Offset Printing 1000 Questions (160-165)

160. What is the basic performance of resin type ordinary offset printing ink?

A: Resin type ordinary offset printing ink is modified by introducing synthetic resin on the basis of oil-based offset printing ink. It is commonly used in offset printing or letterpress color printing production. It is mainly used for printing books, textbook covers, posters and packaging. Trademarks such as line and field version of the main ordinary color prints.
The general composition of resin type ordinary offset printing ink: 25% to 30% of resin in the binder, 20% to 40% of dry vegetable oil, 15% to 25% of mineral oil (ink oil), and 20% of pigment and filler ~30% or so.

Features: It has good color performance, high coloring concentration, a certain resistance to water and acid, strong adhesion, imprinted ink layer can completely cover and contain pigment particles, color and gloss are better.
Drying type: Infiltration and oxidative polymerization type.

Varieties: According to the color sub-resin type ordinary offset inks include yellow, red, blue, green, purple, brown, white and black, etc., among them, yellow ink is divided into lemon yellow, transparent yellow, light yellow, yellow, dark yellow and Orange, etc.; red ink is divided into light red, pink, gold, red, dark red, orange and rose, etc.; blue ink is divided into peacock blue, sky blue, blue, dark blue, blue and light blue.
Printing suitability: It is mainly used for sheet-fed single- and double-color offset printing machines with printing speeds of 3,000 to 5,000 rpm, and non-coated papers such as offset printing papers, writing papers, book covers, and food (candy, popsicle) wrapping papers. Matching use, also applies to letterpress printing paper (copper paper).

161. In actual printing, what matters should be paid attention to when adjusting the compatibility of resin type ordinary offset printing ink?

Answer: When printing with resin-based ordinary offset printing ink, it is usually necessary to make appropriate adjustments to certain suitability of the original ink according to the technological conditions, or to allocate inter-color and complex-color inks. The general usage is as follows.

(1) Consistency: Resin type varnish is usually used. When reducing the thinness, it is usually appropriate to use a 6th resin varnish 4%, and an appropriate amount of thinner can also be used for thickening.

(2) Viscosity: It is generally adjusted with an ungreaser or a tackifier. If the consistency is appropriate, when the viscosity needs to be reduced, an anti-adhesive agent can be added by about 3%, and the excess is easy to get dirty, which also affects the dryness and the ink film glossiness. If the viscosity is not enough, an appropriate amount of tackifier may be added.

(3) Dryness: The product's original ink usually does not contain driers. When it is used, white dry oil should be added about 4% depending on the type and climatic conditions used. If necessary, 0.5% of dry oil can be added to shorten drying. process.
(4) Concentrated color matching: The same series of color inks are used in this product.

(5) Light-tune color matching: The use of diluting agent is the main method, but for those prints that generally do not emphasize lightfastness, transparent dip-light or white oil can be used, and appropriate amount of white dry oil can be used to help dry and enhance gloss. However, it should be used with the actual amount of use, not long home.

162. What are the basic properties of resin-based bright offset inks?

A: Resin type bright offset ink is one of the commonly used mid-range offset inks.

Uses: mainly for printing calendars, pictures, color magazines, such as the use of mesh-based color printing or the use of color printing, and for letterpress printing paper products, trademarks and other color printing parts use.

Composition: resin in the binder is about 35% to 40%, dry vegetable oil is about 30%, mineral oil (ink oil) is 15% to 25%, and the rest is pigments, fillers and accessories.

Characteristics: It has good color expression and color concentration. The ink has a larger viscosity and better printability and dryness. The linking material can completely cover the pigment particles, bright and bright, with a high gloss.

Drying type: The drying process of the glossy resin type offset printing ink is mainly based on oxidative polymerization, but it also has the form of penetrating gelation.

Variety: At present, common resin type bright offset inks include yellow ink, red ink, blue ink, green ink, white ink, and black ink. Among them, yellow ink is divided into lemon yellow, transparent yellow, light yellow, yellow and dark yellow, red ink is divided into pink, gold, red and dark red; blue ink is divided into peacock blue, sky blue, blue and dark blue Wait.

Printability: It is mainly suitable for sheet-fed single-color and double-color offset printing machines with a printing speed of 5,000 prints/hour. It can be used with offset printing paper, glass paperboard, etc. It is also suitable for the printing of advanced non-coated papers such as supercalender offset printing paper and embossed cover paper.

