Peel Test Method Research Articles

A Peel Test Method to Characterize the Decay Law of Prepreg Tape Tack at Different Temperatures.

The tack of prepreg is a key factor affecting the automatic tape laying process. During the manufacturing process of large composite parts, prepreg material may be stored at room temperature for several days, resulting in a decrease in its tack. In this study, a new tack test tool was designed, and the decay rate of prepreg tack at different temperatures was tested. We proposed a prepreg tack decay model, which assumes that the main factor in tack decay is the reduction in resin chain activity during storage. The maximum deviation between the model calculation results and the experimental results of the tack decay rate is 9.7%. This study also proposed a new statistical unit for prepreg tack, which can establish the relationship between the tack of prepreg and its remaining storage time and reduce prepreg management costs.

Direct Metal Layer Forming with Good Adhesion on Porous AAO Films by Electroless Cu Plating

Porous anodic aluminum oxide (AAO) films have great potential for micro and nano fabrication. Development of metallization techniques for AAO films is necessary for AAO device fabrication. In this work, a process for electroless Cu plating on AAO films was investigated. A quick Pd2+ removal process after activation improved the adhesion between plated copper (Cu) layer and AAO films. Since the Pd catalyst at the AAO top surface was effectively removed by a complex agent, the plating reaction started approximately 15–20 μm deep in the nanopores. The Cu was continuously deposited to the top of the nanopores and finally covered the AAO surface. The adhesion strength between the Cu films and AAO films measured by the 90° peeling test method was over 0.5 kN/m. Successful electroless Cu plating on AAO is an all-wet chemical batch process that does not require sophisticated fabrication facilities, and can be used as a low-cost metallization process for producing AAO microdevices.

Correlation between Surface Energy and Adhesion Force of Polyethylene/Paperboard: A Predictive Tool for Quality Control in Laminated Packaging

Poor adhesion continues to be a problem for manufacturers of laminated packaging. Therefore, the aim of this research was to study the effect of flame treatment, the type of coating, and starch application on the adhesion force of polyethylene/paperboard. The force of adhesion was determined using the peel test method; the paper surface energy was assessed by contact angle analysis; and paperboard roughness was determined by profilometer. The flame treatment did not affect the surface roughness but significantly increased the paperboard surface energy. The paperboard coated with polar latex showed much higher surface energy than the paperboard coated with nonpolar latex. The adhesion force of polyethylene presented a linear correlation to the surface energy of the paperboard. Therefore, the surface energy of paperboard is an excellent indication of its adhesion force to polyethylene, and this represents a very reliable and practical method in terms of quality control in the paper industry for producing laminated packages.

Assessing surface weathering by revision and implementation of the peeling-test: In situ sampling and integrated analyses

Weathering diagnostics is mainly focused on the characterization of deterioration patterns in a mostly descriptive and non-quantitative way. Several authors tried to numerically evaluate rate and extent of the decay features highlighted in case studies. Among others, the peeling-test method was developed to recast reliable data in describing decohesion of surfaces. Such methodology is affected by high operator dependency, due to manual application of the tape on the surface and high variability in the patch area and tape typology. Our study was aimed at improving the methodology by the implementation of a device able to warrant a well-defined pressure during the application, a constant strapping angle along with the standardization of the scotch tape area and typology, obtaining reliable semi-quantitative and qualitative analyses. The revised methodology was then tested on a cladded wall in the Staglieno Monumental Cemetery in Genoa. The site was addressed by multi-scale analysis (i.e., weathering maps sketched from macro-scale observation, surfaces analyses and micro-sampling through peeling). The application of the methodology allowed highlighting the presence of capillary rise up to 1–1.5 meters height and a more weathered central area. On the whole, our protocol allowed reproducible factual sampling, and, on statistically significant population, the categorisation of decay intensity.

