Principle and Characteristics of bronzing process for Pantone Cigar Paper Boxes (Part 2)

Principle and Characteristics of bronzing process for Pantone Cigar Paper Boxes (Part 2)

In addition to achieving accurate bronzing position, smooth and bright surface, balanced pressure, uniform, no foaming, no paste plate and other requirements, but also special requirements of bronzing pattern edge can not have obvious indentation, bronzing anodized aluminum in hot stamping surface to have good adhesion, and no obvious scratching and scratching phenomenon. As we all know, the bronzing process is actually a paper heat and compression process. In the process of production, various adverse factors of paper deformation should be reduced as far as possible, which is of great help to the smooth progress of the post-bronzing process and the improvement of the qualified rate of the product. Let's talk about the control, failure and elimination of bronzing quality:

First, bronzing plate

The production of bronzing plate mainly adopts photographic etching process and electronic engraving technology, and the material is mostly copper plate or zinc plate. Copper plate material is delicate, surface finish, heat transfer effect is better than zinc plate, the use of high quality copper plate can improve the gloss of bronzing text and outline clarity. The traditional photographic etching technology is simple, low cost and short service life. It is mainly used for the bronzing of text, bold lines and general images. Electric carving making bronzing plate can show rich and delicate level changes, its high printing resistance, suitable for cigarette packaging, fine product quality requirements, large batch product packaging.

Two, bronzing suitability

It refers to the selection of anodized aluminum model and the matching between bronzing speed, temperature, pressure and other factors. The process flow of bronzing is as follows: prepare a plate for hot stamping -- pad plate -- adjust hot stamping process parameters -- test hot stamping, sample signing and formal hot stamping.

Three, bronzing failure and elimination

Hot stamping is not or hot stamping is not real: this is related to the surface characteristics of the printing, the properties of electrolyzed aluminum, hot stamping temperature and pressure and other factors.

1, printing surface spray too much powder, printing ink is not dry or the surface contains viscosity withdrawal agent, light oil and other additives, will prevent the adsorption of aluminum and paper. It can be used to remove powder from the printed surface or to solve the problem in the printing process.

2. Improper selection of anodized aluminum will also directly affect the bronzing fastness. Should be based on the size of the bronzing area, the characteristics of the hot stamping material comprehensive consideration of what type of electrochemical aluminum. There are many models of anodized aluminum materials on the market, and all kinds of models should have different materials of substrate and the most appropriate range of hot stamping, they are mainly based on the adhesion and peel degree in the process of use to distinguish.

Aluminized aluminum matching can refer to the following categories: ordinary products on the bronzing (general ink) aluminized aluminum 88-I type, KURZ PM type: cigarette bags, cosmetics and other concentrated ink printed matter (including gold, silver) bronzing aluminized aluminum 88-2 type; Cigarette labels, cosmetics packaging and other fine stroke hot stamping anodized aluminum are 88-3, 88-4, PM288 and other suitable for 0PP or PET coated paper and UV ink board, polishing paper and other products hot stamping anodized aluminum are 88-4, K series, LK series, and SP series.

3. The matching between stamping equipment, stamping time and stamping temperature is not correctly mastered, which affects the fastness of stamping and the clarity of graphic outline. For example, high speed round press is fast, embossing line contact, hot stamping temperature is higher than circular or flat pressing. Under normal circumstances, the temperature of round stamping is 190% ~ 220℃, the temperature of round stamping is about 130℃ ~ 150℃, and the temperature of flat stamping is about 100℃ ~ 120℃. Of course, hot stamping time, hot stamping temperature and production efficiency are largely restricted by the transfer performance of aluminum oxide. We should also pay attention to check whether the pressure is balanced, part of the graphic hot stamping is not to check whether there is damage to the stamping plate.

Pull back: pull back refers to the printing ink or printing piece polishing oil after hot stamping. The main reason is that the printing surface ink is not dry or the printing surface UV after processing is improper, resulting in the printing surface ink, UV oil and paper surface combination is not strong. Should wait for printing dry before bronzing. In addition, electrolyzed aluminum materials with low separation force and excellent thermal transfer property can be selected.

4, paste plate and hot stamping after anodized aluminum discoloration paste is mainly due to poor bronzing plate, anodized aluminum installation slack or anodized aluminum walking foil is not correct caused. Anodized aluminum discoloration after hot stamping is mainly caused by high hot stamping temperature. In addition, anodized aluminum wrinkle is also easy to cause hot stamping color stacking uneven discoloration, can be solved by properly reducing the temperature. For the round flatting model can be installed in the foil delivery place fan, keep the foil float, avoid before hot stamping anodized aluminum touch bronzing plate and burnt.

5, graphic outline deficiency: need to cover the processing of bronzing, for fear of gold foil easy to wipe off and hot stamping and then coating. This is easy to cause the film (especially the matte film) will destroy the surface gloss of aluminum oxide, water-soluble glue coating should not be used, otherwise it will cause the aluminum oxide surface black, and it is easy to cause the gold powder stuck on the edge of the picture and text resulting in deficiency phenomenon.