Acrylic Tape Research Articles

Effect of Surface Treatment on Tensile Strength of Steel Single Lap Joints Bonded with Double-Sided Acrylic Foam Tapes for Naval Applications

This study investigated single lap joints in steel used for naval carpentry. The surface was mechanically treated, and then a double-sided acrylic foam tape was applied with varying surface preparation conditions. Specifically, three different conditions were examined. Tensile tests revealed that changing the type of surface preparation significantly affects the mechanical strength of the joints. The best mechanical properties were achieved when a primer was used. Our results demonstrate that this method can be effectively employed in naval applications as an alternative to welding for non-structural applications, such as the installation of brackets for mounting electrical devices (e.g., sockets).

Strength and Ultrasonic Testing of Acrylic Foam Adhesive Tape

Adhesive joints are some of the oldest inseparable connections, and were used much earlier than other non-separable connections (e.g., welded, soldered). Adhesives are widely used in the manufacture of vehicles, household appliances, aircraft, and medicine. One disadvantage of adhesive joints is their long bonding time (amounting, for example, to 72 h for polyurethane adhesives used in bus roof bonding), and another is their production of harmful waste. Tapes that are adhesive coated on both sides are increasingly being used to join parts during production. Such tapes have lower strength than traditional adhesives, but their bonding time is much shorter. In addition, the amount of waste remaining after production is minimized. Tapes, like adhesives, dampen vibrations well and seal the materials being joined. The purpose of this study was to evaluate the influence of selected factors on the quality of tape–steel sheet joints and to assess the possibility of testing acrylic tape–steel sheet joints using ultrasonic methods. It was found that the preparation of a surface for bonding has a significant effect on the quality of the joint, and it was confirmed that non-destructive evaluation of the quality of the tested joints by the ultrasonic method is possible. The decibel drop in the height of the first and fifth pulses obtained on the screen of the ultrasonic defectoscope was proposed as an ultrasonic measure. The highest-quality joints were characterized by a measure in the range of 12 dB, lower-quality areas of about 8 dB, and tape-free areas of about 5 dB. At the same time, it was noted that in the case of proper surface preparation, there was cohesive failure of the joint during breakage.

Compliant frame geometry for DEMES-based gripper and flapping wing actuators: A comprehensive design study

Dielectric elastomer minimum energy structures (DEMES) have attracted significant attention in the recent past because of their ability to switch between multiple equilibrium states. The DEMES is formed when a pre-stretched elastomer film adheres to an inextensible frame and is further allowed to attain an equilibrium configuration as a result of energy minimization. While several researchers have investigated; both theoretically and experimentally, the underlying mechanics of DEMES, a majority of them deploy simplistic boundary frames (square/rectangular/circular) to obtain the requisite minimum energy configuration. In this paper, we demonstrate that this seemingly restrictive choice of using simplistic frame geometries can be given away by designing more complex-shaped compliant frames capable of producing useful modes of deformation. To demonstrate this idea, two prototypes; namely, the four-arm gripper actuator and the flapping-wing actuator, are studied numerically and experimentally. In both cases, a single compliant frame is used to realize the respective configuration, thus circumventing the need to assemble multiple MES on a common platform. In tandem, we investigate the role of reinforcements in (a) controlling the warping in MES and (b) maximizing actuation in the desired mode of deformation. Finite element analysis are carried out using the ABAQUS to determine the equilibrium configuration of the actuators, and subsequently their electromechanical behavior. Experimental investigations involve the utilization of the commercially available VHB 4910 acrylic tape in conjunction with PET frames and 3D-printed reinforcements. Excellent qualitative agreement is achieved between the numerical predictions and the experimental observations. Finally, we allude to a few innovative frame architectures leading the MES of engineering interest.

