Toner (printing)
In earlier photocopiers, this low-cost carbon toner was poured by the user from a bottle into a reservoir in the machine[citation needed].
Later copiers, and laser printers from the first 1984 Hewlett-Packard LaserJet,[3] feed directly from a sealed toner cartridge.
[6] Toner manufacturers maintain a quality control standard for particle size distribution in order to produce a powder suitable for use in their printers.
Toner has traditionally been made by compounding the ingredients and creating a slab which was broken or pelletized, then turned into a fine powder with a controlled particle size range by air jet milling.
Toner fused to skin eventually wears off, or can be partially removed using an abrasive hand cleaner.
[9] If toner spills into the laser printer or photocopier, a special type of vacuum cleaner with an electrically conductive hose and a high efficiency (HEPA) filter may be needed for effective cleaning.
As a fine powder, toner can remain suspended in the air for some period, and is considered to have health effects comparable to inert dust.
Research by the Queensland University of Technology has indicated that some laser printers emit submicrometer particles which have been associated in other environmental studies with respiratory diseases.
Classifying toner to the desired size distribution produces off-size rejects, but these become valuable feedstocks for the compounding operation, and are recycled this way.
Some consideration and fewer industry attempts have been made to reclaim waste toner by cleaning it and "remanufacturing" it.
Most paper recycling facilities mix toner with other waste material, such as inks and resins, into a sludge with no commercial use.
[citation needed] Since toner consists of several copolymers and it is a carbon-based material, it can be used as a useful modifier for the asphalt industry.
It has been shown that inclusion of left-over burnt toner enhances the rheological and mechanical properties of asphalt binder, significantly.
Such an application can be placed as an environmentally friendly alternative to prevent soil contamination due to the landfilling of waste toner.
