Adhesives and Sealants for Packagings

Introduction

The variety of modern packaging products that are available today would not be possible without contemporary adhesive systems. The evolution of the packaging industry has closely matched the development of new adhesive materials and production processes. These trends have lead to high quality and solutions for technically demanding packaging structures.

Adhesives are used in packaging in three basic ways:

Very often the drivers for new types of packaging originate at the consumer. The following consumer trends have noticeably affected the industry:

• Detailed information is being printed directly on the package or adhered to the package walls with a label
• Food packaging has responded to the busy schedule of today's consumer leading to frozen food, chilled convenience foods, and microwaveable meals
• Easy to open packaging is being designed for older consumers and those with disabilities
• New packaging designs have responded to the rising demand for smaller portions packaged in convenient formats
• Consumers are also demanding greater packaging security, especially for the protection of children and elderly.

The manufacturer or converter of modern day packaging is also demanding new materials and processes. There is a need for adhesives and joining processes that can handle a wide variety of new packaging materials at ever increasing speeds and efficiencies. In addition, manpower shortages and cost control require higher and higher degrees of mechanization. Assembly methods are needed that are:

• more flexible,
• easier to operate,
• run at higher speeds with more accuracy

Production speed is of primary importance in today's packaging industry. For example, lamination line speeds of up to a few hundred meters per minute or container assembly rates of several hundred per minute are sometimes required.

Fast setting packaging or case sealing adhesives also require:

• high wet tack,
• machineability,
• low cost,
• water resistance in addition to fast set.

Other key requirements are clean processing, good adhesion, and adequate heat resistance sufficient for warehouse conditions. Manufacturers of packaging adhesives are also looking for low odor and low color for more attractive products.

An important parameter for the choice of a packaging adhesive is the surface properties of the packaging materials to be bonded. Packaging materials have developed from simple paper and board materials to more sophisticated coatings, printing, and coextrusions.