Transparent Plastic Materials Research Articles

Embedding constructed refractive index graded antireflective coating with high abrasion resistance and environmental stability for polycarbonate glass

Polycarbonate (PC) is a durable and transparent optical plastic material commonly used as shatter-resistant alternative to traditional optical glass. Broadband antireflective (AR) coatings with excellent mechanical strength and environmental stability are essential for PC to achieve high light transmission and visual quality. In this work, chloroform vapor treatment was employed to partially embed the silica coating into the PC substrate for adhesion enhancement, which also divided the silica coating layer into bottom and middle layers with different refractive indices. The contact between the silica nanoparticles and the substrate was transformed from “point-contact” to “area-contact”, which enhanced the adhesion between coating and PC substrate. After the deposition of a top layer coating consisted of silica nanoparticles with smaller diameter, a triple-layer refractive index graded AR structure was constructed. Hexamethyldisilazane vapor surface modification was performed to decrease the surface free energy of top coating layer. The triple-layer coating coated PC exhibits superior antireflection property with an average reflectance of only 0.43% over a wide wavelength range of 400–1000 nm. After 100 times of friction or 5 months of exposure to a contaminated environment, the reflectance of coated PC shows barely noticeable difference, indicating its excellent mechanical strength and environmental stability.

Dual roles of a transparent polymer film containing dispersed N-doped carbon dots: A high-efficiency blue light converter and UV screen

We report the synthesis of a transparent plastic material with very high performance ultraviolet (UV)-blocking and blue-light (440 nm) emission. Polyvinyl alcohol (PVA) was employed as a transparent plastic matrix that disperses N-doped carbon dots (N-CDs) prepared via hydrothermal treatment of citric acid, ethylene diamine, and HCl solution. Luminescence of these N-CDs is excitation-independent and the quantum yield (QY) is maximal at an excitation wavelength range of 350–370 nm, in the UV-A radiation segment of the solar spectrum. By encapsulating N-CDs in a polyvinyl alcohol (PVA) matrix, the absolute QY achieves 91%, which is higher than in aqueous solution. As the particle concentration increases in PVA matrix or in solution, UV absorbance increases and QY decreases. On the other hand, UV absorbance of the film is proportional to thickness with no appreciable deterioration in QY, a quality that is beneficial for UV light absorption as well as conversion into blue light. We propose that this N-CD/PVA composite is an ideal transparent plastic for UV-ray shielding, as well as being useful for blue light emission, composed only of eco-friendly nontoxic elements. The high UV absorption and strong luminescence of N-CDs are beneficial also for other applications that include anti-counterfeiting (secret inks) and greenhouse sheathing that simultaneously blocks UV-rays while generating blue light to promote plant growth.

White marking inside the transparent plastic materials by 1.55 μm nanosecond pulse fiber laser

In this paper, the authors report that it is possible to create a white marking inside transparent plastic materials by heating them to a temperature close to the threshold of creating a void and using a fiber laser. Heating plastic materials and using a fiber laser enable the threshold to be in excess only in the focus position, and a white marking is created. The authors experimented with polycarbonate and polyethylene terephthalate as the transparent plastic materials, and a 1.55 μm nanosecond pulse fiber laser as the laser equipment. They irradiated laser in the sample inside while heating. As a result, when polycarbonate was heated to 150 °C and polyethylene terephthalate to 50 °C, a void was created at the focus position. Therefore, the authors successfully created a white marking inside the transparent plastic materials by heating them and using a fiber laser.In this paper, the authors report that it is possible to create a white marking inside transparent plastic materials by heating them to a temperature close to the threshold of creating a void and using a fiber laser. Heating plastic materials and using a fiber laser enable the threshold to be in excess only in the focus position, and a white marking is created. The authors experimented with polycarbonate and polyethylene terephthalate as the transparent plastic materials, and a 1.55 μm nanosecond pulse fiber laser as the laser equipment. They irradiated laser in the sample inside while heating. As a result, when polycarbonate was heated to 150 °C and polyethylene terephthalate to 50 °C, a void was created at the focus position. Therefore, the authors successfully created a white marking inside the transparent plastic materials by heating them and using a fiber laser.

