PC Sheet Research Articles

Hybridization of thermoplastic/glass fiber reinforced epoxy composites for lightweight structures

Understanding how different hybrid composite designs under flexural, interlaminar shear and fracture is the objective of this study. The hybrid composite was manufactured utilizing the hand-layup process to produce three different laminate arrangements beside the neat composite. The effects of PC integration and position through the hybrid composites were evaluated, and an analysis of the damage mechanisms was performed. The results demonstrated that incorporating the PC sheet resulted in an improvement in overall performance. Additionally, delamination was determined to be the most prevalent type of failure, followed by fiber and matrix breakage and plastic deformation of PC sheet.

Increasing Bending Strength of Polycarbonate Reinforced by Carbon Fiber Irradiated by Electron Beam.

In an interlayered carbon fiber-reinforced polycarbonate polymer (CFRPC) composite composed of three sized of CF plies, alternating between four PC sheets, designated [PC]4[CF]3, and a new process of activating CF cross-weave cloth plies directly on both sides with homogeneous low-energy electron beam irradiation (HLEBI) before lamination assembly and hot pressing at 6.0 MPa and 537 K for 8 min was produced. Experimental results show that a dose of 215 kGy of HLEBI raised the bending strength, σb, at each experimental accumulative probability, Pa, with the σb at a median Pa of 0.50, increasing by 25% over that of the untreated sample. Three-parameter Weibull analysis showed that when quality can be controlled, a dose of 215 kGy of HLEBI can raise the statistically lowest bending strength, σs, at Pa = 0 (94.3 Mpa), with a high correlation coefficient. This is because, although it had a higher bending strength than that in the other experimental conditions, the weakest sample of the 215 kGy data set had a much lower σb value than that of the others. Electron spin resonance (ESR) of the CF showed that naturally occurring dangling bonds in CF were increased at 215 kGy. Charge transfer to the PC occurs, apparently generating stronger bonds, which are possibly covalent, resulting in enhanced adhesion at the CF-PC interface.

Forensic significance of perforation pattern in polycarbonate sheet against 9 × 19 mm projectile

Polycarbonate is widely used as structural material due to its extreme resistance to impact and perforation. In a crime involving firearms, the bullet may impact various objects fitted with or made of polycarbonate sheets leaving high chances of discovering the fractured PC sheets and fragments at the scene of crime; hence, these objects may become objects of the criminal investigation. In the present work the perforation pattern of PC sheets of thicknesses 8 mm, 10 mm, 12 mm and 15 mm at firing ranges 5 m and 10 m when impacted against 9 ×19 mm full metal jacket (FMJ) bullet were examined. It was observed that after impact, the PC sheet develops entry hole smaller than the calibre of bullet; formation of crack zone, plastic zone; and petalling on the distal face was observed. It was found that as the thickness of the sheet increases, the diameter of the entry hole increases, the diameter of the exit hole initially increases and then becomes constant. At 5 m range of fire the trend of crack zone becomes nearly constant from 8 mm to 15 mm thickness, however, at 10 m range of fire crack zone increases from 8 mm to 15 mm thickness. Furthermore, the diameter of the plastic zone increases as the thickness of the sheet increases (from 8 mm to 15 mm, respectively).

Boosting additive circular economy ecosystems using blockchain: An exploratory case study

The role of new technologies such as additive manufacturing and blockchain technology in designing and implementing circular economy ecosystems is not a trivial issue. This study aimed to understand if blockchain technology can be an enabler tool for developing additive symbiotic networks. A real case study was developed regarding a circular economy ecosystem in which a fused granular fabrication 3D printer is used to valorize polycarbonate waste. The industrial symbiosis network comprised four stakeholders: a manufacturing company that produces polycarbonate waste, a municipality service responsible for the city waste management, a start-up holding the 3D printer, and a non-profit store. It was identified a set of six requirements to adopt the blockchain technology in an additive symbiotic network, bearing in mind the need to have a database to keep track of the properties of the input material for the 3D printer during the exchanges, in addition to the inexistence of mechanisms of trust or cooperation between well-established industries and the additive manufacturing industry. The findings suggested a permissioned blockchain to support the implementation of the additive symbiotic network, namely, to enable the physical transactions (quantity and quality of waste material PC sheets) and monitoring and reporting (additive manufacturing technology knowledge and final product's quantity and price).Future research venues include developing blockchain-based systems that enhance the development of additive symbiotic networks.

