Recycling of pre-consumer waste toner is practiced by most manufacturers. 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. Post-consumer waste toner appears primarily in the cleaning operation of the photo-printing machine. In early printers, as much as 20 to 25% of feed toner would wind up in the cleaner sump and be discarded as waste. Improved printer efficiencies have reduced this waste stream to lower levels. Some printer designs have attempted to divert this waste toner back into the virgin toner reservoir for direct reuse in the printer; these attempts have met with mixed success. Some consideration and fewer industry attempts have been made to reclaim waste toner by cleaning it and “remanufacturing” it.
Toner can be washed off skin and garments with cold water. Hot or warm water softens the toner, causing it to bond in place. Toner fused to skin eventually wears off, or can be partially removed using an abrasive hand cleaner. Toner fused to clothing usually cannot be removed.
Toner particles have electrostatic properties by design and can develop static-electric charges when they rub against other particles, objects, or the interiors of transport systems and vacuum cleaner hoses. Because of this and the small particle size, toner should not be vacuumed with a conventional home vacuum cleaner. Static discharge from charged toner particles can ignite dust in the vacuum cleaner bag or create a small explosion if sufficient toner is airborne. This may damage the vacuum cleaner or start a fire. Toner particles are so fine that they are poorly filtered by household vacuum cleaner filter bags and can blow through the vacuum motor or into the room.
Unfused toner is easily cleaned from most water-washable clothing. Because toner is a wax or plastic powder with a low melting temperature, it must be kept cold while cleaning. The washing machine should be filled with cold water before adding the garment. Two complete wash cycles improves the chances of success. The first may use hand wash dish detergent, the second may use regular laundry detergent. Residual toner floating in the rinse water of the first cycle will remain in the garment and may cause permanent graying. A clothes dryer or iron should not be used until all toner has been removed.
The specific polymer used varies by manufacturer but can be a styrene acrylate copolymer, a polyester resin, a styrene butadiene copolymer, or a few other special polymers. Toner formulations vary from manufacturer to manufacturer and even from machine to machine. Typically formulation, granule size and melting point vary the most.