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Insecticide Aerosol Tin Can: Root Cause Analysis of Inner Coating Swelling & Weld Pitting and High-Solvent Liquid Adaptation Solutions
2026-06-15
Frequent Quality Failures in Storage and Terminal Sales: High-Solvent Liquid Damages Can Protection System
In the mass application scenarios of kerosene-based insecticide aerosol tin can, most brands face hidden can failure risks. Different from visible deformation and leakage, solvent-induced defects have a long incubation period, which usually break out during finished product storage, terminal distribution or consumer use, often leading to batch scrapping and brand reputation damage, becoming a neglected hidden danger in insecticide packaging production.
SAILON’s technical team has long-term experience in customized aerosol can supporting projects and has handled numerous real customer complaints. The most typical working condition is that ordinary coated tinplate Aerosol Cans filled with high-proportion kerosene and xylene-based insecticides will develop slight coating blisters after 60-90 days of normal temperature storage. Over time, the coating suffers from large-area swelling, peeling and delamination. Peeled coating debris mixes with the liquid and forms brown flocculent impurities, while dense pitting rust holes appear on the weld repair coating, causing irreversible quality defects.
Many product R&D and procurement personnel misjudge the root cause and simply attribute defects to unqualified tinplate base materials. However, massive test data proves that most failures stem from mismatched compatibility between high-activity solvents and ordinary inner coatings, as well as insufficient protection of weld repair processes. Superimposed auxiliary corrosion factors such as trace moisture and acidic impurities in the liquid will further accelerate coating damage and metal corrosion.
High-Solvent Formula Corrosion Mechanism: Complete Process from Coating Swelling to Weld Pitting
To completely solve the long-term protection problem of insecticide Aerosol Tin can, it is essential to clarify the complete logic of solvent corrosion, instead of relying on conventional coating processes to resist corrosion blindly. Kerosene and aromatic hydrocarbon solvents commonly used in insecticides have a solubility parameter of δ≈8-9, which is highly consistent with the molecular parameters of ordinary epoxy inner coatings, forming the core cause of continuous coating erosion.
In the closed filling and long-term static storage environment, solvent molecules continuously penetrate into the molecular gaps of coating resin, break the stable cross-linking structure of the coating, and cause gradual water absorption and volume expansion. Long-term monitoring data from our laboratory shows that when the coating swelling rate exceeds 5%, the adhesion between the coating and tinplate substrate drops sharply, generating irreversible internal stress between layers, and eventually leading to blistering, delamination and peeling, directly exposing the metal substrate to the liquid medicine.
The weld repair zone of the can body is the weakest link in the entire protection system, which is also a blind spot in many standardized production processes. In conventional aerosol can production, the temperature drops rapidly after high-speed weld welding, and the subsequently sprayed repair coating cures quickly with insufficient cross-linking density and larger molecular gaps than the main can body coating. High-activity solvents precisely penetrate through these tiny gaps, erode the underlying tin-iron alloy layer, trigger electrochemical corrosion, and gradually form visible pitting rust holes, even causing micro-leakage and liquid deterioration in severe cases.
More importantly, most kerosene-based insecticides contain trace moisture and acidic hydrolysis by-products. Even if the impurity content is lower than 100ppm, it will form a synergistic corrosion effect with kerosene solvents, accelerating coating damage and metal pitting, and greatly shortening the safe storage cycle of long-term storage insecticide aerosol tin can.
Full-Dimensional Comparison of Three Mainstream Solvent-Resistant Can Solutions
Based on tens of thousands of groups of compatibility test data, SAILON has optimized three mature custom insecticide aerosol tin can customized solutions for insecticide products with different solvent concentrations, storage cycles and compliance standards. These solutions cover all gradient solvent working conditions, balance protection performance, production cost and compliance standards, and adapt to mass production and long-term storage requirements.
