In pace with increasing concern on the environment, the flexo printing keeps growing fast than ever, mainly applied to paper, film, and laminated material.
At present, CI flexo printing machine is widely used in the field such as paper package, sanitary package, beverage package, food and medical package. If we talk about the percentage of flexo application in these fields, it varies from country to country. Namely flexo printing plays 100% in Europe & America, 80% in South Asia, and15%-20% in China. In comparison, rotogravure is dominant in Japan and South Korea.
Flexo or gravure, which has more advantages in the flexible package? This article will illustrate by comparing the fixed investment, plate investment, and running cost.
Flexo vs Gravure in Equipment Investment
As shown in Table 1, an 8 colors CI flexo press of European brand will cost 1.5 to 2 million Euros. Gravure press of Europe or Japan brand will cost about 1.3 to 2 million Euros. In conclude, the price of imported CI flexo press almost equals to that of imported gravure press.
According to some statics in the market, China-made CI flexo press will cost about 0.5 to 1.1 million Euros. China-made gravure press will cost 0.2 to 0.8 million Euros. It is obviously that the investment of a China-made CI flexo press is higher than that of China-made gravure press.
|Flexo||1200-1500mm||8-10 colors||1.5-2 million Euro||Europe brand|
|Flexo||1200-1500mm||8-10 colors||0.5-1.1 million Euro||HY-Flexo(Huayang)|
|Rotogravure||600-1250mm||8-10 colors||1.3-2 million Euro||Europe & Jap|
|Rotogravure||600-1250mm||8-10 colors||0.2-0.8 million Euro||Beiren, Huitong|
Apart from the printing machines, a printing factory also need to have stock of 10-20 pieces anilox, 20-30 pieces of print sleeves, 1-2 bridge sleeves, and 1 set plate mounting machine.
Plate Storage and Maintenance Cost
The flexo plate, made of photopolymer, is light and easy for storage. It can be stored vertically or horizontally. About 10 to 20 pieces plates can be stored per square meter. Generally, if a CI flexo press has average 300 to 500 jobs for running, which requires 50 square meters for plate storage. It is recommended that plate stored in an environment with constant temperature.
Besides, about 200 square meters are required for the storage of anilox sleeve, print sleeves and other accessories.
The gravure plate roller, made of steel, copper, chrome, is very heavy (10kg/piece). The weight of gravure plate roller for an 8 colors printing job will exceed 80KG. Usually it is storage vertically or placed in shelf. Generally, it requires 100 to 500 square meters shelf. Due to heavy structure, the investment of warehouse in gravure plate roller is higher than other type of printing machine.
Plate Service Life
The flexo plate costs RMB 0.2-0.3/cm²while rotogravure plate costs RMB 0.15-0.2/cm². It is obviously that the flexo plate costs 20% to 50% higher than that of rotogravure.
The service life of flexo plate lasts between 500,000 and 1,000,000 runs, while rotogravure plate lasts over 1,000,000 runs.
However, the flexo plate can be made within 1 to 2 days, much efficient than rotogravure plate which takes 3 to 7days.
Flexo printing, especially CI flexo press can run at a speed of 350m/min to 500m/min, while rotogravure can only run at a speed of 120 to 200m/min when handling stretchable film.
b. Register precision
The web path for one flexo unit is 0.4m to 0.6m, while web path for one rotogravure unit is 4m to 6m.
It always happens that rotogravure cannot reach an accurate precision, especially as the printing width expands. While handing stretchable material, flexo register precision stays much stable. Taking LDPE film as example, the flexo qualified rate is 5% to 10% higher than that of rotogravure. Generally, the flexo register can reach 0.1 to 0.2mm, while some Europe brand can reach 0.05 to 0.08mm. The rotogravure register can only reach 0.3 to 0.5mm.
While handing stretchable film, rotogravure can only run narrow web with low printing speed. Flexo is 4 to 6 times faster than rotogravure in printing stretchable film. For this reason, majority of stretchable film are printed by flexo press.
c. Energy consumption
As shown in Table 2, after comparing a 10 colors CI flexo press with a 10 rotogravure press, it is very obvious that the energy consumption by flexo is lower than rotogravure, regardless steam heating or electrical heating.
|Unit price (¥/Ton)||230||230|
|Unit price (¥/KW)||0.8||0.8|
d. Ink consumption
As we know, the flexo printing applies thinner ink than rotogravure printing does. Therefore, flexo consumes less ink than rotogravure. Another important factor is that flexo has closed ink chamber, which reduces the volatilization to the maximum extent. Compared to the rotogravure with open ink chamber, flexo ink consumption is 40% to 50% less than rotogravure.
e. Job change efficiency
According to the data from actual production, it will take 1.5 to 2 hours for the job change for an 8 colors rotogravure printing machine, with 200m to 300m waste. For the same working condition, it will take 0.75 to 1.5 hours for the job change for an 8 colors servo drive CI flexo press. As to the new type CI flexo press with auto ink wash and pressure adjustment, it takes only 0.5 hour for the job change.
Rotogravure printing adopts single blade with heavy pressure, while flexo printing adopts double blades with light pressure. Therefore, flexo consumes 30% blades less than rotogravure does. However, flexo adopts 0.55mm double side adhesive tape for plate mounted to sleeve, while rotogravure does not need adhesive tape.
As the growing concerns on the environment, government authority imposes strict rules on the VOCs control. As a result, many printing factories invest millions to ten millions RMB on the VOCs treatment facility, which occupy large workshop space and has a high running cost.
Despite the fact that both flexo and rotogravure print on flexible films with solvent based ink, the eco-friendly water-based ink will be the trend in the near future. It is obvious that water-based ink is more easier applicable to flexo printing that rotogravure printing. Currently, water-based ink has been used in flexo printing on the breathable film. Due to the eco-friendly feature, water-based ink is widely used in printing on food, beverage, and medical package. Meanwhile, unlike the solvent-based ink, water-based ink does not have the fire risk caused by static or concentrated solvent.
As the flexo printing has absolute advantages in handing stretchable film, thus is able to achieve high printing speed, precision register, and less wastage. By reducing the web thickness, the package cost will be reduced as well.
From above article, flexo and rotogravure has advantages respectively. According to the data from some printing factory, rotogravure has running cost advantage in the small orders, as the plate making cost is lower. However, flexo has running cost advantage in the large batch orders, because of its high efficiency, low energy consumption, high qualified product rate.