Are the two-component fluorosilicone coatings that have similar viscosity and solid content directly interchangeable? It's not just about the nominal values. When selecting, one should first confirm the mixing ratio, operation time, curing conditions, substrate type and batch measurement range, and then evaluate the bonding strength, oil resistance, hydrophobicity, temperature resistance and curing quality based on actual working conditions such as bonding, surface modification, immersion or spraying. Ultimately, whether to adopt it should be confirmed through small-scale tests, pilot production and final product verification.
The key points for acceptance in different applications are not the same. When used for bonding, attention should be paid to shear strength, internal failure rate, oil resistance and temperature resistance; when used for surface modification, attention should be paid to hydrophobicity, hand feel, wear resistance and appearance uniformity; when used for immersion or spraying, attention should be paid to dilution compatibility, coating uniformity, curing speed and coating defects. Just saying "semi-transparent and similar viscosity" is not enough to determine that they can be replaced.
First, compare the key indicators under the same conditions
IOTA FLSR8520 is a two-component bonding liquid fluorosilicone material. Components A and B are mixed in a mass ratio of 1:1, with a mixed viscosity of 50–5000 mPa·s (25℃), an operation time of 2–4 h (25℃), a solid content of 30–70%, a density of 1.02–1.40 g/cm³, and a cured hardness of Shore A 22, a tensile strength of 3.0 MPa, a elongation at break of 265%, a tear strength of 10.2 kN/m, and a shear strength of 100% internal failure on PET. Product Introduction
Before placing an inquiry and sending samples, both parties should clearly define the following information:
Material category and chemical composition, confirming that the candidate materials belong to the adhesive type two-component fluorosilicone coatings.
Mixing ratio, operation time and curing conditions, confirming the operating time range at 25℃ and whether heating curing is required.
Viscosity test temperature, method, unit and actual measured values for each batch, avoiding substituting only typical values for delivery limits.
Test methods and allowable ranges for mechanical performance indicators such as solid content range, density, hardness, tensile strength, tear strength, etc.
Usage, target substrate, operating temperature, contact medium, diluent and unacceptable failure phenomena.
The purchase specification should clearly state the allowable range, testing method and acceptance conditions, rather than just stating a nominal interval. Typical values can be used to understand product characteristics, but cannot automatically be regarded as the commitment for each batch delivery.
Which differences are worth checking apart from viscosity and solid content?
Table
Verification items How to compare Relationship with application
Mixing ratio and operation time Confirm the 1:1 mass ratio, operation time at 25℃, and curing conditions Effect on the construction window, mixing uniformity, and curing quality
Viscosity and dilution compatibility Compare viscosity changes under actual dilution solvents and ratios Effect on impregnation, spray coating uniformity, and run-off
Base material bonding performance Compare shear strength, cohesive failure rate, oil resistance, and temperature resistance on the target base material. This product can achieve 100% cohesive failure for PET, but the bonding performance on other base materials needs to be verified separately. Product performance involving oil resistance or high/low temperature conditions should be tested for adhesive retention rate under corresponding conditions.
Surface performance Compare hydrophobicity, hand feel, wear resistance, and appearance uniformity Effect on surface modification results and coating durability
Curing inhibitors Confirm whether to avoid contact with nitrogen, sulfur, phosphorus, and heavy metal compounds Prevent incomplete or non-curing leading to bonding failure
Determine verification priorities according to application
Bonding application
Compare shear strength, cohesive failure rate, oil resistance, and temperature resistance on the target base material (such as PET, PA, metal, glass fiber, etc.) according to actual process. This product can achieve 100% cohesive failure for PET, but the bonding performance on other base materials needs to be verified separately. Product performance involving oil resistance or high/low temperature conditions should be tested for adhesive retention rate under corresponding conditions.
Surface modification application
Maintain the base material, coating method, dosage, and curing conditions consistent, and observe hydrophobicity, hand feel, wear resistance, appearance uniformity, and coating adhesion. If the base material needs to be further processed or exposed to media in the future, the subsequent processes should also be included in the acceptance.
Impregnation or spraying application
Compare coating uniformity, run-off, bubbles, curing speed, and coating appearance under actual dilution solvents, dilution ratios, coating methods, and curing conditions. Low viscosity after dilution may cause run-off, while high viscosity may affect penetration and coating. The appropriate range should be determined through gradient tests.
