HP Designjet L25500 series Add New Substrate and Image Quality Troubleshooting procedures Version 8.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting © Copyright 2010 Hewlett-Packard Development Company L.P. All rights are reserved. No part of the document may be photocopied, reproduced or translated to another language without the prior written consent of the Hewlett-Packard Company. Notice The information contained in this document is subject to change without notice and should not be construed as a commitment by the Hewlett-Packard Company.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting TABLE OF CONTENTS 1. Summary ..........................................................................................................3 2. Substrate loading and RIP media preset .............................................................4 Recommended print modes ....................................................................................................7 Print-mode parameters ...............................
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 1. SUMMARY This section summarizes the procedure to bring a new substrate into operation with the printer. Once the Add New Substrate procedure is completed, the number of passes used for printing can usually be changed without the need for any extra action. See How to print faster. The Add New Substrate procedure consists of the following steps: Load substrate and align printheads 1.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 2. SUBSTRATE LOADING AND RIP MEDIA PRESET 1. Check whether your media preset is available from your RIP’s Web site or from your substrate vendor’s Web site. If not, you have three options: a. Check the media preset availability in: http://www.hp.com/go/L25500/solutions b. Use a RIP media preset for a substrate of the same or a similar family.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Substrate family (or printer media preset) Description Fabric substrates are usually composed of polyester fibers. Fabric Some of the fabric substrate types come with a liner to avoid the ink passing through the substrate. Fabric materials that are very stiff (such as polyester canvases) should preferably be loaded as “banner”. Example: HP Wrinkle-free Flag with liner...
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 2. Load the substrate. If the substrate is narrower than the maximum width, it’s best to locate the substrate at the left end of the spindle so that it is centered in the print zone. 3. Disconnect OMAS in the RIP if the substrate is transparent or dark, or if the printer recommends you to do so during the substrate load operation. 4. Launch Printhead Alignment. 5.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Recommended print modes Better Image Quality Faster printing Print mode Bidirectional/ Unidirect. 4 pass Bidir 6 pass Bidir 8 pass Bidir 10 pass Bidir 12 pass Bidir 16 pass Bidir 18 pass *) Bidir 20 pass Bidir 24 pass Bidir 28 pass Bidir Legend ->Start here Self-Adhes.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Print-mode parameters Setting Explanation If too low If too high Number of passes The number of passes specifies how many times the printheads will print over the same area of substrate. The amount of ink fired per time unit is larger and ink has less time to dry on the substrate. This may create coalescence and banding. Colors are vivid, print quality is high, needs lower curing temperature.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 3. OPTIMIZE SUBSTRATE SETTINGS HP and third-party media presets use their own settings which have been optimized to maximize printing performance in terms of image quality and speed. You may need to vary the settings for your specific substrate, so below we list the recommended defaults for a ‘generic’ substrate to use as a starting point for the “add new substrate” process.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting The meaning of these settings is explained in the table below: Setting Explanation Drying temperature Heat applied in the print zone removes water and fixes the ink film to the substrate. This parameter determines the substrate surface temperature in the print zone. Print quality defects such as banding, bleeding and coalescence may occur.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Setting Explanation If too low If too high Cutter enabled If enabled, the internal cutter cuts the substrate transversally after every print. Disable the cutter in the following cases: Substrate advance compensation Your printer was calibrated at the factory to ensure that it advances the substrate accurately when using supported substrate types in normal environmental conditions.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Setting Explanation If too low If too high Input tension Tension is applied to the substrate from the input roll. It needs to be constant over the full width of the substrate. • The substrate skews and may become increasingly wrinkled in the printing zone. • Substrate advance may be irregular, resulting in horizontal banding. The substrate may be permanently deformed or damaged.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Advanced settings There are also a number of advanced parameters available for further optimization. These should not be changed unless you have reached this point following the “troubleshoot substrate issues” process. Remember that you can return at any time to the defaults using the “reset to defaults” feature in the RIP (if implemented by your RIP).
