Search Results (64)

Biodegradable polymers offer environmental advantages compared to fossil-based alternatives, but they currently lack the stretchability required for demanding applications such as mesh fabrics for woven flexible intermediate bulk container (FIBC) bags and stretch, shrink, and cling films. The goal of this research is to enhance the stretchability of biodegradable blends based on 80% poly(butylene adipate-co-terephthalate) (PBAT) and 20% poly(lactic acid) (PLA) through reactive extrusion. Radical initiator (dicumyl peroxide (DCP)) and chain extenders (maleic anhydride (MA), glycidyl methacrylate (GMA)) were employed to improve the melt strength and elasticity of the extruded films. The reactive blends were initially prepared using a batch mixer and subsequently compounded in a twin-screw extruder. Films were produced via cast extrusion. 0.1% wt. DCP led to a 200% increase in elongation at break and a 44% improvement in tensile strength. Differential scanning calorimetry and scanning electron microscopy revealed enhanced miscibility between components. Shear and complex viscosity increased by 38% and 85%, compared to the neat blend, respectively. Reactive extrusion led to a better dispersion and distribution of the phases. An improved interfacial adhesion between the phases, in addition to higher molecular weight, led to enhanced melt strength and improved stretchability. Full article

A recently proposed method called “controlled swelling of monolithic films” was implemented to prepare ultra-high-molecular-weight polyethylene (UHMWPE) ultrafiltration membranes. For the first time, the effect of UHMWPE molecular weight (MW) on the structure and properties of the membranes prepared via this special case of thermally induced phase separation was studied in detail. The morphology and properties of the membranes were studied using SEM, DSC, liquid–liquid displacement porometry, and standard methods for the evaluation of mechanical properties, permeance, rejection, and abrasion resistance. High-quality membranes with a tensile strength of 5.0–17.8 MPa, a mean pore size of 25–50 nm, permeance of 17–107 L m⁻² h⁻¹ bar⁻¹, rejection of model contaminant (blue dextran) of 72–98%, and great abrasion resistance can be prepared only if the MW of the polymer in the initial monolithic film is sufficiently high. The properties of the membranes can effectively be controlled by changing the MW of the polymer and the mass fraction of the latter in the swollen film. Shrinkage is responsible for the variation in the membrane properties. The membranes prepared from a higher-MW polymer are more prone to shrinking after the removal of the solvent. Shrinkage decreases before rising again and minimizes with an increase in the polymer content in the swollen film. Full article

Due to increasing environmental concerns and the constant development of the bottling industry, research into the environmental impact of beverage packaging processes is crucial. The aim of this article is to determine the environmental impact, in selected aspects, of automated beverage bottling and packaging processes using life cycle analysis (LCA). The analysis covers key process stages, such as filling, packaging and internal transport, in the context of raw material consumption, but also energy and waste generation. This work focuses primarily on the impact of changing the raw material used for bottle and shrink film production on the environmental impact of the studied technical facility within the adopted system boundaries and on analyzing scenarios for the management of these post-consumer materials. This research has shown that the stage associated with the greatest negative environmental impact is the shrinking of the film around the bottles. Furthermore, it has been demonstrated that recycling plastic film and bottle waste is a more environmentally friendly solution than landfill disposal. The analysis shows that using recycled materials in the tested production line allows for the reduction of harmful emissions and a reduction in the overall environmental footprint of the tested system. Full article

This study includes a simulation of two variants of a 1 MW photovoltaic farm, differing in the types of photovoltaic modules used in the PVSyst program. The first uses monofacial modules, and the second uses bifacial. The studies showed an 8% increase in the energy obtained in the variant with bifacial modules, under the assumed simulation conditions. In the next stage, an environmental analysis was carried out using the Life Cycle Assessment (LCA) method with a “gate-to-gate” approach for the mass packaging process in three different variants, differing in the source of energy powering the machines in the SimaPro program. In the first variant, electricity from the national energy mix was used. In the second, in addition to energy from the same mix, natural gas was additionally used in the shrinking stage of the film. In the third variant, energy obtained from a previously designed photovoltaic farm was considered. The results showed an about 80% reduction in the carbon footprint of the tested process in the case of changing the energy source to energy from a PV installation. Full article

