Pub Date : 2024-09-12DOI: 10.1177/0021955x241281655
Roberto González-Navarrete, Agustín Vidal-Lesso, Héctor Plascencia-Mora, Juan F Reveles-Arredondo
The triply periodic minimal surface structures remain issues for attention, offering advantages such as high porosity and a significant surface area to volume, which are important in applications related to bioengineering, heat exchangers, energy absorption, among others. In this work, the elastic modulus and structural response of the I-WP cellular structure were studied for several relative densities through Gibson-Ashby model, numerical modeling, and experimental test. The constants C and n for the Gibson-Ashby model were estimated and exhibited an approximate common value at different relative densities. The constants exhibit good correlation with experimental results from relative densities of 30%, 50%, and 60%; and accurately predict the elastic modulus for densities of 55% and 70% with low errors of 3.09% and 9.89%, respectively. The constant values for C and n, indicate a mixed mode of deformation with bending as the primary governing factor. The combination of Hooke’s law and the Gibson-Ashby model provided a practical approach for predicting the reaction force with errors ranging from 1.98% to 15%. These findings contribute to providing C and n constants to understand the elastic modulus and structural response of the I-WP cellular structure and offer valuable insights for material design and engineering applications. In addition, the validated models provide an efficient procedure for predicting material behavior under compression conditions, saving time and resources compared to full-scale experimental testing. Overall, this study offers potential for further research in mechanical properties analysis.
三周期最小表面结构具有高孔隙率和显著的表面积与体积比等优点，在生物工程、热交换器、能量吸收等相关应用中具有重要意义，因此仍然是值得关注的问题。在这项工作中，通过吉布森-阿什比模型、数值建模和实验测试，研究了 I-WP 蜂窝结构在几种相对密度下的弹性模量和结构响应。对 Gibson-Ashby 模型的常数 C 和 n 进行了估算，并在不同相对密度下显示出近似的共同值。这些常数与相对密度为 30%、50% 和 60% 时的实验结果具有良好的相关性，并能准确预测密度为 55% 和 70% 时的弹性模量，误差分别为 3.09% 和 9.89%。C 和 n 的恒定值表明了以弯曲为主要控制因素的混合变形模式。胡克定律和吉布森-阿什比模型的结合为预测反作用力提供了一种实用的方法，误差在 1.98% 到 15% 之间。这些发现有助于提供 C 和 n 常量，以了解 I-WP 蜂窝结构的弹性模量和结构响应，并为材料设计和工程应用提供有价值的见解。此外，经过验证的模型为预测压缩条件下的材料行为提供了有效的程序，与全面的实验测试相比，节省了时间和资源。总之，这项研究为力学性能分析方面的进一步研究提供了潜力。
{"title":"I-WP geometry structural assessment: A theoretical, experimental, and numerical analysis","authors":"Roberto González-Navarrete, Agustín Vidal-Lesso, Héctor Plascencia-Mora, Juan F Reveles-Arredondo","doi":"10.1177/0021955x241281655","DOIUrl":"https://doi.org/10.1177/0021955x241281655","url":null,"abstract":"The triply periodic minimal surface structures remain issues for attention, offering advantages such as high porosity and a significant surface area to volume, which are important in applications related to bioengineering, heat exchangers, energy absorption, among others. In this work, the elastic modulus and structural response of the I-WP cellular structure were studied for several relative densities through Gibson-Ashby model, numerical modeling, and experimental test. The constants C and n for the Gibson-Ashby model were estimated and exhibited an approximate common value at different relative densities. The constants exhibit good correlation with experimental results from relative densities of 30%, 50%, and 60%; and accurately predict the elastic modulus for densities of 55% and 70% with low errors of 3.09% and 9.89%, respectively. The constant values for C and n, indicate a mixed mode of deformation with bending as the primary governing factor. The combination of Hooke’s law and the Gibson-Ashby model provided a practical approach for predicting the reaction force with errors ranging from 1.98% to 15%. These findings contribute to providing C and n constants to understand the elastic modulus and structural response of the I-WP cellular structure and offer valuable insights for material design and engineering applications. In addition, the validated models provide an efficient procedure for predicting material behavior under compression conditions, saving time and resources compared to full-scale experimental testing. Overall, this study offers potential for further research in mechanical properties analysis.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"28 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-10DOI: 10.1177/0021955x241281880
