In custom label stickers, waterproof and oil-proof performance is a core indicator affecting their lifespan and application scenarios. Especially in humid, oily, or outdoor environments, if the label cannot resist moisture and oil penetration, it can easily lead to blurred text, label detachment, or material deformation. Improving this performance requires comprehensive optimization from three dimensions: material selection, processing, and structural design, forming a multi-layered protection system.
Material selection is fundamental; priority should be given to surface materials with natural waterproof and oil-proof properties. Film materials such as PET (polyethylene terephthalate), PVC (polyvinyl chloride), and PE (polyethylene) effectively block moisture and oil penetration due to their dense molecular structure and low surface energy. For example, PET film has excellent chemical resistance and mechanical strength, maintaining the integrity and readability of label stickers even after prolonged contact with oil or humid environments; while PE film, due to its flexibility and low-temperature resistance, is often used in scenarios requiring frequent bending or low-temperature storage. In contrast, while paper surface materials are cheaper, they require subsequent processing to achieve waterproof and oil-proof effects. Therefore, film materials are the preferred choice for improving performance.
Surface coating is crucial, forming a protective layer through lamination or application of special varnishes. Label sticker lamination involves covering the label surface with a transparent film, such as BOPP (biaxially oriented polypropylene) or PET film, which not only isolates moisture and oil stains but also enhances the label's abrasion resistance and UV resistance. For example, laminated labels are less prone to leaving marks when wiped or lightly scratched and maintain their vibrant colors for a long time. Varnish application involves printing a layer of transparent varnish onto the label surface, forming a dense protective film. Varnishes come in various types; general-purpose varnishes enhance the label's gloss and water resistance, matte varnishes create a frosted texture and reduce reflections, and abrasion-resistant varnishes, by adding silicone additives, make the label surface smoother and reduce friction damage during transportation or use.
Chemical coating technology provides labels with more durable protection. By applying a fluorinated or silicone-based chemical coating to the label sticker surface, surface energy is significantly reduced, making it difficult for moisture and oil stains to adhere. For example, fluorinated coatings offer excellent hydrophobic and oleophobic properties, allowing labels to be easily wiped clean even when exposed to oil. Silicone coatings enhance the label's flexibility and temperature resistance, making them suitable for high or low temperature environments. These chemical coatings are often used in conjunction with film facestocks to create double protection, further improving the label's durability.
Optimized structural design enhances the label's edge protection. For instance, raised or recessed rings along the label edges prevent moisture penetration from the sides; adding an aluminum foil strip to the back of the label strengthens adhesion to the substrate and prevents moisture from seeping in from the bottom. This design is particularly suitable for labels that require prolonged immersion or exposure to humid environments, such as equipment nameplates and outdoor advertising.
Adhesive selection also affects water and oil resistance. Highly water-resistant adhesives, such as hot melt adhesives or acrylic adhesives, should be used to ensure the label does not detach due to adhesive failure in humid environments. For example, hot melt adhesives melt at high temperatures and solidify rapidly, forming a strong adhesive layer with excellent water resistance; acrylic adhesives, on the other hand, possess excellent weather resistance and chemical stability, making them suitable for long-term outdoor use.
Controlling the production environment is crucial for ensuring stable label performance. Excessive humidity can cause label stickers to absorb moisture and deform, while temperature fluctuations can affect the adhesive's bonding effect. Therefore, production workshops must maintain constant temperature and humidity, and labels must undergo thorough drying after production to ensure complete evaporation of moisture. Furthermore, the surface of the object to which the label will be applied must be clean and dust-free before application to prevent dust or oil from affecting the adhesion.
Application scenario adaptability requires adjustments to the protection scheme based on specific needs. For example, food packaging labels must use materials and adhesives that meet food safety standards; outdoor identification labels need enhanced UV resistance; and chemical equipment labels need chemical corrosion resistance. Targeted optimization ensures that labels perform optimally in specific environments.