Flexible UV photodetector based on graphite/titanium dioxide through facile transfer of pencil drawn graphite films on desired substrates

Assembly of graphite structures through pencil drawn method is considered among the most facile and inexpensive approaches for a wide range of electronic and optoelectronic applications. However, the typical limitation of this methodology is that the films and structures can be drawn on a very limited number of substrates. Here, we report a novel methodology for the transfer of pencil drawn graphite films on desired substrate. The graphite films are transferred from cellulose paper, textile and wood paper onto flexible and transparent acrylic tape. The novel wood paper substrate is also used for the fabrication of bar device using a mask which is then transferred onto the acrylic tape. TiO2 nanoparticles paste is coated on the surface of transferred bar device. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction analysis, and UV–visible spectroscopy of graphite and graphite/TiO2-NPs electrodes are performed respectively to study their morphological, compositional, structural and optical features. The fabricated device acts as a UV photodetector and delivers a photocurrent as higher as 197.68 μA, photoresponsivity of 8.94 mA W−1, detectivity of 4.16 × 109 Jones at bias voltage of 5 V, response time of ∼860 ms and recovery time of ∼890 ms. The flexibility of the demonstrated photodetector is evaluated through recording changes in photocurrent under bending positions from 0 to 150°, and after employing bending cycles up to 1000. The results show that the fabrication of photodetector is facile and low-cost, and it offers valuable working compatibility under bending strains. Moreover, the flexibility of photodetectors enables their effective integration with human skin and clothes for human health monitoring applications.

Water Resistance of Acrylic Adhesive Tapes for Rooftop Fastening

Rooftop solar modules are usually held in place by racks or frames that are mechanically attached to a roof structure and/or by heavyweight, ballasted footing mounts. These mounts ensure that the panel system remains in position against wind load. However, mechanical connectors create penetrations into the water-resistant layer of the roof, whereas ballasted footing mounts cause a significant additional load on the load-bearing structure of roof. For these reasons, adhesive connection seems to be a beneficial solution. Acrylic adhesive tapes, marked as VHBTM, may provide sufficient strength, and they have no need for mechanical fasteners or ballast. Acrylic adhesive tapes also provide a comfortable, fast, and efficient bonding process with no curing compared to liquid adhesives. On the other hand, resistance to water at load-bearing joints has not been sufficiently studied yet and could be critical for connections exposed to the outdoor environment. The present study aims at the determination of water resistance and durability of the VHBTM tapes from the GPH series, which are typically used to bond a variety of substrates including many metals. The mechanical properties and failure modes are compared for the specimens before and after a 21-day immersion in water. A significant reduction in strength was observed, depending on the substrate material. The study of chemical changes in the acrylic tape and in its leachate through infrared spectroscopy (FT-IR), X-ray fluorescence, and X-ray diffraction analyses clarified the reduction in mechanical properties. The selected VHBTM tape demonstrated strong resistance to the effects of water. However, the overall strength of the joint after immersion was significantly impacted by the decrease in adhesion to a specific substrate.

Development of a testing machine for biaxial testing of soft tissue and biomaterials

Knowledge of the mechanical properties of soft tissues and biomaterials is the keystone for predictive modeling in cardio- and endovascular surgery, traumatology and orthopedics, neurosurgery, and the development of tissue-engineering constructs. Needed mechanical properties can be only explored via experimental tests. Therefore, mechanical experiments are forming the foundation of medical decision support systems, which are impossible without adequate mathematical models of the processes involved. Sirius University of Science and Technology has launched the project "Experimental research and mathematical modeling of the mechanical behavior of biomaterials". The goal of the project is to create an infrastructure for experimental study of the mechanics of soft tissues and biomaterials. At this stage, a machine for biaxial testing of soft tissues and biomaterials has been developed and put into trial operation. The developed machine takes into account the features of working with soft tissues: small sample size, maintaining certain environmental conditions to preserve the sample, various types of sample gripping to minimize edge effects and no slippage, non-contact methods for assessing displacement and deformation fields, variability in sample loading protocols. The result of the test is a data set that includes a test report and synchronized output readings of strain gauge, temperature, optoelectronic sensors with high-resolution images. Uniaxial verification tests of acrylic tapes VHB4910 were carried out by the developed machine. The results were compared with data obtained on a commercial dynamic mechanical analyzer RSA-G2 (TA Instruments) for similar materials under the same test conditions. A series of biaxial cyclic experiments were carried out for the pericardium of cattle, the cardiovascular patch Ecofolon PS04/PS01 (JSC NPK Ecoflon, St. Petersburg, Russia), and the GoreTex vascular graft (W.L. Gore and Associates, USA).

