HP color laserjet 4500 Manuale Utente

106 Chapter 6 Toner cartridge information

 EN

After printing a document on a HP LaserJet printer, folding it, and 
sending it through the mail, you might observe that a portion of the print 
image was transferred to opposing surfaces of the folded document. 

The laser printing process uses a pigmented plastic powder (toner) to 
form a print image that is first transferred to a sheet of paper (or other 
print medium) and then melted (fused) onto the surface of the paper to 
form a permanent image. Though paper is usually thought of as being 
“soft,” it is actually quite abrasive. When the printed page is folded, 
movement under pressure between a paper surface and the toner 
image may cause the paper to abrade (scratch) the toner, causing a 
transfer of the toner material onto the opposing surface of the paper. 
This can be demonstrated by rubbing a print image against (or into) a 
clean sheet of paper.

Some machinery, such as that used by the U.S. Postal Service to sort 
mail, can apply the necessary pressure and agitation to cause this toner 
image transfer phenomenon.

To minimize this effect:

•

Minimize the amount (or height) of toner used to produce the print 
image.

•

Use a paper that is less abrasive.

•

Ensure optimal fusing of the toner (print) image to the paper.