In many North American mills, there is lack of sorting out of Stickies (such as plastics, waxes, glue) because the process is very expensive. The lack of control here causes various problems.
Problems with recycled paper products
- faded print
- labels and tape not sticking
- porosity with suction cups
- Complete package failure in high humid environments.
Pros and Cons of Virgin vs. Recycled
Most mediums are recycled, making a single wall sheet about 33% recycled and double wall sheet 40% recycled, All corrugated sold in North American has recovered fiber in its construction.
To make an informed and strategic decision it is necessary to examine the life cycle of a paper product and evaluate starting at the fiber source through the manufacturing process to product use. Paper fibers can be reused from four to nine times depending on the paper grade. Or put another way the fiber lost from using recovered paper varies from 10 to 30 percent depending on the type of paper that is being made (an egg carton versus a glossy magazine). Factors that determine how many times fibers can be reused for each paper type include the ability of the collection system to recover paper, losses from the de-inking process and the decline in fiber strength with each use. In many cases, these losses result in poorer performance in paper because the fiber length becomes so short they do not interlock well and result in poor performance. Virgin stock never has this problem because the entire fiber is used in tacked and generally out performs recycled paper in bother burst strength and Edge-Crush (ECT).
The fact about recycled paper made in many North Amarican mills is the lack of sorting out of contaminates (Stickies). Sorting out these stickies is very expensive and is typically where recycled paper makers take short cuts. The lack of control here causes problems in making combined corrugated board, conversion into finished boxes and ultimately the final user. Stickies such as plastics, waxes, glue (book binder) gelitenize under high temperatures and works it way through the refining process and as the pulp gets pumped onto the wire and the water begins to reduce due to heat and drainage, these stickies create a moisture barrier that prevents optimal absorption. Once the paper passes through the Calendar Stack (Giant Iron) of the paper machine, it creates a film of which causes a multitude of issues with absorption of corn starch, inks and glues in the construction and conversion corrugated products.
Many end users of recycle paper products complain of faded print, labels and tape not sticking, warping, porosity with suction cups and complete package failure in high humid environments.
Most businesses today have a vested interest in minimizing their environmental impact, whether to lower operating costs, improve brand reputation or out of a sense of corporate social responsibility. In corrugating industry, “going green??? often focuses on building an effective environmental strategy around forest based resources such as corrugated products. A key consideration in developing and implementing this strategy is the paper decision and often the decision is framed as a choice between corrugated paper with recycled content and corrugated paper made with virgin fiber. Both methods, if performed responsibly, are environmentally necessary and good for the earth.