Seal Strength Research Articles

Composite PLA films incorporated with micro/nano boron nitride for sustainable food packaging

This study aims to develop polylactic acid (PLA) based composite films with improved mechanical and barrier properties through incorporation of micro boron nitride (BN) and nano boron nitride (NBN). PLA-based films were produced using BN and NBN at varying concentrations (1 – 10% (w/w)), and characterized in terms of physical (color and thickness), mechanical (tensile strength, elongation at break, and heat seal strength), barrier (water vapor transmission rate (WVTR)), antimicrobial, and morphological properties. ΔE and whiteness of the composite PLA films increased, while transparency decreased with increased BN and NBN concentrations. Compared to the control PLA films, the tensile strength of the 1% BN or NBN added films increased by 28% or 40%, respectively. Adding BN and NBN to the PLA matrix significantly reduced the WVTR (p ≤ 0.05). Antimicrobial activity against S. aureus and E. coli was not detected. Multivariate data analysis enabled discrimination of composite PLA films based on simultaneous evaluation of their specific film characteristics. This study reveals the ideal film formulation to produce boron nitride incorporated composite PLA films with proper properties, holding potential to be used as an alternative biodegradable material for sustainable packaging of foods to replace petroleum-based materials.

Upgrading properties and circularity of the recycled flexible polypropylene by developing composites with an optimal combination of a fumed silica and maleated polypropylene copolymer: Influence of the addition of copolymer, type of fumed silica and the silica/copolymer ratio on packaging properties

Rigid polypropylene is mechanically recycled but flexible polypropylene is mostly used in energetic valorization because of the poor properties of the recycled polymer. A recycled polypropylene-based composite with outstanding properties for flexible food packaging was developed. For the first time, the influence of maleated polypropylene copolymer addition and the fumed silica/copolymer ratio on the packaging properties of recycled flexible polypropylene under the effects of silica hydrophilicity was investigated. The structural, morphological, thermal, mechanical, melt flow, overall migration, water vapor barrier and sealing properties of the developed nanocomposites were analyzed. Prominently, the addition of 1:1 maleated polypropylene and hydrophobic nanosilica improved the global performance of all tested methods. The recycled polypropylene had an overall migration to olive oil of 17 mg dm−2, exceeding the limit allowed for food packaging, but the developed added-value composite reduced it to the tolerance limit according EU legislation. The seal strength was drastically increased by 50 % with adhesive peeling, high thermal stability, and well-dispersed particles without affecting the ductility.

Thermal and heat-sealing properties of polyvinyl alcohol/cellulose nanocrystals-based nanocomposites for food packaging

Food packaging materials require advanced properties (UV barrier and antioxidant/antimicrobial) to extend the shelf-life of packaged products. Recently, we have developed biodegradable nanocomposites by incorporating cellulose nanocrystals (CNCs) and active agents (titanium dioxide nanoparticles and apple peel extract) into polyvinyl alcohol (PVA). These nanocomposites exhibited advanced properties and many demonstrable advantages in food packaging. Herein, the thermal stability, melting behaviors, and heat-sealing properties of these nanocomposites are investigated to demonstrate their potential production at the industrial level and practical use. The results showed that the PVA/CNC-based nanocomposites exhibited thermoplastic properties and had sufficient heat-sealability. The PVA/CNC-based nanocomposites presented lower melting temperatures (217.7–224 °C) than pure PVA (226 °C). Furthermore, their seal strengths (15.1–1238.1 N/m) are similar to those of petroleum-based food packaging polymers (polypropylene: 300–1100 N/m, low-density polyethylene: 677.7 N/m) and can be controlled by adjusting the sealing temperature, which is useful for various food packaging applications.

Development of a Biopolymer-Based Anti-Fog Coating with Sealing Properties for Applications in the Food Packaging Sector.

