en este página ofrecamos respuestas a preguntas frequentes - esta sección solo está disponible en inglés.


1. FAQ Medios de Impresión Digital Grafiprint

  • Check whether the correct colour profile has been selected and whether the ink limit has not been altered. Also make sure you are using the correct linearization.
  • Check the temperature settings of the heating system (pre and/or post heating settings, etc...). It is possible that they are too low.
  • Try adjusting the print speed, print head interval or idle time between passes, head speed, media motion speed, ...).
  • Check whether the correct printer driver is being used. Also make sure the printer driver version is up to date.
  • Check the dithering setting. Changing the patterns will reflect in the printout.
  • Check whether the dot size has been altered or has been set incorrectly.
inkbleeding
  • Check whether the print head is correctly lined up (head adjustment, Uni or Bi directional adjustment, ...).
  • Check whether all nozzles are open (nozzle check).
  • Check whether the print head is clean (head cleaning).
  • The media transport may be too high or too low. Check by adjusting the media feed, ...
  • If the media transport is too high, it could make the material slip.
  • Try unidirectional printing to see whether the problem still occurs.
  • Check the temperature settings for all the heating elements (pre and/or post heat settings).
  • Check whether the media have been loaded correctly into the machine.
  • Check whether the ink limits have not been changed or an incorrect linearization is being used.
  • Check whether the correct/latest printer driver is being used.
  • Make sure the take-up and the roll-down mechanisms work in unison with each other.
banding
  • Check whether the bi-directional printing option is correctly lined up.
  • Check the air humidity in the room (air too dry), and make sure the roll has acclimatized to the room temperature.
  • Check whether the waiting cycle during bi-directional printing is not too long.
  • Check whether the correct driver settings are being used and whether you are using the latest printer driver.
lawnmowereffect
The medium is showing waves/tunnels (cockling) as a result of which the print head strikes the media (head strike)

  • Make sure the printer heater temperature is set between 35°C and 45°C. This temperature setting can vary depending on the environment and the different media being used
  • Check whether the vacuum on the machine is functioning correctly.
  • Check whether the media have been loaded straight in the machine.
  • Check whether the roll is not sagging on the take-up and media feed roll mechanism.
  • Check whether all heating elements are working correctly.
  • Check whether there is no uneven or varying temerature across the width of the print area, because of faulty heating elements
  • Check whether the vacuum is not set too high or too low.
  • Check whether media have been loaded correctly and are sitting straight in the machine.
  • Check for problems with the print head carriage, which may be causing the print head to vibrate while printing.
lines in vinyl
  • Check the print heads. They may need cleaning (head cleaning)
  • Check whether the vacuum is not set too high
  • Check for contamination, due to poor ventilation or fume extraction on the printer, causing the overspray to settle on the print media>
darkspots
  • The print media have been contaminated with airborne silicon or solvent particles
  • Some printers come with transport flanges. Make sure these flanges are always used
  • If your printer uses transport rollers on which the print media have to rest, make sure these rollers are cleaned each time you replace the print media roll. If the roller system is contaminated, the contamination will appear on the print media
  • Static electricity can also cause contamination by attracting airborne particles on the surface of the printable media. Make sure the printer has a good earth connection. In some cold climates it can generate air pockets that are statically charged. To counter this you might need to construct a device in the form of an "earthing strip" that runs across the width of the print media to earth the static
  • Use a sharp knife if the printer is cutting the print media. If not, white particles can lay down on the printed and unprinted surface
white spots
  • Check the print heads. They may need cleaning (head cleaning)
  • Check the ink levels
  • Check the air humidity. It may be too high
  • Make sure there is no contamination in the air (solvents, etc...)
  • Static electricity can also cause contamination by attracting airborne particles on the surface of the printable media. Make sure the printer has a good earth connection. In some cold climates it can generate air pockets that are statically charged. To counter this, you might need to construct a device in the form of an "earthing strip" that runs across the width of the print media to earth the static.
  • Check whether the distance between the print head and the material is at the correct height according to the profile
  • Check whether the nozzles of the print head are spraying correctly.
  • Check the settings in the software
  • Check whether the file that you are trying to print is not a low-resolution file
  • Check whether the temperature setting is not too low (pre and/or post head settings)
  • Some printers do not have the facility to dry the print completely. To solve this problem, an additional third party heater can be added to the machine to speed up drying times
  • Make sure the print head is clean (head cleaning)
  • Can be caused by faulty print head / nozzles
  • May mean print head wipers need replacing
  • Can be caused by problems with static, causing ink droplets to be deflected
  • Can be caused by bad ink viscosity, due to poor third party inks or ink pre-heaters being faulty
  • Never mix various kinds of ink
  • Check whether the print is not overloaded with too much ink.
  • Make sure the correct colour profile has been selected.
  • Check whether the temperature is correct for the specific print media.
  • Make sure the ink has sufficiently dried. This can take up to a period of 24 hours to 48 hours. Depending on the environment variables (tempeture, humidity, ...), it may be necessary to prolong the drying time
ink not keying
  • This is hard to define as it depends on environmental issues (temperature, humidity and high saturation of inks, ...). In most cases we can say that the drying time is between 24 hours and 48 hours.
  • The ideal situation would be to lay the prints on a screen printer's drying rack. This type of rack is angled and will allow the solvent gases to roll off the printed surface. The other alternative is to either hang the prints out or to very loosely roll the media up and put it upright on an elevated grill, so the solvents can fall through the roll and fall onto the floor
  • Make sure the car is free of wax, (silicones), grease and dirt. Clean the surface with a preferred degreasing agent. The final cleaning should, however, be performed with a mild detergent (e.g. isopropanol, ethanol, ...). Please make sure when you use these chemicals, the room is well ventilated
  • Do NOT use a textile cloth for cleaning the surface. Use soft paper tissues and make sure you discard and replace the tissue regularly, otherwise you will only collect the silicones and move them around the surface of the paint
  • Always clean small areas of the vehicle at a time, paying special attention to deep recesses, and DON'T FORGET to replace the tissue as frequently as possible
  • Do NOT laminate your print until it has had sufficient time to dry (between 24 and 48 hours). If you laminate too early, you will trap the solvents, which will eat into the printed surface and make the media become very brittle. This will also make removability an issue when the media are removed, causing the glue to be left behind on the surface. Another issue is that the solvent becomes trapped and weakens the adhesive.
  • Maintenance of the printer
    Make sure the printer is always perfectly clean. Follow the manufacturer's maintenance instructions strictly
  • Climatic control
    Check the temperature and the air humidity in the room where you are printing. Make sure it stays as constant as possible
  • Avoid dust and dirt
    Make sure the medium is always stored in its original packaging, and don't leave the medium in the printer at night
  • Temperature settings
    A good adjustement of the heating elements is necessary to avoid bleeding, banding and stripes
  • Correct colour profiles
    A good colour profile and linearisation is required to obtain a good print quality
  • Printer settings
    Make sure the settings of the printer are correctly set for a certain medium (print head height, media feed, temperature, etc...)
  • Knowledge
    Make sure you get to know your printer and the software, so you know where you can find all settings and what they are meant for


