Glue Film Research Articles

Sensing Performance of Ethanol Microfiber Probe Augmented by ZnO Nanosheet and UV Glue Film

A microfiber reflective ethanol gas sensing probe was designed and fabricated. The single-mode fiber was heated and stretched to prepare a microfiber taper, on which a mixed material of ZnO nanosheets and UV glue was built by the dip-coating method. The influencing factors on its sensing performance for ethanol have been discussed, including the dozen ratio of ZnO nanosheets, UV glue materials, and end-face morphology. As the concentration of ethanol gas increased, the intensity of the reflection spectrum increased with the responding sensitivity of 7.28 × 10−4 dBm/ppm. The exchanging efficiency of the optical signal is enhanced by the strong evanescent field of the microfiber taper. This sensing probe is convenient for high-density integration and working in a small space and is capable of high-performance monitoring for ethanol at room temperature.

H2O2-mediated tannin bio-based wood adhesive inspired by starfish structure and phenol-amine synergy

High-performance formaldehyde-free bio-based wood adhesives are extremely attractive because of the friendliness and sustainability of their ingredients and resources. This work reports a phenol-amine synergistic tannin bio-based adhesive inspired and designed by insect exoskeleton hardening and starfish structure. The phenol-amine synergistic strategy is based on Schiff base reaction and Michael addition between the benzoquinone group of tannin acid (TA) and the nucleophilic amino group of polyamines (PA XN , X = 4, 5 and 6, X represent the number of amino-terminal groups), which is supplemented by oxidation-induced quinone cross-linking in TA and the combination of covalent and non-covalent bonds. The proposed TAPA wood adhesives with the three-dimensional dense cross-linking network may dissipate stress via hiding sacrificial bonds, which can form a compact glue film to prevent the infiltration of water molecules as well as increase thermal resistance. FT-IR, XPS, and solid 13 C NMR demonstrated the tannin-based phenol-amine network was formed by cross-linking imine covalent bonds. DSC, TG, and DMA revealed reduced melting and glass transition temperatures, as well as improved thermal stability, which are conducive to the cross-linking and curing of adhesives. In detail, the dry lap shear strength of TAPA adhesive increased by 170% from 0.8 MPa to 2.16 MPa compared with pure TA adhesive by using poplar veneer as wood substrate; and the wet lap shear strength made a breakthrough from 0 to 1.06 MPa, exceeding the minimum requirement (0.7 MPa) defined by the China national standard (GB/T 17657–2013). Given this, a high-efficiency, green, and economic phenol-amine synergistic strategy are beneficial to the development of formaldehyde-free bio-based wood adhesives and multifunctional application of agricultural and forestry residues. Schematic illustration of developing phenol-amine synergetic TAPA wood adhesive inspired by insect exoskeleton hardening. • Tannin-based wood adhesives were prepared by phenol-amine synergy strategy. • FT-IR, XPS, 13C NMR, SEM, DSC, TG, and DMA characterization were carried. • Phenol-amine cross-linking network connected by covalent bonds and non-covalent bonds. • TAPA adhesives showed enhanced bonding strength, waterproof and thermal properties. • The formation of cross-linking network help to improve the performance.

Fabrication of the Fabry–Pérot cavity with acrylate AB glue film via dual pressure assistance for humidity sensing

A method for fabricating a thin film Fabry–Pérot (F–P) cavity via dual pressure-assisted acrylate AB glue was studied. The method pressurizes both the acrylate AB glue to generate bubbles and the subsequent inflated film to make it thinner and more sensitive. The F–P cavity was fabricated by attaching the ultrathin film to a glass tube end face and a single-mode fiber in the glass tube to form a two-beam interference model. On the basis of two cycles and several repeated experiments for the humidity gradient, the linear and stable characteristics, and the humidity sensitivity of the F–P cavity with a thin film was demonstrated. The humidity sensitivity was 80.68 pm/% RH and 82.17 pm/% RH under two rising humidity experiments. Acting as the humidity sensing material for the first time, the acrylate AB glue film of the F–P cavity shows good stability and repeatability. In addition, the dual pressure-assisted method introduces a way to produce fiber-optic sensors with ultrathin film.