Characterisation of metal–thermoplastic composite hybrid joints by means of a mandrel peel test

Fastener free metal–carbon fibre reinforced thermoplastic composite hybrid joints show potential for application in aerospace structures. The strength of the metal–thermoplastic composite interface is crucial for the performance of the entire hybrid joint. Optimisation of the interface requires an evaluation method for these hybrid structures. This work demonstrates the applicability of a mandrel peel test method for this purpose. The suitability of the mandrel peel test for certain hybrid joints is evaluated. Furthermore, a series of parameters in mandrel peel test are assessed in order to optimise the evaluation of the performance of metal–thermoplastic interface.

Optimization of the tape placement process parameters for carbon–PPS composites

The interrelation between process parameters, material properties and interlaminar bond strength is investigated for the laser assisted tape placement process. Unidirectionally carbon reinforced poly(phenylene sulfide) (PPS) tapes were welded onto carbon woven fabric reinforced PPS laminates. The laminate and tape temperature distribution was measured during the welding process. The mandrel peel test method was applied to quantify the bond strength. The experiments demonstrated that an excellent bond quality can be obtained at high velocities and low input power in case the laser is primarily aimed at the tape. For these settings, the tape temperature exceeds the laminate temperature, while the latter stays well below the melt temperature of the PPS.

Improvement of the adhesive peel strength of the secondary barrier with level difference for LNG containment system

Cryogenic Containment Systems for LNG (Liquefied Natural Gas) ships are required to satisfy durability and safety for 40years of operation. Membrane type LNG containment ships generally consist of three parts such as the primary barrier which is made of stainless steel, the secondary barrier which is made of composite or metal foil, and the insulation board which is made of polymer foam. The secondary barriers which are the face parts of sandwich insulation boards are adhesively bonded with metal strips to keep the gas tightness. When LNG is loaded in the containment system, large thermal stresses are generated in the metal strips due to the cryogenic temperature of LNG (−163°C). If there is a level difference between the insulation boards, the adhesively bonded metal strips are subjected to peel stress due to the level difference.In this work, FEM analysis was performed to calculate the critical peel load with the level difference of 3mm between the insulation boards due to the non-uniform flatness of the inner hull structure of LNG ships. To verify the adhesive strength, a new peel test method representing height differences of the secondary barrier was developed. Finally, the adhesive was reinforced with E-glass fiber to increase the peel strength of adhesive and the optimal areal mass of E-glass fiber reinforcement was determined by the new peel test method.

Standardization of peeling tests for assessing the cohesion and consolidation characteristics of historic stone surfaces.

A peeling test known as the “Scotch Tape test” has been used for more than 40 years in conservation practice for assessing the consolidation efficiency of degraded stone. However, the method has not been supported by any standard or reliably verified recommendations for its application. Its applicability is overestimated, and its unrestricted use without adequate knowledge and sufficient understanding can lead to non-comparable, non-reproducible and, in many cases, incorrect and severely biased results and assessments. This paper presents the results of a recent study focused on establishing limits for application, reliable procedures and a “standard” protocol for testing the cohesion characteristics of brittle and quasi-brittle materials, mainly mortars and stones. The main application strategy exploits repeated peeling in the same place on a surface in order to eliminate the effect of the natural decrease in the detached material from the subsurface layers, which might be incorrectly interpreted as a consolidation effect. There is a discussion of factors influencing the performance of the peeling test method, and examples of peeling measurements on various natural and artificial stones are presented.

Development of a Mode III fatigue test method and a peel test method for tire specimens

Crack growth plays an important role in the durability of tires, and it is necessary to evaluate the characteristics of crack growth and tearing energy accurately. Since a crack around the belt edge is subjected mainly to interlaminar shear deformation, a Mode III fatigue test method was developed. In addition, a peel test method was developed to assess the tearing energy. Based on the fatigue and peel test results, the effects of heat aging, temperature and belt stiffness were analyzed.

