PS-101 Preparing for Your Success
The Pressure-sensitive Label Construction Module 4: Adhesives
Pressure-Sensitive Adhesive Features Coating Technology Adhesive Chemistry Adhesive Selection Criteria & End Use
Adhesive Technology > A pressure-sensitive adhesive is generally a soft, viscous (has flow abilities) material that is sticky to the touch. When applied to a substrate with slight pressure, the adhesive will begin to flow into the surface.
Adhesive Technology Pressure Sensitive Adhesives Hot Melt Solvent Emulsion Rubber Rubber Acrylic Acrylic Perm Rem Perm Rem Perm Rem Perm Rem Three Primary Coating Technologies (how the adhesive is applied to the liner): Hot Melt Solvent Emulsion Two Primary Adhesive Bases (what the adhesive is made of): Acrylic Based and Rubber Based
Coating Technologies TECHNOLOGY CHARACTERISTICS Hot Melt Coated in molten state. Typically lowest cost method. Typically not suitable for film constructions. Yellowish tint. Primarily rubber based adhesives. Solvent Coated as a solvent solution. Environmental costs. Robust performance. Provides and maintains high clarity. Rubber and Acrylic adhesives Emulsion Coated with components suspended in water. Provides and maintains high clarity. A wide range of performance is available. Primarily acrylic based adhesives.
Rubber Based Hot Melt and Solvent Technology vs. Rubber versus Acrylic Based Adhesive Performance Acrylic Based Solvent and/or Emulsion Technology ADVANTAGES: High initial tack Excellent long term adhesion High affinity to low energy substrates (plastic containers) DISADVANTAGES: Narrow service temperature range Poor solvent resistance Poor UV stability Yellow in color Potential for poor wide web converting ADVANTAGES: Wide service temperature range Good solvent resistance (solvent) Good UV stability (solvent) Excellent clarity Excellent long term adhesion May be repositionable (emulsion) Excellent wide web converting DISADVANTAGES: Medium initial tack Less affinity to low energy substrates.
Pressure-Sensitive Adhesives Permanent - Label cannot be removed without damage to the label or substrate Removable - Label can be removed at a desired time without damage to the label or substrate Specialty - Designed for specific end-use requirement Heavy Coat Weight B / Light Coat Weight A Pattern Gum Photoluminescence Repositionable / Ultra-Removable All Temperature / Cold Temperature
Trademarked Brands and Product Names Avery, Avery Dennison, and Fasson are trademarks or service marks of Avery Dennison Corporation. All other brands and product names are trademarks of their respective companies. Use of these images is intended to demonstrate applications for Avery Dennison products and services. This display does not indicate affiliation, sponsorship, approval or endorsement by the manufacturers of the products and the owners of non-avery Dennison brands.
The Pressure-sensitive Label Construction Module 5: Adhesive Selection Guide
Adhesive Selection Guide > What surface will the labels be applied to?» Surface composition» Contour» Texture > Does the label need to be permanent or removable? > What are the conditions in which the labels are being applied?» Moisture and/or high humidity» Temperature» Unusually dusty or dirty» Clean room > How will the labels be applied?» Auto applied or by hand» How fast will they be applied?» Repositionability required?» For how long? > What are the exposure conditions?» Outdoor (vertical or horizontal)» Chemicals» Abrasion» Surface protection required? How is the label applied? How is the label being used?
