Volume 21 Issue 2

Consistent heat sealing is a critical aspect of paper cup manufacturing, ensuring both liquid tightness and a visually appealing finish. Given the high production volumes in the disposable cup industry, optimizing energy consumption while maintaining good seal quality is critical to minimize waste and resource use. A mechanical testing device for quantifying the side seal strength of finished cups was developed to replace the subjective hand-peel method. Unlike laboratory testing with pre-sealed samples, the proposed test method accounts for stresses imposed on the seal area during the converting process. The device allowed for the objective comparison of cup side seals produced from two different materials sealed using two different technologies: ultrasonic and hot air. The experiments yielded largely consistent results and offered insights into material-specific behaviors in the cup manufacturing process, which involves shorter heating, cooling, and forming cycles than those in other coated paperboard conversion processes. In addition, ultrasonic sealing was shown to have an advantage in sealing consistency over hot-air sealing. The developed test method showed potential as a repeatable evaluation tool for side seal strength in finished paper cups, facilitating quality control across high-speed production lines.

Polylactic acid (PLA) is a rigid biopolymer, while poly(butylene adipate-co-terephthalate) (PBAT) is a flexible biodegradable polymer. To comprehensively enhance the mechanical properties of PLA/PBAT composites, sunflower straw cellulose nanofibers (SSCNFs) were isolated from sunflower straw (SS) via TEMPO oxidation treatments and used as reinforcement. Using a PLA/PBAT blend (60:40 by mass) as the matrix, SSCNFs-reinforced PLA/PBAT composites were prepared using a co-precipitation and hot-pressing method. The morphology and structure of the SSCNFs were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and nanoparticle size and zeta potential analysis. The mechanical and thermal properties of the composites were tested. The tensile and flexural properties of the composites were improved with increasing SSCNFs content. When the SSCNF content was 16 wt%, the composites reached a tensile strength of 20.06 ± 0.61 MPa (an 11.69% enhancement), a tensile modulus of 732.57 ± 42.72 MPa (a 56.64% enhancement), a flexural strength of 31.76 ± 0.54 MPa (a 20.21% enhancement), and a flexural modulus of 2030.42 ± 36.37 MPa (a 77.50% enhancement). Although thermal stability and water absorption were slightly decreased, UV shielding capacity and hydrophobicity were enhanced. The prepared composites exhibited well-balanced overall performance and potential for replacing traditional commercial polymers.

Deep drawing of paperboard enables highly productive forming processes for packaging products made of a recyclable material. However, the inherent anisotropy and low elasticity of paperboard pose challenges for deep drawing processes, especially resulting in direction-dependent springback and wrinkling of the formed parts. This paper presents an approach that addresses these challenges by using a segmented blank holder. The goal is to improve component quality both locally and globally by applying different blank holder forces to each segment. To this end, a concept is presented for a pneumatically driven segmented blank holder, along with two different forming geometries. Deep-drawing tests with segment-specific blank holder force distributions were performed and compared with those using a conventional blank holder. Although segmentation of the blank holder did not improve performance when the force per segment was identical, an uneven force distribution was able to improve forming in terms of shape accuracy and wrinkle pattern. Depending on the selected force distribution, significant compensation for springback anisotropy and the creation of wrinkle-free straight areas was shown to be possible.

Potato pulp was demonstrated to be a superior lignocellulosic feedstock for cellulose nanocrystal (CNC) production, addressing critical limitations of conventional potato peel-derived CNCs. CNCs with 90.6% cellulose content and 73.4% crystallinity through optimized chemical processing, surpassed peel-based CNCs (70% to 75%) while requiring 33% shorter hydrolysis time. The resulting CNCs demonstrated exceptional thermal stability (315 °C vs. 290 to 300 °C for peel) and adsorption capacity for Pb²⁺ (7.15 mg/g), While recent advanced chemical treatments of potato peel (e.g., intensive esterification, phosphorylation) have reported very high adsorption capacities (e.g., ~217 mg/g for Pb²⁺) for effective drug-carrier functionality, these achievements often come at the cost of process complexity, chemical intensity, and potential impacts on biocompatibility. In contrast, the pulp-derived CNCs achieved effective heavy metal removal, promising drug loading potential through a markedly simpler and less chemically intensive standard sulfation process. This efficiency is attributed to the feedstock’s inherent advantages: a significantly lower lignin content (0.65% vs. 5.2 to 20% in peel) and a high sulfate group density (zeta potential: −39.9 mV), which enhances colloidal stability and available binding sites. Cytotoxicity assays confirmed superior biocompatibility at concentrations up to 2000 µg/mL, outperforming peel-derived CNCs (typically >500 µg/mL).

The feasibility was explored for synergistic addition of coal slime and silica calcium slag for saline-alkali soil improvement. A pot method was used to evaluate the effects on physicochemical properties of saline-alkali soil and wheat growth. The results demonstrated that the density and bulk density of saline-alkali soil were reduced with the synergistic additions, but the water content and the contents of organic matter, nitrogen, phosphorus, and potassium in the soil were increased. The emergence and growth height of wheat seedlings was found to be effectively improved. In terms of the emergence, no matter what proportion of M-G (coal slime: silica calcium slag ratio) was used, the emergence of wheat was greater than 70% when the addition amount was at 20%. In terms of seedling length, when the aggregate addition reached 35%, the high coal slime content (M-G 3:1) did not play a greater role in fostering the development of wheat. Therefore, with M-G 1:1, 35% addition of the soil can meet the growth needs of wheat in the early stage. In summary, the synergistic addition of coal slime and silica calcium slag has a promising application in the field of saline-alkali soil improvement.