Parallel-structured Fabry-Perot interferometers gas pressure sensor with ultraviolet glue sensitization based on dual Vernier effect

A parallel-structured Fabry-Perot interferometers (FPIs) gas pressure sensor with ultraviolet glue sensitization based on dual Vernier effect has been proposed and experimentally investigated, which was fabricated based on the FPI coated with ultraviolet glue film and the FPI fully filled with ultraviolet glue. Owing to the unique features of the parallel-structured FPIs, the reflective spectra of them shift to opposite directions as ambient gas pressure varies. Two FPIs serve as sensing reference for each other in gas pressure sensing, generating the dual Vernier effect to enhance Vernier effect. The proposed gas pressure sensor exhibits a high sensitivity of 131.88 nm/MPa and provides new strategies and ideas for fiber-optic sensing filed.

Mechanical properties of mammalian and fish glues over range of temperature and humidity

In this work, the mechanical properties of seven animal glues commercially available for conservation practice are compared. The performance of these materials within ranges of temperature and relative humidity commonly found in uncontrolled environments was quantified on cast glue films using dynamic mechanical analysis (DMA) and tensile testing. The applied experimental protocol resulted in the identification of phase transitions between the glassy and rubbery states and the evaluation in those states of the stiffness, viscoelasticity, strength, and strain at break of each tested adhesive. The presented results allow for the prediction of environmental conditions at which specific glues may fail and may help to select the most appropriate adhesive, from a mechanical point of view, for particular applications.

Sensitivity-enhanced temperature sensor based on Mach-Zehnder interferometer coated with thermal-sensitive material.

In this paper, a Mach-Zehnder interferometer temperature sensor with a single-mode fiber-thin-core fiber-single-mode fiber cascaded is designed. When the light is transmitted from the single-mode fiber to the thin-core fiber, different modes will be excited because of the mode-field mismatch. Optical power from the input fiber can be partly coupled to the cladding modes of the thin-core fiber, and the cladding modes of the thin-core fiber then re-coupled to the lead-out fiber, which constitutes the Mach-Zehnder interferometer in the output single-mode fiber. To improve the temperature sensitivity of the sensor, we coated the thermal-sensitive material (such as polymethoxane or ultraviolet glue) on the surface of the thin-core fiber. The experimental results show that the temperature sensitivity of the sensor coated with a polydimethylsiloxane film was increased from 32.0 to 90.0 pm/°C, about three times, compared to the uncoated thin-core fiber sensor. When the surface of the thin-core fiber is coated with an ultraviolet glue film, the temperature sensitivity of the sensor was increased from 32.0 to 166.8 pm/°C, about six times. The designed sensor, with compact structure, simple production, strong robustness, and high sensitivity, has a wide application prospect in industrial production and national defense technology.

Study on degradation of Cambodian panel painting during UV aging

AbstractIn this research, the glue films, ground and paint layers were aged under UV‐C radiation. The glue films were prepared using tamarind gum and liang‐chey resin powders. The ground (calcium carbonate mixed with tamarind glue) and paint layers (red cinnabar, malachite, Prussian blue mixed with liang‐chey resin) were applied on the iron wood using traditional tempera technique. The degree of disintegration was determined using scanning electron microscopy with energy dispersive X‐ray instrumentation, thermogravimetric analysis, attenuated total reflectance Fourier transformed infrared spectroscopy and powder X‐ray diffraction. The tamarind film turned brown after 14 days. While, liang‐chey resin film did not show any significant color change. The thermogravimetric analysis showed the lower thermal stability of the aged tamarind film. The discoloration and cracking on the ground layer surface stemmed from the disintegration of tamarind binder. After 14‐day exposure, the color of red cinnabar changed from bright red to dark red with black spots all over the surface. These spots were identified by powder X‐ray diffraction measurements as β‐HgS (black). After prolonged UV exposure, the white solid was appeared on the cinnabar surface and identified as anhydrite (anhydrous CaSO4) and gypsum (CaSO4.2H2O). The yellow color appeared on the malachite surface might come from the discoloration of the tamarind glue binder in the ground layer. While the brown layer found on aged Prussian blue surface was confirmed as the mixture of β‐PbO2, Pb3O4, and β‐FeOOH.

