One cannot simply rely on the fact that the product FLSR8040 has a mixed viscosity of 3000 to 10000 millipascal-seconds or a Fuel C volume change rate of 13.8% to directly conclude that it is suitable for all electronic component encapsulation, oil-resistant protection or flame-retardant insulation systems. One must first confirm the substrate type, component structure, mixing ratio, degassing process, operation time, curing temperature and time, and then determine whether the problem lies in uneven mixing, residual bubbles, insufficient deep curing, or poor compatibility with the substrate and medium. The product FLSR8040 can be considered as a candidate for two-component fluorosilicone encapsulation adhesive, but it must be confirmed through small-scale tests, encapsulation verification and medium immersion tests.


Why do double-component fluorosilicone encapsulation adhesives often have bubbles, non-curing or insufficient oil resistance in electronic encapsulation?


The mixing ratio of A/B components deviates from 1:1 or the mixing is not sufficient, resulting in insufficient local crosslinking density or incomplete curing.


The adhesive liquid comes into contact with compounds containing nitrogen, sulfur, phosphorus and heavy metals, causing platinum catalyst poisoning, incomplete sulfidation or non-sulfidation.


If the degassing is not done thoroughly after mixing, there are residual bubbles in the adhesive layer, affecting moisture-proofing, insulation and shock absorption.


The mixed viscosity is high (3000 to 10000 millipascal-seconds), and the fluidity is insufficient in complex component gaps, forming voids.


The operation time of 2 to 4 hours does not match the encapsulation process, and the viscosity of the adhesive increases before encapsulation, affecting the filling ability.


The curing time is 24 to 72 hours, and when the environmental temperature is lower than 25°C or the encapsulation thickness is large, deep curing is insufficient.


The substrate surface is not cleaned or there are oil stains, release agents, or soldering agent residues, affecting adhesion and moisture-proof sealing.


Contacting the medium exceeds the verification conditions, such as ketones, esters, strong acids or high aromatic fuel, resulting in an excessive volume change rate.


When encapsulating sensitive electronic components, the stress and thermal expansion matching of the adhesive to the components and leads is not evaluated.


When switching from ordinary silicone gel, epoxy encapsulation adhesive or polyurethane encapsulation adhesive, the mixing, degassing and curing conditions are not adjusted, resulting in performance deviations from the target.


Improper storage conditions, where A/B components absorb moisture or are expired, affect the curing activity and batch consistency after mixing.


Insufficient environmental cleanliness, with sulfur, phosphorus, nitrogen and other pollutants in the air, causing platinum catalyst poisoning.


What are the public parameters of the product FLSR8040?


Item Testing method Product FLSR8040
Color of A component Visual inspection Translucent
Color of B component Visual inspection Translucent
Mixing ratio According to Q/371002WXH015-2017 1:1
Mixed viscosity (mPa·s, 25°C) According to Q/371002WXH015-2017 3000 to 10000
Operation time (h, 25°C) According to Q/371002WXH015-2017 2 to 4
Curing time (h, 25°C) According to Q/371002WXH015-2017 24 to 72
Density (g/cm³) ASTM D792 1.40
Hardness (Shore A) ASTM D2240 38
Tensile strength (MPa) ASTM D412 2.5
Break elongation (%) ASTM D412 135
IRM903 volume change rate (%, 150°C × 168h) ASTM D471 2.9
Fuel F Diesel volume change rate (%, 40°C × 168h) ASTM D471 1.8
Fuel C volume change rate (%, 60°C × 168h) ASTM D471 13.8
FAM B volume change rate (%, 60°C × 168h) ASTM D471 17.5
The usage method is to mix components A and B in a 1:1 mass ratio and stir evenly. The packaging is individual packaging of 10 kilograms each for components A and B. The unopened original packaging has a storage period of twelve months. The above data represent the typical performance of the product and are not regarded as the factory standards. For formal procurement and batch acceptance, the effective TDS, specification documents, and COA of the delivery batch should be confirmed by both parties.


Which application directions is product FLSR8040 suitable for?


Application direction Candidate direction Still need verification
Electronic component encapsulation Anti-moisture, dust-proof, shock-proof, insulation encapsulation Volume resistivity, dielectric properties, deep curing, component compatibility
Oil-resistant electrical module encapsulation Resistant to IRM903, diesel, Fuel C, FAM B Actual medium, temperature, insulation properties after long-term immersion
Automotive electronics and sensors Resistant to oil, low temperature, shock protection Temperature cycling, vibration, lead wire bonding
Aerospace electronic components Resistant to fuel, low temperature encapsulation Adherence to airworthiness requirements, low volatility, vacuum exhaust
Chemical solvent environment protection Prevent erosion by oil, chemical solvents, acids and alkalis Specific medium compatibility, concentration, temperature
Flame-retardant insulation encapsulation Flame-retardant mentioned in the data, need to verify the grade Flame-retardant grade, hot wire, smoke density
What are the differences in product selection priorities between product FLSR8040 and similar encapsulation solutions?