Flexible and sustainable electrode platforms are essential for the development of eco-friendly sensing devices. In this work, interdigitated electrodes (IDE) were fabricated via 3D-printed mold using graphene conductive ink on thermoplastic starch (TPS) films derived from sugar palm starch. The TPS films were prepared through solution casting with 30 wt% glycerol as a plasticizer, followed by the casting of graphene conductive ink onto the TPS substrate using 3D-printed molds with finger spacings of 1 to 3 mm. Morphological analysis revealed a well-distributed graphene layer with a thickness of 32.9 µm on the TPS film, which enhances mechanical stability and ensures high electrical conductivity. Electrochemical impedance spectroscopy (EIS) showed that the charge transfer resistance (R_ct) increased from 8.46 × 10⁵ Ω to 3.36 × 10⁶ Ω as electrode finger spacing increased from 1 mm to 3 mm which highlights the influence of gap on electron transfer. These findings confirm that biodegradable TPS substrates combined with graphene inks yield low-cost, flexible, and conductive electrodes with strong potential for electrochemical sensing applications.

Psidium guajava leaf extract was utilized to produce CuO NPs and CuO/ZnO nanocomposites in this work. X-ray diffraction patterns showed the proper phase of the synthesized sample, and using Scherrer’s equation, the mean crystallite sizes were calculated to be 13.05 nm and 13.07 nm for CuO nanoparticles (NPs) and CuO/ZnO nanocomposite, respectively. From transmission electron microscopy images and particle size distribution from ImageJ, the samples had larger sizes of 84.6 nm and 96.6 nm, respectively. Fourier transform infrared (FTIR) spectroscopy also indicated the successful fabrication of the CuO NPs and CuO/ZnO nanocomposite, as the IR spectrum showed peaks at 611 and 521 cm⁻¹ for Cu–O and Zn–O, respectively. The biological activities were found to be higher for the CuO/ZnO nanocomposite than the CuO NPs alone. The inhibition zones recorded were 28 mm and 25 mm for Bacillus. subtilis and Staphylococcus aureus, respectively, followed by 24 mm and 21 mm for Salmonella typhi and Klebsiella pneumoniae, respectively. The nanocomposite exhibited selective cytotoxicity properties because the IC₅₀ values for Wi38 (normal human fibroblast cells) and SKOV3 (human ovarian carcinoma cells) were 295.48 and 81.87 µg/mL, respectively. Antioxidant analysis of (2,2-diphenyl-1-picrylhydrazyl) (DPPH) radical scavenging activity was found to be 6.93 µg/mL for the nanocomposite.

Amid the global energy crisis and the pursuit of carbon neutrality, biomass-derived carbon materials (BDCs) have emerged as promising sustainable candidates for energy applications due to their abundant sources, tailorable hierarchical porosity/heteroatom doping, and remarkable properties. This review systematically summarizes recent advances (2020 to 2025) in BDCs for supercapacitors, secondary batteries (lithium/ sodium/potassium-ion), and electrocatalysis (ORR/OER/HER/CO₂RR). The review focuses on the synthesis-structure-performance correlation, highlighting how pore architecture, heteroatom incorporation, and morphology govern electrochemical performance. Key challenges including precursor inconsistency, imperfect structure control, and scalability in sustainable production are critically assessed. Future prospects are proposed, including machine-learning-guided material design, in situ/operando mechanistic studies, and practical device integration. This work offers insightful guidance for the rational design of BDCs toward practical energy storage and conversion systems.

Precise segmentation of subtle wood defects is crucial for optimizing wood utilization and product value. Despite the prevalence of deep learning in wood defect detection, its deployment in real-world forestry environments is impeded by three primary challenges: 1: The limited capacity of traditional models to represent low-contrast, faint defect features; 2: feature ambiguity caused by complex background interference; and 3: entrapment in local optima because of insufficient global feature integration. To surmount these obstacles, this study proposes WD-SEG (Wood Defect Segmentation), a high-performance model tailored for complex forestry scenarios. The architecture integrates three core modules: an Augmented Feature Network (AFN) to mitigate spatial information loss; a Threshold Filtering Network (TFN), which leverages cosine similarity to adaptively suppress background noise; and a novel Interstellar Collision Optimization (ICO) algorithm to accelerate convergence and bypass local optima. Experimental evaluations on the wood defect training dataset demonstrate that WD-SEG outperforms state-of-the-art models, achieving an Intersection over Union (IoU) of 87.97% and an accuracy of 90.02%. Furthermore, generalization tests on wood defect datasets confirm the model’s robustness, yielding an IoU of 86.50%. By introducing a novel “Enhance-Filter-Accelerate” framework, this study provides a precise, robust solution for automated wood quality inspection in resource-constrained environments.

Effects of microhabitat were studied relative to the growth and fruit yield of Cornus mas L. (Cornelian cherry) populations in a Mediterranean ecosystem. Two contrasting natural habitats were compared: rocky slopes and streamside environments in southwestern Türkiye. A total of 60 mature trees (30 per habitat) were sampled during the 2025 growing season. Tree height, basal diameter, diameter at breast height (DBH), crown diameter, age, fruit number, and total fruit weight were measured to assess growth and yield responses. The results revealed pronounced habitat-related differences in reproductive performance. Trees growing in rocky habitats produced approximately 60% more fruits and 85% higher total fruit yield compared with those in streamside habitats. Analysis of variance indicated that habitat effects were statistically significant (p < 0.05) for most growth and yield traits, except for tree height and crown diameter. Correlation analyses demonstrated strong positive relationships between growth parameters and fruit yield, with basal diameter emerging as the most reliable predictor of reproductive output. Rocky habitats appeared to provide more favorable conditions for fruit production, likely due to improved drainage, enhanced light availability, and reduced interspecific competition. The study provides valuable insights for the sustainable management, conservation, and potential cultivation of C. mas.