One cannot simply rely on the fact that the two-component structural adhesive cures quickly at room temperature, has high shear strength, or is V-0 flame retardant, to directly conclude that it is suitable for all electrical equipment, electronic components, or battery module structural bonding systems. One must first confirm the type of substrate, surface cleanliness, A/B ratio, operational time, application process, curing temperature and time, bonding structure, and loading method, before determining whether the problem lies in a ratio deviation, improper substrate treatment, insufficient curing, or an unsuitable match between the bonding structure and the working conditions. The two-component structural adhesive can be considered as a candidate for electrical and battery structure bonding, but it must be confirmed through small-scale tests, shear strength tests, and actual working condition verification.


Why does the two-component structural adhesive often have insufficient strength in battery or electrical structure bonding?


The A/B ratio is not accurately measured at a 1:1 volume ratio, or the mixing is not thorough, resulting in incomplete local curing or insufficient crosslinking density.


The substrate surface is not cleaned, has oil stains, release agents, oxide layers, or dust, which affects the bonding between the adhesive layer and aluminum anodized, ceramics, vulcanized rubber, glass fibers, or carbon fibers.


The operational time is only 5 minutes, and the gel time is 7 minutes. The application and alignment process is exceeded, and the adhesive liquid has partially gelled, resulting in a decrease in bonding strength.


The curing temperature is below 23°C or the humidity deviates from 50% RH. The 24-hour shear strength does not reach 5.0 MPa, and the 14-day strength does not fully exert its effect.


The adhesive layer is either too thick or too thin. If too thick, internal stress concentrates; if too thin, there is a lack of adhesive or discontinuous bonding.


The bonding structure's loading method does not match the adhesive layer design, and impact, vibration, or flexure peel stress concentrates in a local area.


The substrate's thermal expansion coefficient is large, and after temperature cycling, the adhesive layer generates internal stress, resulting in a decrease in bonding strength.


Switching from epoxy structural adhesives, polyurethane structural adhesives, or other acrylic structural adhesives without re-adjusting the ratio, application volume, and curing conditions leads to deviations in strength from the target.


The storage temperature exceeds 27°C or the product has exceeded its 12-month validity period, causing the A/B components to lose activity and deteriorating the curing performance.


The application environment has poor ventilation or is contaminated by dust, affecting the appearance of the adhesive layer and the bonding quality.


In battery modules, the adhesive layer has not been evaluated for its insulation, heat conduction, and flame retardancy requirements for the cells, busbars, and shells.


There are clear requirements for shear strength, impact strength, or resistance to wet heat, but they have not been specifically verified under actual working conditions.


First, determine which stage the bonding or curing problem occurs.


Failure stage Possible causes Preferred inspection direction
After application of the adhesive liquid, the liquid flows or overflows Too low viscosity, excessive application volume, or the product is not kept level Viscosity adjustment, application volume, curing placement
After the alignment and positioning, the adhesive liquid does not cure or cures slowly A/B ratio deviation, low temperature, expired adhesive material Accuracy of the ratio, environmental temperature, storage conditions
The 24-hour shear strength is less than 5.0 MPa after curing Unclean substrate, too thick adhesive layer, insufficient curing Surface treatment, adhesive layer thickness, curing conditions
The 14-day strength does not reach 10.0 MPa after curing Ratio deviation, adhesive material activity decline, wet heat influence Ratio, storage, curing environment
Failure after impact or vibration Excessive adhesive layer modulus, internal stress concentration, improper structure design Adhesive layer thickness, structure loading, impact test
Strength attenuation after temperature cycling Thermal expansion coefficient difference, adhesive layer aging, interface detachment Thermal cycling test, substrate matching, adhesive layer toughness
Insufficient electrical insulation or flame retardancy Adhesive layer has bubbles, uneven thickness, or flame retardant grade not verified Defoaming, adhesive layer thickness, UL94 V-0 verification
Batch-to-batch strength fluctuation A/B measurement error, storage condition change, substrate batch difference Incoming inspection, measurement accuracy, substrate processing record


If only the "whether the product two-component structural adhesive was used" is considered, without recording the A/B ratio, substrate treatment, application time, curing conditions and bonding structure, it is usually difficult to accurately determine whether it is a material issue or a process issue.