Carbon dioxide-based copolymers such as polypropylene carbonate (PPC) can offer the double environmental benefit of capturing CO₂ and replacing oil-based raw materials in the plastics industry with renewable ones. However, their production at an industrial level is still limited by the range of applications in which their physicochemical properties are competitive and ideally surpass those of fossil-based polymeric commodities. This work introduces PPC materials with high-stretch and self-healing properties that were prepared by copolymerization of CO₂ and propylene oxide using tailored Zn glutarate catalysts. The PPC materials were analyzed in terms of composition, molecular weight, thermal and mechanical behavior, particularly focusing on their tensile properties, strain recovery, creep response, and self-healing ability. All the prepared PPC materials showed good ductility and self-healing properties. The most promising ones achieved excellent and fast recovery of extremely high elongations (>700%), still reaching remarkable values (>600%) after proper self-healing. These high-stretch and self-healing PPC materials are completely amorphous, present good optical transparency, and can be processed using techniques normally used for other thermoplastics. Therefore, they are promising for a variety of applications, including shrink films and self-healing packaging, thus providing new, valuable perspectives for the industrialization of these CO₂-based polymers. Full article

The post-use management of plastic films, including shrink films, poses a significant environmental and technological challenge for the industry. Due to their durability and difficulty in degradation, these wastes contribute to environmental pollution, generating microplastics and greenhouse gas emissions during improper disposal. This paper examines different post-use management methods for shrink wrap, such as recycling, landfilling, and incineration, and assesses their impact on the environmental impact of the bottle packaging process using a life-cycle analysis (LCA). This study shows that the recycling option has the lowest potential environmental impact. Compared to other post-use management options, recycling reduces the potential environmental impact by more than 50%. The analysis also shows that the tested scenario using recycled film and photovoltaic energy has the lowest potential environmental impact. Using recycled film and powering the process with renewable energy reduces the potential environmental impact by about 95% compared to Scenario 1 and by about 85% in Scenario 3. Full article

To analyze the progression of Leidenfrost evaporation, traditional experiments were conducted manually to generate a complete evaporation curve. However, physical constraints render Leidenfrost evaporation experiments inherently time-consuming and susceptible to uncertainty. To address these challenges, this study aimed to develop an automated system using webcams for real-time image acquisition and processing, as well as a syringe pump constructed using an Arduino microcontroller, a stepper motor, and 3D-printed components. In the domain of real-time image processing, the radii of levitated droplets were determined using circular detection techniques. By fitting the droplet radii over hundreds of consecutive frames, it was concluded that the shrinking rate of levitated droplet radii remain constant when the radius exceeds 0.6 mm, and the evaporation time is accurately derived. A moving average algorithm was employed to identify the heat transfer area as well as the evaporation time between the boiling droplet and the hot surface, enabling simultaneous calculation of the heat flux. The automated system was then used to perform Leidenfrost experiments under varying experimental parameters, and was compared to manual methods to demonstrate its superior precision in both the film boiling and nucleate boiling regimes. For example, the automated system was utilized to perform a series of experiments as the Weber number increased from 7.01 to 23.18. The detected Leidenfrost temperature rose from 154 °C to 192 °C, while the evaporation time decreased from 85.2 s to 78.9 s. These findings were consistent with previous studies and aligned with physical expectations, reinforcing the reliability of the system and its results. Full article

Multi-layer films are one of the most challenging classes of polymer waste for recycling, as they consist of a mixture of constituent materials like polyethylene (PE), polyamide 6 (PA6), and ethylene vinyl alcohol (EVOH). This study investigates the characterization, washing, and mechanical properties of recycled blends derived from such multi-layer films. Raman spectroscopy and Differential Scanning Calorimetry (DSC) were used to characterize the individual components in single- and multi-layer films, and distinct properties of LDPE, LLDPE, PA6, and EVOH were observed. Mechanical properties enhanced by proper shredding, washing procedures, and multiple combinations of polyethylene blends were investigated to optimize the mechanical characteristics of the recycled materials, especially strain at break. Additionally, the shrinkage behavior of the recycled films was compared to commercial shrink films, demonstrating their potential for use in industry packaging applications. These results highlight a more sustainable possibility for multi-layer packaging applications. Full article