2. FAQ Laminados Grafiprint

  • In order to avoid differences in tension, we advise you to rol the print with the printed side outwards. By doing so, the release liner won't come loose from the vinyl and the lamination process will be a lot easier.
  • Prints are protected by a laminate. However, moisture can seep in between the laminate and the print from time to time. In order to avoid this, we advise you to apply the laminate with an overlap or use an edge sealing varnish
  • The laminates become statically loaded during the laminating process. This can be more or less, depending on the weather conditions and the processing of the laminate. Laminates that are statically loaded attract a lot of dust. Make sure the static electricity is well conducted during the laminating process.
  • The perception of light depends on the medium that it has to pass through. You often get another refraction of the light, and thus another perception of the light
  • Our experience tells us that the colour of the print is influenced by the following factors after laminating:
    • Look of the laminate (gloss or matt), causing different reflections and refractions of the light. This is influencing the transmission of the light
    • Thickness of the medium. A thinner vinyl is always more transparent than a thicker one
    • The thickness of the adhesive layer and the type of adhesive influences the transparancy
  • Sometimes during the cold lamination process, you can get tiny air bubbles. These bubbles are especially visible in large dark areas (e.g. black). These bubbles will disappear after about 24 hours. They can be avoided by heating the pressure rolls slightly, up to about 30°C, or by lowering the laminating speed. Sometimes a combination fo both these options is required
  • Do NOT laminate your print until it has had sufficient time to dry (between 24 and 48 hours). If you laminate too early, you will trap the solvents, which will eat into the printed surface and make the media become very brittle. This will also make removability an issue when the media are removed, causing the glue to be left behind on the surface. Another issue is that the solvent becomes trapped and weakens the adhesive
  • It is absolutely necessary that all solvents have evaporated from the print before you laminate it. The drying time depends strongly on the environmental conditions (air humidity, temperature, position for drying, etc...). Solvents that are trapped in between the digital print medium and the laminate will start evaporating as well, causing bubbles to appear under the laminate. At the same time, large parts of the laminate can come loose
  • The difference is in the application. They are both acrylate based and have similar peeling values. Dispersion (or water based) adhesive is suitable for indoor applications and short term outdoor applications (1 to maximum 3 years), whereas the solvent based adhesive can endure more extreme conditions (up to 7 years outdoors). A solvent based adhesive is usually more insensitive to higher temperatures (with regard to ageing
  • As for wet applications, a dispersion based adhesive has the tendency to become white in extreme wet conditions (with submersion), this discoloration also vanishes of its own
  • Manufacturing / coating of a film with a dispersion based adhesive is more environmetally friendly as there are no by-products, whereas coating films with a solvent based adhesive produce fumes which cannot be released directly into the atmosphere. Grafityp's production plant uses an environmentally friendly gas wash installation to remove the solvents before the air is released into the atmosphere. The solvents that are trapped in water are then pumped into septic tanks, where they are naturally broken down by bacteria. Once the recycling is complete, the water is reused in the gas wash system
  • The type of adhesive, whether dispersion based or solvent based, has no influence on the printing quality. The printing quality is more media vs. printer related than adhesive related. It also depends on the ink used, whether or not the ink can affect the adhesive
  • It is very hard to determine an exact time scale as many variances contribute, such as: ambient factors (temperature, air humidity, UV radiation, pollution), position and location of the print, ink quality, pigment type, density of ink and quality of the digital print medium, etc...
  • In general we can say that laminating a print will increase its life span, however this may vary by country and UV light intensity.
  • Laminating water based dye inks is also beneficial as the laminate will protect the print against moisture. However, these inks are normally designed for indoor use and laminating them for use outside would not be advisable as they would start to fade within a matter of days.
  • Laminating a print will protect the surface from contamination such as dust, grime, humidity and chemicals, which might deface or damage it. Outdoor laminates have a UV inhibitor which also protects the print from premature fading. Laminating can also protect a print against physical damage, such as scratches caused by cleaning the print surface with abrasive cleaning products
  • Gloss laminates will improve the image by lifting the print and adding more depth to the colours. Using a matt overlaminate will alternatively flatten a print, reducing light reflection and glare, making it easier to view from different angles. This method is preferred for displaying at indoor events, such as exhibitions, shop displays, etc... In addition lamination also makes the final product more robust and easier to handle upon application