Packaging forms an integral part of the production management systems of an organization. Thousands of varieties of paper boards, fiberboards, chipboards and other types of cartons and boxes are used for storing and shipping a wide variety of materials. Once a manufacturer has finalized the type and size of the box to be used, the next step is to determine the best way to seal it. The type and strength of the corrugated box, the shape of the container, and the type of laminates being used help in determining the kind of adhesive to be used for sealing them. Different types of adhesives including hot melt products, water-
based cold glue that uses natural or synthetic polymers, and industrial tapes are used to seal the packages before storing and shipment.
Adhesives for Case and Carton Sealing
Adhesives used for cases and cartons have to be durable enough to withstand the rigors of shipping plus the varying conditions of a product during its lifecycle. The most preferred option for a case and carton sealing is the hot melt range of adhesives. The market for hot melt adhesives is projected to grow at a CAGR of 4.8% between 2022 and 2027. These hot melt adhesives cool down quickly after application and provide better excellent strength.
While traditional hot melt adhesion techniques involved the use of heated tanks that were more prone to char-induced maintenance, the new tank-free systems are more efficient and increase the working uptime of packaging lines. Again, manufacturers have the option of choosing from two types of hot melt adhesives: Ethylene Vinyl Acetate or EVA and metallocene. While EVA can penetrate all types of coatings, it may char at high temperatures. In contrast, metallocene shows stability in all temperature conditions.
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The selected hot melt adhesive is applied to seal the flaps of cartons and cases so that the material inside is not damaged or destroyed. The adhesive is applied at an elevated temperature to one flap which is subsequently placed in contact with the surface of the second flap. The two flaps are then compressed to form a bond that seals the package.
Tips for Improved Efficiency of Adhesives
The efficiency of the adhesive used should be such that the integrity of the sealed carton or box remains intact during shipping as well as on the receipt. The package should, however, easily open when the two flaps are pulled apart. The strength and the efficiency of the hot melt adhesives depend on several factors like:
● Substrate and its temperature
The temperature at which they are applied
● Amount of adhesive applied and the size of the carton or case to be sealed
● Compression time and
● Open time
Some tips to maintain the performance of the hot melt adhesives are:
● Maintaining the ambient conditions and ensuring that they do not change even for a short time.
● Not using substrates that were not stored in proper conditions or were not brought to room temperatures before their usage.
● Using the right quantity of adhesive and avoiding excess application which can
actually slow down the setting time while reducing the efficiency.
● Keep in mind the environment in which the carton or cases are going to be shipped.
● Remember that the listed melt temperature of an adhesive is not an indication of its heat resistance ability.
Choosing the right adhesive and its careful application keeping in mind the product being packed and the temperature during its shipment is important for the best results.