Adhesive Selection Guide Are there special application or exposure conditions the label must withstand? Minimum Application Temperature Lowest temperature at which the label is applied to the substrate Service Temperature Temperature range that the label will be exposed to over its expected lifetime Hot Fill and Fresh Bottle Labeling Requires special facestock/adhesive combination Storage Conditions Ideally should be 50%RH and 72ºF
Adhesive Selection Guide It is important to identify the exact type of substrate being used. Plastic as a description is not enough. The level of adhesion will vary with the type of plastic being used. Plastic Type Plastic Description Examples PET Polyethylene terephthalate 2 Liter soft drink bottles, crystal clear squeezable bottles HDPE High density polyethylene Milk jug bottles, colored semi rigid bottles PVC Vinyl (Polyvinyl chloride) Vinyl binders, bags LDPE Low density polyethylene Plastic bags PP Polypropylene Diapers, straws PS Polystyrene Expanded foam, casings for compact disks, components for copiers O, MR Multi-Resin & other Plastics
Adhesive Selection Guide - Surface Energy Ability of the adhesive to 'wet out' over the surface of a material Low-surface energy materials prohibit wet out (beads of water on a waxed car) High-surface energy materials have excellent wet out and provide best adhesion Rubber based adhesives generally offer better adhesion to low surface energy substrates May require special treatment (Corona treatment; primers; top coatings) On some low surface energy materials, adhesion levels will improve with longer dwell times High Surface Energy Copper Aluminum Zinc Lead Stainless Steel Glass High Surface Energy Plastics Kapton Phenolic Alkyd Enamel Polyester Epoxy paint ABS Polycarbonate PVC Acrylic Noryl Low Surface Energy Plastics Polystyrene EVA Polyethylene Nylon Polypropylene Tedlar Teflon
Adhesive Selection Guide What is the texture of the substrate (the surface to which the label will be applied)? A rough surface may require a stronger bonding adhesive or a heavier adhesive coat weight to achieve acceptable adhesion *** Remember, adhesion to any substrate is achieved by the adhesive flowing into all areas of the substrate and bonding with them Adhesive Facestock Substrate
Adhesive Selection Guide What is the shape of the substrate surface? Curved Surfaces Containers with less than 1 in diameter require a highly aggressive adhesive one that adheres quickly and will not lift on the edges and a flexible facestock. A wrap around (overlap) label may be preferable for very small diameter labeling. This type of application also requires flexible facestocks and high tack adhesives. Do not apply varnish at the overlap! Compound Curves Will require a special label shape and a flexible facestock for conformability to the surface. Film generally performs better for compound curves.
Adhesive Selection Guide Is the application surface clean or contaminated? Contaminated Surfaces Adhesion problems due to contaminated surfaces are often a major cause of pressure sensitive failing to perform as expected or tested. Typical Contaminates: Oil, grease, dust, dirt, moisture, ice, even fingerprints. All keep the adhesive from touching the actual surface! Mold Release Agents: Another typical contaminate seen when labeling plastic and glass containers. Consider the use of wrap around (overlap) labels where contamination is present and cannot be removed.
Adhesive Selection Guide Are there any plasticizers present that will deteriorate the adhesive properties? Plasticizer: This is a component used in vinyl which controls the degree of softness or pliability of the vinyl. A highly plasticized vinyl will be very soft and pliable while a low plasticized vinyl will be very stiff.» A plasticizer in contact with some adhesives will degrade adhesive bond strength. It may be necessary to use a plasticizer resistant adhesive. Pre-testing is always advisable by accelerated aging when the existence of plasticizers are suspected.
Adhesive Selection Guide Are there any special application and/or exposure conditions that the label must withstand? Special Conditions Temperature extremes, outdoor weather exposure, ultra-violet light exposure, sterilization processes. Questions to consider» Will the label be exposed to large amounts of moisture? If so, a moisture resistant facestock should be selected.» Will there be prolonged exposure to ultra-violet light? Long term exposure to U.V. light deteriorates rubber based adhesives. Special adhesives may be needed if transparent facestocks are to be used or the labels are to last an exceptionally long time. Concentrated U.V. exposure will also affect the graphics on the label so this consideration is particularly important where long label life is desired.» Will the label be exposed to elevated temperatures above +200 F for an extended period? If so, an acrylic adhesive combined with film or foil may be required.
Trademarked Brands and Product Names Avery, Avery Dennison, and Fasson are trademarks or service marks of Avery Dennison Corporation. All other brands and product names are trademarks of their respective companies. Use of these images is intended to demonstrate applications for Avery Dennison products and services. This display does not indicate affiliation, sponsorship, approval or endorsement by the manufacturers of the products and the owners of non-avery Dennison brands.
2011 Avery Dennison Corporation. All rights reserved. Avery Dennison and all other Avery brands, product names and codes ar e trademarks of Avery Dennison Corporation. All other brands and product names are trademarks of their respective owners. Fortune 500 is a trademark of Time, Inc. Personal and company names and other information on samples depicted are fictitious. Any resemblance to actual names and addresses is purely coincidental. Revised May 2011