Traditionally, engineers, machine builders and systems integrators have treated assembly and packaging separately. But, the lines of distinction are starting to blur, as more and more manufacturers integrate their assembly lines with blister packers, cartoners, case packers, palletizers and other types of packaging machines.
Not surprisingly, the two disciplines share many similarities, and while the challenges are different, the goals remain closely aligned: eliminate waste, reduce cost and improve time to market.
In addition, assembly machines and packaging equipment often use similar technology, including controls, drives, sensors, servos and software. Both systems also use similar parts-marking or labeling technology, and machine vision technology is commonly applied to both processes. Finally, adhesives and ultrasonic welding can be used not just to assemble products, but to close and seal boxes, cartons and pouches as well.
Of course, for all the similarities, there are also some fundamental differences. For instance, most packaging functions are performed dynamically-while the product or part is moving. In sharp contrast, most assembly functions are performed with the product or part stationary.
Another key difference between the two is line speed. Packaging processes tend to have higher line speeds than their assembly counterparts, often four or five times faster. This is because most packaging machines don't index or stop like assembly machines, and part tolerances are much more relaxed compared to assembly lines.
Although thousands of different packaging styles and configurations exist, nearly all packaging boils down to two basic types: primary packaging and secondary packaging.
Primary packaging refers to the packaging that immediately envelops a product, protecting it until it can be used by the consumer. Examples of primary packaging include blister packs, clamshells and trays.
Secondary packaging is the outer package into which the primary package is placed. Its major function is to protect the product during shipping and distribution. Examples of secondary packaging include cartons, containers and pallets.
Similarly, although there are numerous types of packaging machines, most fall into a few basic categories:
- Filling machines that measure a predetermined volume, weight or number of product and fill it into a bag, bottle, box, container, sack, tube or other type of package.
- Closing machines that seal or close filled packages by crimping, folding or tucking. Adhesives, gummed tape and ultrasonic welding are often used, in addition to heat sealing.
- Cartoning machines that erect and close carton blanks or folded and side-seam sealed cartons.
- Wrapping machines that wrap a flexible material, such as plastic film, around a product or group of products.
- Pallet forming machines that form, dismantle or secure pallets and other loading units.
Some packaging equipment performs multiple functions. Also, as is the case in the world of assembly, most of today's packaging machines are flexible, featuring modular configurations and layouts to maximize application flexibility and minimize reconfiguration time.