Diffusion Aided Joint Healing in Polymers at Interfaces

This article reports the results of diffusion studies of 4,4′-diphenyl methane diisocyanate (MDI) at 40°C into different kinds of thermoplastic materials, and, thereafter, application of the same concept in polymer joint healing at interfaces. Two categories of samples were used for adhesion studies: (1) aged at 40°C for 100 h and (2) non-aged samples. The adhesion/failure strength at the interface was measured using a peel test method. The thermoplastic materials used were a copolymer and/or blends of the following polymers: polystyrene-co-maleic anhydride (SMA), polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), and silicone-acrylate rubber (SAR). A gravimetric method was used to measure the mass uptake and the optical microscopy was employed for the determination of the diffused layer of MDI into the thermoplastic materials. In two of the thermoplastic blends, glass fiber (GF) was also blended along with the copolymers. MDI was found to have no diffusion in neat/pure SMA copolymer, whereas the diffusion coefficient for PC/ABS was the highest for the samples investigated. The results are discussed in terms of functional groups present in the different interacting materials. In general, the aged samples showed higher adhesive strength than the non-aged samples.

Tape-Peel Testing as a Simple Method to Evaluate the Adhesion of Coated Layers on Metal Core PCB

Conventional printed circuit boards (PCBs) may be replaced by thinner metal-core boards for some applications, as well as for package substrates. Using thin, metal-core technology may provide advantages for radio frequency (RF) circuits and packages, and increase heat dissipation for high power applications. The metal-core technology discussed in this paper has several layers including the metal core, electro-coated dielectric, sputtered metal layers, and electroplated copper. For PCB and substrate reliability, it is important to have sufficient adhesion between the dielectric layer and plated copper. Sputtered metal layers with cleaning pre-treatments are one of the methods to improve the interfacial adhesion. This paper describes an efficient testing method for the adhesion of a thin sputtered metal layer to a dielectric substrate. In this method, adhesive tape was attached to the surface and peeled off at 90 degrees in a tensile tester. Due to the sub-micron thickness of the sputtered layers, conventional peel test methods could not be applied. Typical adhesion testing of upper layers like paint coatings use a lattice pattern. The new method provided a convenient, repeatable way to evaluate the adhesion of three different sputtered metals with fifteen different pretreatment combinations. The test results were used to choose the sputtered metal and were later confirmed by testing the copper plated assembly using the metal adhesion specification in the industry standard IPC-TM-650. A review of other methods and the need to identify an easy to use method which can provide repeatable quantitative measurements.

Adhesive Strength of Marine Mussel Plaques to Soda-Lime Glass

Mussels living in the ocean adhere to shore reef and each other with byssus formed by insolubilization of adhesive proteins, whose application to the new bio-adhesion material has been expected. Their adhesive strength has not been accurately measured because peel test method is not established since the contact areas between a plaque and the substrate are less than 1 mm2. Present paper attempts to measure adhesive strength of the plaques using original simple peel test method and investigates the influence of environmental change on the adhesive strength and the change of the adhesive strength in the lapse of time. The results show that the adhesive strength of the plaques decrease with the change in the environment by transferring mussels from the beach to an experimental environment and the adhesive strength changes along with the elapsed time after the plaques are secreted.

Evaluation of adhesive properties of three resilient denture liners by the modified peel test method

The characteristics of adhesive properties between a denture base and resilient denture liner were investigated by a modified peel test with an L-shaped metal attachment. Three commercially resilient denture lining materials, namely GC Reline Soft (S), GC Reline Extra Soft (ES), and GC Reline Ultra Soft (US), were evaluated. Acrylic resin (GC Acron) was used as denture base material. Peel specimens consisting of the denture base acrylic resin and resilient denture liner were tested after storage for 1 and 30 days in distilled water at 37°C. The modified peel test method gave load–displacement curves and work of adhesion (WA) values of the denture base material and resilient denture liner. The WA of specimens after 1 day of storage ranged from 1.71 to 2.55Nmm−1 and increased in the order from US to S to ES. On the other hand, the WA of specimens after 30 day of storage ranged from 1.44 to 2.47Nmm−1 and increased in the order from US to ES to S. US had significantly lower WA after 1 and 30 days of storage than did S and ES (P<0.05). Comparison of the WA between 1 and 30 days, reveals large differences for ES and US, but not for S. This could be explained by the difference in failure modes. Within the limitations of this investigation, it was concluded the modified peel test is effective for evaluating the adhesion between denture base material and a resilient denture liner.

