Guide to using oil repellent for water-based plastic paint: 5-step tips to make plastic coatings "oil-repellent"
Have you ever been troubled by plastic products covered with oil and fingerprints? Want to keep the plastic shell fresh
and clean at all times, but don't know how to do it? In fact, just add oil repellent to water-based plastic paint to make
the coating have "self-cleaning" ability. But how to use oil repellent? How much to use? What should be paid attention
to during construction?
Step 1: Choose the right product to match your needs
Oil repellent is not a "master key", different types of products are suitable for different scenarios. Pay attention to the
following key points when choosing:
Applicable resin system
Confirm whether your water-based plastic paint is acrylic, polyurethane or other resin type, and choose an oil repellent
that is compatible with it. For example, fluorocarbon oil repellents are suitable for most water-based systems, while
silicones may be more suitable for specific resins.
Functional requirements
Basic oil repellent: suitable for daily scenes such as kitchen supplies and toys.
Oil repellent + antibacterial: suitable for fields with high hygiene requirements such as maternal and child products and
medical equipment.
Oil-resistant + wear-resistant: suitable for high-frequency use scenarios such as automotive interiors and home appliance
shells.
Environmental certification
Prioritize products that have passed environmental certifications such as RoHS and REACH to ensure safety and
non-toxicity.
Tips: Before purchasing, you can ask the supplier for a technical manual or sample test to ensure that the effect meets
expectations.
Step 2: Accurate blending, dosage is the key
The amount of oil-resistant agent added directly affects the oil-resistant effect and cost of the coating, and the following
principles must be strictly followed:
Recommended dosage
Usually 1%-5% of the total amount of water-based plastic paint (specific details are subject to the product manual).
Excessive dosage may cause the coating to lose transparency or weaken adhesion, and insufficient dosage will result in
poor oil-resistant effect.
Mixing techniques
Pre-dispersion: Add the oil-resistant agent to a small amount of water or solvent, stir at a low speed until uniform, and then
add it to the main paint.
Avoid high shear force: High-speed stirring may destroy the molecular structure of the oil-resistant agent. It is recommended
to use a low-speed disperser (300-500 rpm).
Curing time
After mixing, let it stand for 10-30 minutes (depending on product requirements) to allow the oil-resistant agent to fully react
with the resin to form a stable system.
Guide to avoiding pitfalls: It is recommended to do a small sample test for the first use to observe the appearance, hardness
and oil-resistant effect of the coating before mass production.
Step 3: Optimize construction, details determine success or failure
The performance of the oil-resistant coating depends not only on the formula, but also on the construction process. The
following are key operating points:
Substrate treatment
Cleaning: Use alcohol or special cleaner to remove oil and dust on the plastic surface.
Grinding: Slightly grind the smooth surface (such as 600 mesh sandpaper) to enhance the adhesion of the coating.
Construction environment
Temperature: 15-35℃ (too low may affect the drying speed, too high may cause poor leveling).
Humidity: ≤80%, avoid high humidity environment causing the coating to turn white or bubble.
Coating method
Spraying: Suitable for complex shapes, spray gun pressure (0.3-0.5MPa) and distance (20-30cm) need to be controlled.
Dip coating/roll coating: suitable for flat or regular shapes, and ensure that the coating is uniform and has no sagging.
Drying and curing
Natural drying: Surface drying takes about 30 minutes at 25℃, and actual drying takes 24 hours.
Forced drying: Bake at 60-80℃ for 30 minutes to accelerate curing and improve performance.
Cold knowledge: The coating thickness is recommended to be controlled at 20-40μm. Too thick may cause uneven
migration of the oil repellent, and too thin will result in insufficient effect.
Step 4: Effect verification, speaking with data
After the construction is completed, how to judge whether the oil repellent effect meets the standard? The following
method is simple and easy:
Water drop angle test
Use a contact angle meter to detect the water drop angle on the coating surface. ≥110° is excellent and 90°-110° is qualified.
Oil stain simulation test
Drop edible oil or mineral oil on the coating surface to observe whether obvious oil beads are formed and easy to wipe.
Durability test
Dip cotton cloth in grease and rub the coating repeatedly 100 times, and then test whether the oil repellent performance
decreases.
Quick self-test method: If there is no professional equipment, you can press the coating with your fingers. If there is no
obvious fingerprint residue, it means that the oil-proof effect is good.
Step 5: Storage and safety, details cannot be ignored
Although the oil-proof agent is easy to use, the following matters should be noted during storage and use:
Storage conditions
Sealed and light-proof, temperature 5-35℃, avoid high temperature or freezing to cause stratification or failure.
Keep away from fire and oxidants, some oil-proof agents may be flammable.
Use protection
Wear gloves and goggles during operation to avoid contact with skin and eyes.
If accidentally contacted, rinse immediately with plenty of water and seek medical help.
Disposal
The remaining oil-proof agent must be handled in accordance with local environmental protection regulations, and
never pour it directly into the sewer.
Environmental reminder: Give priority to biodegradable or low-VOC oil-proof agents to reduce the impact on the
environment.
Conclusion: From "clumsy hands" to "painting expert"
The use of water-based plastic paint oil repellent is not complicated. You only need to master the five steps of "selecting
the right product, precise mixing, optimizing construction, verifying the effect, and safe storage" to make plastic products
easily "oil-repellent". Whether it is DIY transformation of household items or mass production of industrial products,
oil repellent can be your right-hand man. Next time, when you are worried about oil stains, you might as well give it a
try - maybe you can also become a "painting expert" in your circle of friends!
Take action: Starting today, use oil repellent to put on "invisible protective clothing" for your plastic products, so that
cleanliness and beauty will always be with you!