The bottle container printing, printing belongs to the surface with curved surface screen printers can be completed. And to use nonpolarized PE, pp materials processed into bottle, such as shampoo, bath dew, cosmetics, pesticides and bottles of printing, generally all choose light curing inks, so must have before printing of PE, pp surface treatment can solve the ink in the attached firmly. So, uv-curable ink best cure conditions? What? PE, pp bottle how to deal with to achieve good ink forme polarization effect of this issue, this paper, in the narrative.
A, bottles (plastic PE, pp, pet, prepress processing requirements and) parameters
Now light curing inks are not directly used for did not handle on the bottle of PE, pp, so, want to print a PE, pp, before printing in the bottle must be on PE, pp, otherwise the uv ink polarization processing not firmly attached. So how to polarization processing?
Polarization processing methods have DuoZhong, in PE, pp plastic bottle and its industry by flame treatment method of most, the flame treatment is the result of using the flame contains o, n0, oh and nh etc, it can put the polymer free radicals such as PE, pp etc surface oxygen extracted, then the mechanism by free radicals surface oxidation, and introduces some of polarity of the oxygen groups happen chain reaction, no broken of polarity PE, pp reach to change its surface of polarization wettability, ensure the ink color fastness to adhere.
The water surface tension of 72.5 DaYin/centimeters, oil surface tension for 25 to 50 DaYin/cm.
The parameters of the flame treatment: there are the flame treatment unit most use gas were burning source, should be controlled air: the gas = 7:1 can reach the blue purple flame, then the flame temperature can amount to 1270. C or so, fire control over the length of the inner core 19 mm, flame core top l0 to surface for-15 mm, contact time for l-4 seconds (ldpe for 1-2 seconds, hdpe for 3 to 4 seconds), rotate speed is 100-150 RPM, can be treated surface depth in 40-the 90 a, make PE, pp surface can reach 45 DaYin/centimeters to meet the fastness ink attached.
To PE, pp plastic bottle flame treatment of polarization effect after the test: when the PE, pp, flame treatment after must achieve > 45 DaYin the original surface tension value can ensure that uv ink firmly attached, flame treatment effect testing therefore is very important, its method has DaYin test pen with ethylene glycol + 35% (65%) was a mixture detection and water detection. At present commonly used to detect, soaking flame treatment is the PE, pp bottle submerged in water purification, all will be removed from the water bottle and then pause (about 10 seconds or so) let excess water drop, then watch the bottle is processing parts surface is full of a layer of water film, even if it is full of and continue the close water more than l5 seconds, show the flame treatment has reached the requirements of printing, if the bottle water film discontinuous surface, even if, as the lotus leaf in water, then must adjust the processing parameters to meet the requirements, such as air and gas combustion ratio, and the flame effective ingredients and PE, pp contact time and distance, and so on.
Second, screen printing process parameters
1. In the printing ink, and stir thoroughly before will splashing ink tank filled in on cover all the ink scrape material in stir well.
2. The screen and nets version. Screen: mesh number > 355 mesh/inches of yellow, high strength, low elongation nets. Nets version: tension 18-25 n/cm, with direct photosensitive plasma or capillary film, film thickness 15 to 25 micron.
3. Plastic blow: hardness of 80 ° polyurethane pointed scrape.
4. Nets version cleansing to use common wash nets water.
5. Curing conditions: high pressure mercury vapor, in/wavelength: 280 380 nm in 365 nm, peak is good. Power: 80-120 w/cm or so. Uv curing light speed adjustment: energy requirements.
Three, the plastic bottle printing good uv ink
1. America's solid curing light ink
(1) the PPC series: can silk screen processed PE, pp, and at the same time on the bottle more can be used in pet bottles of free of treatment, can have the effect of high adhesion, high gloss, bear the ink layer, if silk screen amber and other non-ferrous pet bottle, the ink in add hardener, can make the ink adhesion higher.
(2) the pci series: the high gloss, can screen printing already processing PE, pp ink bottle, high adhesion strength, good resistance to water.
2. Germany's curing inks highlights
(1) serit985uv with high gloss and good liquidity, such as add hardener is more chemical resistance, suitable for already processing PE, pp and PVC.
(2) serie988v in different material, have good viscous, liquidity, anti chemical properties, applicable to the already processing PE, pp, PVC, ps and pet, etc.
3. Japan article 10 light curing inks
Rcperg/rcpep-2 (hv) has the flexible, chemicals resistant performance, good adhesion, used for has been treated PE, pp bottle.
4. The French dolby light curing inks
Poiycolor/polyplus series, apply to has been treated PE, pp and pet bottle and high gloss printing ink, has the fine particles uv, high density, color, printing eligibility good and processing PE, pp, good adhesion to enhance water resistance, can add hardener coatings and special of two-component epoxy resin silk screen ink (series 8500), the ink used in glass, metal, spray version processing PE, pp, base material.