The quest for sustainable and functional food packaging materials has led researchers to explore biopolymers such as pullulan, which has emerged as a notable candidate for its excellent film-forming and anti-fogging properties. This study introduces an innovative anti-fog coating by combining pullulan with poly (acrylic acid sodium salt) to enhance the display of packaged food in high humidity environments without impairing the sealing performance of the packaging material-two critical factors in preserving food quality and consumers' acceptance. The research focused on varying the ratios of pullulan to poly (acrylic acid sodium salt) and investigating the performance of this formulation as an anti-fog coating on bioriented polypropylene (BOPP). Contact angle analysis showed a significant improvement in BOPP wettability after coating deposition, with water contact angle values ranging from ~60° to ~17° for formulations consisting only of poly (acrylic acid sodium salt) (P0) or pullulan (P100), respectively. Furthermore, seal strength evaluations demonstrated acceptable performance, with the optimal formulation (P50) achieving the highest sealing force (~2.7 N/2.5 cm) at higher temperatures (130 °C). These results highlight the exceptional potential of a pullulan-based coating as an alternative to conventional packaging materials, significantly enhancing anti-fogging performance.

Strategic Oversight and Quality Validation in Spice Production Enhancement

This study examines the effectiveness of a comprehensive control management and quality control system in the seasoning production process, focusing specifically on a menu-specific seasoning variant (MSS). The methodology encompassed various stages including material acceptance, sieving, mixing, and final packaging, integrated with stringent control measures such as equipment and facility cleaning, material separation, and machine maintenance. Quality control tests conducted included sodium chloride content, pH analysis, seal strength, and bubble tests. Results indicate that these systematic processes significantly enhance product quality by ensuring compliance with predefined quality standards. The implications of this study suggest that rigorous process oversight and detailed quality assessments can markedly improve the reliability and safety of food seasoning products, providing a framework for industry-wide best practices. Highlights: Process Management: Systematic control measures, including equipment and facility cleaning, ensure a contamination-free production environment. Quality Control: Rigorous testing, including sodium chloride content and pH analysis, guarantees that the products meet established quality and safety standards. Product Compliance: Implementation of advanced control and quality assurance protocols ensures that products consistently comply with industry standards. Keywords: Instant Seasoning, Quality Control, Safety Standards

Alaska Pollock-derived Gelatin Sealant has Higher Sealing Strength than, and Comparable Biocompatibility with, Fibrin Sealant in Porcine and Rat Dural Injury Models.

Burst strength study in porcine dural models and functional and histological study in rat dural models. This study aimed to investigate the sealing strength and biocompatibility of Alaska pollock-derived gelatin (ApGltn) and fibrin sealants in disrupted dural injuries. Disruption of the dura mater occurs during spine surgery, leading to cerebrospinal fluid leakage. Fibrin sealant is usually applied to ruptured sites; however, it lacks sealing strength. A novel biocompatible sealant composed of ApGltn was recently demonstrated to have good burst strength and biocompatibility in the porcine aorta. Ten porcine dura maters with central holes were covered with ApGltn and fibrin sealants (five samples per group). The maximum burst strength of each sealant was measured, and histological examination was performed after burst testing. Twenty-seven dura maters of male Wistar rats were used for functional and histopathological evaluations. The rats were treated with three surgical interventions: defect + ApGltn sealant; defect + fibrin sealant; defect alone (nine rats per group). Macroscopic confirmation of the sealant, hindlimb motor function analysis, and histopathological examination were performed at 2, 4, and 8 weeks after the procedure. The maximum burst strength of the ApGltn sealant was approximately 4.4 times higher than that of the fibrin sealant (68.1±12.1 vs. 15.6±8.7mmHg; P<0.001). Histological examination confirmed that the ApGltn sealant showed tight adhesion to the dural surface, whereas a gap was observed between the fibrin sealant and the dura mater. In the rat model, the ApGltn sealant resulted in spinal function and dural histological findings similar to those of the fibrin sealant. The ApGltn sealant had a higher sealing strength than, and comparable effect on dura regeneration with, the fibrin sealant.