Investigations on the adhesion and interfacial properties of polyurethane foam/thermoplastic materials

AbstractThe adhesion and interfacial properties of polyurethane (PU) foams with thermoplastic (TP) materials were investigated using different techniques. The adhesion performance of PU foam with TP materials was evaluated using the peel test method, and the adhesion durability was checked after different climate treatments. X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and contact angle measurements were used to study the surface and interface morphology of PU foam and TP material system. Three types of PU foam samples which differ in their composition and also five commercially available TP blends systems, based on poly(carbonate), poly(styrene‐co‐maleic anhydride), poly(acrylonitrile‐butadiene‐styrene), and silicone acrylate rubber have been used. The slow reacting foam shows the best adhesion properties with all the TP materials. The climate treatments strongly effected the PU foam adhesion durability with poly(carbonate) containing TP materials (70–80% loss in adhesion), but nearly no effect with poly(styrene‐co‐maleic anhydride). The samples with lowered adhesion could be separated by peeling without visible foam residues on the TP surface. AFM, XPS, and surface tension studies have shown that the surface properties of the TP material are still governed by the PU foam. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 479–488, 2007

Adhesive Strength of Plaque to Soda-Lime Glass in Marine Mussel

Mussels living in the ocean adhere to shore reef and each other with byssus formed by insolubilization of a bonding protein, whose application to the new bio-adhesion material has been expected. Their adhesive strength has not been accurately measured because peeling test method is not established since the contact areas between a plaque and the substrate are less than 1 mm2. Present paper attempts to measure adhesive strength of the plaque using original simple peeling test method and investigates the influence of environmental change on the adhesive strength and the change of the adhesive strength in the lapse of time. The results show that the-adhesive strength of the plaque decreases with the change in the environment by moving mussels from the beach to an experimental environment and the adhesive strength changes along with the elapsed time after the plaque is formed.

1016 温度履歴がムラサキイガイ付着盤の接着強度に及ぼす影響(G02-1 バイオエンジニアリング(1),G02 バイオエンジニアリング)

The adhesive protein of the mussel is expected as an ingredient of the new adhesive, there are few studies about the mechanical characteristic of the protein. In this study, curing temperature dependence of the adhesive strength was investigated from the viewpoint of mechanical strength. The original peel test method by spatula-shaped probe was used for the measurement of the adhesive strength. The effect of a temperature hysteresis in curing on the adhesive strength to substratum of the protein by changing curing temperature was examined. The results show that the adhesive strength depended on curing temperature in a range of 20-70℃.

Protocols for the Measurement of Adhesive Fracture Toughness by Peel Tests

This article reports on the work of the European Structural Integrity Society Technical Committee 4 (ESIS TC4) and its activities in the development of test protocols for peel fracture. Thirteen laboratories have been working on peel test methods in ESIS TC4 since 1997 and their activities are ongoing. The aim of the work is to develop robust and credible test methods for the determination of adhesive fracture toughness by peel tests. Several geometric configurations have been used, namely, multi-angle fixed arm peel, T-peel, and roller assisted peel in the form of a mandrel test. The starting point of their work is an established analysis of a peel method that is often developed from a global energy approach. The adopted analysis is combined with an experimental approach in order to resolve ambiguities in the determination of adhesive fracture toughness (G A ). The test methods involve the measurement of peel strength in order to calculate the total input energy for peel (G) and the calculation of the plastic bending energy (G P ) during peel. The latter is often obtained from a measurement of the tensile behaviour of the peel arm. Adhesive fracture toughness is then G – G P . Four ESIS TC4 projects are described. The first relates to fixed arm peel whilst the second and third involve both fixed arm and T-peel. The fourth project combines mandrel peel and fixed arm peel. Each project uses different types of polymeric adhesives in the form of quite different laminate systems. The selection of the laminate system enables all characteristics of laminate property to be embraced, for example, thin and thick adhesive layers, polymeric, and metallic peel arms and a range of flexibility in the laminates. The development of the enabling science required to establish the test protocols is described and software for conducting all calculations is referenced.