In-situ measurement of the acoustic performance of a nearly-enclosed barrier prototype on an existing line in the urban rail transit system

The acoustic performance of a nearly-enclosed prototype meant to attenuate urban rail transit (URT) noise was measured in situ on an existing line. The prototype is constructed on a viaduct on Line 1, Ningbo, China, with a 2-meter-wide opening at the top. A series of measurements while trains passed by were carried out with twelve receiver positions at the site without and with the prototype. Train speeds were measured using a piezoelectric acceleration sensor located on a rail foot. By correcting pass-by levels for train speed, the measured results show that the nearly-enclosed prototype provides an attenuation with a maximum of 17 dB(A), and a minimum of 6 dB(A). One-third octave band spectrum analysis shows that the insertion loss specific to rolling noise yields on average more than 15 dB. Furthermore, comparisons between measured and predicted results by using 2.5-D boundary element method (2.5-D BEM) show that both of the employed PC and PMMA sheets could not provide sufficient transmission loss for the prototype in a real situation. Nevertheless, the nearly-enclosed prototype is effective against rolling noise for the URT system.

Metal-Decorated Phthalocyanine Monolayer as a Potential Gas Sensing Material for Phosgene: A First-Principles Study.

Research into a gas sensing material with excellent performance to detect or remove toxic phosgene (COCl2) is of great significance to environmental and biological protection. In the present work, the adsorption performance of COCl2 on pristine phthalocyanine (Pc) and metal-decorated Pc (MePc, Me = Cu, Ga, and Ru) monolayers was studied by first-principles calculations. The results show that the absorption process of COCl2 on pristine Pc and CuPc both belong to physisorption, indicating that they are not suitable gas sensing materials for COCl2. When Pc sheets are decorated by Ga and Ru atoms, the adsorption of COCl2 is changed into chemisorption, and the corresponding adsorption energies are −0.57 and −0.50 eV for GaPc and RuPc, respectively. The microcosmic mechanism between COCl2 and adsorbents (GaPc, RuPc) was clarified by the analysis of the density of states, the charge density difference, and the Hirshfeld charge. In addition, the COCl2 adsorption results in a significant conductivity variation of the RuPc monolayer, demonstrating it exhibits a high sensitivity to the COCl2 molecule. Meanwhile, quick desorption processes were noticed at various temperatures for the COCl2/RuPc system. Consequently, the RuPc monolayer can be considered as a potential candidate for phosgene sensors because of the moderate adsorption strength, high sensitivity, and fast desorption speed.

Investigations on formability of tailor laminated sheets in single point incremental forming

In this article, formability of tailor laminated sheets in single point incremental forming (SPIF) is investigated using forming limit curve (FLC) and maximum formable wall angle determined theoretically and incremental sheet forming tests. Two different sheet materials namely aluminum alloy AA5083 and polycarbonate were laminated in two different configurations, that is, AA5083/PC, and AA5083/PC/AA5083. FLCs were determined for the laminated sheets using deformation instability method and compared to that of the base sheets. It was observed that formability of the laminated sheets was higher than that of the PC and AA5083 sheets for plane strain case. The maximum formable wall angle was determined by varying the wall angle till the onset of fracture through deforming the sheet into square pyramid shapes. Deformation depths at the onset of fracture for the incrementally formed laminated sheets got decreased with the increase of forming wall angle. Optical macrographs of the cross-sections of the deformed laminated sheets with maximum forming wall angles were taken, and variations of sheet thicknesses along the center line of the deformed sheets were compared for the different cases. Higher triaxiality of AA5083/PC/AA5083 sheet results in lower formability compared to AA5083/PC sheet obtained from membrane analysis. Formation of bump structure due to delamination during SPIF of laminated sheets could be avoided using proper selection of tool path.