DETERMINATION OF THE EFFECTS OF DIFFERENT PACKAGING METHODS AND MATERIALS ON STORAGE TIME OF DRIED APPLE

The aim of this study was to determine the effects of different packaging materials and packaging methods on changes in product characteristics during the storage period of dry products. In the experiments dried apples were used which were cut into cubes as dry product. In the packaging of dried apples, transparent doypack, metallized doypack, aluminum doypack, transparent plastic and paper materials are used. Dried products are placed in packing materials using special dosing machines to be 200 g each in each case. While atmospheric and vacuum packaging applications were used as packaging methods, only atmospheric packaging method was used in transparent plastic and pouch paper packages in terms of material properties. A total of 30 samples were prepared from each application. The packaged products were stored in the cabins in the SDU Agricultural Machinery and Technology Engineering Department laboratory. The temperature and humidity values in the cabin are recorded in the storage case. The products were stored for one year and one sample was opened and analyzed every fifteen day during the preservation process. The result of the study showed that the vacuum packaging is more successful and the aluminum layer material as the packaging material provides the highest protection. This study was supported by the BAP department of Suleyman Demirel University (Project Number: 4419-M1-15). Article DOI: https://dx.doi.org/10.20319/mijst.2018.42.238255 This work is licensed under the Creative Commons Attribution-Non-commercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.

Optimization of Pulsed Nd:YVO4 Through Transmission Laser Welding of Transparent Acrylic and Polycarbonate

In the present work through transmission laser welding (TTLW) of two transparent plastic materials namely, Acrylic and Polycarbonate at varied levels of laser power, scanning speed and frequency have been carried out to form lap joints without application of filler material. The effect of input parameters on the weld quality has been studied through inspection and tests. Statistical software Design Expert 10 has been applied for design of experiments and analysis purpose. Breaking load and weld width have been considered as responses. Response surface methodology (RSM) has been applied for multi-objective optimization for minimization of weld width and maximization of breaking load simultaneously. Confirmatory tests have been conducted to validate the applied optimization techniques.

Biological Control of Southern Red Mite, <i>Oligonychus ilicis</i> (Acari: Tetranychidae), in Coffee Plants

The species of mite Oligonychus ilicis (McGregor) (Tetranychidae) is an important pest of dicotyledonous plants, cosmopolitan and polyphagous, reported in seven countries from four continents, feeding on 34 plant species of 15 families. The spider mite O. ilicis is known in Brazil as coffee red spider mite, and as southern red mite most in other countries. In Brazil O. ilicis has been reported as the second most important pest of “Conillon” coffee, Coffea canephora Pierre & Froehner, in the state of Espírito Santo. Depending on the number of mites per leaf of arabica coffee, Coffea arabica L., the rate of potential photosynthesis can be reduced by 37% to 50%. In the present study, it was investigated the potential of the two predatory mites which, among others, naturally occurs in coffee plantations, Euseius alatus DeLeon and Amblyseius herbicolus (Chant) (Phytoseiidae), in the control of O. ilicis in coffee plants. It was used potted coffee plants in this research, with approximately 100 cm high, growing in a greenhouse covered with transparent plastic and shading material of 50% sun protection factor, and with fine mesh on all the sides. Results showed that both species of predatory mites, A. herbicolus and E. alatus, are efficient in reducing the mobile phases—larvae, protonymphs, deutonymphs and adults—of the southern red mite O. ilicis. So, the importance of conservation and increase number of these predatory mites in the field coffee growing is essential for implementing the southern red mite integrated management tactic, since these species are of natural occurrence in coffee plants.