Formulating PBS/PLA/PBAT blends for biodegradable, compostable packaging: The crucial roles of PBS content and reactive extrusion

The use of biodegradable polymers such as Poly (lactic acid) (PLA), Poly(butylene succinate) (PBS), and Poly(butylene adipate-co-terephthalate) (PBAT) is constantly increasing to try to substitute non-biodegradable plastics. Blending is a viable option to improve the morphology and the mechanical and heat resistance properties of biodegradable polymers. Thus, in this work, a biodegradable and compostable PLA/PBAT blend was improved by adding PBS, leading to non-reactive, melt-mixed PLA/PBAT/PBS ternary blends. The PLA/PBAT ratio was fixed at 1:1, while the PBS varied from 0 to 40 wt%. Polarized Light Optical Microscopy (PLOM) imaging showed that micro-spherulitic PBS was localized at the interface between PLA and PBAT in the blend, acting as a compatibilizer, reducing the interfacial tension and refining the ternary blend's morphology. Consequently, the mechanical properties improved, such as the elongation at break, which increased from 70 to 300 %. However, these tertiary non-reactive blends were found to lack adequate rheological properties to be processed by blown film extrusion. Therefore, reactive blending was performed by adding peroxide and carbodiimide, leading to a finer morphology and improved rheological properties. Thus, these reactive blends were successfully processed by blown film extrusion. Two types of blown films were produced, Tubular and Champagne films (DDR/BUR ratio of 37.6 and 5.2, respectively). Both types of blown films exhibited adequate ductile mechanical properties for film packaging applications, as well as high seal strength and good thermal resistance. In addition, their specific mechanical properties were a function of blend composition and the degree of biaxial orientation produced during the extrusion-blowing process.

Improvement of heat-sealing strength of chitosan-based composite films and product costs analysis in the production process

The primary objective of this study was to enhance the heat-sealing strength of composite films made from chitosan and analyze the associated product costs. The approach adopted involved formulating chitosan-based composite films by incorporating gelatin and green seaweed extract. This strategic combination resulted in a notable improvement in heat-sealing strength. The ensuing attributes underwent meticulous examination, encompassing seal strength, FTIR spectroscopy, FE-SEM surface morphology analysis, and DSC thermal properties determination. Data analysis was rigorously conducted using the SPSS program, with outcomes presented as mean values accompanied by standard deviations. Disparities were discerned at a 95% confidence level, ensuring statistical robustness. The findings unveiled that the incorporation of 10% gelatin and 1% green seaweed extract substantially enhanced the seal strength of the chitosan-based composite films. Notably, the introduction of green seaweed extracts disrupted interactions between chitosan's structure and various molecular vibrations. This disruption, coupled with increased ionic interactions and hydrogen bonding, led to improved molecular interdiffusion, ultimately resulting in modified heat sealability. The study identified the optimized conditions as 10% gelatin and 1% green seaweed extract concentrations, which produced the highest seal strength at 19.4 N/m. Further evidence from scanning electron microscopy demonstrated improved interfacial adhesion, attributed to the adjusted surface morphology. The film surface did not contain small scattered particles and presented a smooth phase. This suggests that the chitosan-based composite achieved good interfacial adhesion between the two components in these films. As an essential aspect for practical application, the total production cost of the films was determined to be 606.84 baht. This information renders the data collection from the study valuable for companies seeking to enhance production efficiency and overall profitability.

Comparison of Marginal Seal and Tensile Bond Strength of an Alkasite, Zircomer, and Bulk Fill Composite to Carious Affected Primary Molars

Assessment of the micro tensile bond strength (μTBS) and microleakage of contemporary restorative materials (Cention N cement (CN), Bulk-fill Resin-based composite (BF-RBC), and Zirconomer Improved) bonded to carious affected dentin (CAD) of primary molars as compared to conventional control Glass ionomer cement (GIC). Eighty human primary molars having scores 4 and 5 of the International Caries Detection and Assessment System (ICDAS) were included. Specimens were randomly allocated into four groups (n = 20) Group I = GIC, Group 2: Zirconomer Improved, Group 3: CN, and Group 4: BF-RBC. All the samples were thermocycled followed by marginal leakage, μTBS, and failure mode assessment using a dye penetration test, universal testing machine, and a stereomicroscope. The μTBS and microleakage results were examined using (ANOVA) and Tukey post hoc tests. Samples from Group 1 (GIC) revealed the highest value of marginal leakage (30.55±10.31 nm) and the lowest recorded value of μTBS (12.28±0.32 MPa). In contrast, the specimens from Group 3 (CN) demonstrated the lowest levels of microleakage (14.89±4.33 nm) and highest bond integrity (18.12±0.79 MPa). Cention N cement and Bulk-fill composite have shown to be reliable options as a restorative material in primary dentition due to their superior tensile bond strength and reduced marginal leakage scores when applied to caries-affected dentin.

