Blowing Process Research Articles

Solid‐phase synthesis of grafted carbon black for superior aging resistance in biodegradable poly(butylene adipate‐co‐butylene terephthalate) composite films

AbstractBiodegradable films mitigate plastic pollution but often lack UV‐aging resistance, shortening their lifespan. While anti‐aging additives can boost the films' durability, small molecule migration constrains the extension of their service life. This study introduces a straightforward solid‐phase reaction for producing carbon black (CB) grafted with the UV absorber UV531, termed CB‐UV531. This material was then blended with the biodegradable polymer PBAT and transformed into a film via blow molding, yielding a durable UV‐resistant biodegradable film (PBAT/CB‐UV531). This solid‐phase grafting reaction does not require any solvents, thereby reducing solvent contamination and waste, and it is simple to operate, allowing for scalable production. Compared to the unmodified CB, the obtained CB‐UV531 exhibits significantly improved thermal stability, which can effectively reduce the loss of UV531 during the subsequent high‐temperature film‐blowing process. Furthermore, the chemically bonded UV absorber on the surface of CB‐UV531, coupled with its reduced particle size, promotes enhanced dispersibility and consistent stability within the PBAT/CB‐UV531 film, markedly improving its long‐term resistance to UV aging. This method is expected to enhance the anti‐aging effects of various commercial light stabilizer additives and can be used to extend the lifespan of different biodegradable materials.Highlights A simple solid‐phase reaction method was developed to prepare CB‐UV531. CB‐UV531 reveals smaller size and superior dispersibility. Biodegradable PBAT/CB‐UV531 film was prepared via a blowing process. UV531 migration loss in PBAT/CB‐UV531 film is significantly reduced. PBAT/CB‐UV531 film shows enhanced thermal stability and aging resistance.

Numerical investigation of the impact of various parameters on blowing accuracy in the XRT intelligent ore sorting machine blowing process

XRT separation equipment is attracting much attention as the mining industry increasingly uses pre-sorting technology. Its sorting accuracy is affected by differences in ore shape and particle size during operation. This paper, in which numerical simulations are conducted to investigate the resistance of ores under various situations, including varying blowing distances, cross-sections, and practical sizes, Additionally, this paper conducts validation tests. The test results indicate that within the 0.1-0.25 m section from the nozzle exit, there is a rapid decrease in velocity, accompanied by a significant change in ore resistance. Beyond the 0.25 m mark, the velocity reduction slows down, while the ore resistance becomes smaller. There exists a notable disparity in the resistance of ores with varying cross-sectional geometries. The size of the jet velocity surface caused by blowing distance significantly influences the resistance of ore with varying particle sizes. Furthermore, the resistance of the ore remains constant subsequent to the impact surface of the ore surpassing the surface of the jet velocity. Consequently, appropriately modifying the blowing distance, inlet pressure, and jet speed in accordance with the cross-sectional area and particle size of the majority of the ores stream can enhance the precision of the sorting process.

STRUCTURE AND DEVELOPMENT OF THE MIDDLE PLEISTOCENE TERRACE OF THE STYR RIVER IN THE AREA OF THE KHRINNYKY RESERVOIR

The article presents new results of the study of the structure of the Middle Pleistocene terrace of the Styr River, probably the oldest among the river terraces preserved in the Styr valley. The main objects of the study were natural outcrops of alluvial and cover deposits, confined to the steep banks of the Khrinnytky Reservoir in the vicinity of the villages of Boremel and Naberezhne. The study was focused on the lower part of the section of terrace sediments, which lies under the Dubno (Vytachiv) soil horizon, which is correlated with the 3rd marine isotope stage (MIS 3). The elevation of the terrace surface above the palaeo-Styr water level is about 20–25 m (16–21 m above the average water level in the reservoir), and the thickness of the loess-palaesoil cover varies from 4–5 m, where the terrace height is minimal, to over 15 m , where the terrace surface is the highest. The main stratigraphic horizons of the Upper Pleistocene are reliably recognized in the section, including two soil horizons of the regional stratigraphic scheme - the widespread Dubno and locally preserved Horohiv (MIS 5). The latter is associated with the base of the loess-palaeosol sequence. The Horohiv pedocomplex is mostly lack in the loess-palaeosol sequences of the coastal cliffs, and if present, it is poorly preserved (truncated), exposed at different altitudes (6–12 m above the reservoir). The poor preservation of the Horohiv pedocomplex is a consequence of intense aeolian (blowing) processes that occurred prior to the formation of the terrace loess cover. The abnormally high altitudinal position of the Horohiv pedocomplex is associated with the accumulation of aeolian sands at the final stage of terrace formation (end of the MIS 6). The presence of paleocryogenic features (syngenetic frost veins and cryoturbations) in the upper part of the alluvium, which can be formed both in permafrost and deep seasonal freezing, indicates its accumulation in periglacial and/or subperiglacial conditions. Key words: river terrace; alluvium; Pleistocene; eolian processes; Volyn’ Upland; Styr River valley.

