Study on the Life of the Blade of Carton Printing Slotting Machine

Carton printing and grooving machine, forming machine and various printing die cutting and grooving and other multifunctional combined machines. It has the characteristics of high-quality high education and compact structure, and is widely used by carton packaging enterprises. Slotting knife is one of the necessary tools, and its service life directly affects the carton slotting quality and manufacturing cost. It is one of the problems that need to be improved in the quality management and cost management of similar enterprises.

In today's fierce competition in the market with quality and price as the core, this issue is increasingly concerned by the leaders of relevant enterprises, prompting enterprises to tap the potential for innovation, cost savings and efficiency, and take the path of intrinsic development. This article discusses how to improve the service life of slotting cutter.

1. Existing problems The shape of the slotting knife at home and abroad is basically similar.

Slotting knife includes two parts: upper knife and lower knife. Common upper knife includes arc knife and curved serrated knife; lower knife has semi-circular acute-angle knife or semi-circular right-angle knife, semi-circular groove wide ring . The industrial cutter blade service life of the grooving knife depends on whether the grooving quality of the cardboard meets the product standard. The grooving quality generally decreases gradually with the wear of the cutting edge of the tool, which will produce burrs, burrs, chipping and waste associated with the phenomenon. When the product does not meet the standard, the grooving knife needs to be replaced.

Although there is a certain difference in the service life of imported and domestic grooving knives, some of the problems are similar: first, the grooving knife (upper knife) can only be used once, and the life is shorter; second, the effect of reusing the knife Poor, unstable grooving quality; third, the blade wear resistance is poor, and some of the blades are partially cracked; fourth, frequent addition of new knives, large expenditure, high production costs.

Second, the main reason analysis

(1) Tool wear is related to the quality of the paper being cut When the slotting knife works, the ruler produces a cutting motion on the cardboard. The surface is subject to relative friction. The content of sand in many paperboards is higher than 5% ~ l0%, and the sand grains produce a strong rubbing effect relative to the cutting edge, causing the metal on the surface of the cutting edge to gradually plastically deform and fatigue wear off. The life of the cutter decreases with the increase of use time and the increase of the sand content (quartz sand, etc.) and impurities of the cut cardboard.

(2) The gap between the upper and lower knives after sharpening the knife is unreasonable, and industrial knives reuse will affect the quality of the product.

1 The form and degree of upper and lower knife wear. The working surface a of the upper blade wears obviously from the range of about 10mm above the cutting edge, the cutting edge of the working surface b has a certain amount of wear, the blades at two acute angles become blunt, and the thickness between the two a surfaces becomes thinner; There is also obvious wear in the range of about 10mm below, there is also some wear on the cutting edge of the working face d, the blade of the acute-angle knife or right-angle knife becomes blunt, and the thickness from the edge of the c-plane to the corresponding end surface becomes thin.

2 Abrasion causes the gap between the upper and lower blade edges to change. Usually people pay more attention to the grinding of working faces a and c, but there is less analysis and research on the gap change caused by it.

3 Ignore the corresponding change in the thickness of the groove width retaining ring. After grinding, the slotting knife has poor effect. This is Tungsten Steel Blades because the thickness of the groove width retaining ring is fixed and the gap between the upper and lower blade edges is unreasonable.

(3) The wear resistance of the tool is related to the material and the hardness of the heat treatment. The wear resistance is related to the material hardness and the nature, number, size and distribution of the hard points in the structure. The higher the hardness, the more refined carbide , The more evenly distributed, the better the wear resistance.

Third, the way to increase life This article mentions some objectively difficult factors or tools that affect life due to accidental bruising, which will not be discussed here. Our subjective and practical approach is to solve the problems of reuse of old knives and selection of new knives, thereby prolonging the service life of slotting knives.

(1) Reasonable gap and grinding of old knives to ensure reuse effect.

1. Grinding the actual measured wear of the old upper blade. In order to unify the size, standardize the knife sharpening, reduce unnecessary cutting edge grinding loss, and measure, record and classify the old upper knife.

2. Check and classify the cutting edge of the lower knife.

(2) Good materials and high hardness

1. Prevent abnormal cracks in the blade. After forging, the steel can reach the shape of the required tool, and it can also make the internal structure tight and the quality of the crystal phase improved, but it is required to avoid forging cracks during the forging process. In the heat treatment process, full consideration should be given to avoid defects such as quenching cracks.

2. Add new knives strictly according to the drawings for acceptance. Carton packaging companies generally purchase new grooving knives through outsourcing and outsourcing. It is important to pay attention to: strict acceptance must be in accordance with the dimensional tolerances, materials, hardness and other requirements specified in the drawings.