1、模切起毛、起塵
問題原因:在模切時,經常會出現模切產品切邊不光潔、起毛的現象,特別是離壓痕線較近的一些切邊處情況更為嚴重。這是由于在模切合壓時,模切版上的膠條、壓痕鋼線對紙張產生了拉力,紙張在未被完全切穿時就被產生的拉力拉斷,出現了毛邊。
解決方法:
首先要根據紙張選用不同類型的模切刀。模切刀包括直紋刀和橫紋刀,兩種紋路的刀鋒又有高矮之分,刀鋒形成的紋路和高矮不同,直接關系到模切質量和模切刀的使用壽命。在避免模切起毛方面,直紋刀比橫紋刀好;在使用壽命方面,矮鋒刀比高鋒刀好。在模切覆膜卡紙時,應選用直紋高鋒刀,且要求刀鋒是磨制的,最好不要采用壓凹凸一次成型工藝,否則壓力太大會對模切產生很大影響;而在加工普通卡紙時宜選用矮鋒刀,并根據紙張纖維的質量來確定刀鋒的紋路。
2、模切機壓痕產生“爆線”和“暗線” 問題原因:“爆線”是指由于模切壓痕的壓力過大,超過了紙張纖維的承受極限,使紙張纖維斷裂或部分斷裂;“暗線”是指不應有的壓痕線,一般是由于模切版和壓痕鋼線選擇不合適、模切壓力調節不當、紙張質量差、紙張纖維方向與模切版排刀方向不一致、紙張含水量低導致柔韌性下降等原因所引起的。
解決方法:選擇合適的模切版;適當調節模切壓力;在模切之前先把待模切的印刷品在車間里放置一段時間;提高車間環境的相對濕度。較好的方法是降低壓痕鋼線的高度,降低的高度通常為0.1~0.2mm,具體要根據紙張定量確定,定量在350g/m2以上的紙張需降低的壓痕鋼線的高度為0.2mm,定量在350g/m2以下的紙張宜降低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.