Extrusion Temperature Range Research Articles

Effect of BaO on viscosity and structure of B2O3–SiO2–Al2O3–Na2O–BaO glass lubricant

AbstractGlass lubricant with a suitable viscosity is critical for the efficient production of high‐quality titanium alloy in hot extrusion process. In this study, a new glass lubricant, (30.93‐0.309x)B2O3‐(48.45‐0.485x)SiO2‐(7.22‐0.072x)Al2O3‐(13.4‐0.134x)Na2O‐xBaO (BSANB), was proposed for titanium alloy hot extrusion. The effect of BaO content varying from 0 wt.% to 15 wt.% on its viscosity was investigated, and the mechanism of viscosity change was clarified through melt structure analysis by using molecular dynamics (MD) simulation, X‐ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The glass viscosity was measured in the temperature range of 950°C to 1100°C, and the atomic self‐diffusion coefficient of the glass melt was calculated. The results demonstrated that the BaO content has a significant influence on the viscosity of the BSANB glass at the hot extrusion temperature range. The viscosity value at 950°C was decreased by 52.87%, from 103.5 Pa·s to 48.8 Pa·s, when BaO content was increased from 0 wt.% to 15 wt.%. MD simulation results of the BSANB glass show that the self‐diffusion coefficient of Si atoms was lower than that of Al and B atoms, indicating that Si‐O bonds were more stable in the melt. The diffusion coefficient of Si atom was directly related to the rheological behavior of the melt, which can be reflected by the melt viscosity. The results of MD simulation, XPS and Raman spectral fitting at 950°C showed an increase in the amounts of Q1, Q0 and [BO4], while the amounts of Q2, Q3, Q4 and [AlO4] were decreased when BaO content was increased from 0 wt.% to 15 wt.%. This demonstrated that the melt network was depolymerized with an increased BaO content, which determined the melt viscosity change. In addition, the mechanism responsible for glass viscosity reduction due to temperature increase was also discussed.

Effects of different extrusion temperatures on the physicochemical properties, edible quality and digestive attributes of multigrain reconstituted rice.

Multigrain reconstituted rice, as a nutritious and convenient staple, holds considerable promise for the food industry. Furthermore, highland barley, corn, and other coarse cereals are distinguished by their low glycemic index (GI), rendering them effective in mitigating postprandial blood glucose levels, thereby underscoring their beneficial physiological impact. This study investigated the impact of extrusion temperature on the physicochemical properties, edible quality, and digestibility of multigrain reconstituted rice. The morphology revealed that starch particles that are not fully gelatinized in multigrain reconstituted rice are observed at an extrusion temperature range of 60 °C-90 °C. As the extrusion temperature increased, the degree of gelatinization (DG) increased, while the contents of water, protein, total starch, and amylopectin decreased substantially. Concurrently, the relative crystallinity, orderliness of starch, and heat absorption enthalpy (ΔH) decreased significantly, and water absorption (WAI) and water solubility (WSI) increased markedly. Regarding edible quality, sensory evaluation displayed an initial increase followed by a decrease. In terms of digestibility, the estimated glycemic index (eGI) increased from 61.10 to 70.81, and the GI increased from 60.41 to 75.33. In addition, the DG was significantly correlated with both eGI (r = 0.886**) and GI (r = 0.947**). The results indicated that the ideal extrusion temperature for multigrain reconstituted rice was 90 °C. The findings underscored the pivotal role of optimal extrusion temperatures in the production of multigrain reconstituted rice, which features low GI and high nutritional quality.

Tensile Properties of 3D Printed Recycled PLA Filament: A Detailed Study on Filament Fabrication Parameters

Polylactic acid (PLA), a biodegradable and biocompatible thermoplastic commonly utilized in 3D Printing filaments, undergoes changes in properties upon recycling. The objective was to elucidate the role of extrusion temperature and screw speed in modulating the quality of recycled PLA filament, as well as in controlling its dimensional attributes. Recycled PLA pellets (3D850D) were extruded using a single filament extruder machine within an extrusion temperature range of 145°C to 165°C and a screw speed varying from 2 rpm to 6 rpm. The extruded filaments were subsequently 3D printed into specimens adopting a 0° raster angle, line infill pattern, and a 100 percent infill density, then tested as per ASTM D638 mechanical standards. The study revealed a profound influence of extrusion parameters on the filament's ultimate tensile strength, yield strength, and diameter. Optimal extrusion conditions - 155°C and 5 rpm - resulted in maximum mechanical strengths, while the parameters yielding filament diameters closest to commercial standards were identified as 5 rpm and 155°C. These results under-score the possibility of optimizing the recycled PLA filament's properties through adept control of extrusion parameters. Consequently, this investigation supports the potential use of recycled PLA filament in the 3D printing industry as a sustainable and performance-efficient material, offering a tangible step towards environmentally friendly additive manufacturing practices.

