All washed up

BitDepth#1483

THE LAST seven years have been a running battle with stains on white and near white clothing, particularly school shirts.

There's a special kind of grime that attaches itself to school uniforms, and while white fabrics makes sense in a tropical climate, getting school-dirtied cloth clean is a special kind of hell.

My washing machine is an energy and water efficient unit that pulls only enough water to do the load it measures on start-up, but embedded crust on white cotton and cotton blends requires hands-on corrective action.

Will the new concentrated laundry detergent sheets help?

This new product is a five-inch square white sheet, usually packaged 30 or more in a cardboard envelope.

This seems like a great idea. One of the problems with detergents is the size and environmentally unfriendly nature of their packaging.

A gallon of liquid soap arrives in a gallon-sized bottle made of plastic that you can’t really use for anything else.

The once ubiquitous cardboard box of Breeze has given way to a rainbow of competing bottles and plastic bags.

The manufacturers of Breeze tried to limit the impact of their packaging by selling the product in an extremely concentrated form that users would mix with water to make up the volume of a larger refill jug.

I don't see that on store shelves any more and it isn't terribly surprising. Washing is hard enough without participating in the packaging process.

High-efficiency machines, in my experience, don't work terribly well with powdered soaps and powdered soaps have to be made liquid before adding to the wash load.

That takes time and a bit of stirring and even after all that effort, it isn't unusual to find the odd undissolved crumb or arc of powdered soap clinging to items in the finished wash load.

For handwashing, though, powdered soap is my preference, because I match effort with long soaks to loosen embedded grit, particularly in white fabric.

It helped to understand how detergents (and, indeed, all soaps) work.

Dirt on its own will simply shake out of fabric. What keeps it in place is oil and grease, readily generated by human skin.

At the heart of soap is the concept of a surfactant, or surface-active agent, a chemical that has two properties, one end that attracts water and another that repels it.

This property attracts the chemical to dirt and grease, where they form a layer that traps oily particles. Agitation (scrubbing et al) helps to separate these micelles of soap-encrusted grime from the fabric.

Unfortunately, this property of detergents isn't great for wastewater, where they create thick emulsions with larger deposits of fats, oils and grease, creating horrors like the clots that must sometimes be removed by hand from a plumbing trap.

Surfactants (along with disinfectants) also inhibit the growth of the beneficial bacteria that are necessary for wastewater treatment.

Are detergent sheets an improvement? To keep the sheets viable they are sheathed in "water soluble" PVOH (polyvinyl alcohol), which breaks down into plastic micro-beads.

Microplastics, including those in face scrub liquid soaps and fine glitter, are invisible contaminants in the environment.

Laundry sheets also aren't terribly efficient. For a handwashing load that I'd normally use a scoop of soap powder to address, the laundry sheet recommends a half-sheet, but a full sheet barely musters the same cleaning power.

Studies suggest that some sheets provide roughly the same cleaning power as plain water, though with Arm & Hammer joining the competitive push, that may change.

Frequent travellers who do some laundry in hotel sinks while on the move may find them useful.

Polymer pods work well, but you need to liquify them before adding them to the wash, so there's little improvement or cost benefit over bulk-packaged detergent.

My battle with persistent grime on whites has moved on to strategically applied raw borax (a key ingredient in powdered detergents) with vinegar (also an excellent replacement for scented fabric softeners). Bleach is entirely too powerful to be hastily splashed around.

Stain removers are just concentrated detergents – you get the same effect from directly scrubbing detergent directly into a stain.

That's also the principle behind our ancestral use of blue soap, which introduces synthetic ultramarine blue pigment to the cloth, shifting its colour response to cooler colours while applying sodium carbonate (soda ash, another detergent additive that softens water by raising its sodium content) directly to the grime. TT's water supply varies in mineral content according to its source, so that's always going to help a bit.

See y'all by the riverside and hold on to a good smooth stone for me.

Mark Lyndersay is the editor of technewstt.com. An expanded version of this column can be found there