Fabrizio Errichiello, Daniele Amato, Mario Penati, Ernesto Di Maio
In this work, we used a 3D scanner for the volume measurement of foamed samples, a long-standing problem in the density evaluation of foams. The 3D scanning density measurement method can be selected as an alternative to or in combination with well-established, classical methods that involve the use of instruments like a caliper, a pycnometer, or other devices based on displacement or flotation principles. In particular, the classical methods show some limitations when the foamed sample geometry is irregular, when the polymer is highly hygroscopic, and when it has open porosities. We have tested numerous foamed samples of different sizes, shapes, densities, materials, and morphologies. We utilized different 3D scanner configurations for their volume measurement and compared the results with geometrical and displacement methods, when possible. Results showed that the proposed method is highly accurate, reproducible, and simple, although some specific precautions should be put in place to avoid misinterpretation by the shape-reconstructing software.
{"title":"Foam density measurement using a 3D scanner","authors":"Fabrizio Errichiello, Daniele Amato, Mario Penati, Ernesto Di Maio","doi":"10.1177/0021955x241281880","DOIUrl":"https://doi.org/10.1177/0021955x241281880","url":null,"abstract":"In this work, we used a 3D scanner for the volume measurement of foamed samples, a long-standing problem in the density evaluation of foams. The 3D scanning density measurement method can be selected as an alternative to or in combination with well-established, classical methods that involve the use of instruments like a caliper, a pycnometer, or other devices based on displacement or flotation principles. In particular, the classical methods show some limitations when the foamed sample geometry is irregular, when the polymer is highly hygroscopic, and when it has open porosities. We have tested numerous foamed samples of different sizes, shapes, densities, materials, and morphologies. We utilized different 3D scanner configurations for their volume measurement and compared the results with geometrical and displacement methods, when possible. Results showed that the proposed method is highly accurate, reproducible, and simple, although some specific precautions should be put in place to avoid misinterpretation by the shape-reconstructing software.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"1 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1177/0021955x241281878
Michelle S Hoo Fatt, Anudeep R Vedire, Akshay K Pakala
Experiments were conducted to characterize the mechanical behavior of Divinycell PVC foams over a wide range of environmental temperatures, from −60 to +80°C. Transversely isotropic properties of the foams, including modulus, strength, and ductility, were found to vary with temperatures between the ductile-to-brittle transition temperature (−60 to −50°C) and just under the glass transition temperature (95 to 100°C). The elastic modulus and yield strength decreased linearly as the temperature increased from −60 to +80°C. Compressive strength also decreased steadily with increasing temperature over the entire temperature range. In contrast, tensile and shear strengths only showed a significant decrease in values as the temperature rose above 23°C (room temperature). Below 23°C, there was a minor change in tensile and shear strengths. Tensile and shear ductility decreased sharply as the temperature decreased from +80°C to −40°C and stabilized between −60 and −40°C, which is close to the ductile-to-brittle transition region. Fractography of the tensile and shear fracture surfaces confirmed brittle fracture at −60°C and ductile tearing at +60°C. Equations were derived to predict modulus, yield strength, compressive, tensile and shear strengths, and ductility at any temperature in terms of room temperature values.
