1、模切起毛、起尘
问题原因:在模切时,经常会出现模切产品切边不光洁、起毛的现象,特别是离压痕线较近的一些切边处情况更为严重。这是由于在模切合压时,模切版上的胶条、压痕钢线对纸张产生了拉力,纸张在未被完全切穿时就被产生的拉力拉断,出现了毛边。
解决方法:
首先要根据纸张选用不同类型的模切刀。模切刀包括直纹刀和横纹刀,两种纹路的刀锋又有高矮之分,刀锋形成的纹路和高矮不同,直接关系到模切质量和模切刀的使用寿命。在避免模切起毛方面,直纹刀比横纹刀好;在使用寿命方面,矮锋刀比高锋刀好。在模切覆膜卡纸时,应选用直纹高锋刀,且要求刀锋是磨制的,最好不要采用压凹凸一次成型工艺,否则压力太大会对模切产生很大影响;而在加工普通卡纸时宜选用矮锋刀,并根据纸张纤维的质量来确定刀锋的纹路。
2、模切机压痕产生“爆线”和“暗线” 问题原因:“爆线”是指由于模切压痕的压力过大,超过了纸张纤维的承受极限,使纸张纤维断裂或部分断裂;“暗线”是指不应有的压痕线,一般是由于模切版和压痕钢线选择不合适、模切压力调节不当、纸张质量差、纸张纤维方向与模切版排刀方向不一致、纸张含水量低导致柔韧性下降等原因所引起的。
解决方法:选择合适的模切版;适当调节模切压力;在模切之前先把待模切的印刷品在车间里放置一段时间;提高车间环境的相对湿度。较好的方法是降低压痕钢线的高度,降低的高度通常为0.1~0.2mm,具体要根据纸张定量确定,定量在350g/m2以上的纸张需降低的压痕钢线的高度为0.2mm,定量在350g/m2以下的纸张宜降低0.1mm。
1, cutting fluff, dust from
Cause of the problem: when in the cutting, trimming cutting products often do not appear smooth, raising phenomenon, especially away from the crease line at the cutting edge closer to some of the more serious. This is due to meet the pressure in the mold, the die on the tape, steel wire indentation produced tension on the paper, the paper has not been completely cut through the tension generated when it was pulled off, the emergence of flash. Solution: First, we must choose different types of paper cutting knife. Straight knife cutting knives, including knives and stripes, two lines of the height of the blade there are points, lines and the formation of the blade height difference is directly related to the cutting quality and cutting tool life. Avoid cutting the fluff side, straight blade knife better than stripes; in service life, high and low front front knife a good knife. Coated paperboard in the die, the knife should be used Ruled Gao Feng, and asked the blade is polished, it is best not to use embossing a molding process, or cutting too much pressure will have a significant impact; in the processing should use short when ordinary cardboard front knife, based on the quality of the paper fibers to determine the blade's lines.
2, die-cutting machine creasing a "critical line" and "dark line"
Cause of the problem: "burst line" refers to cutting indentation pressure, exceeding the tolerance limits of the paper fibers, so that part of the paper fiber breakage or fracture; "dark line" refers to the undue indentation line, usually As the die and the indentation steel wire selection is inappropriate, improper cutting pressure regulation, poor quality paper, paper fiber direction and die-cutting direction inconsistent row, due to the low water content of paper decreased flexibility caused by other reasons.
Solution: Choose the appropriate die; proper cutting pressure adjustment; in the cutting die before the first print to be placed in the workshop for some time; increase the relative humidity of the workshop environment. A better approach is to reduce the height of indentation steel wire, reducing the height is usually 0.1 ~ 0.2mm, the specific quantitative determination according to the paper, quantitative in 350g/m2 paper to be lower than the indentation height of 0.2mm steel wire quantitative in the following paper 350g/m2 should reduce 0.1mm.