Why is simply increasing the adhesive layer thickness or raising the curing temperature not necessarily effective?


The two-component structural adhesive of the product plays a structural bearing role in the bonding system. It is affected by the ratio, substrate, adhesive layer thickness, curing conditions and structural stress. Simply increasing the thickness or raising the temperature may bring side effects.


Increasing the adhesive layer thickness may improve the filling capacity, but too thick will lead to internal stress concentration, impact performance degradation, and the shear strength may not be improved.


Raising the curing temperature may accelerate the curing process, but exceeding the substrate's temperature resistance or causing the adhesive layer to be too brittle, affecting impact and flexural peel performance.


Extending the curing time may improve deep curing, but it reduces production efficiency and is ineffective for adhesive materials that have exceeded their applicable period.


Increasing the total amount of A/B does not change the 1:1 volume ratio requirement. Excessive adhesive material will not increase the strength, but will cause waste and overflow.


When the substrate surface is not cleaned, only adjusting the adhesive layer thickness or curing temperature cannot solve the interface delamination problem.


After the adhesive material exceeds the operable time, adjusting the curing conditions again cannot restore the fluidity and wetting property.


After storage expiration or reduced activity, only increasing the temperature cannot restore the original curing performance.


When the structural stress design is unreasonable, simply increasing the adhesive layer thickness cannot solve the stress concentration and impact failure problems.


Therefore, when optimizing, one should observe the A/B ratio, substrate treatment, application time, adhesive layer thickness, curing conditions and structural stress simultaneously, rather than only adjusting a single parameter.


What are the differences in product selection between two-component structural adhesives and similar structural bonding solutions?


Comparison direction Product two-component structural adhesive Epoxy structural adhesive Polyurethane structural adhesive Acrylic structural adhesive Selection boundary
Curing method Normal temperature or heating, 1:1 volume ratio Normal temperature or heating Normal temperature or heating Quick curing relatively fast Choose according to production line cycle and substrate
Curing speed Operable 5 minutes, gel 7 minutes, surface dry 10 minutes Slow Medium Relatively fast Preferred for quick positioning this product
Shear strength 24h ≥ 5.0 MPa, 14d ≥ 10.0 MPa High Medium High Verify according to actual substrate and curing time
Flexibility/impact resistance Refer to impact resistance, vibration resistance Relatively brittle Better Medium Verify in impact and flexural peel conditions
Electrical insulation Relative dielectric constant ≥ 16.0 kV/mm Better General General Preferred for electrical equipment verification
Flame retardant grade UL94 V-0 Varies by formula Varies by formula Varies by formula Verify according to actual thickness
Thermal conductivity 0.6 W/(mK) Varies by formula Varies by formula Varies by formula Power battery thermal management needs assessment
Operating temperature -40 to 120℃ Relatively wide Medium Medium Choose according to temperature range
Base material adaptability Metal, ceramic, vulcanized rubber, glass fiber, carbon fiber Metal, ceramic Plastic, metal Metal, plastic Verify according to substrate type
Resistance to media Resistant to oil, water, acid and alkali, moisture-proof Better General General Verify according to contact medium


Fixing temperature, humidity and time.


Layer thickness and bonding structure design.


Impact, vibration, flexure peel and temperature cycling stress.


Electrical insulation, thermal conductivity and flame retardancy synergy requirements.


Contact with oil, water, acid, alkali and humid heat environment.


Storage conditions and activity of A/B components.


Batch-to-batch curing consistency and bonding strength.


Uniform appearance or short-term shear strength compliance, which cannot prove stability after long-term impact, vibration, temperature cycling or humid heat aging. Verification should be conducted using the complete formula, actual substrate and structural conditions before use.