A numerical analysis of the elastic-plastic peel test

The adhesive fracture energy, G c, is determined from two types of elastic-plastic peel tests (i.e. the single-arm 90° and T-peel methods) and a linear-elastic fracture-mechanics (LEFM) test method (i.e. the tapered double-cantilever beam, TDCB method). A rubber-toughened epoxy adhesive, with both aluminium-alloy and steel substrates, has been used in the present work to manufacture the bonded joints. The peel tests are then modelled using numerical methods. The overall approach to modelling the elastic-plastic peel tests is to employ a finite-element analysis (FEA) approach and to model the crack advance through the adhesive layer via a node-release technique, based upon attaining a critical plastic strain in the element immediately ahead of the crack tip. It is shown that this ‘critical plastic strain fracture model (CPSFM)’ results in predicted values of the steady-state peel loads which are in excellent agreement with the experimentally-measured values. Also, the resulting values of G c, as determined using the FEA CPSFM approach, have been found to be in excellent agreement with values from previously-reported analytical and direct-measurement methods. Further, it has been found that the calculated values of G c are independent of whether a standard LEFM test or an elastic-plastic peel test method is employed. Therefore, it has been demonstrated that the value of the adhesive fracture energy, G c, is independent of the geometric parameters studied and the value of G c is indeed a characteristic of the joint, in this case for cohesive fracture through the adhesive layer. Finally, it is noted that the FEA CPSFM approach promises considerable potential for the analysis of peel tests which involve very extensive plastic deformation of the peeling arm and for analysing, and predicting, the performance of more complex adhesively-bonded geometries which involve extensive plastic deformation of the substrates.

Adhesion Improvement of Copper Plating on PPO Resin for Printed Wiring Boards Material using Low Temperature Plasma Treatment

An investigation was performed on the interfacial control between polyphenyleneoxide (PPO) resin and copper conductor with a low temperature plasma treatment in order to find a new method for fabricating an insulation layer and a conductor layer. Various plasma treatments on the surface of PPO resin plate were carried out with three kinds of oxygen gas, nitrogen gas and argon gas under the constant treatment condition of pressure 30 Pa, power 50 W and time 600 s. The interfacial strength between PPO resin and copper plating was estimated by the peel test method. Furthermore, an XPS analysis and an AFM observation were carried out to investigate the surface characteristics of PPO resin. As a result, it was found that their surface energy largely increased, and functional groups (carboxyl group, hydroxyl group, carbonyl group) were formed on the surface after all plasma treatments. The peel strengths after plasma treatments were increased and the surface energy and these peel strengths showed a linear relation. And also, it became clear that the skewness value of surface roughness is an effective parameter for evaluating the peel strength of copper plating in the case of surface characterization formed by plasma etching.

高分子フィルム上に形成したぜい性薄膜の界面付着強度評価

This paper demonstrated Multi-stages peel test method to evaluate the interfacial adhesion strength between brittle thin film and polymer substrate for flexible optoelectronic devices. The mechanical properties of polymer substrate are strongly influenced by UV irradiation. Therefore, it is considered that the UV irradiation also affects the interfacial adhesion strength between ceramic thin film and polymer substrate. The interfacial adhesion strength was measured by Multi-stages peel test. The results show that the interfacial strength depends on the peeling angle and UV irradiation makes the interfacial adhesion weaker. In-situ observations under tensile test of PET/ITO film were also carried out to investigate the fracture process of brittle thin film under tensile loading. The results show that the crack initiation on brittle thin film decreased after UV irradiation. It is considered that since the interface was damaged due to UV irradiation and the rigidity of interface decreased, the shear stress at the interface between PET/ITO interfaces cannot be high enough to make new cracks.