UV light oil printing PE bottle of three basic common sense

UV light oil printing PE bottle of three basic common sense

 The bottle surface printing belongs to the container, with curved surface screen printing machine can be completed. On nonpolar plastic PE, PP plastic material processed into the bottle, such as shampoo, bath dew, cosmetic, pesticide bottles such as printing, general is to choose light curing inks, necessary before printing for freedom of will handle plastic PE, PP plastic surface printing ink adhesion on its strong. So, what is the best curing premise of uv-curable ink? PE plastic, PP plastic bottles intended polarization doctrine disposal ability to reach good results? On the issue, the narrative below.

A, UV light oil, basic common sense

  1. The effects of the composition of the UV light oil in ink

    ①Reaction diluent (also known as diluent monomer) is a kind of small molecular weight, low molecular weight chemicals, can reduce the viscosity, the wandering pigments and dilution effect of the resin, resolution ink surface features, such as viscosity, hardness, tender. Non-volatile, and participate in UV curing resin crosslinking reaction.

    ②Additives: everything pigments, smooth agent, thickening agent, filler, promote the solid agent, etc., affect the color of the ink, the curing speed, the ink layer thickness and ink printing eligibility and weather resistance, etc.

    ③Light solid resin: first part of the UV light oil film, the UV light oil of cohesion, resolution of the UV light oil sheen, attached to the output. Differences of differences of printing inks resin to comply with the material of disagreement substrates.

    ④Exciting agent: chemical crosslinking reaction. Photochemical reaction, exciting agent once excited after receiving the photon light will become very exciting and lively, attack at home base, energy transfer to other photosensitive polymer, make its chain reaction, the single molecule, additives, light solid resin together, constitute a reticular structure constant ink conjunctival strong adhesion on the substrates.

    2.UV light oil curing and the requirement of curing system

    ①The type of reflector: gather the type, the gathered and polyhedral reflection. Common used to gather, the gathering and more reflective surface are commonly used to curing light oil (no ink coloring materials)

    ②The UV lamp, UV lamp power to content can reach the requirement of curing through UV light oil. The longest use of a UV lamp life means less beyond 1200 hours, average suggests using l000 hours should be changed. After every time necessarily clean tube, clean anticlockwise turn 1/4 weeks of tube (can be repeated three times in installation and be careful when cleaning the UV lamp.

    ③System testing: available energy meter measuring the output of energy of the UV lamp. UVIMAP waveform display are used to draw out the UV map, based on the UV map, detection of curing system; If draw energy diagrams are pointed, curing system have no problem; If the top is hump, clarify reflector with the dust; If the top is round to clarify lamp aging, according to the aging degree of the change of the loss should be replaced.

    ④Curing light elements:

  UV lamp power: the UV light radiation, also calls the penetrating power, must be satisfied the UV curing ink requirements, if the UV lamp power does not apply, even if the illumination time longer, perhaps curing times repeatedly, also means less ink completely cured. So when the UV lamp power does not apply, are required to pass through high power lamp to make ink curing, announced this is due to the low power lamp UV light means less penetration to the bottom of the ink layer, make the bottom does not cure.

  Curing speed, curing speed from the two aspects to consider. One is the energetic curing; Second is the best cure speed cure. Method is the selection of optimal curing speed at a certain speed after UV curing machine first, if again accelerated curing speed, until after curing machine is out of ink layer means less curing, at this moment, will be able to determine the best curing speed, namely the beginning not curing speed 0.8 = the best curing speed.
The UV lamp spectrum wavelength limitations: the spectral sensitivity of the limitations of the UV lamp must match the UV light oil. General requirements the wavelength of the UV lamp limited for l80-420 nm.

    ⑤Attach the output of the test:

   The calendar after UV machine cooling to room temperature, can be up to draw frame to 66 mm, can only be discouraged from inferior to mutilate row wear ink film, with 3 m - 600 # tape test attached, tested with efforts to clarify the following questions:

  If no ink layer on tape, then clarify curing is superior, attached to the output.
  If mark all transferred to the tape, to clarify there are four problems: ink series didn't choose the right (that is, with substrates material don't match) substrates tuomoji contains a lot of plasticizer or appearance; Substrates surface tension is too low, it should be for freedom or has good disposal without disposal; Bad ink curing.
  Imprinting edge does not transfer, and local transfer center to the tape, there is no completely curing is to clarify, this is because the lamp power does not apply or lamp power content but curing speed is too fast.
Become a ghost, and indicate the ink not completely cured.
If dieyin, the second color output owe good, tape test, only the second lost, clarify the first color excessive curing if dieyin test after two layers are lost to clarify the first layer curing lack. When folding color printing UV curing rules for 7030 or 70% curing rule, 30% did not cure, finally curing ink layer should be 100%.

    ⑦The influence of additives.

   Additive can affect the ink to some functions, such as participate in exciting agent, can progress, but will affect the tender sex of ink, and participate in the amount of too much, will be immediately discouraged from less printing provoked crosslinking.

    ⑧Process the premise:

  UV light oil in printing screen ordinary selects the high tension, low extension rate, the s-class plain wire mesh or single flat screen. Net frame strength.

