Adhesives for flexible packaging

A specific method of analysis has been developed by Sapici, a manufacturer of PU adhesives for flexible packaging, to... 

And there are many other recent developments, such as do-it-yourself adhesives and sealants, laminating adhesives for flexible packaging, reinforcements in construction and civil engineering, many agglomerations (composite boards, ete.), dental repair, repairs on metal parts, etc. 

A detailed study of PU adhesives for flexible packaging is provided in Volume 4 by the chapter PU adhesives for laminating by J-F LECAM. 

Radiation-curable laminating adhesives for flexible packaging... 

Recently, there has been significant interest in EB-curable laminating adhesives for flexible packaging. EB curing offers a number of potential advantages over solvent-based. 

Dearborn, Mi., 26th-29th Oct. 1997, p.397-423 EPA AND FDA REGULATIONS AS FACTORS IN THE CONVERSION FROM SOLVENT TO WATERBORNE ADHESIVE SYSTEMS FOR FLEXIBLE PACKAGING Simmons R A Keller Heckman LLP (Adhesive Sealant Council)... 

The flexible materials used for medical device packages include a plastic film that is usually a lamination or extrusion-coated material. The material most commonly used for flexible packaging applications is oriented polyester (e.g.. Mylar ), which is used as a base for properties such as dimensional stability, heat resistance, and strength with an adhesively laminated se layer such as low-density polyethylene, which provides the film structure with heat sealability. The variety of film combinations is virtually unlimited and the performance properties of the film can be customized to meet the requirements of the package specifications and the medical device. Other examples of film constructions are... 

Wider application of radiation-curable adhesives in flexible packaging Reduced cost of adhesives Improved adhesion properties Reduced odour Reworkable adhesives Adhesives for PET. 

Summary The broad objectives of technology developments in radiation-curable adhesives are to achieve the required mix of cohesive and adhesive properties, reduced odour and addressing toxicity and safety concerns. Recently, various players have focused on developing technology for laminating adhesives and PSAs, specifically for flexible packaging. 

Water-borne adhesives are preferred because of restrictions on the use of solvents. Low viscosity prepolymers are emulsified in water, followed by chain extension with water-soluble glycols or diamines. As cross-linker PMDI can be used, which has a shelf life of 5 to 6 h in water. Water-borne polyurethane coatings are used for vacuum forming of PVC sheeting to ABS shells in automotive interior door panels, for the lamination of ABS/PVC film to treated polypropylene foam for use in automotive instmment panels, as metal primers for steering wheels, in flexible packaging lamination, as shoe sole adhesive, and as tie coats for polyurethane-coated fabrics. PMDI is also used as a binder for reconstituted wood products and as a foundry core binder. 

The PSA formulator can also take advantage of plasticizers. For example, polyether-based plasticizers have both good low-temperature flexibility and good hydrophilicity. Using these properties, acrylic PSAs have been formulated with these types of plasticizers to obtain high adhesion to food packages stored under refrigerated conditions [102]. Similarly, polyether plasticized acrylics have been used to make repulpable PSAs [103]. 

As a result of extensive development and testing by thermoprocessing or aseptic techniques, the use of flexible, laminated aluminum pouches and formed aluminum containers for shelf-stable foods is nearing commercial reality. The increasing use of aluminum for food packaging has been made possible by successfully combining it with specialized plastics, papers, adhesives, and coatings. In many applications, aesthetic as well as protective characteristics are also provided. 

Trace Solvent Removal. Several papers were written by Nadeau (4) and by Gilbert (5) and co-workers on gas chromatographic methods for determining solvent traces remaining in flexible packaging films after printing or adhesive lamination. With proper equipment and techniques,... 

This paper discusses how tightening environmental regulations in the USA are encouraging a shift from solvent-based to waterborne adhesives for use in flexible packaging applications. It also looks at how new adhesive systems have a relatively easy path to Food Drug Administration clearance for food packaging uses. 

---