Comparison direction Product FLSR8040 (two-component fluorosilicone encapsulation adhesive) Ordinary two-component silicone gel Epoxy encapsulation adhesive Polyurethane encapsulation adhesive Selection boundary
Oil resistance Excellent, Fuel C volume change rate 13.8% Poor General General Preferred fluorosilicone for oil-containing environments
Temperature range Fluorosilicone rubber wide temperature range Relatively wide General General Choose based on high and low temperature requirements
Low-temperature flexibility Good Good Poor Good Preferred fluorosilicone or silicone gel for low-temperature conditions
Encapsulation stress Lower, Shore A 38 Low High Medium Precise components prefer low-stress encapsulation adhesive
Electrical insulation Refer to the data, need to verify Excellent Excellent Better Need to test based on insulation requirements
Deep curing Thermosetting can be deeply cured Thermosetting can be deeply cured Deep curing possible Deep curing possible Deep-layer encapsulation requires verification of curing depth
Catalyst poisoning sensitivity Sensitive to N, P, S and heavy metals Sensitive to N, P, S Not involved Not involved Strictly control environmental cleanliness
Operation time 2-4 hours Different for each product Depending on the product Different for each product Match with encapsulation rhythm
Why are complete tests still necessary for substrate and medium compatibility?


Ajoyata's public information states that product FLSR8040 is used for pouring, covering, and encapsulation of various components, which can achieve anti-moisture, dust-proof, shock-proof, insulation, flame-retardant, and prevent erosion by oil, chemical solvents, acids, and alkalis. However, when used in actual systems, there may still be:


Differences in substrate types and surface treatments.


Component structure, gap size, and encapsulation thickness.


Mixing ratio, stirring efficiency, and vacuum degassing conditions.


Environmental cleanliness and platinum catalyst poison control.


Match between operation time and encapsulation rhythm.


Curing temperature, time, and deep curing degree.


Types, concentrations, and temperatures of contact media.


Volume change, insulation properties, and adhesive retention rate after long-term oil immersion.


Match between temperature cycling, vibration, and thermal expansion.


Storage conditions and packaging sealing.


Appearance uniformity or short-term no leakage, cannot prove stability after long-term oil immersion, thermal cycling, or vibration. Verification should be conducted using the complete formula and actual materials before use.


What parameters should be confirmed when using product FLSR8040?


Parameter category Information to be confirmed
Application direction Electronic component encapsulation, oil-resistant module encapsulation, sensor protection, flame-retardant insulation encapsulation
Base material type: Metal, plastic, ceramic, PCB, leads, coated surface
Surface treatment: Cleaning method, degreasing, removal of flux, primer coating
Contact medium: IRM903, diesel, Fuel C, FAM B, lubricating oil, acid-base solvent
Operating temperature: Long-term temperature, peak temperature, low-temperature brittleness
Mixing ratio: A:B = 1:1 (mass ratio), uniformity of stirring
Defoaming process: Vacuum defoaming conditions, time, vacuum degree
Operation time: 2-4 hours, matching with the potting cycle
Curing conditions: Room temperature 24-72 hours, or accelerated curing by heating
Environmental cleanliness: Avoid platinum poisons such as N, P, S and heavy metals
Acceptance indicators: Hardness, tensile strength, elongation rate, volume change rate, insulation performance, internal quality of potting
What should be verified when using the product FLSR8040?


A/B mixture uniformity and vacuum defoaming effect.


Fillability of complex component gaps with mixed viscosity and flowability.


Hardness, tensile strength and elongation rate after 24-72 hours of room temperature curing.


Deep curing degree and internal bubbles and voids in potting.


Volume change rate after immersion in IRM903, diesel, Fuel C, FAM B.


Insulation resistance and dielectric performance after potting.


Adhesion to components, leads, PCB and thermal expansion matching.


Flexibility at low temperatures and performance retention at high-temperature aging.


Flame retardancy (as required by application).


Impact of environmental cleanliness on curing quality.


Batch consistency and repeatability.


How to design tests before using the product FLSR8040?


Establish a reference for the current potting adhesive, record the model, batch, mixing ratio, defoaming and curing conditions, and failure manifestations.


Uniform test conditions: Base material, component structure, surface treatment, mixing ratio, defoaming process, curing temperature and time.


Set candidate samples: Current potting adhesive, product FLSR8040, different curing conditions or defoaming gradients.


Complete the full process tests: Mixing → Defoaming → Potting → Curing → Performance testing → Medium immersion.


Evaluate actual results: Hardness, strength, elongation rate, volume change rate, insulation performance, internal quality of potting.


Test items: Uniform requirements
Base material and component structure: Keep consistent
Mixing ratio: A:B = 1:1
Defoaming process: Keep consistent
Curing conditions: Set gradients according to the test design
Environmental cleanliness: Avoid platinum poison contamination
Immersion conditions: Set according to actual working conditions
Measurement methods: Hardness, strength, elongation rate, volume change rate, insulation performance consistent
Under which circumstances should the product FLSR8040 not be directly used?