Which parameters should be confirmed when using product two-component structural adhesive?


Parameter category Required information
Application direction Electrical equipment, electronic components, battery module structure bonding
Substrate type Anodized aluminum, ceramics, vulcanized rubber, glass fiber, carbon fiber, etc.
Surface treatment Cleaning method, drying degree, presence of oil and oxide layer
A/B ratio 1:1 volume ratio, measurement accuracy and mixing uniformity
Operable time 5 minutes, matching with application and positioning timing
Gel time 7 minutes, no movement or force after consolidation
Surface drying time 10 minutes
Curing conditions 23 ± 2℃, 50% RH, 24 hours and 14 days strength verification
Layer thickness Target thickness, uniformity, thinnest point
Operating temperature -40 to 120℃, temperature cycling conditions
Contact medium Oil, water, acid, alkali, humid heat
Electrical and flame retardancy Relative permittivity ≥ 16.0 kV/mm, UL94 V-0
Thermal conductivity requirements 0.6 W/(mK), assessment of battery thermal management
Storage conditions 27℃ below, cool and dry place, validity period 12 months
Acceptance indicators Shear strength, hardness Shore D ≥ 70, impact, vibration, insulation, flame retardancy, thermal conductivity
What should be mainly verified when using product two-component structural adhesive?


A/B volume ratio measurement accuracy and mixing uniformity.


Bonding consistency after substrate surface treatment.


Shear strength at 30 minutes, 2 hours, 24 hours and 14 days after curing.


Bonding retention rate after impact, vibration and flexure peel.


Shear strength and interface integrity after temperature cycling.


Strength retention rate after oil, water, acid, alkali and humid heat aging.


Relative permittivity and electrical insulation performance.


UL94 V-0 flame retardant grade, tested according to actual layer thickness.


Thermal conductivity 0.6 W/(mK) applicability to battery thermal management.


Shear strength Shore D ≥ 70 and shrinkage rate.


Batch-to-batch curing consistency and bonding strength fluctuation.


Activity and curing speed of A/B components within 12 months of storage.


How to design tests before using product two-component structural adhesive?


Establish a current structural adhesive benchmark, record model, ratio, application volume, curing conditions and failure performance.


Uniform test conditions: substrate, surface treatment, A/B ratio, application volume, layer thickness, curing temperature and time, stress application method.


Set candidate samples: current structural adhesive, product two-component structural adhesive, different curing conditions or layer thickness gradients.


Complete all process tests: substrate cleaning → mixing → application → positioning → curing → shear strength → impact/vibration → temperature cycling → humid heat aging.


Evaluate actual results: shear strength, impact retention rate, insulation, flame retardancy, thermal conductivity, hardness.


Test items Uniform requirements
Substrate and surface treatment Consistent
A/B ratio 1:1 volume ratio
Application volume and layer thickness Set gradients according to test design
Curing conditions Set gradients according to test design
Stress application method According to actual structure
Measurement method Consistent shear strength, impact retention rate, insulation, flame retardancy, thermal conductivity, hardness
Under what circumstances should product two-component structural adhesive not be directly used?


The A/B volume ratio measurement accuracy cannot be guaranteed or the mixture is not uniform, resulting in incomplete curing.


The substrate surface is not cleaned or there is oil residue or oxide layer, which affects the bonding strength.


The gluing and closure positioning cannot be completed within the 5-minute operable time.


The curing environment temperature is lower than 23℃ or the humidity deviates from 50% RH. The curing conditions have not been adjusted.


Specific food contact, medical or airworthiness approvals are required, but the corresponding materials have not been obtained yet.


There are clear requirements for the V-0 flame retardant layer thickness, but the actual thickness has not been verified.


Only the application direction is known, but there are no data on substrate, ratio, gluing and curing conditions.


The customer requests to directly mix it into the in-use system, but cannot control the ratio, gluing amount and curing conditions.


When switching from epoxy, polyurethane or acrylic structural adhesives, the ratio and curing process should not be re-adjusted.