High-sensitive fiber-optic pressure sensor based on Fabry-Perot interferometer filled with ultraviolet glue film and Vernier effect

A high sensitivity fiber-optic pressure sensor based on Fabry-Perot interferometer filled with ultraviolet (UV) glue film and Vernier effect was proposed and demonstrated. The sensor is composed of a sensing Fabry-Perot (FP) cavity and a reference FP cavity in parallel. The sensing cavity is fabricated by splicing a section of silica tube (ST) to the lead-in single-mode fiber (SMF), and filling a thin layer of UV glue at the end-face of the ST. The reference cavity is made by sandwiching a section of ST between two SMF. The parallel cavities generate the Vernier effect due to a similar free spectrum range, which significantly improves the sensitivity of the sensor. The proposed sensor with good repeatability and reliability was used to monitor the change of air pressure, and provided a high sensitivity of −38.3 nm/MPa. The sensor exhibited the potential applications in the fields of aerospace industry, biological diagnostics and environmental monitoring.

Adhesives for increasing the bonding strength of in situ manufactured metal-composite joints

In this present work, the potential of metallic parts, locally reinforced with a continuous glass fibre reinforced thermoset material, pre-impregnated with an epoxy matrix (prepreg), was evaluated by differential scanning calorimetry (DSC), single-lap shear tests and 3-point bending tests of a metal-composite hybrid hat profile. This technology is evaluated regarding an automotive use case, the DSC experiments in combination with moulding trials have proven curing times below 30 s for a moulding temperature of 180°C. A bonding strength of 13.5 MPa was characterized for a co-cured fibre-reinforced plastic (frp) onto a metallic joining partner. By additionally introducing an epoxy glue film as a bonding agent, which is co-cured together with the frp, the bonding strength can be increased significantly up to 25.4 MPa at the expense of the curing time. The mechanical tests on the hybrid hat profile have shown an increase of energy absorption compared with non-reinforced hat profiles. Here, also an additional glue film extends the performance regarding a co-cured plastic reinforcement without glue film. The influence of the storage conditions of the uncured prepreg materials on the mechanical performance was evaluated by a simulated physical ageing at elevated temperatures, followed by a mechanical characterization of the bonding strength and part performance. Also the effect of different testing temperatures and testing velocities on the capability of the metal-composite hybrid part is illustrated.

Realization of Microlens Array on Flat Encapsulant Layer for Enhancing Light Efficiency of COB-LEDs

The conventional chip-on-board light-emitting diodes (COB-LEDs) with flat encapsulant layer present low light efficiency due to the total internal reflection (TIR) happens at the encapsulant-air interface. In this study, microlens array was realized on the flat encapsulant layer of COB-LEDs to diminish the TIR at the encapsulant-air interface. The microlens array was fabricated by selectively exposing the UV glue film in UV-light through a pre-designed photomask. Micro-pillars form after the UV-light exposure and microlens array forms spontaneously due to the wetting process of uncured UV glue on the micropillars. The geometry of the microlens array was experimentally optimized, and the light efficiency enhancement of COB-LEDs by the microlens array was analyzed. The results show that optimal geometry of microlens array with curvature of ~41° and base diameter of ~87 μm can be realized by adjusting the UV-light exposure time as >40 s and UV glue film thickness as >80 μm. Compared to the traditional flat encapsulant layer, the microlens array with optimal geometry increases the light efficiency of blue and ~5000 K white COB-LEDs by 50.9% and 9.31%.

Predicting the Behavior of Paper and Board Surfaces in Gluing, Printing and Coating Processes

Almost all paper is produced for further converting, it means it may undergo gluing, coating and/or printing. Therefore, normally certain specifications are agreed between the supplier and converter based on standard testing methods like Cobb, Gurley, Bendtsen, HST or Smoothness Beck etcetera and these specifications are binding. The problem is that sometimes there are still problems in the converting although all the specifications are met. In this case, nobody knows why these problems have occurred. We must look at the rough principles of the three typical converting processes like gluing, printing and coating. It is important to understand that nowadays all these processes are very fast, and things happen within milliseconds or just a few seconds. Because these processes are so fast, the surface of the paper or board that is converted plays a very important role. If we look more detailed at the gluing process, we can basically split it into 3 phases. In the First PHASE, a liquid film is applied on the paper or board surface by a pressure impulse within very short time. Here we talk about microseconds or milliseconds. The result depends on the rheology of the liquid, the strengths of the pressure impulse （which depends on the machine speed and settings） and the surface porosity of the substrate. Here, most important for the anchoring of the glue is the surface pore structure which is the relevant parameter to characterize. In PHASE 2, the water from the glue that has been applied will be absorbed. This is mainly controlled by the surface sizing/hydrophobicity of the substrate. Here the surface sizing or surface hydrophobicity is very important for the dewatering of the glue and to increase its viscosity to reach an optimal bonding. So, the surface hydrophobicity is the relevant parameter to characterize in this phase. PHASE 3 is the drying and hardening of the glue film which takes place after several minutes and hours. Because converting processes are very fast without phase 3, fast evaluation method is preferable. In this paper we introduce PDA/EST to evaluate penetration and predic behavior of paper and board surface for converting processes.