Changes in microstructure and mechanical properties of 2219 Al alloy during hot extrusion and post-extrusion aging

2219 Al alloy is widely used in the aerospace industry owing to its outstanding properties. In this study, we evaluated the effects of the extrusion temperature and extrusion ratio on the microstructure and mechanical properties of extruded 2219 Al alloy specimens, including the changes during post-extrusion aging. In the extrusion temperature range of 380–500 °C, the mechanical properties of the bar after extrusion at 470 °C were the best. Furthermore, extrusion ratios up to 25:1 produced extruded rods with excellent mechanical properties and microstructure. Increasing the extrusion temperature increased the dissolution of the eutectic θ phase in the solid solution and accelerated the breakage of the inclusions contained Mn/Fe. Some larger and coarse as-cast grains were mechanically fractured during hot extrusion, with the fragments then rotated towards directions with high Schmid factors, thus forming banded dynamic recrystallization regions. The grain boundaries of the recrystallized grains were predominantly low-angle boundaries. The 2219 Al alloy aged at 170 °C for 16 h produced the densest and most uniform distribution of needle-like nanoscale θ′ phase inside the grains, resulting in an average hardness of 149 HV. Further increasing the aging time and temperature resulted in the aggregation and growth of θ′ phase precipitates.

Effect of Varying Hot Extrusion Temperatures on the Properties of a Sinterless Turning Induced Deformation Processed Eco-Friendly Mg-Zn-Ca Alloy

In this work, Mg-4Zn-1Ca (wt. %) alloy was primarily processed by disintegrated melt deposition. The resulting ingots were further pre-processed by the turning induced deformation technique (TID), and the turnings were subsequently consolidated by the hot extrusion process and sinterless powder metallurgy. A range of extrusion temperatures (200, 250 and 300 °C) was tested to understand the effect of the extrusion temperature on tailoring the microstructure and properties of TID-processed Mg-4Zn-1Ca (wt. %) alloys. The results indicated that the combined effect of TID and extrusion temperature plays a significant role in grain refinement, specifically at 200 °C. Overall, the sample extruded at 300 °C showed the best microhardness and compressive yield strength values. The resistance to ignition and wet corrosion increased and decreased, respectively, when the extrusion temperature was increased. Variations of basal texture and fine grain strengthening due to variations of extrusion temperature led to different properties peaking at different extrusion temperatures. Microstructure-property relationships are therefore discussed, highlighting that different extrusion temperatures have characteristic effects in improving and lowering the properties. Many of the investigated properties of TID-processed alloys exceed that of commercial Mg alloys, suggesting the capability of the sinterless TID technique to develop as an economical industrial way of recycling and manufacturing magnesium-based materials.

Influence of filament fabrication parameter on tensile strength and filament size of 3D printing PLA-3D850

Polylactic acid (PLA) is a popular and widely used thermoplastic material used in fused filament fabrication (FDM) due to its biodegradability and biocompatibility. This paper aims to study the effects of extrusion parameters on the tensile strength quality of the 3D printing filament. The research began by extruding a 3D850D grade PLA pellet from Ingeo, NatureWorks, USA into a single filament extruder machine with an extrusion temperature range from 165 °C to 185 °C and a screw rate of 2 rpm to 6 rpm. The dog bone design (ASTM D638) with a 90° raster angle of line pattern and 100 % infill density was used for the fabrication of 3D printed specimens. Taguchi method was implemented to design the experiment to achieve the optimized parameters, and lastly, a tensile test was conducted to analyse the strength quality of the extruded filament through the 3D printing process. The result of the current study shows that the optimum extrusion temperature and speed that achieve the highest tensile strength with a good filament size of PLA-3D850 is around 175 °C and 4 rpm respectively.

