The first mass-produced toothbrush was dreamed up by a man in prison
In the 1700s William Addis, after a spell in prison, began drilling holes into a handle and gluing in tufts of bristle. It was the first toothbrush made at scale, and the method closely resembles the staple-set technique that factories use to make brushes today.
Brushes are far older than toothbrushes. Around 3500 BC Egyptians tied split palm leaves and animal hair to twigs to paint pottery and tomb walls, and China was developing its own brushes at about the same time, eventually refining writing brushes through more than 120 production steps. Renaissance painters relied chiefly on round brushes, as recorded in Cennino Cennini's craftsman's handbook, because makers could not yet build ferrules suitable for flat ones.
The metal ferrule changed that. Instead of lashing bristles with cord, makers pressed them into a U-shaped metal channel and crimped it shut, producing tougher brushes that held their shape. Industrialisation followed: machines for drilling brush handles were patented in the 1850s, Anton Zahoransky pioneered brush-inserting machines, and America's first brush factory opened in New York in 1859. Modern five-axis machines can place tufts in complex custom patterns.
Some brushes skip staples altogether. In epoxy-set construction, bundles of filament are sealed in resin, sometimes reinforced with stainless steel staples. Because the seal leaves no cavities where bacteria can hide, such brushes are used in food processing, pharmaceutical plants, aerospace and cleanrooms.
Filament choice is a small science of its own. Stiffness depends on the material's modulus, diameter and trimmed length, and testers measure bend recovery and fatigue over repeated flexing. Nylon resists abrasion, polyester shrugs off moisture, polypropylene tolerates most solvents and acids, and wire of steel, brass or phosphor bronze scours rust. Tampico, a plant fibre, withstands heat and softens in water, while hog, horse and goat hair still suit paint because they hold oil. A paintbrush releases paint mostly from its sides, where capillary action holds it.
Source: Brush