Practical applications of transparent and opaque microperforated and microslit absorbers

architectural acoustics. Currently, the architectural acoustic community faces ever changing challenges that require innovative approaches to absorb sound. Due to the importance of day lighting in sustainable design certification, such as LEED, and the concern about particulate material from fiberglass and mineral wool, there has developed a need for transparent and translucent absorptive materials that do not require the use of fibrous porous absorption. One approach has been the development of microperforated and microslit foils and panels with sub-millimeter openings that provide significant viscous losses when spaced from a boundary. In addition, opaque FSC certified, AWI Premium Grade, Class A fire rated microperforated veneered wooden panels have also been enthusiastically accepted by architects, since the microperforations are relatively invisible at normal viewing distances. The theoretical absorption mechanism of microperforated and microslit surfaces is well documented in the literature and comparisons between calculated and measured absorption coefficients will be illustrated. This presentation will also review practical applications of various transparent foil and plastic panel materials, as well as microperforated veneered wooden panels.

Antistatic surface properties of plastics using donor-accepter molecular compounding antistatic agent

Abstract In order to obtain transparent plastic material with antistatic property for optical communication application, cyclo olefin polymer (COP)/BN105 composite materials prepared by using injection molding have been evaluated. Surface resistance of the molded product decreased to 2×1011 Ω/sq along with an increase in BN105 content range up to 2 wt%. The samples showed excellent property to prevent the surface from dust adhesion. In addition, the samples containing BN105 less than 5 wt% did not show any decrease in transmittance without any significant change of tensile strength. The results indicate COP/BN105 as a promising plastic composite material with sufficient antistatic property as well as high transparency.

Selection of optimal parameters for laser transmission welding of polycarbonate using desirability function analysis

Now-a-days polycarbonate is widely used in aircrafts as transparent plastic materials due to its high impact strength, outstanding dimensional stability at elevated temperatures, aesthetics, high-heat, flame, and UV resistance. Laser transmission welding of polycarbonate is investigated in present research work with the objective to select the optimal process zone for obtaining high quality joints. Planned experiments and subsequent analyses are carried out. Desirability function analysis in combination with response surface methodology is applied for development of the mathematical models and optimization of process parameters. Objectives are set to maximize the weld strength and to minimize the weld width. Optimal process conditions are attained to satisfy multiple objectives, simultaneously, which ensure overall quality improvement of the product.

Gas chromatographic–mass spectrometric analysis and subsequent quality improvement of plastic infusion packaging materials

Although the opalescence of sterile transparent plastic materials utilized for the packaging of parenteral infusion drugs is a serious quality problem, most suppliers do not report the exact compositions of such polymers, and no literature data are available. Similarly, no information is available as concerns the potential incompatibility of the inner bag and the overpouch. Our gas chromatographic–mass spectrometric study revealed that the cause of the opalescence is the presence of a low-molecular-weight slip additive, 13-docosenamide (erucamide), which is transferred into the primary infusion bag from the overpouch during the heat-sterilization process. Autoclaving trials confirmed the analytical results. In view of these findings, a new slip additive-free overpouch has been produced as secondary packaging material, which does not give rise to opalescence.

Pulsed 2 Micron Wavelength Fiber Lasers for Packaging

Fiber laser sources near 2um wavelength have attracted intense interest in recent years because of the combination of high laser efficiency, strong absorption of many visible transparent materials, outstanding reliability, as well as retina safety. In this presentation, we report our latest developments of various 2um fiber lasers at AdValue Photonics for packaging applications, especially Q-switched and mode-locked 2um fiber lasers using our proprietary infrared glass fiber technology. We demonstrated and commercialized the first all-fiber Q-switched single-frequency laser at a wavelength near 2um using our proprietary rare-earth doped gain fibers. The laser pulsewidth can be 20ns and 180ns, and the peak power can be more than 10kW. Most transparent plastic materials have a relatively strong absorption near 2 micron wavelength, so 2 micron Q-switched fiber laser is one of the ideal laser for transparent plastic welding, marking, cutting, and drilling. Silicon has a good optical transmission near 2 micron wavelength, which allows 2 micron Q-switched to process the material after pass through the silicon wafer as well as remove residual materials containing any organic components. In this presentation we will describe detailed experimental results and present material processing samples for packaging applications.