Hydrophobic polyethylene film prepared by film blowing process for preservation of fried shrimp rolls

Hydrophobic coatings have wide applications, but face challenges in food flexible packaging in terms of poor adhesion and inadequate wear resistance. Health hazards and poor adhesion drive the search for novel hydrophobic coatings substitutes. Here, we introduced rationally synthesized carnauba wax-SiO2 microspheres as a component to composite polyethylene (PE) film construction, and created a wear-resistant hydrophobic composite PE film via the blown film technique. The resultant hydrophobic composite film demonstrated an enhanced water contact angle from 86° to above 100°, coupled with favorable mechanical properties such as wear resistance, tensile strength and effective barrier performance against water vapor and oxygen. Upon implementation in the preservation of a Cantonese delicacy, Chaoshan fried shrimp rolls, it was observed that at 25 °C, the carnauba wax-SiO2-PE composite packaging film extended the shelf life of the product by 3 days compared to pure PE film.

A facial method for constructing superhydrophobic surface by one-step surface etching combined with melt blowing process

It is a challenge to prepare fluorine-free superhydrophobic surfaces by simple methods. In this work, a simple and effective method for constructing a superhydrophobic surface was developed by combining in situ nanofibrillating melt blowing processs and one-step surface etching. Firstly, the randomly stacked meltblown microfibers as microstructure transformed the wetting performance of the surface from hydrophilic to hydrophobic. Then, by tuning the etching time, the outmost nanofibrils within the microfibers were exposed to form nanostructure thereby achieving superhydrophobic performance with a contact angle of 153°. The superhydrophobicity of the as-prepared nonwoven was maintained after various harsh treatments, such as strong acid, strong alkaline, sandpaper abrasion, and ultrasonic washing, showing stable water repellency ability. In addition, the superhydrophobic nonwoven showed promising application in self-cleaning and oil–water separation. Thus, this work not only prepares a superhydrophobic surface but also proposes a new idea for designing a micro-nano hierarchical structure on the surface.

Porous Melt Blown Poly(butylene terephthalate) Fibers with High Ductility and High-Temperature Structural Stability.

In this study, porous poly(butylene terephthalate) (PBT) fibers were produced by melt blowing cocontinuous blends of PBT and polystyrene (PS) and selectively extracting the interconnected PS domains. Small amounts of hydroxyl terminated PS additives that can undergo transesterification with the ester units in PBT were added to stabilize the cocontinuous structure during melt processing. The resulting fibers are highly ductile and display fine porous structural features, which persist at temperatures over 150 °C. Single fiber tensile testing and electron microscopy are presented to demonstrate the role of rapid quenching and drawing of the melt blowing process in defining the fiber properties. The templated highly aligned pore structure, which is not easily produced in solvent-based fiber spinning methods, leads to remarkable mechanical properties of the porous fibers and overcomes the notoriously poor tensile properties common to other cellular materials like foams.

Numerical Analysis of Postcombustion Effects on the Supersonic Jet Behavior

During the top blowing process of the basic oxygen furnace, the oxygen jet may react with CO before it reaches the surface of the molten bath. This combustion reaction affects the dynamic characteristics of the jet, which, in turn, affects its interaction with the bath. In this study, a numerical model is developed to investigate the transient and steady combustion characteristics of the supersonic jet emitted from the top lance. The transient combustion simulation shows that the CO ratio gradually decreases while the CO2 mole fraction increases at the interaction boundary region between jet and ambient due to the chemical reactions. In addition, the jet profile is changed when the postcombustion is introduced. Due to the flame formation and turbulence change at the jet combustion interface, the axial velocity at height of 2 m (x = 73 re) is 89% higher than that of the noncombustion reaction jet flow. In the results, it is demonstrated that the combustion interface is favorable to reduce the jet decay, resulting a higher dynamic pressure before the jet reaches the bath surface. Furthermore, a higher core temperature and lower density are obtained for the combustion jet compared to that of without combustion reaction.

