Adhesives

Introduction to Adhesives Testing Services

Our adhesive testing services use specialised analytical techniques to evaluate the mechanical strength, long-term durability, and operational performance of adhesives and bonded assemblies. These materials are instrumental across numerous industrial sectors, facilitating the lightweighting of components, the substitution of traditional mechanical fasteners, and the permanent bonding of heterogeneous materials. Systematic testing protocols ensure that adhesive systems maintain functional integrity under rigorous thermal, chemical, mechanical, and environmental stressors, thereby serving as a critical requirement for product safety, technological innovation, and sustained performance.

Infinita Lab works with domestic and U.S.-based laboratories to deliver precise, efficient, high-fidelity performance analysis for a wide range of industrial applications. The organisation’s technical proficiency encompasses structural adhesives, pressure-sensitive adhesives (PSAs), hot-melt systems, and advanced speciality bonding solutions tailored for the aerospace, automotive, electronics, packaging, and construction industries.

Our Adhesive Testing Services

Peel Strength Testing

Peel strength testing is one of the most fundamental characterisations of adhesive bond performance, measuring the force required to peel a bonded assembly apart progressively. Different peel geometries – 180°, 90°, and T-peel – are applicable depending on the adherend flexibility and joint configuration. Peel testing is critical for packaging laminates, pressure-sensitive tapes, automotive interior bonds, and electronics films.

Relevant ASTM Standards:

• ASTM D903 – 180° peel or stripping strength testing for adhesive bonds between a flexible adherend and a rigid substrate, measuring the average peel force per unit width (N/mm or lbf/in). Used for packaging laminates, PSA tapes, automotive interior bonding, and electronics protective films, with failure mode (adhesive, cohesive, or substrate) documented alongside the peel strength value.
• ASTM D1876 – T-peel resistance testing for adhesive bonding two flexible adherends, peeling them apart in opposite directions at approximately 90° each – applicable for flexible-to-flexible laminate bonds, flexible packaging, and tape-bonded assemblies where both adherends are flexible.
• ASTM D3167 – Floating roller peel resistance testing for adhesive bonds, evaluating an adhesive’s ability to withstand peeling forces for specimens bonded from a flexible to a rigid substrate using a floating roller fixture to maintain consistent peel geometry throughout testing.
• ASTM D3330 – Peel adhesion testing for pressure-sensitive tapes in 180° and 90° configurations on stainless steel substrates, measuring adhesive strength for masking, packaging, medical, and speciality tape specification and product development. 
• ASTM D6862 – 90-degree peel strength testing for adhesives between a rigid and a flexible adherend, the most common method for determining 90° peel resistance – used for acceptance testing, quality control, and product development of structural and pressure-sensitive adhesives.

Lap Shear & Shear Strength Testing

Lap shear testing is the most widely used method for evaluating the structural bond strength of adhesives in shear, directly measuring the load-carrying capacity of an adhesive joint under in-plane tensile loading. These tests are essential for the selection and qualification of structural adhesives in automotive, aerospace, and industrial assembly applications.

Relevant ASTM Standards:

• ASTM D1002 – Apparent shear strength testing for single-lap-joint adhesively bonded metal specimens by tension loading (metal-to-metal), one of the most commonly used tests for structural adhesives in industrial and automotive manufacturing.
• ASTM D5868 – Lap shear adhesion testing for fibre-reinforced plastic (FRP) adherends, measuring the shear strength of adhesive bonds in composite-to-composite and composite-to-metal single-lap joints for aerospace, automotive, and construction structural adhesive qualification.
• ASTM D3165 – Shear strength testing of adhesives in tension-loaded single-lap-joint laminated assemblies, used to create design parameters for bonded composite and metal assemblies in structural applications.
• ASTM D3528 – Double-lap shear testing for strength properties of adhesive-bonded joints under tension loading, reducing peel force components, and better isolating shear failure for metal-to-metal and composite adhesive joint qualification.

Tensile Strength Testing

Tensile adhesive strength testing evaluates the force required to pull an adhesive bond apart perpendicular to the bonded surface, providing butt-joint tensile strength data for adhesive material selection, quality assurance, and joint design in demanding structural and speciality applications.

Relevant ASTM Standards:

• ASTM D897 – Tensile properties testing for adhesive bonds using butt-joint (block-shaped) specimens, assessing the tensile strength of adhesive bonds between two parallel, flat adherend faces – the standard method for characterising adhesive bond tensile strength for quality control and specification compliance.
• ASTM D2095 – Tensile strength testing for adhesives using bar-and-rod butt-joint specimens, providing tensile strength data for adhesives used in demanding structural and industrial applications requiring perpendicular pull-apart loading characterisation.