{"title":"Effect of temperature on the mechanical behavior of pvc foams","authors":"Michelle S Hoo Fatt, Anudeep R Vedire, Akshay K Pakala","doi":"10.1177/0021955x241281878","DOIUrl":"https://doi.org/10.1177/0021955x241281878","url":null,"abstract":"Experiments were conducted to characterize the mechanical behavior of Divinycell PVC foams over a wide range of environmental temperatures, from −60 to +80°C. Transversely isotropic properties of the foams, including modulus, strength, and ductility, were found to vary with temperatures between the ductile-to-brittle transition temperature (−60 to −50°C) and just under the glass transition temperature (95 to 100°C). The elastic modulus and yield strength decreased linearly as the temperature increased from −60 to +80°C. Compressive strength also decreased steadily with increasing temperature over the entire temperature range. In contrast, tensile and shear strengths only showed a significant decrease in values as the temperature rose above 23°C (room temperature). Below 23°C, there was a minor change in tensile and shear strengths. Tensile and shear ductility decreased sharply as the temperature decreased from +80°C to −40°C and stabilized between −60 and −40°C, which is close to the ductile-to-brittle transition region. Fractography of the tensile and shear fracture surfaces confirmed brittle fracture at −60°C and ductile tearing at +60°C. Equations were derived to predict modulus, yield strength, compressive, tensile and shear strengths, and ductility at any temperature in terms of room temperature values.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"16 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142219390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-29DOI: 10.1177/0021955x231225383
Xiangbo Shu, Huifeng Xi, Xiaogang Wang, Shiqing Huang, Bowei Wang
This paper presents the preparation of a partially open-cell and partially closed-cell flexible polyurethane foam material (flex-PUF), which exhibits improved cushioning performance compared to conventional protective materials. Hollow Glass Microspheres (HGM) were used as a filling material to enhance the compressibility of the material. In order to investigate the effects of HGM on the multi-impact protection and vibration damping performance of flex-PUF with different thicknesses, flex-PUF samples filled with varying volume fractions of HGM were subjected to multi-impact testing and dynamic viscoelasticity experiments. The destructive mechanism of HGM under impact was observed using scanning electron microscopy (SEM). The experimental results revealed that, under the same impact energy conditions, filling flex-PUF with HGM reduced the maximum impact displacement while enhancing energy absorption, although at the expense of cushioning performance. As the number of impact increases, the stiffness of flex-PUF decreased. In the vibration experiments, as the frequency increased, the proportion of flex-PUF’s viscous damping energy dissipation decreases.
{"title":"Preparation and energy absorption of flexible polyurethane foam with hollow glass microsphere","authors":"Xiangbo Shu, Huifeng Xi, Xiaogang Wang, Shiqing Huang, Bowei Wang","doi":"10.1177/0021955x231225383","DOIUrl":"https://doi.org/10.1177/0021955x231225383","url":null,"abstract":"This paper presents the preparation of a partially open-cell and partially closed-cell flexible polyurethane foam material (flex-PUF), which exhibits improved cushioning performance compared to conventional protective materials. Hollow Glass Microspheres (HGM) were used as a filling material to enhance the compressibility of the material. In order to investigate the effects of HGM on the multi-impact protection and vibration damping performance of flex-PUF with different thicknesses, flex-PUF samples filled with varying volume fractions of HGM were subjected to multi-impact testing and dynamic viscoelasticity experiments. The destructive mechanism of HGM under impact was observed using scanning electron microscopy (SEM). The experimental results revealed that, under the same impact energy conditions, filling flex-PUF with HGM reduced the maximum impact displacement while enhancing energy absorption, although at the expense of cushioning performance. As the number of impact increases, the stiffness of flex-PUF decreased. In the vibration experiments, as the frequency increased, the proportion of flex-PUF’s viscous damping energy dissipation decreases.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"56 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-25DOI: 10.1177/0021955x241246066
Louise Le Barbenchon, Jean-Benoît Kopp
Research on nanocellular foams is motivated in part by the promise of physical properties, in particular mechanical properties, that can go beyond the classical mechanical framework. However, due to the difficulty in obtaining foams of a given density but different cell sizes, determining the effect of cell size on the mechanical properties of polymer foams remains a challenge. To overcome this difficulty, studies on the mechanical behaviour of mesocellular, microcellular and nanocellular polymer foams have been compiled in this review article. After describing the different cellular structures between meso-, micro- and nanocellular foams, the mechanical properties are examined as a function of relative density and cell size. It is shown that for small strains and at low strain rates, nanocellular foams exhibit mechanical behaviour predicted by the Gibson and Ashby model. Relative density remains the first important factor to be taken into account when studying the Young’s modulus and buckling stress of nanocellular foams. The focus then shifts to fracture properties, as microcellular foams have already been shown to be far superior to more conventional foams. As studies are still scarce and different methodologies have been used, no general conclusions can be drawn. However, the fracture and impact properties could be greatly improved by this change in scale. The local confinement of molecular chains in polymeric nanocellular foams or the relaxation of the triaxial stress state in front of the crack tip could explain these observations.