Degradation behavior of multilayer pouches containing liquid and powder hot sauce for Meal, Ready-to-Eat (MRE) rations

Hot sauce is a highly desired condiment by Warfighters. This research investigates possible multilayer Meal, Ready-to-Eat (MRE) ration packaging films for hot sauce, focusing on performance and characterization of film degradation. Four films were made into pouches for an accelerated storage study at 80°F and 100°F with hot sauce (liquid and powder) and water as a control. For a comprehensive examination of the unique characteristics presented by the innermost layers, particularly linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), and polypropylene (PP), evaluations were conducted on the mass, thickness, morphology, chemical composition of the innermost layer, barrier performance, and seal strength of each type of pouch at one, six, and 12 months. Sensory tests evaluated the food quality of hot sauce. Liquid hot sauce caused delamination of two pouch structures after one month of storage at both storage temperatures. At 12 months, liquid and powder hot sauce delaminated another pouch structure at 80°F, reducing its seal strength by 62 % and 24 %, respectively. Only one pouch structure exhibited no notable degradation at 12 months, and hot sauce quality was effectively preserved. This research provides a comparative analysis of the effects of liquid and powder hot sauce on multilayer pouches, offering new insights into how hot sauce induces degradation in these pouches, which could guide future design of MRE ration packaging.

Investigation of microstructure and mechanical properties in dissimilar-metal welding between ferritic stainless steel and Co-based superalloy using electron beam welding

This research investigates the relationship between the microstructure and mechanical properties of electron beam welding joints, with a particular emphasis on the influence of varying electron beam currents on AISI 410L stainless steel plates and NS163 Co-based superalloy wires, which is a rare and novel form of welding. An increase in beam current led to a gradual transformation of the weld microstructure from columnar to equiaxed grains, creating finer and more homogeneous grains. Macrosegregation was also observed, a consequence of the liquidus temperature difference between the weld metal (WM) and base metal (BM). The segregation structure exhibited irregularly shaped beaches near the fusion line and islands of unmixed and partially mixed NS163 within the WM. This phenomenon was more pronounced in samples with a lower beam current. Given the limitations in BM shape and WM size, nanoindentation was employed to characterize the strength of welded joints. In conjunction with microhardness measurements, it was confirmed that the weld is strengthened under different electron beam currents, with higher current resulting in a more significant strengthening effect. This study also underscores the value of nanoindentation in evaluating the weld strength of brush seals without destruction.

Development and characterization of cinnamon essential oil incorporated active, printable and heat sealable cellulose nanofiber reinforced hydroxypropyl methylcellulose films

Cellulose nanofiber (CNF) reinforced hydroxypropyl methylcellulose (HPMC) films were incorporated with antioxidant cinnamon essential oil (CEO) to develop active, printable, and heat-sealable films. CEO was carried into the films via three types of active systems: β-cyclodextrin (β-CD) encapsulation, cellulose nanocrystal (CNC) Pickering emulsion (CNC-P), or the combination thereof (CNC-P/β-CD). The films were characterized for their mechanical, physicochemical, structural, thermal, and optical properties along with CEO release, printability, and heat seal strength. The Control film (without active CEO) and CNC-P film showed the highest transparency, 17.02% and 18.17%/mm, respectively, followed by the CNC-P/β-CD (12.86%/mm) and β-CD (11.68%/mm) films. A significant difference (P < 0.05) in water vapor permeability (WVP) was observed between the Control film stored at 33% RH (72.01 g mm/m2 d kPa) and 53% RH (54.45 g mm/m2 d kPa) whereas no difference in WVP for β-CD, CNC-P, and CNC-P/β-CD films under RH range of 33–84% (P > 0.05). The presence of active CEO in the films enhanced the moisture barrier and stability of films without influencing the mechanical and thermal properties of the films. The CEO incorporated films via both CNC Pickering emulsion and β-CD encapsulation prolonged the release of CEO. All CEO incorporated films were printable by inkjet and stamp inks and showed good heat seal strength (∼61–73 N/m). This study provided new strategies to develop cellulose-based active films with extended antioxidant function and sealable and printable properties to replace single-use plastic packaging for various food, especially high-fat food items.

