Packing Phase Research Articles

Synergistic Effects of Solid and Solvent Additives on Film Morphology Enable Binary Organic Solar Cells with Efficiency of Over 19%

AbstractRegulating the film morphology features of the photoactive layer is critically important for developing high‐performance organic solar cells (OSCs). Adding solvent or solid additives is widely used to realize fine‐tuned film morphology. However, most high‐performance OSCs are processed only using single component additive, either solvent additive or solid additive. Herein, two structurally similar analogs of 1‐benzothiophene (BT) and benzo[1,2‐b:4,5‐b']dithiophene (BDT) are applied as volatilizable solid additives and are used with the well‐known solvent additive 1‐chloronaphthalene (CN), respectively. Comprehensive morphology analysis revealed that the addition of BT with better volatilization can promote the formation of stronger molecular packing and desirable phase separation, resulting in higher charge mobility and more efficient charge separation. However, the insufficient volatilization of BDT caused excessive aggregation, leading to severe recombination. Consequently, the PMZ‐10:Y6 based binary OSCs treated with the hybrid additives of CN and BT delivered a notable efficiency of 19.03%, which is one of the best values of the Y6‐based binary devices reported so far. Overall, this work highlights the importance of hybrid additive strategy and the reasonable combination of solid and solvent additives in further advancing the development of OSCs field.

Periclase-magnesium aluminate spinel ceramics filter with excellent purification efficiency on molten steel prepared from Mg(OH)2: Effect of fused MgO content

Reticulated ceramic filters are widely used in the field of steel purification to improve the quality of steel products. In this work, periclase-magnesium aluminate spinel ceramic filters with microporous MgO coating were fabricated by using Mg(OH)2 as raw material. The effect of fused MgO content on the microstructures, mechanical properties and filtration capacity of filters on Al2O3 inclusions in molten steel was comparatively studied. The results indicate that the particle packing and liquid phase sintering cooperated to promote the formation of neck connections between microporous MgO particles, which increased the cold compressive strength and thermal shock resistance of the filters. Furthermore, the results from the immersion test in molten steel demonstrate that an appropriate amount of high-temperature liquid phase and the relatively microporous structure of filter skeleton were favorable for filters to filtrate Al2O3 inclusion in molten steel. Overall, the filter with 30 wt% fused MgO had the best comprehensive performance with a cold compressive strength of 0.68 MPa, a residual retention of cold compressive strength after three thermal shock recycles of 79.07 % and a filtration efficiency of 79.06 % in reducing the total oxygen content of the steel.

Tailoring Cyano Substitutions on Quinoxaline‐based Small‐Molecule Acceptors Enabling Enhanced Molecular Packing for High‐Performance Organic Solar Cells

AbstractCyanation is a common chemical modification strategy to fine‐tune the energy levels and molecular packing of organic semiconductors, especially materials used in organic solar cells (OSCs). Generally, cyanation is used to modify the end groups of high‐performance small‐molecule acceptors (SMAs). However, the cyanation strategy has not been investigated on the central backbone of SMAs, which could introduce stronger intermolecular interaction and enhance the π–π stacking for rapid charge transport. This paper, for the first time, reports a new cyanation strategy on the central benzo‐quinoxaline core and synthesizes two novel A‐DA'D‐A type SMAs, named BQx‐CN and BQx‐2CN, with mono‐ and di‐cyanide groups, respectively. Through tailoring the number of CN groups, the BQx‐CN‐based OSC exhibits the best device performance of 18.8%, which is significantly higher than the non‐cyano BQx‐based one. The reason for the superior performance of BQx‐CN‐based devices can be attributed to the fine‐tuned energy level, stronger packing, and ideal phase segregation, which lead to superior exciton dissociation, faster charge transport, and suppressed recombination, therefore the highest fill factor (FF) and power conversion efficiencies (PCE). The research demonstrates the effectiveness of the cyanation strategy on the central core of SMAs for enhanced molecular packing and better performance of OSCs.