High-Precision Gluing Tasks Based on Thick Films of Glue and a Microrobotics Approach

Micro-assembly using glue is an industrial need, but at the microscale, the gluing process appears highly challenging. Especially when the thickness of the glue film is large relative to the size of components to be assembled. Moreover, the down-scaling of passive techniques used at the macroscale (such as using reference surfaces) are widespread, but require highly complex and dedicated procedures to reach the required precision (typically 1 μm or below). To address this, we propose an original approach for micro-assembly that consists of using a thick film of glue (glue thickness typically >50 μm) with an active microrobotic control. This approach enables us to have high precision positioning of the two components during the gluing task. The proposed approach appears highly versatile and flexible because it is independent of many parameters that usually influence gluing tasks. Several experiments without the use of the proposed approach show that the typical order of positional drift from curing could be of 5 to 15 μm. Finally, experimental results using the proposed approach demonstrate that a positioning accuracy of 200 nm can typically be obtained, which validates the approach and suggests its potential interest to industry.

Numerical Investigation of T-joints with 3D Four Directional Braided Composite Fillers Under Tensile Loading

Numerical studied on T-joints with three-dimensional four directional (3D4D) braided composite fillers was presented in this article. Compared with conventional unidirectional prepreg fillers, the 3D braided composite fillers have excellent ability to prevent crack from penetrating trigone fillers, which constantly occurred in the conventional fillers. Meanwhile, the 3D braided composite fillers had higher fiber volume fraction and eliminated the fiber folding problem in unidirectional prepreg fillers. The braiding technology and mechanical performance of 3D4D braided fillers were studied. The numerical model of carbon fiber T-joints with 3D4D braided composite fillers was built by finite element analysis software. The damage formation, extension and failing process of T-joints with 3D4D braided fillers under tensile load were investigated. Further investigation was extended to the effect of 3D4D braided fillers with different braiding angles on mechanical behavior of the T-joints. The study results revealed that the filling area was the weakest part of the T-joints where the damage first appeared and the crack then rapidly spread to the glue film around the filling area and the interface between over-laminate and soleplate. The 3D4D braided fillers were undamaged and the braiding angle change induced a little effect on the bearing capacity of T-joints.

Moisture uptake and permeability of canvas paintings and their components

Abstract Canvas paintings may show significant dimensional changes and experience internal stresses with fluctuating relative humidity. The relatively high and rapid absorption and drying of moisture within the different layers makes them more vulnerable than panel or wall paintings in comparable conditions. The dynamics of the moisture response is controlled by the water vapour permeability of the different layers. This paper presents a quantitative investigation of the vapour sorption and permeability of a selection of canvas painting components and of reconstructed paintings made of them. The selection of test samples was based on a survey of the materials used by Cuno Amiet in his early work and encompasses linen canvas, collagen glue sizing, chalk-glue ground and brown umber pigmented oil paint. Dynamic Vapour Sorption (DVS) tests were performed to obtain sorption isotherms. The vapour permeability was analysed in terms of the vapour resistance of layers and measured by means of wet cup and dry cup tests as well as in double chamber tests. The principle of incremental resistances was used to discriminate between the properties of the different layers. Whereas glue and canvas are comparable in being strongly absorbent, it appears that their vapour resistance is very different: a continuous glue film has a much higher vapour resistance than a canvas. In this context, we found that the method of applying glue sizing on a canvas influences the permeability of the resulting sized canvas: a gel size forms a more continuous glue film and hence leads to higher vapour resistance of the system, as opposed to a liquid size. Chalk-glue grounds have low moisture sorption, when compared to the high absorption of the proteinaceous glue, because they consist largely of chalk particles, which are not hygroscopic. The umber oil paint stands out for its low sorption and its high resistance to vapour transfer. These results characterise the highly heterogeneous nature of the multi-layered system of a painting in a quantitative way, enabling to better interpret damage phenomena and to make computational predictions of the influence of changing boundary conditions.

