General packaging decoration prints have colourful quality requirements. So, the influence factors of packaging printing colorful what? Below a brief analysis.
A, paper whiteness and absorbing to the influence of printing color brilliance
Paper whiteness is printing colorful foundation. The ideal paper to reflect close to all of the color tone, and ash, black, partial green, partial red or other partial color paper can absorb part of the incident color tone, leading to the imprinting hue, brightness and saturation will be affected, and ultimately for the performance of the color difference. This is equivalent to join in the ink of part of the other ink, do well the ink is not pure, so as to give a person a kind of dulling, turbidity and partial color feeling.
Paper main ingredients for cellulose, rubber, packing, etc. And the ink flow part is the connection material, ink pigment by connection material in the paper surface conjunctival dry and attachment. The main components of the paper and ink are asymmetric type of molecule, when they are close to each other, rely on secondary bonding force that molecular on paper complete attachment.
We are now packing decoration prints mostly used coated white board paper, wood pulp liner white board paper, ordinary cardboard paper, wood pulp liner cardboard paper, kraft paper and white cardboard. Because different paper mill production technology difference, causes the surface of the paper whiteness and smoothness significant difference. Therefore, press in stamping moment, ink connection stock liquidity in high low molecular part is pressed into the paper larger pores, connection material began to separate from the ink. If the ink pigment content high, and the ink film can be formed in a large number of small capillary, these a large number of small capillary keep connection material ability, than paper surface of fiber clearance absorption connection material ability much more. If the pigment content is low, will appear ink adhere to the paper on the surface, the connection material most into paper gap in, cause the thing on printing ink film partial thin, pigment particle bare, the final color not bright-coloured.
Second, the ink transfer and rolling process to the influence of printing color brilliance
If the color in the coating and ink roll when ink fountain not clean, mixed with other color, it will be bound to cause partial color, also cause color not bright-coloured. Therefore, in the color change, be sure to put the ink fountain, ink roll and water roller clean, especially dark in light color more attention should be paid to clean. Typically, the dark ink wash clean, then shovel on the part of the use of light color ink, beating well after period of time, and then to cleaning.
For double color machine and multicolor offset press, especially fluctuation unit Shared a roller equipment, more attention should be paid to melange happening. Once mixed color will cause partial color, the color is not bright.
3 ink excessive emulsion and add put additives on the influence of printing color brilliance
The traditional offset printing mode, the main or rely on ink balance to complete the printing process. According to the ink transfer process analysis, ink emulsification is inevitable. But excessive emulsion of ink, can cause printing color dodge, stale wait for a phenomenon, which reduce the color brilliance.
Offset according to the need to join all kinds of additives, such as thinner, drier, etc. These additives to join too much, sometimes also can affect printing color brilliance. Thinner have white ink, white oil, etc. White oil is mainly composed of magnesium carbonate, stearic acid, ink oil and water mixture of emulsion. The emulsion to ink emulsification, causing colour and lustre is dim.
Drier is mainly metal soap class, but also strong emulsifier, a small amount of drier to ink emulsion have stable function, but the quantity added to too much, can cause serious emulsion ink.
In addition, for the graphic area less prints, in each cycle to wavers fill add new ink quantity is less, so long-term retention in the ink roll of these ink will undergo several embellish version fluid mixing, squash and roll-off, causing serious emulsion ink, the bright colors. (Gold Printing Group)