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Setting Explanation If too low Warm-up drying temperature offset Offset added to the drying temperature (see main settings). Their sum determines the effective surface temperature that the substrate in the print zone must reach before printing starts. This sum value is displayed in the printer front panel while the printer is preparing to start printing.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Minimum drying power The minimum power applied in the drying module while printing, so that the drying resistor does not cool off too much in lightly inked areas. Hewlett-Packard A heavily inked area that comes after a lightly inked area will have bleeding or coalescence defects. The substrate is damaged in blank or lightly inked areas of the print, especially at a high number of passes.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Temperature profile Many of the main and advanced substrate settings are related to temperature control, since this is a critical area for correct printing results with latex inks on a wide variety of substrates. The diagram below graphically represents the evolution of drying and curing temperatures during the various printing phases.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 4. IMAGE QUALITY TROUBLESHOOTING Before continuing, please check the following items: • Ensure that all previous steps in the “Add New Substrate” procedure have been followed. • Check that the substrate physically loaded is the same that has been specified in the front panel and in the RIP.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Substrate jams, ink smears or deformation Problem description Substrate jams or ink smears at any distance in the image Substrate jams, ink smears or deformations (curling, bubbles) only on the first 200 mm of the image. Cause Solutions Substrate may have been loaded with too much skew.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Checking the ink quantity on the substrate Check whether the ink quantities in your preset are adequate. Too much ink The patch shows one or more of the problems indicated on the drawings. The last 2 or 3 top scales of the plot look the same: Vertical banding: Solutions: • Lower the ink quantity using your RIP (consult your RIP documentation). • Choose a media preset that uses less ink.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Correct ink quantity The top scales of the plot show a smooth increase: - The patch has no defects. - An increase in ink quantity results in higher color density. Ink smudge and image durability problems Problem description Solutions Ink smudges in any area of the image when touched. • Increase the curing temperature in steps of 5ºC as many times as needed.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem description Solutions Oily finish in any area of the image. • Do not store prints partially covered or with printed faces touching each other. • Increase the curing temperature and drying temperature in steps of 5oC as many times as needed. • Increase the number of passes. • Decrease ink quantity (this is always an option).
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Graininess appears in different areas of the plot • Ensure that vertical correction is disabled. Select the icon, “Image Quality Maintenance”, then “Disable Vertical Correction”. • If the problem persists, perform printhead alignment. Select the icon, choose “Image Quality Maintenance”, then “Align Printheads” and “Auto PH alignment”.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Vertical banding Problem description Solutions Vertical banding due to wide straight bands with different darkness and/or graininess separated by about 0.8 in (21 mm). You can typically find it in some vinyl and banner substrates in medium-density area fills such as grays, violets and greens. • Perform printhead alignment.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem description Solutions Irregular or isolated vertical bands. • Increase the vacuum in steps of 10mmH2O. • In backlit applications, increase the number of passes to 20 or more and change the drying temperature up and down in steps of 5ºC. • If it happens at the beginning of the job, try disabling the cutter and advancing the substrate manually about 100–150 mm before printing the first plot.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem description Cause The banding is affecting all the colors across the job and is produced by thin horizontal lines (dark or light). If you are using 4 or 6 passes, the cause could be a substrate advance problem. Note: With 8 passes or more, it is unlikely that a substrate advance problem will create banding. See the graininess section for more details.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem description The banding affects one or only some colors. Cause The cause could be a defective printhead. If bands appear and disappear intermittently along the job, the printheads could need a more intense printhead maintenance. Hewlett-Packard Solutions Step1: Select the icon, then “Image Quality maintenance”, then go to “Clean Prinheads” and “Print Test plot”.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem description Cause Another cause could be a fiber attached to the ink funnel or to any of the printheads. Solutions First check the ink funnel in the following way: 1. Select the icon, then “Replace PH cleaning kit”. 2. When the message “Open the right door to replace the PH cleaning kit” is displayed, press the Cancel button on the front panel. 3.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem description Cause The banding affects mostly dark or saturated colors. If banding is only in area fills near the edges of the substrate, the cause could be insufficient drying of the ink. Banding in any area of the job could be caused by an inaccurate color profile. Solutions • If possible, reduce the ink quantity in your RIP options. • Use a higher number of passes.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Black areas look hazy or image gloss is not completely uniform Problem description Solution Black areas do not look totally dark or look hazy. • Use a higher number of passes. • Laminate the printed image. • Optimize black and dark colors using HP media presets following the recommendations in the Color reproduction tricks section.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 5. HOW TO PRINT FASTER The “Add New Substrate” procedure already described will give you sellable indoor print quality for the majority of available substrates. However, sometimes substrates support faster printing while providing adequate quality for many applications. This section describes tips to speed up printing: • Decrease the number of passes.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 6. PRINTER COLOR CALIBRATION AND SUBSTRATE COLOR PROFILING The printer can already be used with the color preset you have selected when following the “Add New Substrate” procedure. However, depending on your color accuracy requirements, you may want to do the following: - Color-calibrate the printer This operation measures the current color performance of your printer and brings it to a known stable point.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 7. COLOR REPRODUCTION TRICKS Latex inks are a new technology, and there are some important guidelines when doing color separations (such as when creating or modifying a new media preset within your RIP) that will help to optimize the printer output in terms of color gamut, ink usage and print quality. These are as follows: 1.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting 8. SUMMARY OF COMMON SUBSTRATE PROBLEMS Here is the table of common problems and the RIP parameters that can be changed in order to solve the problem. There is also a potential side effect that you may see in some cases.
HP Designjet L25500 printer series Add New Substrate and Image Quality Troubleshooting Problem Parameter Increase/ Decrease Potential side effect Modify color separations and black color generation resources Black areas look hazy or image gloss is not completely uniform Hewlett-Packard Drying temperature Increase Substrate jam, ink smears, damaged substrate Number of passes Increase Reduction in printing speed Curing temperature Decrease Durability loss (smudge) or oily finish 34