Mitigating the Blunt Trauma of Soft Armour Panels using Polycarbonate Sheets: A Cost-effective Solution

Reduction of back face signature (BFS) or blunt trauma of soft armour panel (SAP) is one of the major aspects of armour design. This research explores the use of stiff polymeric materials (polycarbonate or PC sheet) to mitigate the BFS of hybrid SAPs. Two sets of SAPs were prepared—the first set comprising of para-aramid based woven fabrics and UD laminates and the second, of ultra-high molecular weight polyethylene (UHMWPE) UD laminates. The areal density of all the panels was within the range of 4.7 ± 0.3 kg m−2. The ballistic performance of SAPs was evaluated in terms of BFS and perforation ratio against a 9 mm × 19 mm lead core bullet fired at 430 m s−1 velocity. The BFS of SAPs reduced when PC sheets were used as backing materials, with a maximum improvement of 27.5% noticed in case of the SAP made from woven para-aramid fabrics. PC sheets were able to replace up to 41% of the high-performance materials thereby reducing the materials cost of armour significantly (38%). The outcome of this research opens up possibilities to replace costly high-performance fabrics with low-cost materials while improving the ballistic performance of SAPs.

Theoretical insight into two-dimensional M-Pc monolayer as an excellent material for formaldehyde and phosgene sensing

Design of the good-performance materials for detecting or removing the toxic formaldehyde and phosgene gases is extremely meaningful to environmental conservation and human health. In this work, the density functional theory calculations were employed to investigate the adsorption behaviors and electronic characteristics of H2CO and COCl2 on the pristine and metal doped phthalocyanine monolayers (M-Pc, M = Al, Cr, Mn, Fe, Co and Ni). The results show that the H2CO is dissociation-chemisorbed on pristine Pc monolayer, while the COCl2 molecule is parallelly physisorbed on it, and the inappropriate adsorption strength restrict its application in gas sensor. While doping Al, Cr and Fe atoms into Pc sheet could efficiently regulate the adsorption ability of these two gas molecules, reaching the adsorption energy of −1.26 to −0.63 eV. The origin of strong interactions between gas molecules and Al/Cr/Fe-Pc monolayer are revealed by the analysis of density of state, charge density difference and Mulliken charge. Additionally, the H2CO adsorption results in the obvious change of electrical conductivity and magnetism for Cr-Pc monolayer, and the recovery time of H2CO molecule is predicted to be 0.04 s at room temperature. Therefore, the Cr-Pc monolayer could be a sustainable gas sensor for H2CO detection with excellent selectivity and sensitivity.

Surface and wetting characteristics of textured bisphenol‐A based polycarbonate surfaces: Acetone‐induced crystallization texturing methods

ABSTRACTPolycarbonate (PC) sheet is a promising material for facile patterning to induce hydrophobic self‐cleaning and dust repelling properties for photovoltaic panels’ protection. An investigation to texture PC sheet surfaces to develop a self‐cleaning structure using solvent induced‐crystallization is carried out using acetone. Acetone is applied in both liquid and vapor states to generate a hierarchically structured surface that would improve its contacts angle and therefore improve hydrophobicity. The surface texture is investigated and characterized using atomic force microscopy, contact angle technique (Goniometer), optical microscopy, ultraviolet‐visible spectroscopy (UV–vis) and Fourier transform infrared spectroscopy. The findings revealed that the liquid acetone‐induced crystallization of PC surface leads to a hierarchal and hydrophobic surface with an average contact angle of 135° and average transmittance <2%. However, the acetone vapor induced‐crystallization results in a slightly hydrophilic hierarchal textured surface with high transmittance; in which case, average contact angle of 89° and average transmittance of 69% are achieved. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43074.

Giant magnetocrystalline anisotropy of 5d transition metal-based phthalocyanine sheet.

Large magnetocrystalline anisotropy energy (MAE) is a critical requirement for nanomagnets for applications in magnetic memory and storage devices. Due to small spin-orbit interaction the MAE of ferromagnetic films or single molecule magnets based on 3d metals is small and in typical magnetic nanostructures it is of the order of 2-3 meV. We show that MAE as high as 140 meV can be achieved by applying an external electric field or a biaxial tensile strain to phthalocyanine sheets decorated by 5d transition metal atoms such as Os and Ir. Our observation is based on a systematic study of 5d transition metal absorbed ploy phthalocyanine (Pc) sheets using first-principles density functional theory (DFT) combined with self consistently determined Hubbard U that accounts for the strong correlation energy. We attribute the high MAE values to dxy and dx(2)-y(2) (dxz and dyz) interaction in Ir (Os) adsorbed structure.

