The boxes come down from storage at this time of year and out come the knitted things with little balls of yarn along the edge. A throw with a trimmed border. A hat. A cushion cover that only appears when the house is full of people. They look simple to wash, and they are not, for one reason that has nothing to do with the knit itself. The trim is a different object from the fabric it is attached to, built in a different way, and it behaves differently in water in every respect that matters.
Yarn wound, cut and tied at the middle
A pom pom is not a solid ball. It is a length of yarn wrapped many times around something, bound hard across the middle, then cut all the way around the outside. Every strand you can see is a cut end, and the ball holds its shape only because all of those ends are clamped together at the center.
The clamp is usually one of two things. The traditional method is a strong thread tied tightly around the middle of the bundle, which is why older pom poms show a visible waist if you squeeze them. The industrial method is a pair of small plastic discs that grip the yarn between them, sometimes with a shank for sewing and sometimes with a prong pushed through the cloth.
Those two cores behave very differently once they are wet, and it is worth knowing which one you have before anything gets soaked. A tied core is fiber, so it swells, then relaxes, and it can loosen. A plastic core is rigid, so it will not loosen, but it does become a hard object with a soft wet ball of yarn around it.
A pom pom trim is a row of these, either attached to a tape or sewn directly along an edge. The tape version is easier to judge because you can see how each ball is anchored. The sewn version hides the attachment inside a seam, so the only way to find out is to tug gently and feel what gives.
Why the middle holds so much water
Each strand of yarn in a pom pom is loose and surrounded by air, and the ball is densest at the center where everything converges. That combination is close to ideal for holding liquid: a great deal of fiber surface to wet, a great many small gaps for water to sit in, and almost no path for air to move through the middle.
Drying works from the outside in. The outer tips are exposed to moving air and lose their water early, which is exactly why a pom pom feels dry when it is not. Under that dry shell sits a compacted wet core, insulated by the dry yarn around it, with no airflow reaching it at all.
Wool and acrylic both do this, for slightly different reasons. Wool fiber takes water into its structure and holds it there. Acrylic absorbs very little but traps a lot between the filaments, so the water sits in the spaces rather than in the fiber. Either way the core stays wet long after the knit it is attached to has finished drying.
The practical consequence is simple enough. If an item has pom poms on it, the item is not dry when the cloth is dry. Squeeze each ball between finger and thumb and feel the center of it. If it is cool and gives up any dampness at all, it needs more time in open air.
Where a stale smell begins
A wet core in a closed closet is the usual source of the faint sour smell people notice on a knitted hat or a trimmed cushion. The knit itself dried, got folded and went away. The balls did not, and they went into the box still holding water in the middle where nothing could reach it.
Fiber that stays damp in still air develops an odor. It is the same effect as a towel left in a heap, except that here the damp part is small, hidden and surrounded by dry material, so nothing on the outside of the item suggests anything is wrong. The smell turns up days later and seems to come from nowhere.
The fix is tedious rather than difficult. Open the item out, separate the balls so they are not touching each other or the cloth, and leave it somewhere with air actually moving. Pressing each one in a towel first takes out a surprising amount, because much of the water in the core is only held there by surface tension in the gaps.
Heat is not the answer on its own, because heat applied to a ball of wet yarn mostly dries the outside faster and seals the problem in. Moving air does more than warm still air does. A pom pom left where a room’s air circulates will give up its core water. One left in a drawer will not.
Agitation and the cut ends
Every strand in a pom pom finishes in a cut. A cut end is a free end, and a free end can be pulled out of the bundle if something grips it and the core lets it slip. That is the entire mechanism behind shedding, and it is mechanical rather than chemical. No detergent causes it and none prevents it.
A wash cycle grips a great many ends at once. Wet yarn is heavier and more slippery than dry yarn, so it slides out of the clamp more easily, and the drum presses the ball against other fabric and against the drum wall for the whole cycle. You find the result as loose fiber in the filter and a thinner, scruffier ball.
Shedding is worst on the first wash and worst on short pile balls, because a short strand has less of its length held inside the core than a long one does. Trimmed pom poms, the very neat spherical kind, are short pile by definition, which is why they look the smartest when new and the roughest after a cycle.
Protecting them is a matter of reducing grip. A mesh bag, or the item turned so the trim faces inward and the whole thing closed inside a pillowcase, keeps other fabric from catching the ends. The balls still move around, but they move against themselves instead of against everything else in the load.
Glue, discs and what comes off
Some trim is glued rather than stitched. On an inexpensive knitted item, a plastic disc core may be fixed to the fabric with a hot melt adhesive, which is strong enough in dry air and much weaker once it is warm and wet. Water works its way between the glue and the fiber and breaks the bond mechanically.
This is why glued balls do not come half off. They come fully off, often several at once, and they turn up loose at the end of the cycle. There is nothing holding them except the adhesive, and once the adhesive has released its grip on the yarn there is no stitching underneath to take over the job.
A pom pom trim mounted on a tape is more forgiving. The tape is normally stitched into a seam, so each ball is anchored through yarn that is anchored through cloth. The failure there is slower and less total: individual balls loosen on their cores and go lopsided rather than detaching altogether.
If you can see glue, a bead of hard clear material at the base of the ball, treat the item as something to clean on the surface and keep out of a drum. That is not caution for its own sake. Adhesive of that kind genuinely does not survive being soaked and then tumbled.
Knitted trim in Cincinnati homes
Cincinnati winters are cold and indoor air turns dry, which is good for drying most things and misleading for anything with balls of yarn along its edge. A hat or a throw left on a shelf will feel bone dry on the surface and still be holding water in every one of them.
The items this matters most for are the ones that spend the rest of the year packed away: the trimmed throw, the hats that come down with the boxes, the knitted covers that only appear when the house fills up with people. Anything that went into storage damp has had a long, still stretch in the dark to go stale.
WaveMAX Cincinnati is on Colerain Avenue, and the useful thing a laundry offers a trimmed item is air. Large dryers move a lot of it on a low setting, and an item spread out rather than crammed in gives every ball a chance to sit in that airflow instead of pressed against a damp neighbor.
Trimmed knits and open air
Trimmed items need room more than they need anything else. Spread across a large drum on a low setting, a knitted throw or a hat has air moving around every ball instead of only around the outside of a packed bundle, and the cores get a real chance to give up the water they are holding.
The machines at our self-service laundry on Colerain Avenue handle the knits and throws that come down from storage, and the large dryers are the part that matters most here, because a trimmed item spread out in moving air on a low setting dries through to the core instead of only on the surface.
Our machines and the store are cleaned daily.
Nou wash-dry-fold service covers the everyday laundry.
For general guidance, The American Cleaning Institute publishes a fabric care guide that is a useful cross-check.
The short version
A pom pom is yarn wound and cut, held together only at a core that is either a tied thread or a pair of plastic discs. The middle is dense fiber with no airflow through it, so it stays wet long after the cloth is dry, and a damp core packed into a box is where a stale smell starts. Cut ends slip out under agitation, and glued balls come away whole.
WaveMAX Cincinnati is at 8449 Colerain Ave, easy to reach from Cincinnati and the surrounding area. If you have a load that will not fit at home, call us at 513-445-4443.