Impact of artificial ageing on the performance of acrylic self-adhesive tapes

The use of sealing tapes in creating a continuous envelope to ensure the airtightness of the building is an essential factor. The study aims to investigate the performance properties of single-sided self-adhesive tapes for building applications and to obtain the changes in these properties due to the effects of environmental factors. The tapes were glued to the different substrates. Peel adhesion, tack of the tapes, and the air permeability of sealed elements were determined. The adhesive tape were aged in the laboratory using two different methods, standard (EN 12024) and a new one, during which the test samples were exposed to the cyclic impact of the temperature and humidity of multiple levels. Analysis of the results showed that the substrate has influence on the adhesive behaviour of the self-adhesive tapes. After artificial aging, in most cases, the performance properties of the tapes do not change significantly. The novel approach allowed the comparison of the influence of different aging factors on the change in the performance properties of the tape and contributed to the development of a methodology for testing the durability of sealing tapes. The effect of substrate on tape adhesion was also investigated, which is useful from both a practical and a methodological point of view.

Synthesis and Characterization of Pressure-Sensitive Adhesives Based on a Naphthyl Curing Agent.

The incorporation of a naphthyl curing agent (NCA) can enhance the thermal stability of pressure-sensitive adhesives (PSAs). In this study, a PSA matrix was synthesized using a solution polymerization process and consisted of butyl acrylate, acrylic acid, and an ethyl acrylate within an acrylic copolymer. Benzoyl peroxide was used as an initiator during the synthesis. To facilitate the UV curing of the solvent-borne PSAs, glycidyl methacrylate was added to introduce unsaturated carbon double bonds. The resulting UV-curable acrylic PSA tapes exhibited longer holding times at high temperatures (150 °C) compared to uncross-linked PSA tapes, without leaving any residues on the substrate surface. The thermal stability of the PSA was further enhanced by adding more NCA and increasing the UV dosage. This may be attributed to the formation of cross-linking networks within the polymer matrix at higher doses. The researchers successfully balanced the adhesion performance and thermal stability by modifying the amount of NCA and UV radiation, despite the peel strength declining and the holding duration shortening. This research also investigated the effects of cross-linking density on gel content, molecular weight, glass transition temperature, and other properties of the PSAs.

Passive Damping of Solar Array Vibrations Using Hyperelastic Shape Memory Alloy with Multilayered Viscous Lamina

A novel passive vibration-damping device is proposed and investigated for a large deployable solar array. One strategy for achieving high damping in a solar panel is using a yoke structure comprising a hyperelastic shape memory alloy and multiple viscous adhesive layers of acrylic tape. The effectiveness of the proposed system in achieving a high damping performance was demonstrated by conducting free vibration and low-level sine sweep tests using a solar array, and a 0.75-m-long flexible dummy structure was simulated. We also investigated the dependence of the damping performance of the proposed structure on the number of viscous lamina layers. Finally, the damping characteristics of the proposed system were assessed under predictable on-orbit temperature conditions.