Effect of TBC plasticization on thin polycarbonate sheet

Tributyl citrate (TBC) plasticizer has been selected to prepare the novel plasticized PC under different time and temperature. The TBC plasticization effect on PC T g, mechanical properties and morphology has been investigated by DMTA, DSC, tensile test and SEM. The results show that the TBC content in PC is controlled by plasticization time and temperature. The mass-loss test has confirmed a less lost rate of TBC in PC. The T g declines gradually with increasing TBC content. The tensile modulus and strength of the plasticized PC also decrease with the increase of TBC content, and an approximate linear relationship is found to exist between the TBC content and the tensile modulus and strength. The SEM images show that significant changes have taken place on the surface and in the cross-section of plasticized thin PC sheet.

Research on the Dimpling in Multi-Point Thermoforming of Polycarbonate Sheet

Growing requirements of small-batch, high-quality and customized products are motivating the development of innovative flexible polymer processing techniques. The paper demonstrates the possibility of employing the multi-point forming (MPF) technology to produce low-cost, small-batch and customized polycarbonate (PC sheet components. Experiments have been performed by means of an experimental setup designed for processing polymer sheet and the overall investigation is focused on the characterization and evaluation of the effects of processing parameters on forming quality. The results show that the forming defects can be eliminated under appropriate processing parameters and that the shape of formed part is in good accordance with the desired shape.

Microcellular foaming of plasticized thin PC sheet I. Effects of processing conditions

Novel microcellular foams using thin plasticized PC sheet were prepared by compression molding. The measurement results showed that T g of plasticized PC was decreased and the molecular chain mobility was increased. Decrease in T g and increase in chains mobility were contributed to the widen of foaming temperature window. Effects of processing conditions on cell size, cell density and relative density were also investigated. The experimental results show that the temperature, tributyl citrate and foaming agent content have more effects on the structures and morphology of the plasticized PC microcellular foam. Effects of experimental conditions on cell size distribution have also been discussed.

Effective Combination of Soft Magnetic Materials for Magnetic Shielding

This study proposes an effective method in the arrangement of layers of high permeability materials for shielding power frequency magnetic field. The side of a neutral ground reactor was blocked with one or two layers of grain-oriented electrical steel (GO), nonoriented electrical steel (NGO), and permalloy (PC). In a weak magnetic field, PC showed the highest shielding performance, whereas GO was the best in a strong magnetic field. NGO had a lower shielding performance than GO, but was better than PC in a very strong magnetic field. When shielding with two layers directly adjacent to each other, the performance level of GO/PC combination (GO is closer to the field source) was between that of GO/GO and PC/PC combinations. When the two layers were slightly separated, on the other hand, GO/PC was most effective in a wide range of magnetic fields. These results are due to the shunt effect of high permeability materials and change of rank of permeability with magnetic field strength between different magnetic materials. Closely adjacent layers act as one body under the regime of shunt mechanism of magnetic shielding. Once the layers are separated, the GO sheet effectively reduces the strong magnetic field first, and then the PC sheet effectively shields the weakened field.

Pre-combustion CO2 capture by transition metal ions embedded in phthalocyanine sheets

Transition metal (TM) embedded two-dimensional phthalocyanine (Pc) sheets have been recently synthesized in experiments [M. Abel, S. Clair, O. Ourdjini, M. Mossoyan, and L. Porte, J. Am. Chem. Soc. 133, 1203 (2010)], where the transition metal ions are uniformly distributed in porous structures, providing the possibility of capturing gas molecules. Using first principles and grand canonical Monte Carlo simulations, TMPc sheets (TM = Sc, Ti, and Fe) are studied for pre-combustion CO(2) capture by considering the adsorptions of H(2)/CO(2) gas mixtures. It is found that ScPc sheet shows a good selectivity for CO(2), and the excess uptake capacity of single-component CO(2) on ScPc sheet at 298 K and 50 bar is found to be 2949 mg/g, larger than that of any other reported porous materials. Furthermore, electrostatic potential and natural bond orbital analyses are performed to reveal the underlying interaction mechanisms, showing that electrostatic interactions as well as the donation and back donation of electrons between the transition metal ions and the CO(2) molecules play a key role in the capture.

Research of Polycarbonate Sheet Processing Based on Multi-Point Forming

Although multi-point forming (MPF) is an advanced processing technique and has been investigated comprehensively as a metal working operation, there are few papers published to deal with MPF of polymers. The present paper reviews the features of MPF and evaluates the possibility of producing polymer components by means of MPF. The experimental research work makes use of PC sheets with a thickness of 3.82 mm. Numerical simulations were performed with the software ABAQUS, then spherical and saddle-shaped components were manufactured by MPF. The geometrical deviations between shaped components and their original CAD/CAM models were obtained to investigate the forming accuracy. The results confirm that MPF of PC sheet has potential for the manufacture of complex components.

