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 adhesives contain solvent as a carrier, which is subsequently dried after application (dry bond laminating), leaving the active resin system on the substrate to be bonded to a secondary substrate to make the lamination. These laminations can contain multiple adhesive layers and are used in a variety of food packaging applications ranging from snack food  to high-demand, retortable packages covering multiple FDA regulations. They are also used in industrial laminating applications such as window film, fabric laminations, and insulation-facing laminates. Dow's solvent-based portfolio is one of the broadest available in the industry.

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 adhesives contain water as their carrier which is subsequently dried after application (dry bond laminating), leaving the active resin system on the substrate to be bonded to a secondary substrate to make the lamination. These products can be used on a variety of film substrates as well as foil and paper. End use applications in food packaging include snack food and bottle labels, as well as microwaveable and boil-in-bag packages. Other applications include medical packaging and flexible industrial laminations. These products are typically machine-ready with no dilution needed and offer fast slit-to-ship turnaround.