Measurement of heat transfer coefficient using termoanemometry methods

This work deals with a measurement of heat transfer from a heated flat plate on which a synthetic jet impacts perpendicularly. Measurement of a heat transfer coefficient (HTC) is carried out using the hot wire anemometry method with glue film probe Dantec 55M47. The paper brings also results of velocity profiles measurements and turbulence intensity calculations.

Imaging of the formerly bonded area of individual fibre to fibre joints with SEM and AFM

Besides the determination of the force and the energy needed to break individual fibre to fibre joints, the investigation of the formerly bonded area (FBA) is of essential importance to learn more about the failure mechanisms of fibre–fibre bonds in general. In this study the surfaces of paper fibres and the FBA of fibre–fibre joints after the determination of the breaking force as well as the bonding energy were analysed by means of low voltage scanning electron microscopy and atomic force microscopy. A comparison between the contact zone of fibres broken at different loading rates as well as under cyclic loading showed that there seems to be no significant difference in the appearance of the FBA in these cases. Only minor delamination of the cell wall could be found in the bonding zone, which indicates no mechanical interlocking of fibrils in the bonding zone. Furthermore, it is shown that some glues used for specimen preparation of fibre–fibre bond strength measurement are forming a glue film on the fiber surface and migrate into the bonding region.

Self-diffraction effects of Gentian violet dispersed in transparent glue films

We report self-diffraction effects appearing in Gentian violet dispersed in a transparent glue film. The diffraction patterns observed by us depend on laser intensity. When samples are exposed to laser irradiation for enough time, a film acts as a holographic medium.

Synthesis and Characterization of Core-shell Acrylic/polyurethane Emulsion with Unsaturated Macromolecule Monomer Method

Acrylic/polyurethane(PUA) hybrid emulsion has been prepared by water-borne polyurethane(WPU) modified with acrylic resin.A method for adding different mass fraction of acrylic(AC) into polyurethane(PU) polymers is proposed and verified through designed experiments.With increasing the polyacrylate(PA) mass fraction in the copolymer,the appearance of the emulsion changes from transparent to opacity,in the meantime,the particle size is increased.The TEM result reveals that PUA latex particles present clear core-shell structure and regular shape,and the size distribution is within the range of 60~120 nm.The results of FTIR indicate that the hydrogen bonding effect of PU hard segment first increased and then decreased,while the ordering of hard segment decreased with increasing the AC mass fraction.Compatibility and degree of mixing were developed under 75%AC added in copolymers.With increasing PA mass fraction,one glass transition temperature existed in the copolymers before the content of AC arrived 75%.Thermogravimetric analysis(TGA) shows that the temperatures for the maximal thermal mass-loss rate rose from 363 ℃ to 412 ℃,and water absorption for samples decreased from 11.3% to 5.7% with the increase of AC fraction.Additionally,the elasticity modulus of PUA was raised from 16.4 to 47.6 MPa,while the tensile strength was increased from 9.0 to 23.7 MPa,and the elongation at break changed from 365% to 408%.Furthermore,the composite latex viscosity is decresed,and the drying time is shortened,while glue film adhesion force becomes better.

2P1-G05 人間親和性を有する高機能型鬱血防止マットの開発(福祉ロボティクス・メカトロニクス(1))

Bed sore is cellular necrosis due to congestion, shear force or moisture. Thus, in this study, we propose a new type of mat system not to occur bed sore for handicapped people who use a wheelchair. This system uses a pneumatic mat to prevent congestion that is stanched blood flow. That is to say, the device has cloth actuators which are constructed with sponge, a glue film and a cloth. Therefore, the stiffness of each actuator can be controlled by inner pressure, so the contact pressure contribution can be changed by making use of pumps and valves. In this paper, we measured pressure distribution, shear force and moisture by using the proposed system. As the result, the effectiveness of proposed system is verified through some experimental results.

1A1-D24 布アクチュエータを用いた鬱血防止マットの開発

In this study, we propose a pneumatic mat to prevent congestion and bed sore using cloth actuators for handicapped people who use a wheelchair. This mat has 6 "cloth actuators" which are constructed with two kinds of sponge. Further, the Sponge is coated with both a glue film and a cloth. Thus, the stiffness of each actuator can be controlled by inner pressure. Moreover, the mat system is composed with cloth actuators, pumps, valves, and a microcontroller. Therefore, we can use the proposed mat as an independent system. In this paper, the effectiveness of the mat is cleared by some experimental results.