Effect of geometrical parameters on the nonlinear behavior of DE-based minimum energy structures: Numerical modeling and experimental investigation

This work presents a finite element framework for simulating the quasi-static response of dielectric elastomer-based minimum energy structure (DEMES). The DEMES is an actuator formed by combining an inextensible frame and pre-stretched dielectric membrane that exhibits the unique shape-morphing characteristics of the actuator. A continuum strain energy-based model is implemented to investigate the impact of the different geometrical parameters on the performance of the DEMES actuator. Finite element analyses are performed using user-defined element (UEL) in ABAQUS for determining the equilibrium shape of the actuators and further investigating their electromechanical response. Experiments are performed using the commercially available VHB-4910 acrylic tape and the PET frames. 3D-printed reinforcements are used to impart anisotropy in the specimen. The findings of the model solutions provide preliminary insights on the alteration of the initial and final configurations of the DEMES affected by different geometrical parameters. It is observed that the shape of the electrode (rectangular, circular and triangular), compliant frame (rectangular, circular and triangular) and implemented stiffeners appreciably alter the attained initial configuration, final configuration and actuation range of the DEMES actuator. In general, this investigation can find its potential use in designing the futuristic DEMES through topological optimization of the compliant electrode and frame geometry together with material anisotropy of the elastomer.

Experimental Investigation of the Failure Scenario of Various Connection Types between Thin-Walled Beam and Sandwich Panel.

The paper presents failure scenarios for various types of connections between a thin-walled beam and a sandwich panel. In addition to standard connections used in civil engineering applications, that is, self-drilling fasteners for sandwich panels, the study examined the use of bolts, blind rivets, and double-sided acrylic tape applied linearly and pointwise. The connections were subjected to the horizontal load applied with constant eccentricity with respect to the plane of the connection surface. This load arrangement simulates the behaviour of a free flange of the thin-walled beam in bending while lateral-torsional buckling occurs. In this way, the research covers the determination of the lateral stiffness of the thin-walled beam-free flange, while the other flange is connected to the sandwich panel using various connection systems.

Bonding of composite parts: advantages and benefits of Structural Adhesives and Self-adhesive Tapes

The bonding process of composite materials is a challenging method in growing markets like Transportation and Construction. Differents methods exist today for the assembly of composite materials: mechanical fixing, ultrasonic welding, structural adhesives and acrylic foam tapes. Each method has its own advantages and drawbacks, but bonding with structural adhesives or acrylic foam tapes offer important benefits compared to mechanical assemblies. Adhesives and tapes allow to bond dissimilar substrates while keeping mechanical performance and improving aesthetics of composite materials. The Transportation market is leading the increasing demand of composite materials and design engineers look for detailed information on bonding methods and the performance of adhesives for the designed vehicles: mechanical and vibrations resistance, tenacity and elasticity, durability and capability to withstand extreme conditions. Design engineers require more than a bonding solution, they need technology partners like 3M providing technical support for project development, materials and adhesives testing, and process consultants for the optimization and automation of bonding processes. Los ingenieros quieren algo más que una solución adhesiva, y buscan socios tecnológicos como 3M. The purpose of this article is to create awareness on 3M new adhesive and tape technologies for multi-material bonding integrating a composite material. Assembly types and solutions allow to find the best adhesive technology for optimal bond design and manufacturing process.

New Version of High-Damping PCB with Multi-Layered Viscous Lamina

In a previous study, a high-damping printed circuit board (PCB) implemented by multilayered viscoelastic acrylic tapes was investigated to increase the fatigue life of solder joints of electronic packages by vibration attenuation in a random vibration environment. However, the main drawback of this concept is its inability to mount electronic parts on the PCB surface area occupied by interlaminated layers. For the efficient spatial accommodation of electronics, this paper proposes a new version of a high-damping PCB with multilayered viscoelastic tapes interlaminated on a thin metal stiffener spaced from a PCB. Compared to the previous study, this concept ensures efficient utilization of the PCB area for mounting electronic parts as well as the vibration attenuation capability. Free vibration tests were performed at various temperatures to obtain the basic characteristics of the proposed PCB. The effectiveness of the proposed PCB was verified by random vibration fatigue tests of sample PCBs with various numbers of viscoelastic layers to compare the fatigue life of electronic packages.