W042008 プラスチック/金属異材直接接合のプロセスとその接合体強度([W04100]機械材料・材料加工部門企画,締結・接合のプロセスと接合部・界面の信頼性評価)

Dissimilar materials laser direct joining between plastic and metal was studied in lap joint configuration. Laser was irradiated from transparent plastic material side. Joining state was strongly depending on material properties of metallic materials because heat energy was generated at the metallic surface. Depth of molten pool formed in metallic material side affected tensile shear strength of the joint. Oxide layer at metallic surface changed absorptivity of laser and might affect chemical bonding between plastic and metal. Bubbles were formed inside plastic nearby the interface. Strength of the joint decreased with increase in density of bubbles. In order to improve strength of the joint, it is necessary to optimize laser irradiation condition with taking several factors influenced into account.

Transparent Restorations: How Franco Minissi Has Visually Connected Multiple Scales of Heritage

The historiography of late-twentieth-century architecture has glorified figures like Carlo Scarpa, Franco Albini, and others for their work on ancient structures. Franco Minissi is known instead for the protection of archaeological sites and also for his controversial use of innovative transparent plastic materials as protective coverings over ruins. By reading his more conventional museum projects alongside his experiments on archaeological sites, this article shows how Minissi expressed his concept of the museum at various scales, from small objects to cultural landscapes. His use of transparent materials was meant to establish a visual connection between all these different sizes of heritage objects, encouraging visitors into a dialogue with the past. As a sensitive museum designer, he always intervened with reversible operations, which has made it easy for contemporary designers to dismantle his work. Yet, as a key figure of the Italian school of critical restoration, his work is worth preserving and continues to offer valuable ideas for contemporary generations.

Intraosseous monitoring and guiding by ultrasound: A feasibility study

An efficient method for navigation within bone tissue boundaries is essential for performance of surgical procedures, e.g. without damaging of adjacent vulnerable organs. The application of sonographic measuring methods for this purpose promises to be effective in the ability to distinguish soft trabecular bone from dense cortical bone, owing to an order of magnitude difference in acoustic density between these structures. For this purpose, a specific method was developed that utilizes propagation of a 5MHz ultrasonic wave through an aqueous milieu. Using this method a 0.2mm resolution in measurements is achieved. This resolution is in an order of magnitude lower than is required for a clinical use. A three-stage experimental approach was adopted: measurements in a cubic “phantom” made of a transparent plastic material, in samples of fresh porcine femora, and in a clinical setting of drilling in the upper and lower jaw during dental implantation surgery in nine patients. Two patterns of the detected ultrasound wave reflections were found: low amplitude reflections from the aqueous surrounding and trabecular bone and highly reflected ultrasound waves from the cortical bone. We show that trabecular and cortical bones are distinguishable by real-time ultrasonic measurement. The distances of the drilled tracts, in the range of 58.0–122.0mm for the “phantom” experiment, 22.6–35.5mm for the ex vivo experiment and 10.0–11.5mm in the clinical experiment, and residual distances to the opposite edge of the tested samples and organs, in the range of 21.0–82.0mm for the “phantom” experiment, 3.8–11.36mm for the ex vivo experiment and 2.1–6.9mm in the clinical experiment, were measured by the presented sonographic method and compared statistically, using linear correlation and Bland Altman plot, to the mechanical and/or radiographic measurements in all three stages of the experiment. A correlation coefficient above 0.95 was considered an indication of high correlation, while a value of 0.75–0.94 was considered intermediate, and a value below 0.75 was considered poor.A very high correlation (p<0.001) and agreement between the sonographic and the “gold standard” measurements techniques, either mechanical or radiographic depending on the experimental setting, were found. Therefore the presented method of intraosseous sonographic measurements may provide an improved method for the monitoring of intraosseous drilling in respect of the currently used mechanical and/or radiographic clinical methods.

