Steam tunnel finishers are simple pieces of equipment that provide extremely reliable production throughout each processing day, but the process of tunnel finishing your garment production is not as simple as one might think.
Just as preventative maintenance is an important part of garment quality, consistency, energy consumption and the reliability of your tunnel finisher, the proper handling of garments and wash-floor etiquette play significant roles in finished quality.
Effective finishing begins with proper sorting, washing and handling.
LOADING BY WEIGHT
An important aspect of proper finishing is putting the correct amount of product into each sling or load. The best way to do this is by weight.
It’s a must for ensuring proper cleaning, as formulas are calculated to provide chemistry according to the volume of goods being laundered. Some plants weigh their goods but don’t load accordingly; others don’t weigh at all. Both are invitations to improper finishing.
Typically, with poly-cotton, you want to load your open-pocket wheels at 80% of their clean, dry capacity.
If you put in 60%, you’ll waste chemicals and water, and goods will be subjected to excessive mechanical action. Roping and tearing sleeves may result.
If you load poly-cotton at 100% you won’t have proper agitation or cleaning, as there won’t be enough chemistry for effective washing, and you’ll create compression wrinkles.
Cotton usually can be loaded at a higher percentage. Permanent press cotton and spun polyester (100% poly) often should be underloaded at 80% and 70%, respectively. Use your garment manufacturer’s recommendations to determine the correct level.
If you fill your wash wheels properly, you’re bound to have some leftover goods, but don’t let this tempt you into improper loading. Instead, do the leftovers in a smaller machine.
If you’ve got 150 pounds left, you’ll get the necessary quality from a 180- or 200-pound wash wheel. The thought of an extra 10 to 20 pounds in a sling for washing is seductive, but it’s not worth it.
Trying to squeeze a little more profitability in this manner will likely cost you more due to customer dissatisfaction. It could also cost you more in production because of rewash.
To reflect the need for different goods to be loaded in different volumes, wash wheel manufacturers are now expressing the sizes of their machines in cubic feet rather than weight capacity.
This fact illustrates that not all goods should be handled the same. However, it requires you to know what a cubic foot of each of your types of goods weighs, as you’re far more likely to weigh your loads as opposed to measuring their dimensions. This method of load calculation can also be problematic since the weight of a soiled garment will be different than the same garment after it has been laundered.
Today, the typical industrial garment wearer will contribute perspiration and some light soil, maybe a little rub-on dirt. This type of light- to medium-soiled garment would likely weigh approximately 1-2% more than the same clean garment.
Likewise, a heavily soiled garment, such as one that includes tar or heavy grease, could weigh as much as 5% more than clean weight. Due to these factors, paying close attention to load weights is a critical step in the wash process.
Before extraction, garments should be cooled to less than 100 F. Other products require temperatures above this level, but if you extract shirts and pants when they’re warmer than 100 F, you will set wrinkles.
Extraction shouldn’t exceed 100 pounds per square inch (less than 100 G-force). Today’s machines enable you to adjust G-force by varying wheel speed. If you adjust this setting for various goods, then you must be certain it’s modified accordingly for each type. More likely than not, you’ll need to slow it down for uniforms.
To dramatize this point for a customer, we ran a load of garments on high-speed extraction. When the cycle had completed, the garments looked like accordions. Some of the garments were run through the plant’s tunnel finisher, while others were pressed. The compression wrinkles set by the extraction were set so hard that they weren’t even removed by the press.
A properly loaded wash wheel that has been properly extracted will produce a well-finished garment. Using the most updated equipment provides the best opportunity to properly process your garments.
One plant was using an older wash wheel and separate centrifugal extractor for its garments while employing a newer machine for polyester tablecloths. The operator rationalized that if the tablecloths were done in the older one, flatwork ironing wouldn’t take out the wrinkles. But if you can’t flatwork-iron flaws out of tablecloths, how can you expect a tunnel to blow the wrinkles out of a garment?
Washing machines built in the 1960s and ’70s were made for cotton, not blends. Hardware manufacturers didn’t modify them for newer fabrics until the late ’70s or early ’80s. Newer machines do a better job on blends and synthetics.
If you prefer separate washer-extractors to tunnel washers, open-pocket models are excellent. They offer superior design and controls. They’re far better equipped for extraction, enabling you to dial into the exact setting you need for all types of goods.