Printing paper notesKraft paper is mainly used for printed paper bags, envelopes, file boxes, product packaging, bag cover, information kits, portfolios, financial statements, which include 60g/m2, 70g/m2, 80g/m2, 100g/m2, 120g/m2, 150g/m2, and even 250~450g/M2 and other specifications. Kraft paper with a hard strong, tough, wear-resistant and susceptible to tearing fault and so on. But Kraft brightness, smoothness and flatness deviation, surface roughness, prone to go up around the torso, hair, shedding phenomenon. Therefore, to use offset printing paper, should have the following points.
1. kraft paper hanging moisture treatment prior to printing. First ragged and uneven surface of the paper out of the paper, and then clean up the surface of paper, trash, and hanging to make kraft paper of temperature and humidity and temperature and humidity offset printing shop of consistency. This prevents the paper upward around the torso due to uneven moisture. After hanging moisture treatment, the paper, and then in paper stacks on top of paper plates, iron, stone compaction, avoiding paper fluffy solid.
2. selected models. For 80g/m2 above a thick kraft paper, it is best not to use small quarto or Octavo printing. 80g/m2 per cent of kraft paper is thick, nozzle tends to suck up when feeding paper. In addition, due to the small paper format, prone to two or more failures, or paper skew in the feed Board. Folio offset or more than fully offset printing 80g/m2 thick kraft paper, the effect will be better.
3. adjust the offset feed system. Due to a thick kraft paper and should therefore be adjusted size of suction nozzle. Meanwhile, paper thickness easily creates a rolling stop accident, so be sure to double before boot print control, skew control, impulse control and electrical devices adjust the fit, prevent kraft paper rolling machines. In addition, the suction nozzle of paper and feed nozzle diameter and thickness are large rubber aprons.
4. printed brown paper when printing plate cylinder and rubber roller centre distance does not change, only adjust the embossing drum and rubber roller centre distance. This Center in the 250~450g/m2 kraft paper can be printed from the 0.2~0.4mm. Kraft paper surface roughness and smoothness, the paper is far less close coated paper, uncoated paper, therefore, printed brown paper printing also increased the pressure. Print 400g/m2 of kraft paper, plate cylinder and rubber cylinder gap is 3.95mm, the rubber roller gap adjustment with the imprint of 3.40mm, plate cylinder the total package for 0.65~0.75mm, total lining rubber roller to 3.15~3.35mm. If printing thick paper thinned out, should be removed from plate lining to reduce the thickness of the lining, adding on to the rubber drum lining; if you turn paper thin and thick, should pump out the increased thickness of the rubber drum lining, plus on the printing plate cylinder lining.
5. kraft paper porous, rough surfaces, paper easy off hair, shedding, so printing to scrub the rubber roller and plate cylinder, avoiding paper, paper dust adhesion to rubber drum and ink transfer on a plate cylinder, resulting in graphic version, lack of fault. If kraft paper lining, shedding is very serious, and when color printing is encountered, if in the summer, can be printed before printing a layer of water, thus reducing paper hair, shedding, making the paper more smooth.