How displacement analysis may aid fault risking strategies for CO2 storage

AbstractDeveloping an accurate understanding of the ways in which faults have grown within a particular region and stratigraphy can aid risk management for CO2 storage sites. Areas of fault interaction lead to differences in the stress field, resulting in an increased strain, which is often accommodated by a high intensity of deformation bands and/or fracturing, dependent on host rock properties. These structures alter the permeability surrounding faults. Hence, detecting areas of interaction of structures throughout the fault growth history allows the identification of locations where high risk may occur in terms of the hydraulic properties of a fault zone. The Vette Fault Zone (VFZ), bounding the Alpha prospect within the potential CO2 Smeaheia storage site, Northern Horda Platform, is shown to have grown from a minimum of seven fault segments. By utilising a comparison with the adjacent Tusse Fault Zone (TFZ), we can identify potential areas of high risk, where fluids may have the ability to flow across or along the VFZ. The high seal strength of the TFZ holding back a large gas column is likely to be created by shale juxtaposition and smearing with cataclastic processes. The same could be assumed for the VFZ, associated with similar tectonics and displaced stratigraphy. However, rather than membrane breaching causing fluids to flow across the fault, potential areas of high risk have been identified at locations of relict breached relay zones, where the initial displacement of the intersecting faults and area of overlap was high. These areas appear to correspond with the location of hydrocarbon contact depth (spill point) along the TFZ. Using the same assumptions for the VFZ, we can observe one potential area of high risk, which lies within the area of suggested CO2 accumulation.

Relationships between Lip Seal Strength, Tongue Pressure, and Daytime Sleepiness in Japanese Workers: A Cross-Sectional Study.

This cross-sectional study aimed to examine the relationships between lip seal strength, tongue pressure, and daytime sleepiness in Japanese workers. A self-administered questionnaire which comprised the Epworth Sleepiness Scale (ESS) was completed by 496 workers, and excessive daytime sleepiness was defined by an ESS score of 11 or over. Lip seal strength and tongue pressure were measured in all participants, and multiple regression analyses were performed to examine the effects of lip seal strength and tongue pressure on daytime sleepiness. The median ESS score was 5.0 (25th and 75th percentiles: 2.0 and 8.0), and 42 (8.5%) workers had excessive daytime sleepiness. The median lip seal strength was 13.5 N (11.4, 16.3), and the tongue pressure was 41.7 kPa (35.2, 48.3). Workers with higher ESS scores had significantly lower levels of lip seal strength than those without, following adjustments for age and body mass index (BMI) values (β (95% confidence interval): -0.043 [-0.081, -0.004]). However, tongue pressure was not significantly associated with ESS score after adjustments for age and/or BMI. These results suggest that maintaining moderate lip seal strength may help prevent excessive daytime sleepiness in Japanese workers regardless of age or BMI.