Environmental Impacts Associated with the Production and Packing of Persian Lemon in Mexico through Life-Cycle Assessment

In this study, the environmental impacts associated with the intensive production of Persian lemons are assessed, including the agricultural and packing phases of the fresh fruit. A life-cycle assessment (LCA) tool was used in accordance with the ISO 14040 and 14044 standards and implemented in SimaPro PhD (9.2) software. The life-cycle inventory database was primarily composed of data collected during field visits to local lemon orchards and the main packing company in the region. The functional unit was defined as 1 kg of packed fresh Persian lemons. The selected impact categories were the carbon footprint, water footprint, and energy footprint, and the results obtained for the defined functional unit were 405.8 g CO2 eq, 40.3 L of water, and 5.9 MJ, respectively. The industrial packing phase of the fruits had a greater impact on the carbon and energy footprints, mostly due to the manufacturing of packaging materials and cardboard boxes, followed by the transportation of supplies. Regarding the water footprint, the agricultural phase was identified as the most significant contributor to water consumption, primarily attributed to maintenance operations and the application of agrochemicals.

Small molecule donor third component incorporating thieno[3,2-b]thiophene unit enables 19.18% efficiency ternary organic solar cells with improved operational stability

The rational design of the third component to enhance the efficiency and stability of organic solar cell (OSC) is a critical and challenge. Herein, a thieno[3,2-b]thiophene (TT) substituted wide-bandgap small molecule donor BTTC, was designed, synthesized and incorporated into the state-of-the-art PM6:L8-BO binary to construct ternary OSC. The rigid side chain and planar molecule skeleton enables strong crystallinity and complementary absorption with binary system. The introduction of BTTC enhanced the molecular packing, fibril-like film and preferred vertical phase separation, yielding balanced and higher charge transport, more efficient exciton dissociation and suppressed charge recombination. Besides, lower energy loss was attained and thus leading to higher open-circuit voltage (VOC). Consequently, the introduction of BTTC achieved the highest efficiency of 18.8% along with extended operational stability. Furthermore, replacing L8-BO to BTP-eC9 further boosted the ternary PCE to 19.18%, standing one of the best charge management in ternary OSC. This work presents efficient rigid side chain substitution strategy to construct the third component of small molecule donor for high performance ternary OSCs with comprehensively improved photovoltaic parameters. This strategy broadens the selection of guest materials toward realizing the actual commercial application of OSCs.

Insight into Multiphase Interlayer Molecular Packing and Stepwise Phase Transition in 4-(Phenylazo)benzoate Anion-Intercalated Layered Zinc Hydroxide.

The properties of layered intercalation hybrids are closely related to interlayer molecular packing. To develop functional intercalation hybrids, it is essential to gain deep insights into interlayer molecular packing. This work reports a new comprehensive insight into the controllable multiphase interlayer molecular packing in 4-(phenylazo)benzoate anion-intercalated layered zinc hydroxide (LZH-4-PAB intercalation hybrids). The new insight breaks up the general understanding that the interlayer molecular packing of anions is usually single-phase, lacking diversity and controllability. Furthermore, it uncovers an interesting stepwise rather than the generally expected continuous phase transition of the interlayer molecular packing. The intercalated 4-PAB anions initially organize into the horizontal monolayer packing (θ = 0°, Phase I), which stepwise transforms to the tilted interdigitated antiparallel bilayer packing (θ ≈ 50°, Phase II) along with an increased intercalation loading and eventually to the vertical interdigitated antiparallel bilayer packing (θ = 90°, Phase III). The LZH-4-PAB hybrids exhibited a greatly enhanced interlayer molecular packing-dependent UV-vis absorption. This study provides helpful guidance for developing property-tailored intercalation hybrids. It may attract new interest in more layered intercalation hybrids. New and rich intercalation chemistry might be discovered in more functional intercalation hybrids beyond the 4-PAB anion-intercalated layered zinc hydroxide.

Pre-phase transition of a Cu2-xS template enables polymorph selective synthesis of MS (M = Zn, Cd, Mn) nanocrystals via cation exchange reactions.

