Written by Steven Tinker, Gurtler Industries, Inc.
Sorting, the first step in the laundry process, can be the most important in maximizing the overall efficiency of the operation. There are several different criteria you can use to sort items in the laundry: soil levels, colors, textile types, or even finishing requirements (ironing, drying, or steam tunnels).
Generally, we start with soil classifications: Light, medium, heavy, and extra-heavy. This allows your chemical supplier to design wash formulas and chemical levels that are most efficient at removing the soil levels associated with the classification. Plus, there may be special soil classifications, such as blood or grease and oil, which may have their own processing and chemical requirements. Blood soils may benefit from an enzyme detergent or additive. Grease or oil soils may require addition of a special detergent additive.
How you measure the sorted loads can affect your efficiency as well. Mike Monahan, chief engineer at Shared Hospital Services in Portsmouth, Va., talked about how loads were measured earlier in his 22-year career. "Back in the old days, we would sort by 'piece count' which was very time consuming having to ensure each individual piece went by the counter," said Monahan. "Now, we sort by weight, and the loads are taken to the washer when they weigh 200 pounds. It’s much faster."
Depending on the wash equipment you have, tunnels or washer-extractors, or a combination of both, you and your chemical supplier may need to take additional considerations. For example, a high-volume operation with a tunnel washer may need to consider the staging of soil classifications. Tunnels run most efficiently when the wash classifications that are passing through are consistent. So, it is best to run with as much of one soil classification as possible before switching to another class. And then, when you switch, make sure the next run is not a major change in soil level; switch from light to medium or medium to heavy, for example. This way, you maximize cleaning while minimizing chemical usage and controlling costs.
Another consideration is textile types: Terry or sheets, cotton or polyester; or colors or whites. Each textile type could require a slightly different wash formula and chemical level. Cotton, especially terry, is much more absorbent than polyester fibers and requires more rinsing to make sure soils and chemicals are released from the inner fibers. Long-term discoloration of terry towels can be caused by insufficient rinsing, cycle after cycle, which allows micro amounts of soil to build up in the fibers, ultimately causing a graying or yellowing of the fabric. Of course, colors should be treated differently than whites. Again, in tunnels, it is not a good idea to mix colored fabric classifications with white classifications, as a dye transfer to the whites can be a potential problem. So, when running whites after colors, make sure that several compartments are run empty before starting the white classifications.
Monahan also pointed out that additives in fabrics may affect the wash formula. “We started using copper-infused textiles for some applications, and because of the oxygenation in our washer, they turned green.” He continued, “We had to decrease the amount of oxygenated bleach in our mix, as well as making sure any loads with those textiles were finished earlier in the day, because they can’t be left in the washer.”
Finishing requirements can also be taken into consideration when sorting. Items that can be taken directly from the extractor to the ironer, such as sheets, can all be sorted together. Some operations with multiple tunnels also may set up one tunnel with high-volume, low-to-medium soil wash classifications, such as poly/cotton sheets and pillowcases, which go directly to an ironer, maximizing efficiency for that one tunnel. In this tunnel, the rinsing will be more efficient, and the wash times could be faster. Also the temperature levels in the tunnel may be lower, giving you an opportunity to conserve energy. A second tunnel may be used for only terry items perhaps with a longer cycle time allowing for maximum rinsing efficiency, and where everything goes to the dryers for final finishing. In this second tunnel, you may require a different chemical mix, including the consideration of a softener to keep the terry items soft and supple. Also, if you use higher temperatures in the final rinse zone, terry items in the extractors will be more efficient, removing a higher percentage of water from the fabric, reducing the time and energy used in the dryers, and maximizing their efficiency. A third tunnel, or perhaps a small bank of washer extractors, could be set up for high soil or specialty items with unique formulas and special chemical additives addressing the specific needs of each class.
How you sort can affect your entire operation. Sorting to specific soil, textile and color levels will affect your overall use of water, energy, and chemistry. And sorting can affect your choices of equipment in the wash and finishing operations. Taking steps to evaluate all your potential classifications, their most effective wash formulas (time, temperature, chemistry), and your equipment capabilities will allow you to maximize throughput and minimize resource requirements.