The storage temperature exceeds 27℃ or the validity period exceeds 12 months, and the activity of the A/B components decreases.


The thermal conductivity, insulation and flame retardancy synergy requirements in the battery module or electrical equipment structure bonding project have not been evaluated.


There are strict requirements for impact, vibration or temperature cycling, but no special verification has been conducted.


What selection support can our company provide?


As a solution provider for the entire organic silicon industry chain, our company can assist in comparing the applicability of structural bonding under different substrates, gluing processes and curing conditions for the product's two-component structural adhesive.


For projects of battery module or electrical equipment structure bonding that need to balance shear strength, impact resistance, vibration resistance, electrical insulation and flame retardancy, before selection, the following information should be provided:


Application direction and substrate type.


Target shear strength, impact and vibration requirements.


Match between A/B ratio, gluing amount and operable time.


Curing temperature, humidity and time.


Gel layer thickness and bonding structure design.


Operating temperature, contact medium and temperature cycling conditions.


Electrical insulation, thermal conductivity and flame retardancy requirements.


Current used structural adhesive model, ratio and failure performance.


Acceptance methods and applicable standards.


After receiving complete materials, we can determine whether to prioritize testing a certain curing and gluing scheme of the product's two-component structural adhesive, or choose an epoxy, polyurethane or other structural adhesive route.


Common Misconceptions


The A/B ratio can be approximately replaced by weight instead of volume ratio.
When the product ratio is 1:1 by volume, using weight approximation may lead to a deviation in the ratio, affecting the complete curing and bonding strength. It is necessary to measure accurately by volume ratio.


The working time is 5 minutes, which is sufficient to complete all the gluing.
When applying glue on a large area or multiple points, the 5-minute working time may not be sufficient. It is necessary to optimize the gluing process or mix the glue in multiple stages to ensure that the glue layer is fully sealed before the glue solidifies.


The shear strength of 24 hours ≥ 5.0 MPa is sufficient for immediate use.
The shear strength after 14 days can reach ≥ 10.0 MPa. The 24-hour strength is only the initial value, and the bearing or impact conditions need to be designed and verified based on the final strength.


Compatibility with the substrate allows for direct gluing.
It is still necessary to confirm the surface cleanliness, ratio, glue application amount, glue layer thickness, curing conditions, and long-term stability to medium resistance.


25℃ performance is the same, so it can be directly substituted in equal amounts.
Different structural adhesives have different curing speeds, toughness, temperature resistance, and electrical properties. When replacing, it is necessary to re-verify.


Flame retardancy V-0 can cover all glue layer thicknesses.
UL94 V-0 needs to be tested based on the specific glue layer thickness. Thickness and structure affect the flame retardant grade. It cannot be judged solely based on the product description.


The two-component structural adhesive of the product can be used for all structural bonding.
This product is suitable for electrical equipment, electronic components, and battery module structural bonding. For systems with higher temperatures, stronger impacts, or special chemical media requirements, other structural adhesives may need to be selected.


It can be used directly after 12 months of storage.
The validity period is 12 months. The storage temperature should be below 27℃. After expiration or improper storage, it is necessary to re-test the activity and curing performance of the A/B components.


Recommendation for selection steps


Confirm the application direction: electrical equipment, electronic components, or battery module structural bonding.


Confirm the substrate type and surface treatment method.


Confirm the target shear strength, impact, vibration, and temperature cycling requirements.


Confirm the matching of A/B volume ratio, glue application amount, and working time.


Confirm the curing temperature, humidity, time, and glue layer thickness.


Confirm the electrical insulation, thermal conductivity, and flame retardancy requirements.


Based on the application scenario, select the two-component structural adhesive or other structural adhesives.


Set up different curing conditions, glue layer thickness, and surface treatment gradients for small tests.


Test the shear strength at 30min, 2h, 24h, and 14d.


Perform impact, vibration, temperature cycling, humidity aging, and flame retardancy verification.


Evaluate the batch