Influences of blowing and internal heating processes on steady MHD mixed convective boundary layer flows of radiating titanium dioxide‐ethylene glycol nanofluids

AbstractThe present analysis intends predominantly to explore the multiple behaviors of radiating ethylene glycol‐based titanium dioxide nanofluids during their steady boundary layer flows near a vertical permeable surface under the prominent impacts of uniform blowing and nonuniform internal heating processes. By incorporating the dynamical contribution of Lorentz and buoyancy forces in the momentum equation and adopting the single‐phase nanofluid approach along with the constitutive equations of the second‐grade rheological model and Corcione's correlations, the governing partial differential equations and their appropriate boundary conditions are derived mathematically based on the boundary layer theory and other admissible physical approximations. After several simplifications, the aforesaid differential formulation is converted into a set of ordinary differential equations and realistic boundary conditions, which are solved thereafter numerically using GDQ's‐NT method. Moreover, it is demonstrated that the strengthening in the blowing and internal heating processes has a boosting effect on the velocity and temperature profiles. However, the other influencing parameters show dissimilar dynamical and thermal trends. Furthermore, it is witnessed that the mixed convective heat transfer, the viscoelasticity trend of the nanofluidic medium, and the nanoparticles’ loading exhibit an enhancing impression on the surface heat transfer rate.

Enhancing dynamic impact performance and cushioning of EVA copolymer foams with thermoplastic elastomers

This study examines the effect of thermoplastic elastomers (TPE) on the physical, mechanical, and dynamic impact properties of ethylene-vinyl acetate (EVA) copolymer foam using traditional chemical blowing process. The blending of EVA with TPE aims to improve both physical and dynamic impact cushioning to achieve optimal energyreturn EVA foam. Comparative analysis reveals that adding a 10–20 wt% fraction of propylene elastomer (POE) to EVA significantly reduces foam density while maintaining dynamic energy absorption and energy return. However, high POE content (30 wt%) leads to inferior mechanical and dynamic impact properties due to excessive softness. Blending EVA with terpolymer elastomer (PTW) enhances compression strength (∼16%), hardness (∼27%), and dynamic energy return (∼9%). EVA/POE/PTW hybrid blend foams display intermediate properties. The impact behaviors of foams vary between high and low dynamic impact loading rates. The presence of TPE enhances cushioning by absorbing impact forces through deformation, with EVA/PTW exhibiting remarkably improved rebound properties. Impact peak force decreases linearly with increasing PTW content. Foam morphology, including phase compatibility, cell size and density, plays a role in determining dynamic impact properties. Hard segmented TPE store more energy and quickly recover, resulting in a higher rebound effect as compared to soft segmented TPE. Incorporating TPE provides the ability to control the EVA foam's dynamic rebound, and impact cushioning, expanding its potential in sports-related applications.

High‐Efficiency Dephosphorization by Bottom‐Blown O2‐CaO Process for Semi‐Steelmaking

In steelmaking, the bottom‐blown O2‐CaO process is used to achieve efficient dephosphorization. However, few studies have applied it to dephosphorization converters. Therefore, this study considers the thermodynamic and kinetic mechanisms of dephosphorization during the process. The selective oxidation transfer temperatures of C and P are calculated. Compared to the combined blowing process, the bottom‐blown O2‐CaO process reduces the optimum dephosphorization temperature from 1593 to 1573 K. Moreover, the FeO content decreases by 20.7% owing to the increased stirring energy and improved kinetic conditions; the binary basicity (R) of the slag increases, and the lime consumption decreases by 2.9 kg t−1. The higher slagging efficiency indicates that the CaO powder melts and dephosphorization is completed during the fire‐spot zone floating process. Furthermore, the optimum FeO content for dephosphorization decreases as R increases. The selective oxidation of C and P can be divided into two stages. The oxidation stage of P preferred C is extended in this process. Overall, the end‐point P content accounts for 22.52% and 46.85% of the samples prepared using the combined blowing and bottom‐blown O2‐CaO processes when the P content is 0.02–0.03%, respectively.