{"title":"A review on the mechanical behaviour of microcellular and nanocellular polymeric foams: What is the effect of the cell size reduction?","authors":"Louise Le Barbenchon, Jean-Benoît Kopp","doi":"10.1177/0021955x241246066","DOIUrl":"https://doi.org/10.1177/0021955x241246066","url":null,"abstract":"Research on nanocellular foams is motivated in part by the promise of physical properties, in particular mechanical properties, that can go beyond the classical mechanical framework. However, due to the difficulty in obtaining foams of a given density but different cell sizes, determining the effect of cell size on the mechanical properties of polymer foams remains a challenge. To overcome this difficulty, studies on the mechanical behaviour of mesocellular, microcellular and nanocellular polymer foams have been compiled in this review article. After describing the different cellular structures between meso-, micro- and nanocellular foams, the mechanical properties are examined as a function of relative density and cell size. It is shown that for small strains and at low strain rates, nanocellular foams exhibit mechanical behaviour predicted by the Gibson and Ashby model. Relative density remains the first important factor to be taken into account when studying the Young’s modulus and buckling stress of nanocellular foams. The focus then shifts to fracture properties, as microcellular foams have already been shown to be far superior to more conventional foams. As studies are still scarce and different methodologies have been used, no general conclusions can be drawn. However, the fracture and impact properties could be greatly improved by this change in scale. The local confinement of molecular chains in polymeric nanocellular foams or the relaxation of the triaxial stress state in front of the crack tip could explain these observations.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"19 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141147112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-01DOI: 10.1177/0021955x241242967
Xiaofei Jiao, Wenjing Zhang, Ruiying Wu, Haiyun Ma, Yunhong Jiao, Li Huo
The production of polyurethane foam (PUF) from green and sustainable agricultural waste reeds could replace traditional petroleum-based PUF. In this paper, reed naturally contains nano-SiO2.was liquefied to reed-based polyol (R-P) using Castor oil and PEG-400 as a compound solvent and H2SO4 as a catalyst, The liquefaction efficiency is as high as 97.16%; Reed-based polyurethane foam (R-PUF) was prepared with R-P, water, and isocyanate by one-pot and free rise method. Moreover, DOPO with a rigid ring and Phosphorus was introduced into the cross-linked structure of rigid PUF as a reactive-type flame retardant. The mechanical properties, microstructure, thermal stability, and flame retardance of the R-PUFs were investigated, The results showed that the density of R-PUF was 33.03 kg/m3, the thermal conductivity was 0.0350 W/(m·K), and the limiting oxygen index (LOI) was 20.5%, which was higher than petroleum-based polyurethane; the 6%-DOPO PUF has better flame retardant and thermal stability. The mechanism of R-PUF added DOPO is intrinsic flame retardant and the result of the presence of the gas phase inhibiting the combustion chain reaction and the coalescence phase blocking the transfer of oxygen and heat to the interior of the foam.