Temperature influenced microstructure evolution and strengthening of 4.5 vol% TiBw/TA15 composites with columnar-reinforced structure fabricated by pre-sintering and hot extrusion

In this paper, 4.5 vol% TiBw/TAl5 composite with columnar network reinforced structure was prepared by pre-sintering and subsequent hot extrusion process. Pre-sintering was conducted at 1100 °C for 0.5 h, and billets were extruded with an extrusion ratio of 10: 1. The extrusion speed was 10 mm/s, and water cooling was adopted. An extrusion temperature range of 925–1100 °C (which covers the phase transition) was used to study the influence of the extrusion temperature on the microstructure evolution and its correlation with strengthening. The results showed that the extrusion temperature played a decisive role in the evolution of the matrix morphology. When the extrusion temperature increased from the (α + β) dual-phase region to the β single-phase region, the microstructure of the composite matrix was mainly composed of elongated α phase and recrystallized α phase. It gradually transformed into a lamellar structure from a high-temperature β phase. TiB whiskers continued to grow and coarsen. The corresponding texture also changed from 〈10−10〉 α//ED component in the dual-phase region to 〈0001〉α//ED and 〈10−11〉 α//ED mixed components, which were related to the high-temperature 〈101〉β//ED component in the β-phase region. Further performance analysis showed that the matrix strength was positively correlated with the content of the lamellar α phase, which increased with the extrusion temperature; however, the strengthening of TiB whiskers was affected by its growth and fragility and displayed a weakening trend. As a result, although the strength of the composite was always better than that of the matrix, its overall strength decreased upon increasing the extrusion temperature, showing the best performance when extruded at 925 °C. The stress of strengthening effect could be accurately estimated by the shear lag model.

Impact on peel strength, tensile strength and shear viscosity of the addition of functionalized low density polyethylene to a thermoplastic polyurethane sheet calendered on a polyester fabric

Coated technical textiles are widely used for several industrial applications. Most of these coated fabrics are made with a polyester fabric and a polyvinyl chloride (PVC) coating but in order to reduce the environmental impact, the producers are willing to substitute PVC by thermoplastic polyurethane (TPU). However, a technological lock of the calendering of TPU on polyester fabric is the ability to get a good adhesion of the coating on the fabric. Producers could increase the temperatures of extrusion of the coating but TPU have a short range of extrusion temperatures making it difficult to extrude. One solution is to make a blend with another polymer which has a higher extrusion temperature range. In the present work, the studies of the addition of low density polyethylene (LDPE) and linear low density polyethylene grafted maleic anhydride (LLDPE-g-Ma) in polyurethane coating on the tensile strength of the sheet and on the peel strength with a polyester fabric have been studied as well as the influence of the extrusion temperature. SEM observations, FTIR spectrums, and viscosity measurements have been performed to understand the behavior of the different blends. Results show that extrusion temperature and penetration depth of the coating in the fabric have a positive influence on the peel strength.

Increase in the Uniformity of Structure and Properties of Extruded Workpieces of Alpha + Beta Lead Brasses

UDC 669.35.5 The effect of temperature ranges is analyzed for heating an ingot of (α + β)-lead brasses on material phase composition in an extruder container and in a fi nished object. It is established that the optimum extrusion temperature range is 780–800oC, i.e., 100oC below the solidus line and above the temperature of phase transition from the (α + β)-condition to the β-condition. Industrial experiments are completed for increasing extrusion temperature and establishing improvement of ultimate strength distribution over the length of a workpiece by 8%, and uniformity of relative elongation distribution by 34%.

Influence of Forward Extrusion on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

The forward extrusion experiments of homogenized AZ80 magnesium alloy were conducted in the extrusion temperature range of 300°C to 420°C and extrusion ratios between 15 and 75 to study the effect of plastic deformation on the mechanical properties and microstructure. The microstructure and mechanical properties of extrudate were measured by tensile tests and optical microscopy. The results demonstrated that the alloy grains were small, and small amounts of black hard and brittle second-phase precipitated at 330°C. When the extrusion temperature was up to 390°C, the grain size increased significantly, but the second phase precipitation became continuous. And then, in the case of the extrusion ratio of 60, the tensile strength of the alloy reached the peak value of 390 MPa. Inhomogeneous precipitation of the second-phase increased with the increasing of extrusion temperature. At the same temperature, the tensile strength increased firstly and then decreased with increasing extrusion ratio. With the gradual increase of the grain refinement, the dispersed precipitates increased and the tensile strength and plasticity reached their peaks when the extrusion temperature was 390°C. As the grain grew, the second phase distribution became inhomogeneous, and the strength and plasticity gradually decreased.