Life cycle analysis (LCA) is a popular tool for determining the environmental impacts of a product in use. The aim of this study is to carry out a life cycle analysis, gate-to-gate, of a mass packaging process using a polyethylene shrinking film with a focus on energy consumption, raw material use and associated emissions, and film post-consumer disposal scenarios. Two different scenarios for the disposal of the shrinking film used in the packaging process were analyzed, namely recycling and landfills. The analysis showed that choosing recycling as the post-consumer management of film waste within the studied system boundaries reduces the negative environmental impact by approximately 17%. The study showed significantly higher environmental benefits in terms of harmfulness to human health for recycling than for landfills. A study of the environmental impact of the mass packaging process depending on the energy source showed that using a renewable source minimizes environmental damage. Three sources of energy options were analyzed, including the country’s energy mix, wind, and solar. The research shows that changing sources to wind power reduces potential damage to human health by 91%, to ecosystems by 89%, and to resources by 92% compared to the country’s energy mix power option. When comparing the results for the renewable energy options, the variant with energy from wind presents lower harm in all three damage categories compared to the solar option. Full article

The leaching kinetics of an industrial iron collector containing PGMs (Pd, Pt, Rh) in HCl and HF solutions were investigated. The effects of the HCl concentration (2.74–6.86 mol/L), the HF concentration (1.46–7.50 mol/L), temperature (323–363 K), and leaching time (0–210 min) on the extraction of Fe into the solution and Si into the gas phase from the iron collector were studied. The HCl concentration had a negative effect on the extraction of Si, which decreased from 78.2% to 58.1% and from 97.4% to 87.2% in the time ranges of 0–30 min and 30–120 min, respectively. This occurred due to the accumulation of Fe²⁺ in the solution and its interaction with HF, which led to a reduction in both the HF concentration and the extraction of Si. In addition, there were diffusion difficulties of the Fe and Si extraction because Fe precipitated on the surface of the cakes in the form of thin-film conglomerates of FeF₂. This was confirmed by the XRF and EDS results, indicating that F was present on the surface of the cakes. The processes of the Fe and Si extraction were diffusion-chemically controlled and diffusion controlled—the apparent activation energies decreased from 26.9 kJ/mol to 7.8 kJ/mol and from 2.2 kJ/mol to 2.0 kJ/mol in the time range of 0–120 min, respectively. Using the shrinking core model and the full factorial experiment model, the kinetic equations, the optimal parameters of iron collector leaching, and the extraction rates of Fe and Si were determined. These optimal parameters ensure the extraction of Fe and Si at the level of 95% with high leaching rates: the HCl concentration of 4.36 mol/L, the HF concentration of 6.93 mol/L, temperature of 363 K, and leaching time of 80 min. Full article

The field of 3D and 4D printing is advancing rapidly, offering new ways to control the transformation of programmable 3D structures in response to external stimuli. This study examines the impact of 3D printing parameters, namely the UV ink thickness (applied using a UV inkjet printer on pre-3D-printed programmable structures) and thermal activation, on the dimensional and surface changes to high-stress (HS) and low-stress (LS) programmable samples and on print quality. The results indicate that HS samples shrink in the longitudinal direction, while expanding in terms of their height and width, whereas LS samples exhibit minimal dimensional changes due to lower programmed stress. The dynamic mechanical analysis shows that UV ink, particularly cyan and CMYK overprints, reduces the shrinkage in HS samples by acting as a resistive layer. Thicker ink films further reduce the dimensional changes in HS samples. Thermal activation increases the surface roughness of HS structures, leading to the wrinkling of UV ink films, while LS structures are less affected. The surface gloss decreases significantly in HS structures after UV ink application; however, thermal activation has little impact on LS structures. UV ink adhesion remains strong across both HS and LS samples, suggesting that UV inks are ideal for printing on programmable 3D structures, where the colour print quality and precise control of the shape transformation are crucial. Full article