Utilization of copper-deficient Cu2-xS nanocrystals (NCs) with diverse crystal phases and stoichiometries as cation exchange (CE) templates is a potential route to overcome the current limitations in the polymorph selective synthesis of desired nanomaterials. Among the Cu2-xS NCs, covellite CuS is emerging as an attractive CE template to produce complicated and metastable metal sulfide NCs. The presence of a reducing agent is essential to induce a phase transition of CuS into other Cu2-xS phases prior to the CE reactions. Nevertheless, the effect of the reducing agent on the phase transition of CuS, especially into the hexagonal close packing (hcp) phase and the cubic close packing (ccp) phase, has been scarcely exploited, but it is highly important for the polymorphic production of metal sulfides with the wurtzite phase and zinc blende phase. Herein, we report a reducing agent dependent pre-phase transition of CuS nanodisks (NDs) into hcp and ccp Cu2-xS NCs. 1-Dodecanethiol molecules and oleylamine molecules selectively reduced CuS NDs into hcp djurleite Cu1.94S NDs and ccp digenite Cu1.8S NCs. Afterward, the hcp Cu1.94S NDs and ccp Cu1.8S NCs were exchanged by Zn2+/Cd2+/Mn2+, and the wurtzite phase and the zinc blende phase of ZnS, CdS, and MnS NCs were produced. Without the pre-phase transition, direct CE reactions of CuS NDs are incapable of synthesizing the above wurtzite and zinc blende metal sulfide NCs. Therefore, our findings suggest the importance of the pre-phase transition of the CE template in polymorphic syntheses, holding great promise in the fabrication of other polymorphic nanomaterials with novel physical and chemical properties.

Theory of Complex Spherical Packing Phases in Diblock Copolymer/Homopolymer Blends

Theory of Complex Spherical Packing Phases in Diblock Copolymer/Homopolymer Blends

Separation and characterization of Gastrodia elata polysaccharides based on asymmetrical flow field-flow fractionation: steric transition phenomenon

Asymmetrical flow field-flow fractionation (AF4), a gentle tool for the separation and characterization of particles and macromolecules, has attracted increased interest in recent years owing to its broad dynamic size range and utilization of "open channel" voids in the packing or stationary phase. A steric transition phenomenon in which the sample elution mode change from the normal mode to the steric/hyperlayer mode occurs. Accurate characterization by AF4 requires the absence of steric transition, particularly when the sample has a broad size distribution, because the effect of the combination of different modes is difficult to interpret. In this study, the relative molecular mass (M), radius of gyration (Rg), and conformation of Gastrodia elata polysaccharides (GEPs) were characterized using AF4 coupled with online multi-angle light scattering (MALS) and differential refractive index (dRI) detection (AF4-MALS-dRI). Steric transition was observed during GEP separation by AF4 owing to the broad size distribution of the molecules. This phenomenon would result in the inaccurate characterization of the GEPs in terms of M and Rg because two GEP groups of different sizes may elute together. In this study, the effects of constant and exponentially decaying cross-flow rates, sample mass concentration, and spacer thickness on steric transition were systematically investigated. The results indicated that a high GEP mass concentration (i. e., 0.75 mg/mL) can lead to steric transition. The spacer thickness affected the resolution and retention time of the GEPs and changed the steric transition point (di). An exponentially decaying cross-flow rate not only adjusted the di of the polydisperse GEP samples but also improved the GEP resolution and shortened the analysis time. The influence of steric transition was solved under the following operating conditions: injected GEP mass concentration=0.5 mg/mL; injection volume=50 μL; spacer thickness=350 μm; detector flow rate=1.0 mL/min; and cross-flow rate exponentially decayed from 0.2 to 0.05 mL/min with a half-life of 2 min. Moreover, the influence of GEP origins and ultrasound treatment time on the M and Rg distributions and conformation of GEPs were investigated under the optimized operating conditions. The results showed that the M and Rg distributions of Yunnan and Sichuan GEPs decreased with increasing ultrasound time. When the ultrasound treatment time was 15 min, the Yunnan GEPs had a loosely hyperbranched chain conformation, whereas the Sichuan GEPs had a spherical conformation. When the ultrasound treatment time was increased to 30 or 60 min, the GEPs from both Yunnan and Sichuan had a hyperbranched chain conformation, indicating that ultrasound treatment resulted in GEP degradation. Under the same extraction conditions, GEPs from Yunnan had larger M and Rg values than those from Sichuan. AF4-MALS-dRI showed good repeatability for the characterization of GEPs under the optimized operating conditions. The relative standard deviations of Rg and M were 0.5% and 1.7%, respectively. The data presented in this study can be used as a starting point for in-depth studies on the structural bioactivity of GEPs.

