Thermal vs. Laser Printing: Which is Greener?

For people concerned about a green office environment - knowledge is power. But the real facts about printer technology are elusive. The primary source of information for buyers is the company who manufactures the printer. So how can two completely different printing technologies, such as thermal printing vs laser printing, be compared relative to their environmental impact?

The most common use of thermal printing is making transaction receipts from gas pumps, ATMs and cash registers. The use of thermal fax machines and copiers in offices has nearly disappeared. Laser printers are found in most offices, including home offices, because of their low operation cost and wide range of features including copying, faxes and scanning.

The State of California has developed a best practices manual for office machines that identifies some criteria to use in measuring the “green-ness” of printing devices. Let’s apply their criteria to see which is greener: thermal or laser printing.

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Selecting printer models that provide a “sleep” mode during inactive periods can save up to 60 percent of power use. Look for printers that comply with Energy Star requirements.

Sharing printers through a network of multiple users saves energy. This is a common technique for laser printers in offices with several employees. It is not very practical, however, for thermal printers which are often incorporated into product sales transaction equipment.

Look at the printer itself for its green design features. Recycleable designs may include use of post consumer waste materials, easily dismantled parts, minimal coatings and labeled parts. A printer’s useable life expectancy and its manufacturer’s commitment to maintaining a supply of replacement parts are considerations in keeping retired printers out of the landfills. In contrasting thermal printing vs laser printing, discarded thermal printers are much smaller in size than most laser printers.

Some printers provide automatic double-sided printing, which saves paper. Paper that has been laser printed can be recycled. Many offices provide bins near the printers to recycling prints which were made in error. Laser printers, able to print onto a variety of paper types, can use recycled paper.

Thermal printers must use special sensitized paper to create a thermal image. Thermal paper cannot be recycled. Because paper receipts are often tossed into paper recycling bins, the thermal paper they are printed on becomes a contaminant, making brown spots on the remanufactured paper.

Consumable parts for laser printers - such as toner cartridges, imaging drums, belts and fusers - are greener as single components. Some manufacturers group toner cartridges together with drums. Then both must be replaced, even if only one part is depleted. Toner cartridges can be refilled or purchased as remanufactured.

A study conducted by Syracuse University’s Department of Mechanical and Aerospace Engineering found that office computers, copiers and printing devices generate both heat and volatile organic compounds (VOC) emissions. Their tests with printers showed significant emission during and immediately following the print cycle with almost no emissions in idle periods.

VOCs regulated by the FCC include benzene, ozone, pentadecane, phenol, styrene, toluene and xylene. Different printing technologies and different printer models produce different VOCs, emissions levels and heat levels. Buyers may ask manufacturers for specific information about VOC emission before purchasing a printer.

Offices are noisy places with people talking and equipment humming. Normal conversations average between 60 and 65 dBA. Thermal printers are advertised at operating sound volumes of 48 dBA. While in print mode, laser printers are about 56 dBA. Some laser printer models have fans that operate independently of printing, running around 35 dBA.

Thermal paper is sensitized for imaging by coating it with chemicals similar to benzene. A heated print head moves across the paper to create a thermal image. In order to make longer lasting images, strong chemical formulas are required. Because of the strong chemical coating, thermal paper is not recycleable.

In laser printing, the toner is made from carbon powder and a variety of polymers. Each manufacturer has its own toner formula. Commonly used polymers are styrene acrylate copolymer, polyester resin, or styrene butadiene copolymer. The toner is melted onto the paper by a fuser to form the image. Laser toner is not classified as a hazardous material.

Images courtesy of Wikimedia.