Sticking Power:

What Are Label Adhesives?

Label adhesives are pressure-sensitive glues applied to the back of a label material. Unlike wet glues that dry to bond, pressure-sensitive adhesives bond when pressure is applied, activating their sticking properties. They are engineered with various chemical compositions to perform optimally in different conditions and on diverse surfaces.

The performance of an adhesive is typically judged by its initial tack (how quickly it grabs), its ultimate adhesion (the bond strength over time), and its cohesion (the internal strength of the adhesive itself).

Common Types of Label Adhesives

Adhesives can be broadly categorised by their intended use and chemical composition:

1. Permanent Adhesives

• Characteristics: Designed for a strong, long-lasting bond that is difficult to remove without tearing the label or leaving residue. Often made from acrylic or rubber-based formulations.
• Applications: Product identification, asset tagging, safety labels, branding, serial number labels, general-purpose labelling where a secure, non-removable bond is required for the lifespan of the product.
• Considerations: Various levels of aggression exist. Some 'extra permanent' options are available for challenging surfaces.

2. Removable Adhesives

• Characteristics: Formulated for clean removal from a surface without leaving residue or damaging the substrate. They offer a strong enough initial tack to hold, but weaken over time or with specific removal techniques.
• Applications: Promotional labels, temporary identification, window decals, pricing labels, labels on reusable containers, items that need re-labelling, or protecting delicate surfaces.
• Considerations: "Removable" does not mean "repositionable." Test on your specific surface, as some surfaces (e.g., certain plastics or very porous materials) can still be affected.

3. Specialty Adhesives

Beyond permanent and removable, a range of specialised adhesives exists for specific, challenging conditions:

• Freezer/Cryogenic Adhesives: Engineered to withstand extremely low temperatures (down to -80°C or even -196°C for cryo). They are applied at room temperature but maintain their bond in freezing conditions without becoming brittle or losing adhesion. Ideal for food packaging, laboratory samples, and cold storage.
• High-Tack / Aggressive Adhesives: Provide an extremely strong bond for difficult surfaces, such as rough textures (e.g., corrugated cardboard, wood), oily surfaces, or low-energy plastics (e.g., HDPE). They are designed to grab quickly and hold firmly where standard adhesives would fail.
• Repositionable / Ultra-Removable Adhesives: Offers a very low initial tack allowing the label to be repeatedly applied, peeled off, and reapplied without losing adhesion or leaving residue. Often used for temporary notes, crafting, or certain promotional items.
• Water Soluble Adhesives: Designed to dissolve completely when exposed to water, leaving no residue. Perfect for reusable containers, food service items, or applications where a label must disappear without a trace during cleaning.
• Marine Adhesives: Specifically formulated for harsh marine environments, offering superior resistance to saltwater, UV exposure, and extreme temperatures.

Key Factors When Choosing Your Label Adhesive

To ensure you select the optimal adhesive, consider these crucial factors:

• Application Surface:
  • Surface Energy: Is the surface high-energy (metal, glass) or low-energy (many plastics like polyethylene, polypropylene)? Low-energy surfaces are harder for adhesives to bond to.
  • Texture: Is it smooth, rough, or porous (e.g., cardboard)? Rough surfaces require more aggressive adhesives to fill gaps.
  • Shape: Is it flat or curved? Labels on highly curved surfaces need adhesives with good conformability.
  • Contamination: Is the surface clean, oily, dusty, or painted? Surface contaminants can severely impair adhesion.
• Environmental Conditions:
  • Temperature: What are the minimum application temperature, the service temperature range (from freezing to high heat), and is it exposed to extreme temperature cycles?
  • Moisture & Humidity: Will the label be exposed to water, condensation, or high humidity?
  • Chemical Exposure: Will it come into contact with oils, solvents, cleaning agents, or other chemicals?
  • UV Exposure: Will the label be outdoors or exposed to direct sunlight, which can degrade some adhesives over time?
• Removal Requirements: Does the label need to be easily and cleanly removable, or is a permanent bond essential? This dictates removable vs. permanent.
• Application Method: Will labels be applied manually or by machine? Automated application may require specific adhesive characteristics for smooth feeding.
• Industry Regulations: For food, pharmaceutical, or medical applications, specific FDA or other regulatory approvals for indirect/direct food contact or medical use might be required.

The Importance of Testing

Given the vast number of variables, the single most important step in choosing an adhesive is **testing**. Always request samples and test them under your actual application conditions before committing to a large order. What works on one surface might fail on another.

Find Your Perfect Label Adhesive with North & South Labels Ltd

The right label adhesive ensures your product information stays put, no matter the challenge. A failing label can lead to costly operational inefficiencies, compliance issues, and damaged brand perception. Don't leave it to chance!

At North & South Labels Ltd, we specialise in understanding these complex requirements. Our team can guide you through the selection process, providing expert advice and samples to help you find the perfect adhesive for your specific application. Partner with us to ensure your labels have the sticking power they need.

Frequently Asked Questions (FAQs)