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The magical aroma of screen printing standard
Time：ã€2015-3-20】 Allã€ã€‘次 ã€Print】 ã€Back】
Flavor capsules coarse particles contained in the smell of printing ink and can not bear the pressure of printing, screen printing process.In their daily lives, when you open the greeting card of a friend sent the smell of an nostrils the smell makes you feel warm, happy and feel at home; when you pick up a perfume ad, do not spray perfume on the picture will be able to emit fragrance; When you are faced with the pleasant name of the dish on a variety of exquisite recipes and realistic pattern of feeling confused, gently touched you can smell the aroma of the dish ... all this will make people feel convenience and pleasure.
With the development of market economy, people's living standards improve, the smell of printing has been widely appear in magazines, advertisements, postcards, greeting cards, calendars, cosmetics and food set of visual, olfactory effect in one print. In fact, if the smell of ink printing children's books, visual and olfactory organic combined, can also increase children's interest in reading. Added to the liquid crystal ink smell of printing, printed floral patterns also show the different color changes with the seasons, the touch will release the scent of various flowers, which is the charm of the smell of printing.
Flavor capsule particles contained in the smell of printing ink is fairly thick, but can not afford the printing pressure, fragrance print screen printing process, occasionally using rotogravure and flexo printing.
And the principle of the smell of screen printing inks
Used by the smell of printing ink from the capsules of fragrance, binders, pigments and other additives. Flavor capsules according to the principle of the emulsion, will spice up the core material dispersed in a hydrophilic natural or synthetic polymer resin in the aqueous phase, classes such as gelatin, gum arabic, polyvinyl alcohol aqueous solution; and dispersed after mixing so that the whole system temperature changes, and change the PH value, or add salt and formaldehyde, alum, etc. The second polymer, a polymerization reaction in the aqueous phase and oil phase at the interface, precipitation of the shell material, dispersion and adsorption in the spice droplet particles to form around the shell, that surrounded the oil droplets the surface of the polymer film, usually of the film is called the fragrance capsule wall material. The spices are coated in thin film curing to generate capsule, gel, and ultimately they got the microcapsules containing spices. The fragrance microcapsules diameter 10 ~ 30mm, wall thickness of about 1mm.
Lightly the friction printed surface will make the ink capsule rupture, spices sealed in the capsule will be flying out of the temporary floating in the air, resulting in flavor. Sachet of protection, this scent can be stored for a long time. Not sachet break the flavor can be retained for several years. Also worthy of note is very small sachet, 10 ~ 30μm of diameter to ensure that in the hand wipe, contact and inhalation of the number of minimal and does not cause skin and respiratory irritation.
The selection of the smell of printing ink
The smell of printing ink for printing the premise of the printed image must be a heavier tone, and the printed image area as large as possible. In this way, to make the paper printed on the surface enough to play a the scent role of micro capsules. Because the concentration of the aroma of the flavor printed depends on the printed matter in the end printing on the number of fragrance microcapsules.
A better and more effective method is scented microcapsules oily polish brush layer in the surface of the printed product. Commonly used method is the glazing coating the printed image through the printing units. In the coating process, it is necessary to ensure sufficient amount of coating, but also must have a good dusting, otherwise, there will be general oily polishing pressure by the wet dry printed materials soiled and adhesion failure caused . How much of the flavor coating coating amount of paper printed products can easily check by visual. Double-check the smoothness and appearance of the varnish coating on gloss to make judgments.
One of the prerequisites for the smell of printing ink supplier must provide a range of additional services. First, the ink supplier to the offset printing process has a wealth of practical experience, the ability to specify a smell of spirits supplier, responsible for the aroma essential oil microcapsules and microcapsules mixed with printing inks, polishes, or dispersion coatings ; Second, the ink suppliers to understand and be responsible for adjusting the ink viscosity, to adapt the printing system. In addition, the completion of the above work on press proofing verification.
In fact, not of each flavor and a fragrance suitable made of microcapsules are difficult to copy such as the smell of leather, chocolate or coffee flavor. The smell of the ink supplier in the design phase of the smell of printing flavor capsule test. Smell of printing, in addition to preliminary trials in the press used exclusively for experimental, but also the smell of printing presses for field sampling, otherwise if it goes into the actual print production, printing effects up short of expectations, causing significant losses.
Paper printing ink taste of the smell of printing results. Therefore, during the smell of printing, should be used in the smaller itself, the taste of ink and paper and ink test. In addition, the additives in printing inks due to volatilization and change the smell of the printed product is expected to, so be careful when conducting smell of printing.
Types of spices used in fragrance printing in the market mainly fruit flavors: green apple, cherry, blueberry, strawberry, watermelon, etc.; class of plants: acacia, cosmos, camellias, cherry blossoms, camellias; drinks and food categories: whiskey , cocoa, tea, mustard, curry, etc.; other categories: mosquito coils, cedar musk, cinnamon, mint, etc.
The printability of the flavor screen printing
Due to the coarser grain size of the microcapsules in the smell of ink, so when the selection screen, should use the permeability of a good nylon single mesh, and the opening degree, the number of mesh 150 mesh. Squeegee is generally used in polyurethane rubber material, such scraper nonporous, corrosion-resistant, stable volume.
Screen printing ink viscosity higher ideal viscosity of about for 2Pa.s around. Before the smell of ink in the screen printing for viscosity adjustment, the best viscometer, weighed and then add a certain amount of diluent, so that it has a suitable viscosity.
Printing smell of ink, speed is not too fast, so as not to squeegee friction produce too much heat leaving the temperature is too high, resulting in the rupture of the microcapsule particles. The printing speed is mentioned here refers to the printing speed of the blade. To ensure quality, the knife speed should speed to fill the ink and release the ink. Cutter speed is too slow, affecting the production rate; knife speed is too fast, causing insufficient to fill the ink imprinting is incomplete, or release the ink could not keep pace, as well as adhesions of the blade is too long, affecting print quality.
Fill in ink and release the ink speed with external size, mesh size and the rheological properties of the ink. The blade speed V through the aperture M. The time required shall be equal to the ink from top to bottom after the time of the screen thickness of F, namely: the M / V = ​​F/V1, where V1 is the flow velocity of the ink in the net hole. If the HowNet hole aperture M, the shear rate of inks can be obtained: S = V1 / (M / 2) = 2FV/M2 where S stands for ink inherent rheological properties, determine the amount of ink flow, regardless of the screen and cutter speed combination, as long as the shear rate remains unchanged, we can guarantee the same ink flow. Thus, using this formula, you can change knife speed. For the smell of screen printing, knife speed speed to fill the ink and release the ink to get a good print quality, to meet the above relations, but also to select the appropriate S values, thus ensuring the micro-capsule is not due to heat and cracked.
Aroma screen printing can not be too much pressure, try to print to find the right pressure. The process of trial and India, in addition to pay attention to the pages of ink scraper scraping action is uniform, but also to observe whether microcapsules rupture, with or without fragrance floating out.
The smell of screen printing ink drying temperature is not too high, or microcapsules rupture, nor can UV drying. We believe that the ideal drying method for evaporation drying. An appropriate increase in the drying temperature and increase the air flow rate can increase the ink drying speed. The screen printing ink solvent evaporation, the gas density is greater than the air density, air drying units, air from the lower part of the effect as well.