As a custom converter of labels and adhesive products, every project requires a complete evaluation of the “label sandwich” or construction. We’ve previously covered the basics of a label construction (here) and facestock options (here), so now let’s take a deeper dive into a some potential adhesive options for the durables market.
Each adhesive type has its unique advantages and disadvantages which is the reason our application team reviews each application to spec in the best fit.
In some instances, a variety of adhesive testing is also required to ensure the durability and functionality of the adhesive selection in the given environment. To find out more about TLP’s adhesive testing lab, check out our overview (here).
Review: Pressure Sensitive Adhesives
Emulsion Based Acrylic Adhesives
Emulsions are acrylic polymer adhesives that are suspended in water. The water-based adhesive is coated onto a facestock, then the water is dried causing the polymers/components to form a pressure sensitive adhesive. These types of adhesives are commonly used in packaging labeling and tapes, non-woven applications such as diapers, in household glues.
Advantages include: good resistance to heat and chemicals, low VOC performance and low odor, relatively lower cost and a broad range of adhesive strength options.
Disadvantages include: poor resistance to water, lack cohesive strength, lack clarity, lack adhesive strength in high temperature and low surface energy applications.
Solvent Based Acrylic Adhesives
Solvent-based acrylic adhesives are created by combining solvents with adhesive components. When the solvents evaporate, the remaining adhesive is structurally stronger, resulting in a more durable adhesive built to withstand chemicals, solvents, and a variety of temperatures. These types of adhesives are commonly used in permanent label applications, automotive applications such as seals and gaskets, noise dampening applications, protective films, and foam tapes among others.
Advantages include: crosslinked adhesive built to withstand chemical exposures and varying temperatures, a variety of options in configuration, and are durable and long-lasting.
The main disadvantage to solvent-based adhesives is that the manufacturing process can produce harmful chemicals as a byproduct.
Rubber Based Acrylic Adhesives
Rubber adhesives come in a variety of options including both natural and synthetic rubbers. Synthetic rubber can be further broken down into hot-melt, solvent, and butyl.. each offering their own unique use cases and benefits. These types of adhesives are commonly used in electrical tapes, carton sealing, and low temperature splicing.
Advantages include: high tack, high shear strength, and good solvent resistance.
Disadvantages include: poor durability in outdoor applications, poor reaction to temperature extremes and UV light, and the tendency to become brittle and break down over time.
Silicon is one of the oldest types of adhesives. It uses the bond strength of silicone to provide a flexible sealant that is best compared to a gel versus the glue-like texture of polymer adhesives. These types of adhesives are commonly used in LED applications, splicing and masking tapes and Kapton/Polyimide tapes and labels.
Advantages include: high flexibility at lower temperatures, consistent performance in a variety of temperatures, excellent aging and UV resistance, and good resistance to solvents.
The main disadvantage for silicone adhesives is the fact that they are significantly more expensive.
Clearly, removable adhesives would be the literal opposite of permanent adhesives. They work by creating bonds within themselves, formulated to remain tacky without a hard set found in permanent adhesives. Ultimately, the cohesive bond can be broken by tensile force (or solvent, water, and/or heat) without damage to the application surface. These types of adhesives are commonly used in food and clothing labels, relabeling applications, masking tapes and shipping labels.
Advantages include: little to no residue once removed and labels that can be reused.
Disadvantages include: increased permanence of adhesive over time, poor performance with exposure to moisture, heat, cold, and corrosive materials, and the potential to be more expensive.
Have a project you’d like to discuss with our application engineers? Contact TLP today.