Regulating the self‐assembly of AB/CD diblock copolymer blends via secondary interactions

AbstractDesigned multiblock copolymers with complex architectures offer unlimited opportunities to obtain novel nanostructured phases, however, their synthesis could be challenging and expensive. An alternative approach to access desired nanostructures is to use blends of block copolymers with simple chain architectures and designed block‐block interactions. We use binary blends composed of AB and CD diblock copolymers as a model system to establish design principles of polymeric blends containing block copolymers. Specifically, we explore the phase behavior of AB/CD blends by using the polymeric self‐consistent field theory to construct phase diagrams of the blends focusing on the sphere‐forming regions in the phase space. We predict the formation of various spherical packing phases composed of either core‐shell‐structured spheres or binary spheres resembling metallic alloys. We demonstrate that the equilibrium morphology can be regulated by adjusting the blend composition and molecular parameters such as block fractions, conformational asymmetry, and segment‐segment interactions. The strategy of using secondary interaction in polymeric blends to control the phase behavior explored in the current study can also be generalized to other soft matter systems.

Theoretical Study of Phase Behaviors of Symmetric Linear B1A1B2A2B3 Pentablock Copolymer.

The nanostructures that are self-assembled from block copolymer systems have attracted interest. Generally, it is believed that the dominating stable spherical phase is body-centered cubic (BCC) in linear AB-type block copolymer systems. The question of how to obtain spherical phases with other arrangements, such as the face-centered cubic (FCC) phase, has become a very interesting scientific problem. In this work, the phase behaviors of a symmetric linear B1A1B2A2B3 (fA1 = fA2, fB1 = fB3) pentablock copolymer are studied using the self-consistent field theory (SCFT), from which the influence of the relative length of the bridging B2-block on the formation of ordered nanostructures is revealed. By calculating the free energy of the candidate ordered phases, we determine that the stability regime of the BCC phase can be replaced by the FCC phase completely by tuning the length ratio of the middle bridging B2-block, demonstrating the key role of B2-block in stabilizing the spherical packing phase. More interestingly, the unusual phase transitions between the BCC and FCC spherical phases, i.e., BCC → FCC → BCC → FCC → BCC, are observed as the length of the bridging B2-block increases. Even though the topology of the phase diagrams is less affected, the phase windows of the several ordered nanostructures are dramatically changed. Specifically, the changing of the bridging B2-block can significantly adjust the asymmetrical phase regime of the Fddd network phase.

Modulating the Self‐Assembly of Coplanar D–π–D Hole‐Transporting Materials via Alkyl Chain Engineering for Efficient and Stable Inverted Perovskite Solar Cells

Rational introduction of flexible alkyl chains into rigid conjugated molecules is a facile but effective strategy to develop advanced organic semiconductor materials for considerable enhancement of photovoltaic performance. Herein, seven hole‐transporting materials (HTMs) via attaching ethyl, hexyl, or ethylhexyl to benzodithiophene π‐linker and bromoethyl, bromobutyl, or bromohexyl to phenoxazine donor (D), respectively, named B2P2, B6P2, B8P2, B6P4, B2P6, B6P6 (N01), and B8P6, are reported. Joint differential scanning calorimetry measurements and thin‐film absorption spectra of representative HTMs, B8P6, B6P4, and B2P2 reveal that alkyl chain modulation on coplanar D–π–D HTMs enables synchronous optimization of their solution processability, molecular packing, and thermal phase transition. Consequently, benefiting from the favorable self‐assembly and surface characteristics of hole‐transporting layers and further induced superior upper perovskite‐growth, B8P6‐ and B6P4 ‐based inverted perovskite solar cells exhibit decent power conversion efficiencies of 20.67% and 20.13%, respectively, prior to that of amorphous B2P2 (19.04%). Analysis on steady‐state/transient photoluminescence spectra and light intensity‐dependent short‐circuit photocurrent and open‐circuit voltage (Voc) demonstrates that more ordered assemblies of HTMs obtained via alkyl chain engineering can facilitate efficient interfacial charge transport/extraction and inhibit detrimental charge recombination, accounting for an enhanced Voc and fill factor.

The developing murine kidney actively negotiates geometric packing conflicts to avoid defects.

The physiological functions of several organs rely on branched epithelial tubule networks bearing specialized structures for secretion, gas exchange, or filtration. Little is known about conflicts in development between building enough tubules for adequate function and geometric constraints imposed by organ size. We show that the mouse embryonic kidney epithelium negotiates a physical packing conflict between increasing tubule tip numbers through branching and limited organ surface area. Through imaging of whole kidney explants, combined with computational and soft material modeling of tubule families, we identify six possible geometric packing phases, including two defective ones. Experiments in explants show that a radially oriented tension on tubule families is necessary and sufficient for them to switch to a vertical packing arrangement that increases surface tip density while avoiding defects. These results reveal developmental contingencies in response to physical limitations and create a framework for classifying congenital kidney defects.