Development and characterization of edible films based on flaxseed gum incorporated with Piper betle extract

There has been a shift from use of petroleum-based plastics, causing serious environmental pollution, towards innovative and biodegradable edible packaging. The present study documents the development of composite edible films based on the flaxseed gum (FSG) modified by the incorporation of betel leaf extract (BLE). The films were assessed for physicochemical, mechanical, morphological, thermal, antimicrobial and structural characteristics. Scanning electron microscopy images indicated that the roughness decreased with an increase in BLE concentration. The water vapor permeability of the FSG-BLE films ranged from 4.68 to 1.59 × 10−9 g s− 1 m− 2 Pa− 1, lower than that of the control sample (6.77 × 10−9 g s− 1 m− 2 Pa− 1). The BLE4 (containing 10 % BLE) films had the highest tensile strength of 32.46 MPa compared to the control sample (21.23 MPa). Similarly, EAB and seal strength of the films incorporated with BLE were ameliorated. X-ray diffraction pattern and FTIR illustrated the shift of amorphous to crystalline behavior and a significant interaction among the BLE and FSG functional groups. Furthermore, the thermal stability of the treated films was not affected significantly however, they showed improved antimicrobial activity with the highest diameter of inhibition zone in the BLE4 sample. This study concluded that the FSG-BLE composite films (BLE4 in particular) can be considered as novel packaging material for food conservation coupled with a potential to enhance the shelf life of perishable food products.

Characterization and qualitative evaluation of cassava starch-chitosan edible food wrap enriched with culinary leaf powders for eco-friendly food packaging applications.

Cassava starch-based edible food wraps were prepared by incorporating leaf powder from Indian curry leaf and Malabar bay leaf, reinforced with different (0.2, 0.4, 0.6, 0.8) wt.% of chitosan. Eleven combinations of films were prepared and their sensory acceptability, physical properties, Fourier-transform infrared spectroscopic (FTIR) spectrum, and scanning electron microscopy (SEM) image, were evaluated. The thickness of the films ranged from 0.198 ± 0.12 to 0.372 ± 0.27 mm. Tensile strength was reported to be the highest (40.71 ± 1.21 MPa) in the curry leaf powder incorporated sample. Maximum elongation at break was reported by bay leaf powder incorporated (5.8 ± 1.59%) sample. The Young's modulus values were observed to be increasing along with the concentration of chitosan. Maximum seal strength values were reported by curry leaf powder incorporated film with 0.8% chitosan (2.93 ± 0.22 N/mm). The leaf powder incorporated samples reported a higher flavonoid content compared to the control. The color analysis (L*, a*, b*) of the films was identical to the natural leaf color. The SEM images indicated a rough texture for the leaf powder incorporated films. The FTIR evaluation confirmed the presence of the respective functional groups. The statistical evaluation done by statistical package for social sciences software showed that all the data were significantly different (P ≤ 0.05.). The study demonstrated the potential of incorporation of leaf powder and chitosan to enhance the properties of starch-based edible packaging.

Morphological, water barrier and biodegradable properties of sugar palm nanocellulose/starch biopolymer composites incorporated with cinnamon essential oils

Abstract In the past few decades, there has been increased interest in the use of natural fibers as reinforcement in bioplastic polymer composites because it is biodegradable. This is a result of the drawbacks of biodegradable polymer-based materials, which are brittle, intractable, and poorly water-sensitive. Natural fibers are chosen because they may be obtained organically, can be collected safely, and can be less expensive. In this work, cinnamon essential oil (CEO)/sugar palm nanocellulose/starch biopolymer composites were casted to investigate the morphological, water barrier and biodegradable properties. From the research, it shows water absorption increased regarding the plasticizer concentration. Besides, water vapor permeability (WVP) and solubility of the different concentration plasticizer used in the biopolymer shows an increasing trend due to high water content. All films degrade completely after the 12th day indicating the biodegradability of the film. Furthermore, seal strength for the lower concentrations of plasticizer shows the higher strength, while GS4.5 cannot be sealed due to high water contents. The images show the compatible films with slightly yellowish and transparent films. The variation of plasticizers did not affect the antibacterial activity of CEO inside the film forming solution. Overall, cinnamon essential oil (CEO)/sugar palm nanocellulose/starch biopolymer composites are good potential to enhance their suitability for food packaging applications.