利用绿色、可持续的农业废弃芦苇生产聚氨酯泡沫（PUF）可取代传统的石油基聚氨酯泡沫。本文以蓖麻油和 PEG-400 为复合溶剂，H2SO4 为催化剂，将天然含有纳米二氧化硅的芦苇液化为芦苇基多元醇（R-P），液化效率高达 97.16%；以 R-P、水和异氰酸酯为原料，采用一锅法和自由升温法制备了芦苇基聚氨酯泡沫（R-PUF）。此外，在硬质聚氨酯泡沫的交联结构中引入了带有硬环和磷的 DOPO 作为反应型阻燃剂。结果表明，R-PUF的密度为33.03 kg/m3，导热系数为0.0350 W/(m-K)，极限氧指数（LOI）为20.5%，高于石油基聚氨酯；6%-DOPO PUF具有更好的阻燃性和热稳定性。添加了 DOPO 的 R-PUF 的机理是内在阻燃，是气相的存在抑制了燃烧连锁反应，凝聚相的存在阻止了氧气和热量向泡沫内部的传递。
{"title":"Preparation and intrinsical flame resistance of reed-based polyurethane foam modified by 9,10-dihydro-9-oxa-10 phosphaphenanthrene 10-oxide","authors":"Xiaofei Jiao, Wenjing Zhang, Ruiying Wu, Haiyun Ma, Yunhong Jiao, Li Huo","doi":"10.1177/0021955x241242967","DOIUrl":"https://doi.org/10.1177/0021955x241242967","url":null,"abstract":"The production of polyurethane foam (PUF) from green and sustainable agricultural waste reeds could replace traditional petroleum-based PUF. In this paper, reed naturally contains nano-SiO<jats:sub>2</jats:sub>.was liquefied to reed-based polyol (R-P) using Castor oil and PEG-400 as a compound solvent and H<jats:sub>2</jats:sub>SO<jats:sub>4</jats:sub> as a catalyst, The liquefaction efficiency is as high as 97.16%; Reed-based polyurethane foam (R-PUF) was prepared with R-P, water, and isocyanate by one-pot and free rise method. Moreover, DOPO with a rigid ring and Phosphorus was introduced into the cross-linked structure of rigid PUF as a reactive-type flame retardant. The mechanical properties, microstructure, thermal stability, and flame retardance of the R-PUFs were investigated, The results showed that the density of R-PUF was 33.03 kg/m<jats:sup>3</jats:sup>, the thermal conductivity was 0.0350 W/(m·K), and the limiting oxygen index (LOI) was 20.5%, which was higher than petroleum-based polyurethane; the 6%-DOPO PUF has better flame retardant and thermal stability. The mechanism of R-PUF added DOPO is intrinsic flame retardant and the result of the presence of the gas phase inhibiting the combustion chain reaction and the coalescence phase blocking the transfer of oxygen and heat to the interior of the foam.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"146 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140561329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-20DOI: 10.1177/0021955x241233246
Andrey Pereira Acosta, Jalel Labidi, Arthur Behenck Aramburu, Sandro Campos Amico, Darci Alberto Gatto, Rafael de Avila Delucis
Rigid polyurethane foams (RPUF) filled with lignocellulosic fillers have gained considerable interest due to their mechanical performance and eco-friendly characteristics. However, their flammability and photodegradation resistance properties still need further improvement, which may be achieved by incorporating various particles. This study investigated the effect of adding 2.5% of wood flour and 5%–15% of an organophilic nanoclay (relative to the wood flour weight) on the RPUF morphology, density, compressive strength, thermal stability, flammability, and photodegradation resistance. The addition of wood flour and nanoclay made the RPUF cells more rounded and disrupted but did not affect density. The compressive properties were adversely impacted. Nevertheless, the nanoclay significantly improved both flammability and photodegradation resistance compared to the neat RPUF.