Phase Control of Colloid-like Block Copolymer Micelles by Tuning Size Distribution via Thermal Processing

The formation of a Frank–Kasper (FK) phase in a one-component block copolymer (bcp) has been attributed to the sufficiently large conformational asymmetry parameter that leads to the deformation of the micellar core into the polyhedral shape templated by the Voronoi cells for relieving the packing frustration of the coronal blocks. Here we present the insight into the evolution of body-centered cubic (BCC) and Laves C14 phases from the corresponding metastable liquidlike packing (LLP) phases in a conformationally symmetric poly(2-vinylpyridine)-block-poly(dimethylsiloxane) (P2VP-b-PDMS) forming the colloid-like micelle with a hard P2VP core and a soft PDMS corona at the temperature of micelle ordering (Tgcorona < Ta < Tgcore). Different thermal processing conditions were applied to produce four distinct types LLP phase characterized by different average micelle size and size dispersity. The LLP phase was found to transform to BCC, C14 and a reorganized LLP phase with increasing polydispersity of particle size, showing the existence of a proper range of size dispersity for the formation of the Laves phase. The real-space analysis of the local environments of the particles revealed that the C14 phase can accommodate the particles with a broader range of interparticle distance and a less uniform local environment, such that the PDMS coronal blocks of the micelles with greater size dispersity suffered a lower degree of packing frustration when they organized into a C14 lattice. In view of the colloid-like nature of the micelle, a size fractionation process found in the crystallization of polydisperse colloidal particles was proposed as the mechanism for directing the effective development of C14 phase from the LLP phase. Due to the metastable nature of the ordered phases, their order–disorder transition temperatures were found to depend strongly on the structures of the LLP phases from which they developed and a strong memory effect underlying the phase transitions was identified.

Acoustic Emission Characteristics of Fracture and Damage in Coal Samples under Overstress Loading and Unloading Paths

Abstract As coal mining depth is over 1000 m, an overstressed effect is commonly observed around working face which shows a higher stress than the ultimate strength of the coal mass. Aiming at the problem of dynamic disasters induced by overstress loading and loading, a true triaxial AE monitoring unit was designed to systematically investigate the acoustic emission (AE) characteristics of fracture and damage. The AE results show that the ring counts of coal sample under true triaxial loading are influenced by three factors: loading level, individual differences, and loading rates. When under lower true triaxial loads, the coal sample damage represented by ring counts appears largely in loading phase, and the quantity is few. When true triaxial loads increase, the number of ring counts, especially in packing phase, increases significantly, which indicates that the damage process is transferred from loading phase to packing phase. The study on evolution laws of microcracks, wave velocity, and energy indicates that, during the initially true triaxial loads, the primary microcracks and the initial loading on primary dense areas contributes to a small amount of lower and higher velocity regions in the sample. Along with the increase of true triaxial loading, the closure of the primary microcracks and the fracture of the dense area result in a transfer and expansion of higher velocity regions and the formation of velocity anomaly regions. When approaching failure, the macrocracks throughout the sample present a large area of lower velocity band. The formation and closure of cracks, the fast transfer of high velocity region, and the velocity anomaly region indicate the unstable status of the sample. During the packing phase of true triaxial loads, the cracks are compacted, and the inner structures are thoroughly damaged in the sample, which eventually presents a continuous damage in a form of the shrink of the lower velocity region and the increase of integral velocity of the sample.

Enhanced Plasmon Based Ag and Au Nanosystems and Their Improved Biomedical Impacts

Numerous specialists and academics have backed the improved physicochemical characteristics of metal substrate (Ag, Au) based composite nanoparticles for a number of applications, including pharmaceuticals, optoelectronics, and environmental impact. Insights of Ag and Au NPs-based nanomaterials will be discussed, as well as important production, physicochemical, and biotechnological characteristics. The plasmon capacities of Ag and Au NPs, along with their customisable form, scale, and surface modification could be described by specified geometries and constituent contents. It was revealed that interaction dynamics of Ag and Au implanted nanomaterials with dopants/defects ratios seem to be more effective in stimulating pathogens by interrupting biochemical reactions. As a result, we focus on defect science in Ag and Au-based nanoscale materials, taking into account surface morphology, ionic packing, and chemical phase assessment. This chapter will cover the important optical, geometrical, and physicochemical features of Ag and Au nanomaterials, and their pharmacological significance.