Development of a simple disposable six minibioreactor system for suspension mammalian cell culture

A simple disposable six minibioreactor system has been developed in order to perform multiple cell culture experiments in parallel, as a tool to accelerate experimentation in cell culture optimization. The system consists of a fixed part containing all instrumentation, sensors and actuators, and a disposable part, a compact unit with six minibioreactors with 10–15mL of working volume each. This single-use unit is made of transparent biocompatible plastic material (polystyrene). Each one of the minibioreactors is equipped with agitation, headspace aeration supply and two optical probes, one for total cells measurement and pH, and another for dissolved oxygen measurement (and consequently the evaluation of Oxygen Uptake Rate, OUR). As an example of application, the performance of the system is successfully demonstrated for the culture of hybridoma cells growing in suspension under different conditions. The results allowed confirming the reproducibility of the system, and the feasibility to follow-up continuously the differences in cell growth, pH, pO2 and OUR evolution when hybridoma cells are cultured in different experimental conditions. For this, three different sets of experiments are considered. First, the use of the same culture medium DMEM supplemented with 10% fetal calf serum in all six minibioreactors. Second, the use of DMEM supplemented with three different FCS percentages (0, 1 and 10%) in two minibioreactors each. Third, the use of two different media (DMEM supplemented with 10% FCS and a chemically defined medium) in three minibioreactors each.

칼라 CCD 영상을 이용한 고휘도 LED 전구의 빔 열화 분석

VLC (Visible Light Communication) is a wireless communication method using light that is visible to the human eye. It has a major advantage that it causes no interference to RF-based devices. This makes wireless communication possible in RF hazardous areas such as nuclear facilities. In order to apply VLC communication in harsh environment of nuclear power plant, the high luminance LEDs, which are key components of the VLC communication, have been gamma-ray irradiated at the dose rate of 4kGy/h during 72 hours up to a total dose of 288 kGy. The radiation induced color-center was formed in the LED housing cap made of transparent plastic or acryl material. The beam degradations of high luminance LEDs by high dose-rate gammaray irradiation are analyzed using color CCD image processing technology.

Inline coating of optical substrates

Applications of such optical technologies as vision care, digital imaging or data communication play an important role in our daily life. Manipulation of light is mainly done using optical lenses. Besides mineral lenses, transparent plastic materials are increasingly gaining in importance. The optical and mechanical properties of lenses are crucially improved by high-quality coatings. This includes primarily anti-reflective coatings to enhance light transmission, hard coats to improve scratch resistance of sensitive plastic substrates and finally clean coats to keep the lenses from catching dust and make cleaning easier. In the following we present modern vacuum coating technologies for the industrial refinement of optical substrates. The focus is on the coating of plastic eyeglass lenses using a revolutionary inline technology. On the one hand, the technology merges all coating steps in a fully automated system, and, on the other hand, enables the flexible combination of different layer stacks necessary for RX-production of ophthalmic lenses. The coating system OPTICUS gives access to this unique inline technology. The design of the OPTICUS is described in the last chapter.

An in vitro assessment by means of laser Doppler velocimetry of the medtronic advantage bileaflet mechanical heart valve hinge flow

Objective The aim of this study was to evaluate the hinge flow field characteristics of the Medtronic Advantage bileaflet valve and compare them with the flow fields of the St Jude Medical standard valve. The present study provides laser Doppler velocimetry results for the Advantage and St Jude Medical valves to make a direct comparison of the flow fields of the 2 valve designs. This study aids in determining the preclinical efficacy of Medtronic’s new bileaflet valve hinge design. Methods Two-dimensional laser Doppler velocimetry was used to measure the velocities in the hinge regions of size 29 Medtronic Advantage and St Jude Medical standard bileaflet valve designs. Exact dimensional models of the bileaflet valves, including the hinge regions, were cast from transparent plastic materials to conduct these measurements under simulated physiologic conditions. Laser Doppler velocimetry measurements were conducted under physiologic conditions, with the valves placed in the mitral position of a pulsatile flow loop. Measurements were taken at several elevation levels in the hinge region. Multiple measurement locations obtained in each plane provided a grid work by which the flow fields could be detailed. Results Velocity measurements obtained for each valve design in the hinge recess were used to reconstruct the flow fields. For the Advantage valve, the peak velocities during leakage flow in the hinge at zero depth, one-third depth, and two-thirds depth levels into the hinge recess were 0.9, 1.6, and 1.8 m/s, respectively. Corresponding values for the St Jude Medical valve were 1.3, 1.6, and 2.1 m/s, respectively. From the reconstructed flow fields, the flow patterns seen within the 2 hinge designs exhibited similar features, with more dynamic flow patterns observed in the Advantage hinge during the forward flow phase. Conclusions The present study demonstrated that the hinge flow dynamics of the Advantage bileaflet design were similar to those of the St Jude Medical hinge design. The velocities within the hinge were slightly higher for the St Jude Medical valve but not significantly different. There appears to be more dynamic flow through the hinge of the Advantage valve during the forward flow phase.

