:117029. 10.1016/j.ces.2022.117029.Search in Google Scholar

(22) Zhang XM, Xu ZB, Feng LF, Song XB, Hu GH. Assessing local residence time distributions in screw extruders through a new in-line measurement instrument. Polym Eng Sci. 2006;46(4):510–9. 10.1002/pen.20456.Search in Google Scholar

(23) Box PEG, Behnken WD. Some new three level designs for the study of quantitative variables. Technometrics. 2012;2(4):455–75. 10.1080/00401706.2012.692423.Search in Google Scholar

(24) Tran TH, Dao TP, Nguyen DC, Lam TD, Do ST, Toan TQ, et al. Application of Box–Behnken design with response surface methodology for modeling and optimizing microwave-assisted hydro-distillation of essential oil from citrus reticulata blanco peel. IOP Conf Ser: Mater Sci Eng. 2019;542(1):012043(5pp). 10.1088/1757-899X/542/1/012043.Search in Google Scholar

(25) Zhang Q, Zhang L, Li X, He Z, Chen S, Zhang D. Response surface methodology for optimizing twin-screw prepared Cistanche deserticola-Potato composite rice. Starch: Int J Investig, Process Use Carbohydr Derivatives: Int Z Erforschung Verarb Verwend Kohlenhydr Derivaten. 2021;73(7–8):1900330. 10.1002/star.202100062.Search in Google Scholar

(26) Singh B, Rachna, Hussain SZ, Sharma S. Response surface analysis and process optimization of twin screw extrusion cooking of potato-based snacks. J Food Process Preserv. 2014;39:270–81. 10.1111/jfpp.12230.Search in Google Scholar

(27) Verma T, Subbiah J. Use of residence time versus screw speed in the response surface model for microbial inactivation during single-screw extrusion of low-moisture food. Food Control. 2020;115:107293. 10.1016/j.foodcont.2020.107293.Search in Google Scholar

(28) Kowalski RG, Dangi A, Gu BJ, Pietrysiak E, Dhumal G, Hause JP. et al. Twin-screw extrusion characterization of two varieties of soft white waxy wheat flours. J Agric Food Res. 2021;5:100178. 10.1016/j.jafr.2021.100178.Search in Google Scholar

(29) Yu H, Xu B, Wu H, Du Y, Liu C, Turng L. Breakup of a viscoelastic droplet in co-rotating non-twin screw channels. Ind Eng Chem Res. 2020;59(33):15075–86. 10.1021/acs.iecr.0c02816.Search in Google Scholar

(30) Inácio EM, Lima CPM, Souza DHS, Sirelli L, Dias ML. Oligomalonate plasticized poly(Lactic Acid) films: Crystallization, thermal, and mechanical properties. Macromol Symposia. 2018;381:1800099. 10.1002/masy.201800099.Search in Google Scholar

(31) Xiong Q, Chen Z, Li S, Wang Y, Xu J. Micro-PIV measurement and CFD simulation of flow field and swirling strength during droplet formation process in a coaxial microchannel. Chem Eng Sci. 2018;185:157–67. 10.1016/j.ces.2018.05.028.Search in Google Scholar

(32) Goyal R, Cervantes MJ, Gandhi BK. Synchronized PIV and pressure measurements on a model Francis turbine during start-up. J Hydraul Res. 2020;58:70–86. 10.1080/00221686.2020.1739048.Search in Google Scholar

(33) Gülçin BD, Elif Ö, Sinem Ç. Optimized removal of cadmium, copper and lead from wastewater by biosorption using cabbage waste and Box-Behnken design (BBD). Anal Lett. 2024;57(2):266–84. 10.1080/00032719.2024.1923974.Search in Google Scholar

(34) Suprapto S, Azizah PA, Ni’mah YL. Silica gel from chemical glass bottle waste as adsorbent for methylene blue: Optimization using BBD. J Renew Mater. 2023;11(12). 10.32604/jrm.2023.031210.Search in Google Scholar

(35) Venkatesh C, Chen Y, Cao Z, Brennan S, Major L, Lyons JG. Devine Declan M. Influence of extrusion screw speed on the properties of halloysite nanotube impregnated polylactic acid nanocomposites. J Polym Eng. 2021;41(6):499–508. 10.1515/polyeng-2020-0123.Search in Google Scholar

(36) Wang K, Tan C, Tao H, Yuan F, Guo LCB. Effect of different screw speeds on the structure and properties of starch straws. Carbohydr Polym. 2024;328:121701. 10.1016/ j.carbpol.2023.121701.Search in Google Scholar

(37) Saha N, Goates C, Hernandez S, Jin W, Westover TKJ. Characterization of particle size and moisture content effects on mechanical and feeding behavior of milled corn (Zea mays L.) stover. Powder Technol. 2022;405:117535. 10.1016/j.powtec.2022.08.013.Search in Google Scholar
Received: 2024-05-04
Accepted: 2024-07-19
Published Online: 2024-11-29

© 2024 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

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https://doi.org/10.1515/epoly-2024-0048
Keywords for this article
asymmetric twin screw; dispersive mixing; droplet; response surface model; particle image velocimetry
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