High Damping Passive Launch Vibration Isolation System Using Superelastic SMA with Multilayered Viscous Lamina

Whole-spacecraft launch-vibration isolation systems are attractive for achieving the goal of better, faster, cheaper, and lighter small satellites by reducing the design-load and vibration-test specifications for on-board components. In this study, a three-axis passive launch-vibration isolation system, based on superelastic shape memory alloy (SMA) technology, was developed to significantly attenuate the dynamic launch loads transmitted to a small satellite. This provides a superior damping characteristic, achieved by superelastic SMA blades stiffened by multilayered thin plates with viscous lamina adhesive layers of acrylic tape. The basic characteristics of the proposed isolation system with various numbers of viscoelastic multilayers were obtained through a static load test. In addition, the effectiveness of the design was validated through a launch environment simulating sine and random vibration tests.

Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism

In this present work, a highly damped deployable solar panel module was developed for application in the 3 U CubeSat. The solar panel proposed herein is effective in guaranteeing the structural safety of solar cells under a launch environment owing to the superior damping characteristics achieved using multilayered stiffeners with viscoelastic acrylic tapes. A holding and release action of the solar panel was achieved by a new version of spring-loaded pogo pin-based burn wire triggering mechanism. A demonstration model of high-damping solar panel assembly was fabricated and tested to validate the effectiveness of the design. The holding and release mechanism achieved using a pogo pin was functionally tested through solar panel deployment tests under ambient room temperature and a thermal vacuum environment. The design effectiveness and structural safety of the solar panel module were validated through qualification-level launch and in-orbit environment tests.

High-damping PCB implemented by multi-layered viscoelastic acrylic tapes for use of wedge lock applications

Wedge locks have been widely used for effective spatial accommodation and easier integration of electronics. However, an increase in the dynamic displacement of the printed circuit board (PCB) with the increase in the board size is unavoidable because the wedge lock provides mechanical fixation only along the edge of the board. This is one of the technical issues in assuring the fatigue life of electronic packages under a severe vibration environment. However, application of a stiffener for the reduction of board displacement leads to an increase in the mass and volume of the electronics. In this study, for implementing lightweight and compact electronics, we proposed a high-damping PCB for effective vibration attenuation caused by high damping characteristics implemented by multi-layered viscoelastic acrylic tapes. The basic characteristics of the proposed PCB were obtained through free-vibration tests under various temperature conditions. Additionally, random vibration tests of PCB specimens with various layers of viscoelastic tapes were performed, and the fatigue life of electronic packages was compared to that of the specimen without tapes.

Polymer multilayers enabled stable and flexible Au@Ag nanoparticle array for nondestructive SERS detection of pesticide residues

The development of flexible and robust plasmonic substrates has become a hot research topic in simplifying and extending the application of surface-enhanced Raman scattering (SERS) technique for real-world analysis. In this work, a facile method to fabricate an Au@Ag nanoparticle array sandwiched between the adhesive acrylic polymer tape and polyethene terephthalate (PET) film (T/Au@Ag/PET) as a high-performance SERS chip was reported for nondestructive detection of thiram on fruit peels. For this SERS chip, the ordered Au@Ag nanoparticle array formed by the self-assembly method was closely-packed, which generated high‐density sub‐3‐nm gaps and could produce high reproducible and sensitive SERS enhancement effects. The measurement of crystal violet with the limit of detection of 7.24 × 10−10 M was realized by targeting Raman shift at 1177 cm−1. Moreover, the excellent flexible feature of acrylic polymer tape enabled the substrate to withstand a tensile strain value of 20% for three cycles without significantly losing its SERS activity. By covering with a PET film, the SERS chip could maintain 87% SERS activity after storage for 60 days in the air environment, and could well withstand the influence of harsh conditions such as high temperature and ultrasound treatments. As a proof of the concept, the SERS tape was directly used to detect thiram on apple, tomato, and cucumber peels via a simple sampling-and-detection procedure, and the detection limit of 5 ng/cm2 was achieved. The T/Au@Ag/PET SERS chip should hold a promising candidate for food safety analysis in the future.