Microflow fields in the hinge region of the CarboMedics bileaflet mechanical heart valve design

Objective: The design of bileaflet mechanical heart valves includes some degree of leakage flow on valve closure for the reverse flow to wash the hinge and pivot region of the valve. It is believed that this reverse flow helps to prevent areas of stasis and inhibit microthrombus formation. However, the magnitude of this retrograde flow may also give rise to unacceptable levels of blood element damage and lead to platelet activation or hemolysis as a result of the increased flow velocities through the hinge region. The purpose of this study was to evaluate the hinge flow dynamics of a 23-mm CarboMedics bileaflet mechanical valve (Sulzer CarboMedics Inc, Austin, Tex) and then to compare the results with those of the St Jude Medical 23-mm Regent (St Jude Medical Inc, Minneapolis, Minn) and Medtronic Parallel (Medtronic, Inc, Minneapolis, Minn) valves studied earlier. This comparison allows new insight into the microflow fields within the hinge region of the CarboMedics bileaflet mechanical valve, which have not been previously assessed during its clinical history. Methods: Two-dimensional laser Doppler velocimetry was used to measure the velocity and turbulent shear stress fields in the hinge regions. To conduct these measurements, exact dimensional models of the bileaflet hinge regions were cast or machined from transparent plastic materials. The experiment was conducted in a pulsatile flow loop with measurements taken at different levels within the pivot and hinge regions. Results: In the 23-mm CarboMedics valve hinge, the phase-averaged forward velocity obtained at the flat level and levels of 190 μm and 390 μm above flat and 1 mm below flat were 0.54 m/s, 0.77 m/s, 0.3 m/s, and 1.0 m/s, respectively. Corresponding values of the peak phase-averaged leakage velocities were 3.17 m/s, 2.91 m/s, 2.52 m/s, and 0.5 m/s, respectively. Corresponding turbulent shear stresses were 5510 dyne/cm2, 5640 dyne/cm2, 4380 dyne/cm2, and 4810 dyne/cm2, respectively. Conclusions: The hinge flow dynamics of the CarboMedics bileaflet design lie somewhere in between those of the St Jude Medical and the Medtronic Parallel valve designs. The fluid dynamics of the investigated valve were found to be similar to those of the St Jude Medical valves, although with slightly higher leakage velocities and turbulent shear stresses. This discrepancy may be a result of the sharper corners associated with the hinge design of the CarboMedics valve. It could also be due to the incremental enlargement of the internal orifice area of the St Jude Medical Regent design.J Thorac Cardiovasc Surg 2002;124:561-74

Selection of a support medium for a fixed-film green sulphur bacteria reactor

The ability of green sulphur bacteria ( Chlorobium limicola) to grow on six different transparent plastic tube materials (PTMs) was tested to determine which material would be best as a support medium in a fixed-film bioreactor. The materials were: Bev-a-Line (polyethylene liner with ethyl vinyl acetate shell), FEP (fluorinated ethylene propylene), Kynar (polyvinylidene fluoride), PFA (perfluoroalkoxy), polypropylene and Tygon (vinyl chloride–vinylidene chloride co-polymer). The materials were soaked in water, autoclaved and added to sterile liquid growth medium. 3 to 7 days after inoculating, the bacteria concentrations in the liquid and on the PTM were measured. There was no distinction in total growth between those tubes with and those without PTMs. In comparing bacteria growth on the PTMs, the fraction of the total growth that was on the tubing was significantly higher for Tygon (1.7%) and Bev-a-line (0.6%) tubing than the other PTMs. In terms of bacteriochlorophyll (bchl) per surface area, again Tygon and Bev-a-line tubing were superior to the other PTMs tested with 220 and 81 mg bchl per square metre of tubing surface area, respectively.