Contaminants in Recycled Paper - Essay Example

Contaminants in Recycled Paper Each year in the United s, Americans use more than 67 billion tons of paper. Paper products make up 40 percent of our waste. (Recycling Facts n.d.) Recycling is a necessity in this situation, as it is a proven benefit to the environment and the long-term future of society. However, the recycling industry struggles with the high cost of filtering out contaminants, making recycled products priced higher than they should be for a product that is made from reused raw materials. This leaves consumers with the dilemma: do the right thing for the environment or save money by purchasing less expensive, non-recycled products In order for the cost of recycling to go down and to make the decision to use recycled products easier on the consumer, the issue of contaminants and how to eliminate them from the materials and pulp needs to be addressed. The types of recycled paper are divided into four major grades, which reflect the quality of the paper. They are as follows: Grade A: Material that comes from waste attained during processing wood, or "mill broke." Grade B: Unprinted waste (i.e. excess paper cut off from pre-cut paper products, such as envelopes and pouches) Grade C: De-inked post-consumer waste Grade D: De-inked mechanically-pulped paper (i.e. newspaper) (Johnson n.d.) Grades A and B represent the virtually 100 percent of paper mill waste that is recycled a back into the milling process. The Environmental Protection Agency (EPA) classifies mill broke (Grade A) as the scraps that are recovered during the paper-making process. (Conservatree 2007, Environmental Definitions) The mills can recycle this at almost zero cost. It is also in the mills' best interest to recycle and re-pulp the unprinted waste (Grade B), as it costs about half of what it costs to recycle post-consumer waste. These two highest grades of recycled paper are both cost-effective and free of contaminants, as it is waste created only by the product production. (Conservatree 2007, Making Paper) Post-consumer waste is where we find both a greater need for recycling and a high risk of contaminants. Depending on their use, these consumer-used products come back to the recycling plants in various forms, such as envelopes, office paper, newspaper, and magazines, and these forms are often full of contaminants. From address labels and no-lick stamps on envelopes, to colored laser printer paper, to self-stick notes, today's recycled raw materials need a lot of work to go through the system and get back into re-usable paper. (Glass 2000, p. 1) And with the demand for recycled raw materials at an all-time high with the environmental concerns of our modern world, we cannot ask the consumers to remove these hindrances before recycling. The industry must make the consumer want to recycle, and consumers will recycle more the easier it is for them to do so. This puts the removal of contaminants squarely on the paper recycling plants. The contaminants that cause the most trouble for the plants are the ones that come from adhesive-based materials. These are referred to as "stickies," as they tend to make their way through the filtering process and form into particles that can gum up machines and lower the quality of the pulp. (Glass 2000, p. 1) This is a big problem with the Grade C paper, of which a large amount comes from offices. Having workers sort through this high volume of paper is not cost-effective, so having equipment that is technologically advanced enough to weed out these contaminants is vital. Fortunately, there is technology available to help alleviate this problem. Older methods of recycling paper into pulp involved using machines that pulverize the raw material with aggressive motion. Often the stickies would disintegrate quickly and make their way through filtering attempts. Today, high consistency batch pulpers and continuous drum pulpers are available, which provide a gentler method of pulping the recycled raw materials. This, in turn, keeps the contaminants from becoming too small and getting lost in the system. (Glass 2000, p. 1) Also, some of the older reverse cleaner systems that remove from the pulp small particles, such as stickies and plastics, have not been reliable with the increase in contaminants. It is not cost-effective to run these unreliable machines, so some plants have shut down their reverse cleaning systems altogether. Reverse cleaning has made way for new, reliable technologies, mainly including advancements in screening. (Glass 2000, p. 2) The improved pulping coupled with higher quality screening is a big factor in keeping the costs of recycling down, as more contaminants are being removed in the screening process. Many plants are now using screens that have slots half the size of what plants were using in the mid-1990s. Combine that with the larger contaminant particles, and many more contaminants are being weeded out in this process. (Glass 2000, p. 2) Another improvement with the screening process is the location and more frequent positioning of the screens. The increased amount of stickies in the recycled raw materials have made plant operators look for ways to have a better chance of eliminating these contaminants completely. Whereas screens used to be placed at the beginning of the line, the placement of the final set of screens at the end of the process, directly in front of the pulp dryer, can be found in many plants today. (Glass 2000, p. 2) Some plants have also found that they can remove stickies and other contaminants more effectively with improved de-inking tools. The upgrading of the floatation cells that aid in the de-inking