by Types of Lamination Adhesives
There are different types of lamination adhesives used depending on the materials being bonded and the end-use requirements of the package. Some of the commonly used lamination adhesives include:
Water-based adhesives: These are environment-friendly adhesives that contain water as the primary solvent. They offer good bonding for papers, films, and non-porous substrates. However, their bond strength is generally lower than solvent-based adhesives.
Solvent-based adhesives: These adhesives use organic solvents like acetone, MEK, and toluene as carriers. They deliver high bond strength but are more toxic compared to water-based adhesives. Solvent-based adhesives are suitable for bonding porous and non-porous substrates.
Hot melt adhesives: As the name suggests, these adhesives are applied in a molten state and bond substrates upon cooling and solidification. Being solvent-free, they are safer for the environment and humans. However, special application equipment is required for hot melt adhesives.
Radiation cured adhesives: These adhesives are cured by exposing them to ultraviolet light or electron beams. They form very strong bonds quickly but require radiation equipment for curing.
Protein-based adhesives: Adhesives made from proteins like soy and casein deliver strong bonds for paper and paperboard packaging. However, their usage is limited since they require special controlled conditions.
Properties and Applications of Lamination Adhesives
The properties of lamination adhesives determine the types of applications they can be used in flexible packaging production.
Packages for dry foods: Water-based adhesives are suitable as they prevent moisture ingress into packages for dry foods like snacks and cereal. These adhesives maintain package integrity while allowing vapors to permeate.
Packages for liquid foods: High-barrier packaging is required to contain liquid foods like juices and sauces. Solvent-based adhesives provide strong and long-lasting bonds for multi-layer laminate structures incorporating PE and EVOH barrier films.
Sustainable packaging: Lamination Adhesives For Flexible Packaging Bio-based hot melt adhesives from renewable sources like plants offer compostable and recyclable packaging options. Their solvent-free attribute also makes them safer for the environment.
Retort packaging: Packages that undergo high-temperature commercial sterilization processes require adhesives like radiation-cured types that deliver high heat resistance to withstand retorting.
Aseptic packaging: Aseptic packages for UHT milk and liquid egg need adhesives providing extremely low permeability to oxygen and moisture. Water-based and hot melt formulations are used.
Factors Influencing Selection of Lamination Adhesives
Manufacturers must carefully choose lamination adhesives based on the following considerations:
Composition of packaging layers: The types of films, foil, and other components in the laminate structure impact adhesive selection.
Required bond strength: The end-use application and durability needs determine if a high, medium or low bond strength adhesive is needed.
Processing temperatures: Adhesives must withstand converting, packaging, and distribution temperatures without delamination.
Permeability and barrier properties: Packages for ambient and long-shelf-life products demand adhesives that do not compromise the barrier integrity of the laminate.
Regulatory standards: Food contact regulations stipulate use of approved adhesives that do not migrate or cause contamination.
Environmental and human safety: More sustainable options like water-based and hot melt adhesives minimize volatility.
Economics: Production volumes, technology investments, and total applied costs influence the best value lamination adhesive choice.
Advancements in Lamination Adhesives
Continuous research and development drives innovations in lamination adhesives for flexible packaging. Newer generations of adhesives address evolving needs like reduced environmental impact, advanced barrier performance, application versatility, and minimized raw material usage. Some emerging adhesive technologies include:
Bio-based adhesives from renewable agricultural sources offer a greener alternative with performance matching petroleum-based formulations. Their biodegradability enhances sustainability.
Self-adhesive films integrate adhesive directly into packaging films, simplifying the lamination process. These one-step self-wound rolls save time and costs.
Hot melt processability at lower temperatures using reactive chemistry extends the versatility of solvent-free adhesives for heat-sensitive substrates.
Lightweight core adhesive formulations utilize minimal adhesive quantities while delivering strong, durable bonds through optimized molecular design.
Radiation-curable and humidity-curable technologies provide new application methods compared to traditional heated roll lamination.
The flexible packaging industry constantly demands innovations from adhesive suppliers to develop diverse, customized solutions supporting changing market and regulatory needs. Advancements in adhesive technologies unlock new sustainable packaging opportunities.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