Carboxylate clays: A model study for polypropylene/clay nanocomposites

Sodium-montmorillonite was intercalated by carboxylate salts to prepare carboxylate clays. The intercalation of sodium acetate doubles the clay basal spacing and no degradation of the carboxylate clay is noticed in the extrusion temperature range. These carboxylate clays were used to synthesize polypropylene-graft-maleic anhydride (PP-g-MA)/clay nanocomposites. Nanocomposites were also produced by a one-pot process using in situ prepared carboxylate clay. The carboxylate salts within the clay layers partially neutralize the maleic anhydride groups of the PP-g-MA matrix, in situ during the melt compounding. The ionic groups of the partially neutralized polymer offer favourable interactions with the clay, hence reinforcing the interfacial bond between the polymer and the clay and improving the composite properties. The use of carboxylate clay clearly improves the clay dispersion into the PP-g-MA matrix and improves the nanocomposite’s thermal and rheological properties.

Extrusion of corn grits containing various levels of hydrocolloids

Fourteen hydrocolloids, locust bean, agar, guar, alginate, tragacanth, carrageenan, xanthan, pectin, gelatin and Methocels A4M, E4M, F4M and K4M were dry blended with corn grits at levels of 0.1, 0.5 and 1.0%. Twenty percent moisture was added and each product extruded in a Brabender Model PL-V500 laboratory extruder at temperatures of 50, 75, 100, 125 and 150°C with a 1:1 screw operating at 100 rpm. Locust bean, agar, guar, alginate, arabic and Methocels E4M, F4M and K4M significantly lowered torque at an extrusion temperature of 50°C, but did not in general produce significant reductions at higher extrusion temperatures. In contrast, tragacanth, carrageenan, xanthan, pectin, gelatin and Methocel A4M did not significantly reduce torque over the concentrations and conditions evaluated during the extrusion of corn grits. All the Methocel derivatives lowered yield at low extrusion temperatures. No gum significantly increased yield over the entire extrusion temperature range evaluated. Therefore, certain gums can significantly reduce torque without influencing yield during the extrusion of corn grits.

A study of the flow properties of glass fibre reinforced PBT in extrusion

The extrusion shaping process of polymer materials is a course of polymer deformation, molten flow and solidification shaping. The melt flow character is one of the important parameters of polymer process-ability; it is usually expressed by a viscosity or flow curve. In the present study, the end effect and the flow properties of glass fibre reinforced PBT melt POCAN B4235 during extrusion have been investigated by using a Rheovis 2100 capillary rheometer. It has been found that the suitable extrusion temperature range of the sample is 240 ∼ 250 °C. Within the apparent shear rate ranged from 50 to 1000 s−1, the flow properties of the sample melt do not obey the power law. The relationship between the shear stress at the wall and the apparent shear rate is approximately linear. Under the lower extrusion temperature and apparent shear rate, the apparent shear viscosity of the sample melt has been found to be sensitive to the apparent shear rate. The dependence of the apparent shear viscosity on temperature does not agree with the Arrhenius equation. The entry effect of the sample melt is significant and the relationship between the entrance pressure drop and the apparent shear rate basically obeys the power law under the experimental conditions.

Effects of compounding and extrusion variables on degree of fusion and impact strength of PVC window profile

AbstractThe effects of temperature in twin screw extrusion of a window profile compound have been studied. Compounds were made with and without an acrylic impact modifier. Fusion levels of the extruded profiles were rated from values of the rubbery plateau modulus at temperatures near 110°C. Impact strength was measured at room temperature using notched tensile specimens at 1 m/s jaw separation rate. The impact strength of these materials does not increase with fusion level once an adequate degree of gelation has been achieved. The impact‐modified compound shows a dramatic improvement in impact strength when the melt temperature was increased from 319°F to 343°F. A further increase to 365°F had no effect. The compound without impact modifier exhibited no improvements in impact strength over the whole extrusion temperature range. Conflicting reports in the literature on effects of fusion level on impact strength of PVC articles probably reflect different interactions between extrusion conditions and compound composition.

Extrusion Stresses, Die Swell, and Viscous Heating Effects in Double‐Base Propellants

A capillary extrusion rheometer was used to evaluate the flow behavior of mixtures of nitrocellulose (12.2% nitrogen) and nitroglycerine when processed using solvent blends of different strengths. The aim of the work was to quantify the effects on flow behavior of “gelatinization,” that is, the degree of breakdown of the fibrous structure of the nitrocellulose. The flow behavior was measured over a range of extrusion temperatures. The results indicate that the materials behave as Herschel‐Bulkley fluids, that the shear stress decreases as gelatinization increases, and that viscous heating is more apparent in poorly gelatinized doughs. Surface temperatures of the extrudate determined experimentally are compared with computer‐modelled values. Die swell measurements decreased with decreasing degree of gelatinization and with increasing extrusion temperature.

