Packaging Adhesives

Heat Seal Coatings

Heat Seal Coatings are thermoplastic coatings used as adhesives to seal one substrate to another.  The coating is typically applied to a flexible substrate, such as film, foil, paper, or non-woven material, and allowed to dry.  The coated substrate does not exhibit tackiness at room temperature and can be shipped to another destination for heat sealing onto another substrate.  This final sealing is formed between the substrate that the coating was applied to, and the substrate that the coating is sealed to, when the adhesive is reactivated using heat and pressure.

Dow manufactures a full line of water-based and solvent-based heat seal coatings for multiple packaging applications, including flexible packaging.  Commonly, heat seal coatings are used to create flexible lids for food packaging containing items, such as vegetables, meat, cheese, condiments, and dairy.  Some heat seal options which comply with the appropriate FDA 21 CFR regulations are also used for lidding onto retortable and ovenable containers.

Non-food contact applications include in-mold labeling for food, beverage, and household packaging.  Medical instrument packaging, pharmaceutical blister packaging, and some industrial applications also make use of heat seal adhesives. Dow offers multiple grades of heat seal adhesives to suit most common coating application methods, including gravure, flexographic, reverse roll, slot die, air knife, and wire wound rods.  Dow's full offering of heat seal coatings is listed below. 

Primers

Primers are used to promote or improve adhesion of a topcoat to a variety of base films including foil, metalized films, paper, and board stock. Often they are applied and immediately top-coated. In some cases, however, they may be applied and wound, but top-coated at a later date. Both water- and solvent-based chemistries are available.

Solvent Based Adhesives

Solvent-based laminating adhesives contain organic solvents as a carrier for the adhesive resins present in the adhesive system. These solvents are dried after application to facilitate a process known as dry bond laminating, which leaves the active resin system on the substrate to be bonded to a secondary substrate to perform laminations between film and foil materials used to construct flexible packaging. 

Solvent-based adhesives constitute some of the oldest chemistries used for flexible packaging applications, and they are still widely used today for several reasons. These adhesives develop good green bond strength quickly, permitting laminates to be postprocessed faster and facilitating shorter turnaround times to complete final packaging. They also create packaging and laminate materials with good appearance and high heat and chemical resistance. 

Flexible packaging laminates made with Dow's solvent-based adhesives can be used in a variety of food packaging applications, including snack food, meat, cheese, frozen foods, chemically challenging foods, and foods that are oily or greasy. Dow's solvent-based laminating adhesives also cater to multiple FDA regulations concerning food packaging that enable high-demand applications, such as boil-in-bag, ovenable, hot fill, and retortable packaging. They are also used in industrial laminating applications, such as window film, fabric laminations, and insulation-facing laminates. Dow's solvent-based laminating adhesive portfolio is one of the broadest and most versatile available in the industry. For more information on these laminating adhesives, explore our options below. 

Solventless Adhesives

Solventless laminating adhesives contain 100% actives and do not have water or solvent carriers. These laminating adhesives are typically used in flexible packaging applications. They are specifically two-component adhesives consisting of an isocyanate and polyol that are mixed and react to form polyurethane. Solventless laminating adhesives provide packaging converters with cost savings by eliminating the requirement of ovens to remove water or solvent carriers in water-based or solvent-based adhesives.

Solventless laminating adhesives are applied to base substrates like films or foils using solventless laminators that can coat the adhesive via smooth roll transfer coating techniques. Coated substrates are subsequently nipped and bonded to a secondary substrate to make the lamination. These laminations may contain multiple laminate layers used to construct flexible packaging.

Flexible packages made with Dow's MOR-FREE™ and PACACEL™ solventless laminating adhesives are used in an array of packaging applications for food and beverages and meet a broad range of FDA regulations. For example, Dow offers several solventless adhesive options with appropriate compliance for snack food, hot fill, boil-in-bag, microwavable, and frozen food packaging. Dow's solventless adhesives also offer moderate chemical resistance and allow for aggressive fill and fatty food applications. These solventless adhesives are suitable for making laminates using most types of films, foils, and paper.

Continue below to view Dow's solventless laminating adhesive options.

Water Based Adhesives

Water-based laminating adhesives use water as a carrier for their resins. These adhesives are subsequently dried after application to facilitate dry bond lamination. After drying, the adhesive resin system remains on the substrate to be bonded to a secondary substrate to form the laminate under heat and pressure. These water-based adhesives provide advantages in sustainability over solvent-based adhesives since they use water as their carrier; they do not release hazardous air pollutants or large amounts of VOCs into the surrounding environment during the coating and drying process. 

These laminating adhesives are highly versatile and can be used to create strong bonds on a variety of materials, including several types of film, foil, and paper. End-use applications for these adhesives include food packaging, medical packaging, and industrial laminates. Laminates made with these adhesives carry food contact approvals for snack food, frozen food, microwaveable food, and warm fill and boil-in-bag packages. These adhesives also provide good chemical resistance and are compatible with chemicals and solvents used in medical applications. These laminating adhesives can create industrial laminates used in thermal and electrical insulations that bond materials, such as PET, polyolefin, and nylon plastic films and foil. 

Whereas solvent-based laminating adhesives require dilution prior to coating onto substrates, these water-based adhesives are typically machine-ready, requiring no dilution. This enables faster slit-to-ship turnaround times. Learn more about our water-based laminating adhesives by reviewing our options below.