HP d640 HP D640 High-Volume Printer - User Manual (Printer and Accessories), C - Page 244

Media Selection Specifications and Guidelines The environmental conditions required to maintain the proper moisture content is 68°F to 75°F (20°C to 24°C) with a relative humidity of 45% to 55%. Table D-3 Moisture content potential problems Too Moist • Paper shrinks unevenly during fusing, causing print quality problems • Overall paper curl increases (increases post-image curl, causes poor toner adhesion, feed and print quality problems) Too Dry • Excess static (causes multi-feeds and paper jams) • Surface electrical resistivity (causes streaking and smudging of loose toner particles) The HP standard for moisture content is 4.7% ± 1% by weight. Although a paper may have the proper moisture content at the time of manufacture, exposure to temperature and humidity extremes may alter the percentage. Fusing Compatibility Media that does not meet HP specifications may: • Discolor • Melt • Scorch • Offset • Release hazardous emissions • Have poor toner adhesion • Break down in other ways • Possibly damage the printer All media used in D640 printers must have the ability to withstand the fusing temperature of 392°C/200°C for 0.1 second, without experiencing any problems. Inspect the rollers for colored ink build-up from pre-printed logos or letterhead and for toner buildup or spots. Inspect printed output for repetitive defects and smearing. If necessary, contact your forms vendor to ensure paper's fusing compatibility with D640 printers. D-8 Using Paper