Multi-base material compatibility application
This product can be used on PET, PA, chemical fibers, glass fiber, leather, metal, and other base materials. However, the surface energy and chemical properties of different base materials vary greatly, so the bonding strength and surface modification effect should be verified separately for each base material. The test results of a single base material cannot be used to infer the performance of other base materials. Product Introduction
How to verify from samples to mass production
First, agree on the acceptance items
Keep the valid technical data, batch records and normal production data of the current materials. Convert customer complaints or historical abnormalities into checkable items, such as adhesive failure, insufficient curing, uneven coating, decreased hydrophobicity or insufficient oil resistance.
Carry out small-scale tests under the same conditions
Keep the current materials as the control. Use the candidate materials with the same substrate, mixing ratio, diluent, coating method and curing conditions. Do not simultaneously adjust other variables. When it is necessary to change the process, set up another test group and record the reasons.
Test production under real conditions
After the small-scale test meets the requirements, confirm the amplification of mixing, coating/immersion/spraying, actual substrate and continuous operation performance. The oil resistance time, temperature range, cycle times and wear resistance times should be determined according to the product life and risks, and do not apply uniform qualified values.
Write the results in the purchase and change requirements
Record the approved mixing ratio, viscosity range, solid content range, operation time, curing conditions, testing methods, applicable substrates and restrictions, and agree on COA, retention samples, batch traceability and change notifications. After the sample passes, still need to continuously observe the subsequent delivery batches.
The basis for judgment should be the pre-agreed acceptance criteria, not "looks similar". If the candidate material only passes a certain test, the conclusion should also be limited to this test and corresponding conditions.
What information to prepare before inquiring from the supplier
You can first provide non-confidential application summaries: material purpose, target substrate, operating temperature, contact medium, coating method (immersion/spraying/brushing), diluent, addition amount, curing conditions, current problems encountered, target market and expected purchase volume. When there are requirements for adhesive strength, oil resistance, hydrophobicity, temperature resistance or compliance, also explain the testing methods and acceptance criteria.
As an organic silicon全产业链 solution provider， Aijota can discuss candidate specifications for the material range and customer conditions of the IOTA FLSR8520 fluorosilicone coating. After the initial selection， then check the corresponding technical data， safety data and batch inspection documents， and the specific applicability is confirmed by actual application verification.
FAQ
Can they be directly replaced if the viscosity and solid content are the same?
No. First, check the mixing ratio, operation time, curing conditions, substrate type and batch measured values, and then compare the bonding strength, oil resistance, water repellency and curing quality. Before applying, it is not advisable to decide on replacement solely based on the nominal viscosity.
2. Operation time: Is 2–4 hours sufficient for construction?
The operation time is greatly affected by temperature. At 25°C, it is 2–4 hours. As the temperature rises, the operation window will shorten. For large-scale construction or in high-temperature environments, the mixing amount and construction speed should be evaluated in advance. In necessary cases, the mixture should be mixed in batches.
3. Can it be diluted at will?
It can be diluted with organic solvents as per the process requirements. However, the compatibility of the diluent with the coating, the viscosity after dilution, the uniformity of application and the curing quality should be verified first. An excessively high dilution ratio may affect the solid content and coating performance.
4. Why can't it come into contact with nitrogen, sulfur, phosphorus and heavy metal compounds?
These substances may interfere with the sulfidation reaction of fluorosilicone coatings, resulting in incomplete sulfidation or non-sulfidation, and subsequently causing bonding failure or deterioration of coating performance. The construction environment and contact materials should be checked in advance. Notes for Attention
5. Does the 100% internal cohesion failure of PET also apply to other substrates?
Not necessarily. The surface energy, chemical properties and surface treatment methods of different substrates vary significantly. The bonding performance of each target substrate should be verified separately. The test results of PET cannot be used to infer other substrates.
6. Can it still be used after more than six months of storage?
The data shows that the storage period in the original unopened packaging is six months, and it should be stored in a cool and dry environment. Whether it can be used after the storage period has expired, it should be rechecked for appearance, viscosity, solid content, post-mixing curing performance and bonding performance, and confirmed through small-scale tests.