Cleavage & Fracture Strength Testing

Cleavage testing evaluates an adhesive bond’s resistance to opening forces applied at one edge of a bonded joint – a critical loading mode for bonded metal structures, electronic assemblies, and structural components where peel-like opening loads arise during service.

Relevant ASTM Standards:

• ASTM D1062 – Cleavage strength testing for metal-to-metal adhesive bonds, measuring resistance to cleavage opening forces for structural metal bonding applications in aerospace, automotive, and electronics assemblies requiring adhesive joint characterisation under wedge-opening loading.
• ASTM D3433 – Fracture strength in cleavage for adhesive joints in peel using double cantilever beam (DCB) specimens, providing mode-I fracture energy (GIc) data for structural adhesives – essential for damage-tolerant adhesive joint design in aerospace and industrial structures.

Fatigue Testing of Adhesive Bonds

Adhesive joints in automotive, aerospace, and industrial structures are subjected to cyclic loading throughout their service life. Fatigue testing of adhesive bonds generates S-N data and defines the endurance limit of the bonded joint under dynamic loading – critical for adhesive joint design in fatigue-critical applications.

Relevant ASTM Standards:

• ASTM D3166 – Fatigue testing for adhesive bonds in shear under cyclic tension loading, generating adhesive S-N fatigue data for structural adhesives in metal-to-metal and composite bonded joints for automotive, aerospace, and industrial fatigue design.

Durability & Environmental Resistance Testing

Adhesive bonds in service are subjected to temperature extremes, humidity, chemical exposure, and aging that can degrade bond strength over time. Durability testing evaluates the long-term retention of adhesive joint performance under accelerated environmental conditioning, validating that bonds will maintain adequate strength throughout their intended service life.

Relevant ASTM Standards:

• ASTM D2919 – Durability testing of adhesive lap-shear joints subjected to sustained tension loading and shear stress, used as an accelerated screening test to determine adhesive joint durability under combined mechanical loading and environmental exposure.
• ASTM D1002 – Lap shear strength testing conducted before and after environmental conditioning to evaluate adhesive bond retention following humidity exposure, temperature cycling, or chemical exposure.

Pressure-Sensitive Adhesive (PSA) Testing

Pressure-sensitive adhesives are characterised by their tack, peel adhesion, and shear holding power when applied under pressure, without heat or solvent activation. PSA testing provides the performance data required for the development and quality control of tape, label, protective film, and medical PSA products.

Relevant ASTM Standards:

• ASTM D3330 – Peel adhesion testing for pressure-sensitive tapes at 180° and 90° peel angles on stainless steel substrates, the primary standard for PSA tape adhesion measurement across masking, packaging, medical, and speciality tape applications.
• ASTM D6862 – 90-degree peel resistance testing for pressure-sensitive adhesives, providing the lowest peel force value among peel geometries and widely used for acceptance testing and quality control of PSA products.
• ASTM D903 – 180° peel strength testing for PSA bonds, providing peel force per unit width data alongside failure mode for PSA label, tape, and protective film qualification.

Thermal Analysis of Adhesives

Thermal analysis characterises the curing behaviour, glass transition temperature, thermal stability, and decomposition profile of adhesive materials – providing data essential for adhesive cure process development, service temperature specification, and quality control of incoming adhesive materials.

Relevant ASTM Standards:

• ASTM D3418 – Differential Scanning Calorimetry (DSC) for adhesive materials, measuring glass transition temperature (Tg), cure state, heat of cure, and oxidative induction time (OIT) – supporting both adhesive formulation development and incoming raw material quality control.
• ASTM E1131 – Thermogravimetric Analysis (TGA) for adhesive materials, providing decomposition onset temperature, thermal stability, and volatile content data for adhesive compound identification and quality assurance.
• ASTM E1640 – Dynamic Mechanical Analysis (DMA) for adhesive films and cured adhesive specimens, measuring the storage modulus, loss modulus, and glass transition temperature, providing viscoelastic stiffness data across the service temperature range.

Outgassing Testing for Adhesives

Adhesives used in spacecraft, satellite assemblies, optical systems, and vacuum environments must meet strict outgassing requirements to prevent contamination of sensitive surfaces, optics, and electronic components.

Relevant ASTM Standards:

• ASTM E595 – Outgassing testing for total mass loss (TML) and collected volatile condensable materials (CVCM) from adhesive materials in a simulated space vacuum environment – mandatory for adhesives used in spacecraft structures, satellite assemblies, and optical systems where outgassing contamination is unacceptable.