{"title":"Photodegradation resistance and flammability of bio-based wood-nanoclay-polyurethane foam nanocomposites","authors":"Andrey Pereira Acosta, Jalel Labidi, Arthur Behenck Aramburu, Sandro Campos Amico, Darci Alberto Gatto, Rafael de Avila Delucis","doi":"10.1177/0021955x241233246","DOIUrl":"https://doi.org/10.1177/0021955x241233246","url":null,"abstract":"Rigid polyurethane foams (RPUF) filled with lignocellulosic fillers have gained considerable interest due to their mechanical performance and eco-friendly characteristics. However, their flammability and photodegradation resistance properties still need further improvement, which may be achieved by incorporating various particles. This study investigated the effect of adding 2.5% of wood flour and 5%–15% of an organophilic nanoclay (relative to the wood flour weight) on the RPUF morphology, density, compressive strength, thermal stability, flammability, and photodegradation resistance. The addition of wood flour and nanoclay made the RPUF cells more rounded and disrupted but did not affect density. The compressive properties were adversely impacted. Nevertheless, the nanoclay significantly improved both flammability and photodegradation resistance compared to the neat RPUF.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"64 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139952659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-20DOI: 10.1177/0021955x241233245
Yuemei Lu, Jianren Liu, Liandeng Wang
In this paper, the PC/ABS notebook computer shells with PET film were prepared using a combined in-mold decoration and microcellular injection molding (IMD/MIM) process. Then the surface quality, morphology, impact toughness and wear resistance were investigated. The results shown that the surface quality is improved by IMD/MIM technology. The three dimensional surface roughness value (Sa) was about 1/3 of that of MIM parts. The cross-section of IMD/MIM samples have three layers. The first layer is a PET film decoration layer with about 132 µm thickness, followed by skin layer (about 22 µm) and foam layer. The range of thickness of the foam layer for the different specimens is about 7803 µm–7820 µm.The cell diameter is between 0.532 µm and 0.638 µm, which is about 2 times than that of MIM parts. Compared with MIM parts, the shape of the bubbles of IMD/MIM parts is ellipsoid with thinner wall. Moreover, the impact toughness of IMD/MIM parts are higher. The best impact toughness is 21.02 KJ/m2 within the scope of this experiment, which is 74% higher than the corresponding MIM part under the same foaming process. This may due to the PET film and micropores could block the initiation of the tip crack. Meanwhile, the IMD/MIM parts have excellent wear resistance property. In most cases, the wear rate of IMD/MIM parts is about 36.6% of MIM part under the same condition.
{"title":"Morphology and properties of PC/ABS notebook computer shell prepared by a combined in-mold decoration and microcellular injection molding process","authors":"Yuemei Lu, Jianren Liu, Liandeng Wang","doi":"10.1177/0021955x241233245","DOIUrl":"https://doi.org/10.1177/0021955x241233245","url":null,"abstract":"In this paper, the PC/ABS notebook computer shells with PET film were prepared using a combined in-mold decoration and microcellular injection molding (IMD/MIM) process. Then the surface quality, morphology, impact toughness and wear resistance were investigated. The results shown that the surface quality is improved by IMD/MIM technology. The three dimensional surface roughness value (Sa) was about 1/3 of that of MIM parts. The cross-section of IMD/MIM samples have three layers. The first layer is a PET film decoration layer with about 132 µm thickness, followed by skin layer (about 22 µm) and foam layer. The range of thickness of the foam layer for the different specimens is about 7803 µm–7820 µm.The cell diameter is between 0.532 µm and 0.638 µm, which is about 2 times than that of MIM parts. Compared with MIM parts, the shape of the bubbles of IMD/MIM parts is ellipsoid with thinner wall. Moreover, the impact toughness of IMD/MIM parts are higher. The best impact toughness is 21.02 KJ/m<jats:sup>2</jats:sup> within the scope of this experiment, which is 74% higher than the corresponding MIM part under the same foaming process. This may due to the PET film and micropores could block the initiation of the tip crack. Meanwhile, the IMD/MIM parts have excellent wear resistance property. In most cases, the wear rate of IMD/MIM parts is about 36.6% of MIM part under the same condition.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"284 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139956659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.1177/0021955x231224770
M. Müller-Pabel, J. Meuchelböck, I. Koch, H. Ruckdäschel, Maik Gude
Understanding the viscoelastic properties of EPP foams is of crucial importance for their use in industrial applications. However, mechanical testing of polymeric foams is challenging due to the difficulties that arise from their morphology. For this reason, here currently available DMA methods using a single drive and a multi-drive rheometer as well as multiple loading directions are investigated in detail. Experimental challenges are highlighted and discussed with regard to foam-specific properties. Special focus is laid on the influence of compressive pre-strain. Based on the results, guidelines to perform reproducible DMA tests on the investigated type of material are derived. In addition, the results give deeper insight into the deformation behavior of bead foams at small strain levels and reveal an early onset of the transition from linear to plateau regime.