A study of the impact of high-speed sealing parameter gradients on the seal strength in a multilayer polypropylene film

Multilayer polymer films continue to be used in food packaging high-speed lines; this research focuses on obtaining better film adhesion under controlled sealing conditions. The present work aims to describe the presence of temperature gradients in the body of the sealing jaw, the dwell time gradients, and the surface pressure gradients, experimenting with a high-speed sealing process. The samples’ adhesion was measured using the peeling test, and the peeling graphs of the tests were analyzed to observe the differences and similarities of each sealing parameter combination. Experimental data were used to generate the surface response families of the seal strength of multilayer polymer film. The model describes, in a 3D space, the influence zones that sealing parameter gradients had on the seal strength. The surface model and experimental data indicate that temperature is a decisive parameter of seal strength.

Heat‐sealing and microscopic evaluation of paper‐based coated materials using various seal bar geometries in vertical form fill seal machine

AbstractWith the growing emphasis on minimization of global plastic waste, flexible fibre‐based packaging has gained significant interest over the past few years. Heat‐sealing technology is commonly applied for vertical form‐fill‐seal machine to provide tight closure of packages for maintaining food quality and shelf life. Several different seal bar geometries and adequate heat‐seal parameters are required to improve the seal tightness of the packages. This study aims to compare the heat sealability of thermoplastic film (OPP/PE) and paper‐based materials in vertical form‐fill‐seal machine using various seal bar profiles. The investigation includes seal strength measurement, understanding the causes of leak formation, seal tightness and inspection of the seal using scanning electron microscopy. Results reveal that OPP/PE material has exceptional seal strength and leakproof ability compared with paper‐based materials. However, it has limited operating window because the material shrinks and coarsens at approximately 140°C. Sealing temperature and dwell time are found to be the major factors affecting the seal strength of paper‐based material. Results reveal the PE‐coated papers exhibit nearly twice the seal strength compared with the dispersion‐coated paper. It was difficult to achieve good hot‐tack values with dispersion‐coated paper. During testing, all the paper‐based materials experience delamination and fibre tear, and its severity increases with the increasing material grammage. As plateau temperature is reached, the fibre delamination remains relatively constant. The serrated geometry of seal bar design plays a significant role in providing a satisfactory airtight seal, particularly around the pouch's layer jump. However, flat seal bar designs are not recommended for gas tight applications for paper‐based materials.

Reduced lip seal strength and missing teeth are associated with poorer masticatory performance in young adults with intellectual disabilities: a cross-sectional analytical study.

Alterations in oral health have a negative impact on the quality of life of persons with intellectual disabilities (PwIDs). Chewing is a process that influences and determines optimal oral health. However, little is known about how intellectual disability (ID) affects masticatory performance. This study aimed to analyse the differences in masticatory performance between young adults with IDs, young adults without IDs and older adults without IDs. A cross-sectional analytical design was used. The masticatory performance was evaluated with a chewing gum validated instrument. In addition, the labial and tongue strength was assessed with the Iowa Oral Performance Instrument. We compared the masticatory performance between groups using one-way analysis of covariance. Body mass index, muscle mass, missing teeth, lip strength and tongue strength were included as separate covariates. A multivariate regression analysis was performed to identify which independent variables could explain masticatory performance in each group. Thirty-two PwIDs, 31 young adults without IDs and 32 older adults without IDs were recruited. PwIDs showed poorer masticatory performance compared with older adults (mean difference: -3.06, 95% confidence interval: -3.87 to -2.26) and healthy controls (mean difference: -2.38, 95% confidence interval: -3.19 to -1.57). The analysis of covariance showed significant difference between groups in the masticatory performance (F=47.35, P<0.001, ηp 2 =0.507). Missing teeth (P<0.001), right lip strength (P=0.025) and tongue strength (P=0.007) as covariables showed a significant interaction with the model. In the PwID group, lip strength and lack of teeth explained 58% of the variance in masticatory performance (R2 =0.580, standard error=1.12, P<0.001). Persons with intellectual disabilities have a poorer masticatory performance than adults without IDs. Our findings indicate that the primary determinants of optimal masticatory function in PwIDs are the strength of the lip seal and the number of missing teeth.