163. In actual printing, what matters should be paid attention to when adjusting the compatibility of resin type light offset printing ink?

Answer: In actual printing, when the resin type glossy offset printing ink is used for proper deployment, the following matters should be noted.

(1) Consistency: Normal adjustments are not required under normal process conditions. If it is too long to be stored and appears to be too thick or poorly fluidized, thinner may be diluted with 3% (or 5% of No. 6 resin varnish), but not excessive.

(2) Viscosity: If the consistency is appropriate and the viscosity is too large, the viscosity may be reduced or decreased as appropriate, and appropriate amount of red dry oil may be added accordingly.

(3) Dryness: Under the normal temperature and humidity conditions, the original ink of this product can be used directly. However, in case of low temperature or high temperature, or when printing on non-coated paper, the ink absorption, smoothness, and pH should be considered, and 3% to 5% of red dry oil should be added as appropriate. In the printing process, if dirty, sticky, or slow drying occurs, white dry oil may be added in an amount of 0.1% to 0.3% to improve the dryness.

(4) Concentrated color matching: The same series of color inks are used in this product, and can be adjusted to a variety of color concentrate color inks.
(5) Light-tune color matching: The use of special lightening agent is the main method, and it is not appropriate to use clear dilute ink or white oil. If it is necessary to substitute, appropriate amount of driers should be added to improve gloss and control its dryness.

164. What are the basic properties of resin-based quick-drying (fast-fixing) offset inks?

A: Resin type quick-drying (fast fixing) offset ink is one of the commonly used mid-range offset printing inks.

Uses: mainly for the printing of New Year pictures, calendars, albums, pictorials and fine arts and other network-based color printing parts, can also be used for letterpress packaging paper products, trademarks and other color plates and so on.

Composition: 25% to 30% of resin in the binder, 25% to 30% of dry vegetable oil, 30% to 40% of mineral oil (ink oil), and 15% to 25% of pigment and filler.

Characteristics: It has good color expression and coloring density, its ink viscosity is large, it has good printing adaptability and fast fixing speed, but if the ink film is overprinted after curing, its penetration gelation and fixing speed turn Slow, but can not achieve the desired fast fixation effect, so the interval between color printing overprinting, play a decisive role in the fixation speed, because the linking material can completely cover the pigment particles, the color is brighter and brighter, the gloss is also good.

Drying type: Mainly infiltration gelation, both oxidative polymerization.

Varieties: Resin-type quick-drying (fast fixing) offset inks are commonly available in yellow ink, red ink, blue ink, and black ink. Among them, yellow ink is divided into lemon yellow, light yellow, yellow and deep yellow; red ink is divided into pink, gold, red and dark red; blue ink is divided into peacock blue, sky blue, blue and dark blue and so on.

Printing suitability: Mainly used for sheet-fed single-color or two-color offset printing machines with a printing speed of 5000-6000 rpm, and can be used with offset printing coated paper, high-gloss printing coated paper or glass cardboard, etc. Paper matching use.

165. In actual printing, what matters should be paid attention to when adjusting the compatibility of resin type quick-drying (fast fixing) offset printing inks?

Answer: In the practical use of printing, it is usually necessary to make appropriate adjustments to certain suitability of the original ink according to the specific technological conditions, or to mix various colors of inter-color or multi-color ink. At this time, attention should be paid to the following matters.
(1) Consistency: It is generally adjusted with an appropriate amount of resin type quick-fixing varnish or thinner, and can also be used with No. 6 resin varnish. If the temperature is low, the ink becomes thick, and the fixing becomes slow, it can be added properly. Mineral oil (ink oil) adjustment.

(2) Viscosity: If you need to adjust the viscosity, you can use a small amount of relieving agent or No. 6 resin to adjust the ink, you can also use mineral oil (ink) adjustment. If the temperature is too high, the ink solvent volatilizes, and when the crust or dry solid occurs on the ink roller, a small amount of resin No. 6 varnish can be added to the transfer roller to reduce the viscosity.

(3) Dryness: Under the normal process conditions, usually do not need to add driers, such as printing the last color or a single color, you can add a trace of white dry oil; in case of temperature and humidity changes in the workshop, causing the paper moisture content changes, When the fixing speed is affected, appropriate measures are taken as appropriate.

(4) Concentrated color matching: The ink of the same series of the product is mixed into a color ink or a complex ink.

(5) Light-tune color matching: The use of withdrawal agent is the main method, and it is not appropriate to use transparent dipping ink or white oil.

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