| Solution | Solvent Resistance Level | Applicable Kerosene Concentration | Cost Level | Curing & Process Advantages | Applicable Scenarios |
|---|---|---|---|---|---|
| High Cross-Linking Epoxy-Phenolic (EP) Inner Coating | ★★★★☆ | ＜30% | Low | Optimized baking curve, coating cross-linking rate＞95%, no substrate exposure after 100+ double-sided MEK wipes, stable adhesion | Water-based & low-solvent insecticides, cost-effective mass production with conventional storage cycle |
| Infrared Secondary Curing + Special Weld Repair Powder Coating | ★★★★☆ | 30%~50% | Medium | Targeted weld reinforcement, repair coating Tg＞120℃, eliminate performance gap between weld and can body | Medium and high-solvent formulas with strict requirements for weld anti-corrosion and long-term storage stability |
| PET/PP Laminated Steel Integrated Can | ★★★★★ | ＞50% | High | Polymer film physical isolation, near-zero swelling rate, no coating peeling or penetration risks | High-strength solvent formulas, ultra-long storage, zero-migration and high-standard compliant products |
28-Day Accelerated Aging Test: Quantitatively Verify Long-Term Protection Performance
To accurately simulate harsh working conditions such as high-temperature storage, closed stacking and long-distance transportation, we conducted a 28-day constant-temperature kerosene immersion aging test at 50℃ in accordance with industry standards, combined with ISO 2409 cross-cut adhesion test and ISO 9227 salt spray test to fully verify the actual protection performance of the three solutions.
- High cross-linking epoxy-phenolic coated cans: Only slight color change on the coating, no blistering, delamination or peeling. The adhesion level remains 4B, fully meeting the long-term storage needs of low-solvent formulas
- Cans with infrared secondary curing weld reinforcement: The overall coating remains intact, with no rust marks or penetration corrosion on welds, completely solving the weak weld defect of traditional cans
- Laminated steel cans: Zero overall changes, the film fits closely with the substrate with no swelling, penetration or corrosion, serving as the optimal protection solution for high-concentration kerosene-based liquids
The test results fully prove that can failures are completely avoidable. Matching the corresponding corrosion-resistant insecticide aerosol tin can solution according to liquid solvent concentration and storage cycle can eliminate most quality risks from the source.
Industry Professional FAQ
Q1: Is laminated steel can mandatory for all high-solvent insecticide liquids?
Not necessarily. Laminated steel cans provide optimal protection but come with higher costs. Blind selection will lead to unnecessary cost waste. For formulas with solvent concentration below 50%, stable anti-corrosion effects can be achieved by optimizing inner coating technology and strengthening weld curing. SAILON provides free coating compatibility tests based on customers’ specific liquid formulas, solvent ratios and storage cycles, matching cost-effective custom aerosol tin can for insecticide solutions.
Q2: Are there clear compliance standards for aerosol can anti-corrosion performance?
General transportation regulations do not specify inner coating materials, but they require pressure vessels to be free from leakage, structural corrosion and strength attenuation during storage and transportation. Meanwhile, FEA industry guidelines clearly recommend that all solvent-based disinfection liquids must complete formula-coating compatibility tests in advance to avoid corrosion and contamination risks during long-term storage and ensure compliant product circulation.
Q3: Do trace moisture and acidic impurities affect can anti-corrosion performance?
The impact is significant. Even if the content of moisture and acidic impurities in the liquid is lower than 100ppm, it will form a synergistic corrosion effect with kerosene solvents, accelerating coating swelling and metal pitting. We recommend strictly controlling raw material purity before filling and adopting matched can coating technology to ensure dual stability of products.
SAILON Professional Technical Service: Eliminate Solvent Corrosion Risks from the Source
Most aerosol can quality accidents are caused by insufficient formula-coating compatibility verification in the early stage. Rectification after mass production and distribution will bring huge loss costs. With years of deep cultivation in the insecticide aerosol tin can customization industry, SAILON owns a complete material laboratory and full set of testing equipment, providing free professional services including formula-coating compatibility test, solvent swelling resistance test and salt spray aging test.
Simply send your liquid samples and production parameters, and we will deliver a detailed professional test report, recommending targeted customized solutions for can material, inner coating technology and weld treatment. We balance cost, performance and compliance, fully guarantee the long-term storage stability of insecticide aerosol cans, and help customers avoid batch scrapping, customer complaints and brand devaluation risks.