process is a solution to improving the quality of the pulp produced without enduring much greater cost. (Glass 2000, p. 3) But what happens if contaminants still get through the manual sorting, screening, and de-inking processes There are some new technologies that can screen pulp to measure for contaminants. In 2004, the Eurocon company released a device called PulpEye. PulpEye uses an image analysis system to analyze pulp, and the device can present researchers with the amount of contaminants per gram of pulp and the overall contaminant percentage. (Pulp and Paper Technology 2007, EUROCON) Pulmac International is another company on the cutting-edge of pulp and paper technology. One of its products is the Pulmac MasterScreen. The website Pulp and Paper Technology describes the Pulmac MasterScreen as "a low consistency screening device designed to mechanically separate fibers from contaminants (including stickies) and shives." (Pulp and Paper Technology 2007, Pulmac) The use of this device allows the recycling plant's operators to troubleshoot its operations, monitor the quality of their output, and optimize their operations by identifying the issues with stickies. (Pulp and Paper Technology 2007, Pulmac) Grade D recycled newspaper - referred to as ONP ("Old News Paper") in the industry - generally does not present as many contaminant issues as recycled office paper does. However, the mixing of different types of paper can be an issue with ONP. Newspaper produces a lower grade of pulp and is not suitable for being re-made into all forms of paper. Often curbside collectors will ask consumers to remove the magazine-like and paper inserts from their newspapers. Other times, in order to facilitate the recycling process on the consumer's end, the inserts will be removed manually at the recycling plant. (Wentzel 2005) Considered the most dangerous contaminant for ONP recycling, glass is a problem at newspaper recycling plants. Shards of glass make their way into newspapers when recyclable materials are not sorted by the consumer. They have a tendency to stick to the paper and, if not sorted out early on in the recycling process, can wreak havoc on the machinery. (Perkowski 2006) Workers remove the large pieces of glass initially, and then the newspapers go through spinning discs that remove the small, stuck particles of glass. Workers then more closely scrutinize the newspaper, and the process is repeated until the operator is confident the ONP is completely free of glass shards. (Perkowski 2006) The ONP recycling companies also utilize some of the same technologies that the higher grade recyclers use, such as the improved screening and the gentler pulping machines. (Glass 2000) With growing environmental concerns comes a greater need for recycling in the future. It is even becoming a mandatory practice to some degree, with minimum recycled-content legislation dictating that certain government agencies and companies must use recycled paper. The EPA currently has a mandate that the federal government, state governments that are funded by the federal government, and other companies and entities that receive federal funding must use paper products that have a minimum of 50 percent recycled content. This cannot be done, however, with computer and copy paper, as the quality demands cannot be met by recycled paper and must contain more that 50 percent virgin pulp. Though, the EPA holds these standards for all other types of paper, such as newsprint, tissue, and corrugated boxes. It is evident that recycling paper is becoming less and less of an option and becoming mandatory. (Alkaline Paper Advocate 1988) Recycling, though it is a process of reusing materials, is not cheap, mainly because of this need to clean up consumer-used products and eliminate contaminants. Whether removing contaminants by hand, by machine, or using technology to check levels after the pulping process, this practice requires many steps and funding to run effectively (see Fig. 1 below). The demand for recycled products, surely to continue to grow over the several next decades, puts the recycling industry in a position to continue to improve its technologies and educate the public about contaminant control. Nevertheless, the more cost-effective the industry can run, the better the long-term benefits for society, the economy, and the environment. Fig. 1 References Alkaline Paper Advocate 1988, 'EPA Mandates Use of Recycled Paper', Stanford University, Standord, California, viewed July 30, 2007 Conservatree 2007, Environmental Definitions, Conservatree, viewed July 30, 2007 Conservatree 2007, Making Paper, Conservatree, viewed July 30, 2007 Diagram of making paper from waste n.d., World Wide Paper and Pulp Supply Website, viewed July 30, 2007 < http://individual.utoronto.ca/abdel_rahman/paper/images/mkfrwste.jpg> Glass, E 2000, 'Deinked pulp mills struggle with 'more of the same' contaminants', Pulp & Paper, viewed July 30, 2007 Johnson, J n.d., Recycled Paper, Ball State University, Muncie, Indiana, viewed July 30, 2007 Perkowski, M 2006, 'Separating the fiber from the glass', The Times, November 23, 2006, viewed July 30, 2007 Pulp and Paper Technology 2007, EUROCON - PulpEye - Pulp Analyzer for Optimal and Stable Pulp Quality, SPG Media, viewed July 30, 2007 Pulp and Paper Technology 2007, Pulmac - Screening and Zero Span Tensile Equipment, SPG Media, viewed July 30, 2007 Recycling Facts n.d., Did You Know Paper Recycling Facts, ChuckGrant.com, viewed July 30, 2007 < http://www.buyrecycled.com/facts.htm> Wentzel, F 2005, 'Small steps help make recycling a bigger success', St. Petersburg Times, May 2, 2005, viewed July 30, 2007 Read More