Automotive catalysts containing Platinum Group Metals (PGMs) are valuable secondary raw materials for refineries. Hydrometallurgical processing of catalysts is ineffective due to the low PGMs content—0.15–0.3%. Therefore, such raw materials are melted into an iron collector containing 1.5–5% PGMs. However, when leaching a collector containing 10–20% Si in both HCl and H₂SO₄, the recovery of PGMs does not exceed 40%. The latter indicates incomplete destroying of the PGM-encapsulating ferrosilicon matrix. To completely destroy the ferrosilicon matrix, it is proposed to carry out the leaching process in a mixture of HCl and HF. In this case, the extraction of Fe into solution and Si into the gas phase (in the form of SiF₄) exceeds 90%. This should be sufficient to completely destroy the ferrosilicon matrix and release PGMs. The current work presents the results of studies of the leaching kinetics of the iron collector containing ferrosilicon in a mixture of HCl and HF using the Shrinking Core Model (SCM). It was found that the greatest positive effect on Fe extraction into solution is exerted by HCl concentration and temperature, while Si release into the gas phase is only influenced by HF concentration. In addition, during the destroying of ferrosilicon, FeF₂ is formed and deposited on the surface of the material in the form of thin-film conglomerates. This leads to diffusion difficulties and a gradual decrease in the intensity of the iron collector leaching 30 min after the start of process. After 120 min, there may be a decrease in Fe recovery into solution. Full article

This article shows an analysis of selected stages of a machine’s life cycle environmental impact in the specific case of machines that package bottles in thermo-shrinkable film. As part of this analysis, laboratory tests were carried out to compare the performance properties of polyethylene films (with and without recycled material). Then, a life cycle assessment (LCA) was carried out within the specified system boundaries using the SimaPro program. Using the ReCiPe 2016 method, differences in the impact of the mass bottle packaging process on the categories human health, ecosystems and resources were determined depending on the shrink film used in the process. These tests showed that the tested batch of film with the addition of recyclates has similar functional properties to traditional ones and can therefore be used in the mass packaging process. The environmental analysis showed that changing the type of film to film with the addition of recyclates results in an almost 70% reduction in the potential negative impact of the process in terms of damage to health and ecosystems, and by 85% in terms of resources. Full article

The aim of this study was to assess the environmental impact of using recycled polyethylene film for shrink-wrapping bottles. For this aim, film properties were tested and the harmfulness of the packaging process was simulated for film made from virgin and recycled material. For the recycled film, the results showed an increase of 14.7% in impact resistance, a change from −21.6 to +94.3% in tear resistance, and a decrease of up to 45.4% in tensile strength in dependence on the test direction. Using differential scanning calorimetry (DSC), the changes in the properties of the two types of film with temperature changes were evaluated. DSC analysis showed that recycled film has a 1.94 °C lower glass transition temperature and a 1.85 °C lower melting point in comparison to polyethylene film. This can reduce the temperature of the packaging process and lead to energy savings. A study conducted with SimaPro 9.3 software showed that a change in films made of virgin raw material to recycled films reduces the negative impact on the environment from 68.5 to 11.5%. The change also reduces resource consumption by about 80 percent. The results of conducted tests and simulations showed that using recycled film for bottle packaging allows reducing the negative environmental impact of examined process, especially in terms of resource consumption and energy savings. Full article

Nowadays, bacteria resistance to many antibiotics is a huge problem, especially in clinics and other parts of the healthcare system. This critical health issue requires a dynamic approach to produce new types of antibacterial coatings to combat various pathogen microbes. In this research, we prepared a new type of carbon quantum dots based on phloroglucinol using the bottom-up method. Polyurethane composite films were produced using the swell–encapsulation–shrink method. Detailed electrostatic force and viscoelastic microscopy of carbon quantum dots revealed inhomogeneous structure characterized by electron-rich/soft and electron-poor/hard regions. The uncommon photoluminescence spectrum of carbon quantum dots core had a multipeak structure. Several tests confirmed that carbon quantum dots and composite films produced singlet oxygen. Antibacterial and antibiofouling efficiency of composite films was tested on eight bacteria strains and three bacteria biofilms. Full article