Preparation of a novel alloy composed of fluorene‐based polyester and polycarbonate and their properties for the optical uses

AbstractThis paper is concerned with the structures and properties for fluorene‐based polyester‐polycarbonate (FBP/PC) alloys. Obtained alloys were characterized thermodynamically, optically, and viscoelastically, and the relationship between drawing behavior and molecular dynamics were also investigated. FBP/PC alloys showed transparent and a single glass transition temperature (Tg) for all compositions that indicated the complete compatibility in FBP/PC alloy systems. Tendency of the maximum draw ratios for alloy sheets was very similar to the profile of Tg versus FBP content. Maximum draw ratio was increased linearly with FBP content, demonstrating the intimate relationship between the large deformation and the molecular motion. A large amount of orientational birefringence occurred in PC sheet, but in the case of FBP/PC alloys and FBP, orientational birefringence was drastically decreased or not observed at all. This meant that positive birefringence of PC molecules was compensated by the absolutely smaller birefringence of FBP molecules. From a molecular mobility perspective, relaxation time (T2) for PC was smaller even at 200°C. However, for FBP and its alloys, T2 were much larger, showing the considerably enhanced molecular mobility in FBP or FBP/PC alloys. In this study, we could first reveal that the relationship between Tg and FBP content was very similar to the behaviors of birefringence (Δn)/draw ratio (λ) versus FBP content, T2 versus FBP content and 1/maximum draw ratio (λmax) versus FBP content. Based on these results, we were able to propose a novel alloy with high refractive index, low orientational birefringence, and higher processability by alloying FBP with PC. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Physical aging and time–temperature behavior concerning fracture performance of polycarbonate

The effects of physical aging on fracture and yielding behavior are polycarbonate are considered. Two groups of Bisphenol A-based polycarbonate, consisted of extruded PC sheets (thickness of 0.25 mm) and injection molded PC bars (thickness of 3.18 mm) are used. These samples were annealed at various temperatures ranging from 60 to 120 °C, for different times varying up to 240 h. For PC sheets the essential work of fracture (EWF) method was used to analyze fracture behavior. The results are compared to the strain energy density with aging time and aging temperature in the ranges investigated. This effect is confirmed by the change in fracture toughness, as measured by three-point bending tests. The concept of fictive temperature ( T f) was used to characterize the degree of aging in the sample. T f of a glass in an aged state at a time t is defined as the temperature at which the volume would be equal to the equilibrium volume at T f if the sample were instantaneously removed to that temperature. Differential scanning calorimetry (DSC) was used to determine T f. The variations of T f with aging time and aging temperature are in agreement with both the strain energy density measurement and the three-point bending tests. These results contradict the effects of aging on fracture toughness observed by the essential work of fracture approach. The latter showed anomalous regions of increasing fracture toughness with aging, leading to spurious conclusions. The brittle–ductile transition in fracture behavior is analyzed by an activation energy approach. Aging increases the brittle–ductile transition temperature and the effect is more pronounced for the lower molecular-weight sample. Fracture tests also showed a decrease in the entropy with aging, confirming the results observed previously from tension and compression tests.

Freibewitterung von Lichtplatten aus Kunststoffen. Eine Langzeitstudie während elf Jahren

Due to their numerous advantages such as low weight, high transparency and impact resistance, transparent multible-skin plastic sheets (e.g., PVC, PMMA, PC, GF-UP) are widely used in applications such as greenhouses, windows, roofs etc. Since degradation due to sunlight and humidity is a critical behaviour inherent to most polymeric materials, it is necessary to determine the influence of prolonged weathering. With this aim, nineteen different sheets were exposed over a period of eleven years at Dübendorf. Test methods as visual inspection, average light transmittance and resistance to hail impact turned out to characterise the influence of weathering on the sheets very well. On the base of the mentioned test methods, the four different materials could be classified in the following range. Because of moderate changing of mechanical behaviour and appearance, the GF-UP materials were most suitable for the application followed by PC sheets. PMMA materials do have an advantage because of their excellent optical properties, but the mechanical behaviour is unsuitable from the beginning. Sheets from PVC showed strong changes of their optical and mechanical behaviours after short-time period and aren't well applicable for long-term exposure.