HP 2420 Service Manual - Page 27

Category Acid content Caliper Curl in ream Cut edge conditions Fusing compatibility Grain Moisture content Smoothness Specifications 5.5 pH to 8.0 pH 0.094 to 0.18 mm (3.0 to 7.0 mils) Flat within 5 mm (0.02 inch) Cut with sharp blades with no visible fray Must not scorch, melt, offset, or release hazardous emissions when heated to 200°C (392°F) for 0.1 second Long grain 4% to 6% by weight 100 to 250 Sheffield Printing and paper storage environment Ideally, the printing and paper storage environment should be at or near room temperature, and not too dry or too humid. Remember paper is hygroscopic; it absorbs and loses moisture rapidly. Heat works with humidity to damage paper. Heat causes the moisture in paper to evaporate, while cold causes it to condense on the sheets. Heating systems and air conditioners remove most of the humidity from a room. As paper is opened and used, it loses moisture, causing streaks and smudging. Humid weather or water coolers can cause the humidity to increase in a room. As paper is opened and used it absorbs any excess moisture, causing light print and dropouts. Also, as paper loses and gains moisture it can distort. This can cause jams. As a result, paper storage and handling are as important as the paper-making process itself. Paper storage environmental conditions directly affect the feed operation. Care should be taken not to purchase more paper than can be easily used in a short time (about 3 months). Paper stored for long periods might experience heat and moisture extremes, which can cause damage. Planning is important to prevent damage to a large supply of media. Unopened paper in sealed reams can remain stable for several months before use. Opened packages of media have more potential for environmental damage, especially if they are not wrapped with a moisture-proof barrier. The paper storage environment should be properly maintained to ensure optimum printer performance. The required condition is 20° to 24°C (68° to 75°F), with a relative humidity of 45% to 55%. The following guidelines should be helpful when evaluating the paper's storage environment: ● Paper should be stored at or near room temperature. ● The air should not be too dry or too humid (due to the hygroscopic properties of paper). ● The best way to store an opened ream of media is to rewrap it tightly in its moistureproof wrapping. If the printer environment is subject to extremes, unwrap only the amount of media to be used during the day's operation to prevent unwanted moisture changes. ENWW Media specifications 13