PAPER HANDLING 1

Now the paper to be printed into a book has been prepared in the warehouse. Before paper was prepared in the printing machine feeder must be ensured a really good condition for printing. Among the signs that paper in good condition for printing, namely: good moisture, flat and smooth surface, not curly edges, unsticky sheets , the pores evenly, dimensions and uniform color tone on all the piles of paper.

If the paper is not in good condition, then it should takes some treatments so that the paper is really ready to be printed. Here are some actions to be performed when the print paper is not in good condition.

1. Paper Too Humid

Paper condition is strongly influenced by the weather. Conditions are sometimes not ideal for printing, for example, is too moist. If the paper is too moist, it will be a long time to dry the ink. This resulted in the set off. Between the sheets one another with mutual sticky sheets and ink too sticking another sheet.

Paper that is too moist can lead to not register. This is caused by the expansion width size paper when it is moist. Put color jog or print color separation and shape the image being damaged by moisture on the paper is not the same. The time set registers happen to use paper moisture good and when a print process mixed with piles of paper that is too moist.

Paper that is too dry is not flexible, less flexible, crumbly, dusty, shrink , is charged static electricity and difficult to cultivate. Paper that is too wet easily torn, limp, expanding and slow to dry the ink. Good paper moisture is between 5 -10% of the weight of the paper.

The moisture level paper should not be absolutely certain percentage. Its humidity most appropriate level in accordance with the relative humidity of the print room. If need be slightly higher than in the printing room humidity levels. Thus, when the paper went to press several times already suffered too intrusive development.

When the paper is too dry, it can be conditioned by blowing blower moisturizer with humidity between 5 to 8% higher than the air humidity in the printing room. Old paper blowed until the moisture together with the air humidity in the room printing or fewer.

The humidity levels can be measured using a Hygrometer paper puncture. The trick is the end of the hygrometer is inserted into a stack of paper, at least 15 cm below the sheet of paper.

Especially for printing separations were really good quality not only necessary practical knowledge, but also the regular technical control. Working with only rely on approximately not justified in the modern enterprise. All must be measured with certainty using the tool.

2. Uniforms Paper's  Pores

The state of the pores paper effect on ink drying. Good paper can absorb the ink evenly, because the pores evenly across the surface of the paper. Similarly, porous paper (eg HVS) dry faster than paper that is not porous (Art Paper, for example).

Sometimes, for various reasons there is a paper that pores are not evenly distributed in the same sheet of paper. Therefore there is a local term drying. In one sheet of paper there is a part that is dry and there are other parts that have not been dried

The condition is caused by a wrong way of fentilation. Paper that is too dry if stacked in a humid room. The part that absorbs the humidity is only around the edges of the paper. Consequently the round piggirannya will expand, while the center is not, so that the paper be bulging in the middle. This is not only troublesome when passing track printing process also causes the edges dries more slowly than the middle.

Sometimes, for various reasons there is a paper that pores are not evenly distributed in the same sheet of paper. Therefore there is a local term drying. In one sheet of paper there is a part that is dry and there are other parts that have not been dried.

The condition is caused by the buildup of a wrong way. Paper that is too dry if stacked in a humid room. The part that absorbs the humidity is only around the edges of the paper. Consequently the round edges will expand, while the center is not, so that the paper be bulging in the middle. This is not only troublesome when passing track printing process also causes the edges dries more slowly than the middle.

And vice versa if the damp paper stacked in a dry, then only part that dries around the edges, while the center was not. This will cause the central part of the paper becomes concave. Impact on cetaknyapun same process, tangled, the register is not right, the middle part is slow to dry the ink.

3. Surface Paper Too Acid

If the paper is too acidic, the resulting ink becomes dry old. The paper surface becomes too acidic, especially when going to press several times, both for input and for print color separations. Paper printed acid in separation widened due to repeated wetting contact with an aqueous solution that is too acidic. The fix is ​​added desiccant (drier) on the ink and acidity in water is reduced. The ideal water pH is between 5.0 -6.5.

4.  Different Sheet Pile of Paper 

This incident stems from a paper mill. In the paper mill, the paper out of the machine-shaped roller rolan paper. At the time the process of cutting into sheets, can be mixed when piled sheets from several different roller storage date. Printing in the warehouse was often the case, if we lack control over paper storage. Supposedly paper printed first come first and which come later printed later. But sometimes we are less careful, especially if overtime. Even so much so when it became a book and combed visible markings, white-third, one-third yellow, one-third somewhat whitish.

Things like that should not happen. In addition to the prints are less satisfactory because it is slow to dry so many who set off well finishing is also not good, mottled paper.