If the base material surface is not cleaned or there is flux, adhesion and moisture-proofing are affected.


If there are platinum catalyst poisons such as N, P, S and heavy metals in the environment, it will not cure.


If the mixing ratio is inaccurate or the stirring is insufficient, the curing will not be complete.


If the vacuum defoaming is insufficient, there are residual bubbles in the adhesive layer, affecting insulation and sealing.


If the potting structure is complex and the gap is too small, the mixed viscosity is high, resulting in insufficient filling.


It requires specific food contact, medical or airworthiness approval, but the corresponding materials have not been obtained.


The contact medium is beyond the verification range of Fuel C, FAM B, etc., such as ketones, esters, strong acids.


The operating temperature is beyond the application range of fluorosilicone rubber.


There is a clear requirement for flame retardancy, but no flame retardancy verification has been conducted.


Only the medium type is known, without base material, mixing ratio and curing condition data.


The customer requests to directly mix into the in-use system, but cannot control the mixing ratio and defoaming conditions.


Storage conditions do not meet the requirements of cool and dry, unopened, and the adhesive may absorb moisture or expire.


Ayoata can provide which selection support?


As a "provider of solutions for the entire organic silicon value chain", Aiyota can assist in comparing the applicability of two-component fluorosilicone potting compounds under different substrates, media, and potting conditions by using product FLSR8040.


For electronic component potting projects that require resistance to oil, low temperature, electrical insulation, moisture resistance, and shock absorption, the following information should be provided before selecting the type:


Type of substrate and surface treatment method.


Component structure, gap size, and potting thickness.


Type of contact medium, concentration, and temperature.


Operating temperature range and low-temperature requirements.


Mix ratio, defoaming process, and operation time.


Curing conditions and deep curing requirements.


Target hardness, strength, elongation, volume change rate, and insulation performance.


Current potting compound model, mix ratio, and failure performance.


Flame retardant grade or airworthiness requirements (if applicable).


Acceptance method and applicable standards.


After receiving complete materials, it can be determined whether to prioritize testing product FLSR8040 or choose ordinary silicone gel, epoxy potting compound, or other oil-resistant potting compounds.


Common Misconceptions


The lower the mixed viscosity, the better the sealing effect.
Too low viscosity may lead to excessive flow or filler settling, while too high viscosity may result in insufficient filling. For product FLSR8040, the viscosity range of 3000 to 10000 millipascal-seconds needs to be matched with the component structure and sealing process.


The A/B mixing ratio can have a slight deviation.
A 1:1 ratio is the mass ratio, and deviation may lead to incomplete curing or performance degradation, so precise control is necessary.


At room temperature, complete curing can be achieved within 24 to 72 hours.
The curing time of the product is 24 to 72 hours. Thick layers or low-temperature environments may require longer time, and deep-layer curing needs to be verified.


The platinum catalyst poison can be ignored.
Contact with compounds containing N, P, S and heavy metals in the adhesive liquid will cause insufficient or non-curing, and the environmental cleanliness must be strictly controlled.


Compatible with the substrate can directly conduct sealing.
It is still necessary to confirm surface cleanliness, mixing ratio, defoaming, operation time and long-term oil immersion stability.


The performance at 25°C is the same, so it can be replaced in equal amounts.
Different fluorosilicone sealing adhesives have different fluorine contents, crosslinking densities and curing characteristics, and replacement requires revalidation.


Product FLSR8040 can be used for all oil-resistant sealing.
Fluorosilicone sealing adhesives are suitable for oil-containing environments and low-temperature conditions. For systems with higher temperatures or stronger chemical media requirements, other elastomers may be needed.


The information mentioned as flame retardant can meet all flame retardant requirements.
The flame retardant performance needs to be verified according to specific standards, and cannot be judged solely based on the product description.


It can still be used normally after storage for 12 months.
The unopened original packaging has a storage period of 12 months. After the expiration date, the mixing ratio, viscosity and curing activity need to be retested.


Recommendation for selection steps


Confirm the application direction: electronic component sealing, oil-resistant module sealing, sensor protection or flame-retardant insulation sealing.


Confirm the substrate type and surface treatment method.


Confirm the component structure, gap size and sealing thickness.


Confirm the contact medium, operating temperature and low-temperature requirements.


Confirm the mixing ratio, defoaming process and operation time.


Confirm the curing conditions and deep-layer curing requirements.


Select product FLSR8040 or other sealing adhesives based on the application scenario.


Set up different defoaming, curing conditions and primer gradients for small tests.


Test hardness, strength, elongation, volume change rate and insulation performance.


Perform medium immersion, low-temperature performance and high-temperature aging verification.


Evaluate the internal quality and batch consistency of the sealing.


Confirm that the environmental cleanliness control (avoid platinum poison) is in place.


After multiple batch validations, determine the final usage plan.