{"title":"On the determination of viscoelastic properties of EPP foam in dependence on pre-strain and loading direction","authors":"M. Müller-Pabel, J. Meuchelböck, I. Koch, H. Ruckdäschel, Maik Gude","doi":"10.1177/0021955x231224770","DOIUrl":"https://doi.org/10.1177/0021955x231224770","url":null,"abstract":"Understanding the viscoelastic properties of EPP foams is of crucial importance for their use in industrial applications. However, mechanical testing of polymeric foams is challenging due to the difficulties that arise from their morphology. For this reason, here currently available DMA methods using a single drive and a multi-drive rheometer as well as multiple loading directions are investigated in detail. Experimental challenges are highlighted and discussed with regard to foam-specific properties. Special focus is laid on the influence of compressive pre-strain. Based on the results, guidelines to perform reproducible DMA tests on the investigated type of material are derived. In addition, the results give deeper insight into the deformation behavior of bead foams at small strain levels and reveal an early onset of the transition from linear to plateau regime.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"1 8","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139148846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-26DOI: 10.1177/0021955x231224769
Zhiqiang Fu, Wujie Zhang, Tong Zhao, Yan Wang, L. Duan, Haozhe Liu
In this paper, quasi-static and dynamic compression experiments were carried out on polyethylene foam by a universal material testing machine and a drop tower impact device. The mechanical response characteristics and energy absorption capacity of polyethylene foam under quasi-static and moderate strain rate (4 × 10−3–102s−1) loading conditions were obtained. An improved constitutive model of strain-rate term coupling strain and strain rate was established based on the Sherwood–Frost phenomenological constitutive model and Johnson–Cook constitutive model. Low Density Foam model combined in the finite element software ABAQUS with the improved constitutive model was used as the parameter definition of polyethylene foam material in the simulation. The drop-tower impact tests at different heights were simulated, and the simulation results were compared with the actual drop tower impact test results. The results showed that the peak acceleration errors between simulation and experiment were less than 7.1%, verifying the accuracy of the constitutive model. This study provides a method of constitutive models and finite element simulation to the performance of polymer foams.
{"title":"Constitutive modeling and simulation of polyethylene foam under quasi-static and impact loading","authors":"Zhiqiang Fu, Wujie Zhang, Tong Zhao, Yan Wang, L. Duan, Haozhe Liu","doi":"10.1177/0021955x231224769","DOIUrl":"https://doi.org/10.1177/0021955x231224769","url":null,"abstract":"In this paper, quasi-static and dynamic compression experiments were carried out on polyethylene foam by a universal material testing machine and a drop tower impact device. The mechanical response characteristics and energy absorption capacity of polyethylene foam under quasi-static and moderate strain rate (4 × 10−3–102s−1) loading conditions were obtained. An improved constitutive model of strain-rate term coupling strain and strain rate was established based on the Sherwood–Frost phenomenological constitutive model and Johnson–Cook constitutive model. Low Density Foam model combined in the finite element software ABAQUS with the improved constitutive model was used as the parameter definition of polyethylene foam material in the simulation. The drop-tower impact tests at different heights were simulated, and the simulation results were compared with the actual drop tower impact test results. The results showed that the peak acceleration errors between simulation and experiment were less than 7.1%, verifying the accuracy of the constitutive model. This study provides a method of constitutive models and finite element simulation to the performance of polymer foams.","PeriodicalId":15236,"journal":{"name":"Journal of Cellular Plastics","volume":"9 24","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139156366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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