The interplay between macromolecular structure, rheology, processing condition, and morphology for (linear) low density polyethylenes in film blowing

Film blowing is a crucial plastic conversion technique for (Linear) Low Density Polyethylene ((L)LDPE), widely employed in the industry. However, understanding its complexities, which involve a delicate interplay between various parameters, such as macromolecular features, flow behavior, processing conditions, and final film performance, remains limited in the literature. Notably, the quantification of processability in film blowing has not yet been adequately addressed. Present study investigates the key parameters in this interplay, introduces a framework to quantify the processability, and establishes its connection with molecular weight (distribution) and the extensional flow behavior of (L)LDPE. Additionally, selected processing conditions are correlated with the crystalline morphology and performance of the films. The findings of this research offer a fundamental understanding of the film blowing process and serve as a valuable baseline for future endeavors involving more complicated polymer systems, such as blends and contaminated recyclates. By shedding light on the crucial parameters and their interdependencies, this work contributes to advancing the efficiency and quality of the process, facilitating the production of high-performance films.

Theory of Movement Behavior of Argon Bubbles in Upper Nozzle of Tundish During Argon Blowing Process

Theory of Movement Behavior of Argon Bubbles in Upper Nozzle of Tundish During Argon Blowing Process

Extrusion-blown oxidized starch/poly(butylene adipate-co-terephthalate) biodegradable active films with adequate material properties and antimicrobial activities for chilled pork preservation

Food safety concerns from spoilage and non-degradable packaging risk human health. Progress made in biodegradable plastic films, but limited study on biomass composite films with favorable morphological, mechanical, and inherent antibacterial properties for fresh meat preservation. Herein, we present a versatile packaging film created through the extrusion blowing process, combining oxidized starch (OST) with poly(butylene adipate-co-terephthalate) (PBAT). SEM analysis revealed even distribution of spherical OST particles on film's surface. FTIR spectra revealed new intermolecular hydrogen bonds between OST and PBAT. While combining OST slightly reduced tensile properties, all composite films met the required strength of 16.5 ± 1.39 MPa. Notably, films with 40 % OST showed over 98 % antibacterial rate against Staphylococcus aureus within 2 h. pH wasn't the main cause of bacterial growth inhibition; OST hindered growth by interfering with nutrient absorption and metabolism due to its carboxyl groups. Additionally, OST disrupted bacterial membrane integrity and cytoplasmic membrane potential. Remarkably, the OST/PBAT film excellently preserved chilled fresh pork, maintaining TVB-N level at 12.6 mg/100 g on day 6, microbial count at 105 CFU/g within 6–10 days, and sensory properties for 8 days. It extended pork's shelf life by two days compared to polyethylene film, suggesting an alternative to a synthetic material.

Large-scale solution blow spinning of flexible carbon nanofibers for the separation applications

Massive production of carbon nanofibers with low thermal conductivity and excellent properties has remained as an extremely challenging. Herein, solution blow spinning technology and textile post-treating technic were introduced to achieve the mass production of carbon nanofibers and its derivative products. Different types of materials (polyacrylonitrile and lignin) were utilized as the spinnable agent and carbon source. A comprehensive investigation was conducted into the influences of raw material components, blow spinning process, and high-temperature pyrolysis process on the performance of carbon nanofibers. Through controlling the solution flow rate (10–50 mL·h−1), different needle diameters (21–25 G) and high pressure airflow (0.2–0.4 MPa), organic solution could be effectively spined into organic fiber precursor. Importantly, with the assistant of textile rearrange and needle punching technics, loose organic sponge can be transformed into blanket with designed thicknesses and shapes. These SBS spined carbon fiber products exhibited ideal compressional resilience ability (up to 60 %), adsorption of toluene, and thermal insulation performance (0.037 W·(m·K)-1).

Fractal Characterization of Particle Size and Coordinate Distribution of Dispersed Phase in the Steelmaking Process of Combined Blowing Conversion

A two-dimensional water model was used to simulate the process of combined blowing. The effect of boundary conditions on the size and coordinate distribution of the dispersed phase was investigated. The results showed that the frequency of the dispersed phase at a certain size level is proportional to its size; the coordinates of the dispersed phase can be expressed in a dimensionless form that shows its uniformity of distribution. An empirical equation for the influence of the boundary conditions on the size and coordinate distribution of the dispersed phase in combined blowing process is also presented.