The hydrostatic extrusion of linear polyethylene at high temperatures and high pressures

An account is given of a series of hydrostatic extrusion experiments which has been carried out on linear polyethylene over a wide range of extrusion temperatures and environmental pressures. The results of pressure-to-pressure hot extrusions, which have been performed on melt crystallised polyethylene and also on pressure crystallised extended chain polyethylene, are discussed, with particular reference to the physical properties of the extruded products.

Intra-crater activity, aa-block lava, viscosity and flow dynamics: Arenal Volcano, Costa Rica

Arenal Volcano has exhibited an almost continuous effusion of lava since September 19th, 1968. Present intra-crater activity is characterized by a relatively quiet rate of effusion accompanied by rhythmic pulsing of the lava due to degassing phenomena. At the vent, the main lava type is aa, which is seldom associated with lava aplastada (flattened lava). This latter lava is formed within the zone of major activity and exhibits smooth, slightly curved, reddish-brown oxidized surfaces which develop irregular cracks on cooling. The genesis of this lava type is due to gas oxidation and rhythmic pulsing. The additional stresses produced by the latter phenomenon (combined with surface tension forces) would hinder the formation of aa lava and generate flattened lava. The dynamic development of lava flows can be explained in terms of three continuous cyclic phases: early, mature and collapsing. A single flow can be divided into four structural units: the upper part (unit a), the middle-upper vesiculated part (unit b), the nucleus (unit c), and the fragmental base (unit d). Rheologically these lavas behave like a Bingham plastic characterized in the field by plug flow. While the 1968–1973 lava flows are characterized by an advanced but incomplete transition from aa to block lava, present flows generally undergo the entire process. In this case the transition zone for a mature flow is located within the middle-lower part of the volcanic cone, reaching an approximate length of 300 m. Transition occurring during the mature phase has been investigated in detail. It is related to the progressive brittle deformation of the middle-upper part (unit b). Fracturing takes place along the side of the plug where the shear strain is higher as well as within the central part where it is due to topographic discontinuities systematically reflected in the mechanical behavior of the rigid plug. Viscosities calculated on the basis of field measurements at 50–200 m from the crater give values of 108 poise. These values are consistent with experimental results obtained in the range of extrusion temperatures (1100–1150°C) and are in good agreement with experiments on suspension rheology in basalts for a similar temperature range and degree of crystallinity. The high viscosity of Arenal lavas can be explained in terms of their high crystallinity (70–80%), lower extrusion temperatures and higher silica content in respect to basalts. The existence of two interstitial immiscible melts also contributes to increase viscosity.

New aspects of the microhardness of ultraoriented polyethylene

The influence of extrusion conditions on the microhardness of ultradrawn polyethylene (PE) has been investigated. The micromechanical behaviour of ultradrawn PE fibres can be defined in terms of a creep constant and a microhardness value (MH) at 0.1 min, relating to the size of indentation under load rather than to the residual dimension. The PE strands show, in addition, a conspicuous anisotropic shape of the indentation pattern (MH‖>MH⊥) which involves a local elastic recovery of the material parallel to the fibre axis. The hardening of the fibres in the parallel and perpendicular direction to the fibre axis is an increasing function of both extrusion temperature and extrusion pressure and can be explained in terms of a simultaneous improvement in the strength and the lateral packing of fibrils and microfibrils in fibre direction. For extrusion temperatures (Te) greater than 134° C the microhardness shows, however, a decrease which is thought to be related to the molecular relaxation occurring in the vicinity of the melting point. In the range of extrusion temperatures (90 to 137° C) and extrusion pressures (0.24 to 0.5 GPa) investigated, the hardness anisotropy on the fibre surface, ΔMH, is a unique increasing function of draw ratio λ. It is completely independent of both the extrusion temperature and pressure. ΔMH in the core of cleaved fibres shows a constant value which is independent of λ and equals the extrapolated value at the surface for the maximum attainable value of λ. The results can be satisfactorily explained if one considers the existing morphological differences between the outer sheath and the inner core of the fibres.