  On the screen tension, tension of error of plus or minus 2 n/cm disambiguation of dispute, printing ink layer is not average, and position deviation can happen.
Net is apart from the ordinary between 2-4 mm, intrusive adjustment should be based on the tension from the net.
  Scraper hardness at 60 ° ~ 90 °, common in India with 80 ° 70 ° machine by hand
  Pre treatment of substrates. Because of the differences substrates data appearance situation to disposal of substrates on appearance, it is attached to the output of UV light oil extreme mainly about the plastic film, usable dip in alcohol or isopropyl alcohol clean cloth to wipe, to remove floating in substrates of plasticizer and appearance is not pure chemicals, such as dust, grease; PPPEPUPET information about surface tension is low, but according to the calendar of thick and thin, discern for flame freedom or corona treatment, to add its surface activity and improve the output. After freedom on the surface of the substrates appearance tension reached 45 dyne/cm or higher is preferred.
  Ink to energetic stir before use, after special is the additive is bound to stir the average, or it will happen some curing with output is strong, some were not cured or not energetic curing with output, poor adhesion calendar will occur.
  The UV lamp power must content requirements and adjust the curing speed.
  After cooling to room temperature curing, with 3 m - 600 # tape row test, 24 hours after curing, attached to the output and reach the best solvent resistance.
Wash the nets, popular washing network water network, but means less than enough alcohol, because alcohol can damage the web template.

    ⑨The influence of weather on UV light oil.

   The influence of the temperature: high temperature, UV light oil of low viscosity, easy happening after printing hair tooth and paste version. Low temperature, high viscosity, does not completely cured. Thus requires refrigerated phlogistic days printing ink, screen printing workshop temperature means less than too much; Early winter arrives in freezing conditions, should be placed in the printing of the temperature, and the appropriate snub curing speed.

Humidity: the influence of humidity affect the surface morphology of substrates and ink printing function of substrates.

    ⑩The effect of color.

  Due to all kinds of color of light reflected differences, so the UV light oil with color differences have an impact on the UV curing ink is seven color of light reflection wavelength and light curing speed.

    B、(plastic PE plastic PP plastic PET bottle, etc.) before printing disposal requirements and parameters

    Current UV curing ink is not directly used for not dispose of PE plastic PP plastic bottle, so to print PEPP bottles, prepress necessary to polarization disposal of PE plastic PP plastic, otherwise means less strong UV ink adhesion. So intended polarization treatment?

  There are many types of polarization disposal method, PE plastic bottle and PP plastic plastic industry greatly with flame treatment method, the freedom of the consequences of the flame is applied ON0OH and NH at home base is contained in the flame, can put the polymers such as PE plastic PP plastic appearance oxygen pumping out, then according to the oxidation mechanism of base appearance, and introduces some broken chain reaction, polarity of oxygen-containing groups attack of non-polar PE plastic PP plastic reach the wettability of polarization to change its appearance, guaranteeing the ink adhesion fastness.
Water surface tension is 72.5 dyne/cm, the oil surface tension for 25 to 50 dyne/cm.
  Flame of freedom parameters: the current unit of a flame treatment use gas for combustion source greatly, should limit air: gas = 71 talents to blue purple flame, the flame temperatures can reach about 1270 c, the flame length temperance in 6-19 mm inner core core is to look at the top of l0-15 mm contact time of l - 4 seconds (LDPE to 1 to 2 seconds, HDPE for 3-4 seconds) reverse speed is 100-150 revolutions per minute, disposable surface depth in 40-90 - a make PE plastic PP plastic surface can reach 45 dyne/cm to satisfied printing ink adhesion fastness requirements.
  For PE plastic PP plastic plastic bottles after the disposal of the polarization of the flame detection results: when the PE plastic PP plastic after flame treatment, necessary to reach > 45 dyne original value talent to ensure that the surface tension of the UV ink adhesion strong, thus flame freedom of testing result is mainly the way with dyne test pen (with ethylene glycol ether 35% + 65% formamide mixed liquid) test and immersion test. Currently used in flooding to test, is the flame of freedom of PE plastic PP plastic bottles all immersed in clean water, then put the bottle out from the water stop less how (about 10 seconds) to let the excess water loss, and then watch the bottle can be disposal site appearance was covered with a layer of average water film, if it was full of and continue to l5 seconds or more hydrophilic, is to clarify the flame treatment have reached the requirement of printing, if the bottle water film could not continue, even after the rain water on a lotus leaf, then you should adjust the freedom of parameters to content requirements, such as air and gas burning rate, flame useful components in contact with the PEPP time and intervals, and so on.

    C、Screen printing process parameters

  1. Thoroughly before printing ink mixing, and splashing in the ink tank cover material all scraped into the ink mixing on average.
  2. The screen and screen. Wire mesh: the mesh > 355 eye/inch yellow, high strength, low extension of network. Screen: tension 18 to 25 n/cm with photosensitive slurry directly or capillary film, film thickness 15 to 25 microns.
  3. The stencil: hardness is 80 ° polyurethane sharp blow.
  4. The screen cleaning water wash with popular network.
  5. Curing premise: medium/high pressure mercury lamp, wavelength: 280-380 nm peak at 365 nm is better. Power: 80-120 - w/cm. UV speed: adjust the curing light energy demand.

TAG:UV light(45)