Morphology manipulation for highly miscible photovoltaic blend of carboxylate-substituted polythiophene:Y6

Polythiophenes and its derivatives (PTs) have attracted extensive research interest in the field of organic solar cells (OSCs) owing to their benefits of low synthesis cost and high scalability of synthesis. However, the efficiency of PT-based photovoltaic devices is far lower than that of the popular push-pull conjugated polymer-based devices. To elevate the photovoltaic performance, pairing PTs with low-bandgap acceptors is highly desirable. Nevertheless, when pairing the prevailing low-bandgap non-fullerene acceptor Y6 with a representative PT derivative named PDCBT-Cl, the OSC delivered an extremely low efficiency of ∼0.1%. The crucial reason for the abysmal performance is the poor morphology with insufficient phase separation induced by the high miscibility between PDCBT-Cl and Y6. How to tune the morphology and promote phase separation is challenging and important for the highly miscible blend system to achieve performance breakthrough. Given that PDCBT-Cl and Y6 are crystalline, in the present study, we promote the formation of phase separation for PDCBT-Cl:Y6 blend by control molecular crystallization, using thermal annealing (TA) at various temperatures. We observed that, phase-separated morphology appeared when TA temperature was higher than the aggregation transition temperature of PDCBT-Cl. Upon TA at 160 °C, ordered molecular packing and appropriate phase separation were obtained for PDCBT-Cl:Y6 blend film, and the device efficiency increased dramatically to ∼10%, which was ∼90 times higher than that of the as-cast counterpart. This study demonstrates that promoting crystallization is an effective means to induce phase separation for the highly miscible blend system with crystallinity.

Soft Alloys Constructed with Distinct Mesoatoms via Self-Sorting Assembly of Giant Shape Amphiphiles.

The packing structures of spherical motifs affect the properties of resultant condensed materials such as in metal alloys. Inspired by the classic metallurgy, developing complex alloy-like packing phases in soft matter (also called "soft alloys") is promising for the next-generation superlattice engineering. Nevertheless, the formation of many alloy-like phases in single-component soft matter is usually thermodynamically unfavourable and technically challenging. Here, we utilize a novel self-sorting assembly approach to tackle this challenge in binary blends of soft matter. Two types of giant shape amphiphiles self-sort to form their discrete spherical motifs, which further simultaneously pack into alloy-like phases. Three unconventional spherical packing phases have been observed in these binary systems, including MgZn2 , NaZn13 , and CaCu5 phases. It's the first time that the CaCu5 phase is experimentally observed in soft matter. This work demonstrates a general approach to constructing unconventional spherical packing phases and other complex superlattices in soft matter.

Soft Alloys Constructed with Distinct Mesoatoms via Self‐Sorting Assembly of Giant Shape Amphiphiles

AbstractThe packing structures of spherical motifs affect the properties of resultant condensed materials such as in metal alloys. Inspired by the classic metallurgy, developing complex alloy‐like packing phases in soft matter (also called “soft alloys”) is promising for the next‐generation superlattice engineering. Nevertheless, the formation of many alloy‐like phases in single‐component soft matter is usually thermodynamically unfavourable and technically challenging. Here, we utilize a novel self‐sorting assembly approach to tackle this challenge in binary blends of soft matter. Two types of giant shape amphiphiles self‐sort to form their discrete spherical motifs, which further simultaneously pack into alloy‐like phases. Three unconventional spherical packing phases have been observed in these binary systems, including MgZn2, NaZn13, and CaCu5 phases. It's the first time that the CaCu5 phase is experimentally observed in soft matter. This work demonstrates a general approach to constructing unconventional spherical packing phases and other complex superlattices in soft matter.

Simulation Opportunities by a Three-dimensional Calculation of Injection Moulding based on the Finite Element Method

Abstract The simulation of injection moulding is essential to meet quality requirements and to increase the efficiency of the design process. In this paper a 3D-finite element model for the simulation of injection moulding is presented. The model's capability comprises the calculation of velocity, pressure and temperature fields as well as the prediction of the flow front position. The numerical approach is mainly based on the Galerkin formulation. Special emphasis is placed on the handling of polymer compressibility in order to enable a realistic simulation of the packing phase. The numerical efficiency has been largely enhanced through the employment of an automatic time step control. In order to demonstrate the code's capabilities and outline advantages and disadvantages over other simulation systems, the calculation results are compared to experimental data and to results obtained from other numerical models.