A Test Stand for Quantifying the Core Gas Release and the Gas Permeability of Inorganically-Bound Foundry Cores

Environmental and work safety aspects necessitate a radical change in the foundry industry. Organic binder systems for foundry sand cores create toxic combustion products and are, therefore, more and more often substituted by inorganic binder systems. While providing an environmental advantage by mainly releasing water vapor, inorganic binder systems impose new challenges for the casting process. The gas release of inorganically-bound foundry cores can lead to increased gas porosity in the cast parts and thus to high scrap rates. The present work aims to gain more understanding of the gas generation and transport in inorganic sand binder systems. We developed a test stand to measure the temperature-dependent core gas release in inorganically-bound foundry cores and their gas permeability. Samples were prepared in a core blowing process and analyzed using the test stand. The measurement results are in good agreement with validation experiments and existing literature.

Process optimization of bottom-blown argon for 130t ladle furnace

ABSTRACT A quarter scale water model experiment is employed to investigate the effect of single and double porous plug placement and blowing flow rates on the mixing time, slag eye area, and slag entrapment depth. As a result, when the blowing flow rate is greater than 180 L min–1, the blowing effect of double blowing plugs is better than that of single blowing plugs. The open eye area and slag entrapment depth in the double blow plug arrangement are smaller than that in the single blow plug arrangement. In general, the ladle refining effect is better when the blow plug is arranged at 0.4R position and the angle between the two blow plugs is 120°. The final recommended argon blowing process is 240–300 L min–1 for the heating and alloying process and 60–120 L min–1 for the soft blowing process, respectively.

Preparation of Cu7.2S4@N, S co-doped carbon honeycomb-like composite structure for high-rate and high-stability sodium-ion storage

Sodium ion batteries (SIBs) attract most of the attention as alterative secondary battery systems for future large-scale energy storage and power batteries due to abundance resource and low cost. However, the lack of anode materials with high-rate performance and high cycling-stability has limited the commercial application of SIBs. In this paper, Cu7.2S4@N, S co-doped carbon (Cu7.2S4@NSC) honeycomb-like composite structure was designed and prepared by a one-step high-temperature chemical blowing process. As an anode material for SIBs, Cu7.2S4@NSC electrode exhibited an ultra-high initial Coulomb efficiency (94.9%) and an excellent electrochemical property including a high reversible capacity of 441.3 mAh g−1 after 100 cycles at 0.2 A g−1, an excellent rate performance of 380.4 mAh g−1 even at 5 A g−1, and a superior long-cycle stability with a capacity retention rate of approximately 100% after 700 cycles at 1A g−1.

Assessment of Modular Construction System Made with Low Environmental Impact Construction Materials for Achieving Sustainable Housing Projects

The construction industry faces a significant challenge in addressing both the housing crisis and climate change. To mitigate this challenge, there has been a push toward the incorporation of industrialization in the construction process to improve product quality, reduce execution times, and lower production costs. However, it is also crucial to implement materials with sustainable characteristics to decrease the environmental impact of housing. In light of this, the present study analyzes the environmental and economic impacts through the development(design) of a modular construction system using materials with low environmental impact. Specifically, the structural components of the system are constructed using plywood boards, thermal insulation is provided by wheat straw, and the interior finish is made of clay plaster. The Skylark 250 model served as the chassis for the structure, with the wheat straw being applied through a blowing process and the clay plaster applied manually. Thermal transmittance, energy demand, environmental impact, and economic analysis were all evaluated for this solution. The study results yielded a modular housing solution with an energy demand of 55 (kWh/m2/year), which, when paired with photovoltaic panels, meets the Net Zero challenge. In terms of construction time, the proposed system requires 44% less time than traditional construction methods and is 29% less expensive economically, making it an attractive option for the housing market.

Numerical Simulation of the Slag Splashing Process in A 120 Ton Top-Blown Converter

Slag splashing operations at the end of the converter blow process can improve the furnace liner life and the converter operation rate. However, the effect of factors on slag splashing at actual dimensions is yet to be fully understood. A three-dimensional transient mathematical model coupled with the response surface analysis has been established to investigate the effects of the amount of remaining slag, oxygen lance height, and top-blowing nitrogen flowrate on the slag splashing process in a 120 ton top-blown converter. The predicted splashing density is validated by the experimental data. The numerical simulation results show that the splashing density and the splashing area ratio increase with the amount of remaining slag, which has the greatest effect on slag splashing. As the oxygen lance height decreases, the splashing density and the splashing area ratio first increase and then decrease. The top-blowing nitrogen flowrate is positively correlated with the splashing area ratio. When the oxygen lance height is high, the impact of the top-blowing nitrogen flowrate on the splashing density is not significant. The splashing density increases with increasing top-blowing nitrogen flowrate as the oxygen lance height is low.