Low-Velocity Impact Characteristics of Hybrid Aluminum/CFRP Single Hat Sectioned Beam Adhesively Bonded Using Adhesive Tape

Single hat sectioned hybrid beams composed of aluminum and Carbon Fiber Reinforced Polymeric materials (CFRP), intended for structural applications in the automotive and aviation sectors, have been studied from the point of their energy absorption capabilities when submitted to transverse low-velocity impact loading. Carbon fiber-epoxy composite prepregs were placed on the inside of the single hat sectioned aluminum sheet and completely cured in the autoclave under the recommended curing cycle. The bonding process between the aluminum sheet and composite layers was achieved by using 3M VHB™ 4930 double-sided acrylic foam tape. Bonding the aluminum and composite layers through adhesive tape eliminates the requirement of surface preparation of the aluminum layer through chemical etching or mechanical abrasion and thereby the strength of the metallic layer is not reduced due to the formation micropores during the chemical etching process. Results are shown in terms of load-displacement and damage morphologies diagrams; characteristic trends are compared and discussed. It was observed that the presence of viscoelastic adhesive tape material restricts the rupture (visual cracks) failure of the outer aluminum layer, resulting in the only impact-induced indentation for all impact energies. Numerical simulations were also performed to characterize and predict the failure mechanism of such hybrid beams when subjected to impact loading. Numerical predictions showed good correlation with experimental results for all impact histories at low and medium impact energies but a showed slight discrepancy for highest impact energy and were not able to successfully capture the system response in the unloading region. Current modeling does not consider damage healing or recovery with unloading and it is difficult to account for such change in material state. This study provides the low-velocity impact characteristics and collapse behavior of the hybrid hat sectioned beams under tensile and shear forces developed by impact loading by providing insight to their primary damage mechanisms relative to the impact energies. It was found that the primary damage of the specimen’s changes from impact-induced indentation, minimal fiber breakage to partial perforation accompanied by larger indentation depth as the impact energy is increased from 6 to 12 J.

CubeSat’s Deployable Solar Panel with Viscoelastic Multilayered Stiffener for Launch Vibration Attenuation

Ensuring the structural safety of a deployable solar panel under a severe launch vibration environment is one of the important factors for a successful CubeSat mission. A CubeSat’s deployable solar panel proposed in this study is effective to guarantee the structural safety of solar cells by attenuating launch loads owing to the superior damping characteristic achieved by a multilayered stiffener with viscoelastic acrylic tapes. The demonstration model of 3 U CubeSat’s deployable solar panel was fabricated and tested to validate the effectiveness of the proposed design. The basic dynamic characteristics of the solar panel were measured through free-vibration tests according to the various layers of the stiffener. Moreover, the characteristics of the deployed solar panel were measured and investigated under various temperatures to predict its capability under in-orbit operation. The effectiveness of the proposed design for launch vibration attenuation was demonstrated through qualification level sine and random vibration tests.

Rate dependent shear debonding between a highly stretchable elastomer and a rigid substrate: Delayed debonding and pre-stretch effect

In this paper, the interfacial shear debonding characteristics and mechanism between a highly stretchable acrylic tape and a rigid polycarbonate strip are explored systematically with three types of in-plane loading. An effective approach is proposed based on the findings to improve interfacial adhesive strength. The debonding energy solely dissipated by breaking the interfacial bonds is found to be closely related to the loading rate, which can be explained by the Chaudhury’s model. Rate dependent delayed debonding is repeatedly observed under various stretch levels. The threshold level of the driving force of delayed debonding is correlated with the intrinsic fracture energy of the interfacial molecular chains and expected to be rate independent. Shear debonding is significantly affected by the pre-existed defects at the interfacial crack front. An effective and easy-to-operate cyclic pre-stretch approach with a moderate amplitude and rate is proposed, which is capable of improving the interfacial reliability by diminishing the pre-existed defects. A quantitative model is also constructed to characterize the pre-stretch effect on the interfacial adhesion.