Micro-nano hot stamping can actually solve so many cigarette pack printing problems
Technological innovation drives industry transformation. In the current development process of the printing industry's green, digital, smart, and integrated 'four modernizations,' various new technologies continue to emerge, and new products are being launched one after another. Printing companies are actively preparing for competition, striving to create their own 'gold-mining tools.' It can be said that technological innovation is becoming the most resonant slogan and the most dazzling symbol of this era. To this end, we are launching the [Innovative Technology] column in hopes of disseminating leading technologies and guiding industry development.
In the development of new cigarette packaging products, hot stamping is an important process to enhance product quality. Hot stamping of the main text and logo is particularly crucial in cigarette packaging processing, playing a key finishing touch role. Traditional hot stamping processes use flat or embossing stamping methods, which make it difficult to integrate decorative patterns with text and logos, resulting in a slightly plain appearance. Micro-nano hot stamping can graphically render text and logos, producing rich texture and light effects, significantly improving the overall quality of the cigarette packaging.
Micro-nano hot stamping involves transferring a hot stamping film onto the printed surface through a metal plate with optical-grade patterns to create high-precision graphic images. These high-precision images achieve micro-nano-level accuracy and offer advantages such as high precision, high brightness, anti-counterfeiting, and low cost. Since micro-nano hot stamping adopts a two-step process of first stamping and then pressing to achieve high-precision graphic image replication, the processing of micro-nano structured stamping plates is particularly important.
Traditional hot stamping plate processing mainly includes two methods: physical engraving and chemical etching. Due to process limitations, lines on hot stamping embossing plates as thin as 0.03mm have reached the mechanical processing limit, making it impossible to accurately reproduce intricate graphic images. Micro-nano stamping plates use laser technology to process patterns with microstructures into special metal plates. These patterns with optical structures can achieve effects like embossing, platinum, laser, Fresnel lenses, etc., through different microstructures. The graphics can vary greatly, expressing richer content, making the main text and logos more refined. While enhancing product quality, the anti-counterfeiting function also reaches a new level.
In this article, the author briefly shares the practical application of micro-nano hot stamping by summarizing several main practical problems it solves in the development of new cigarette packaging products.
Solving the texture problem of main text and logo hot stamping
Processing of main text and logos usually relies on hot stamping, primarily using embossing, which provides a strong metallic texture and three-dimensional effect, with a clear theme that better highlights brand philosophy. Typically, the individual characters of the main text and logos on cigarette packages are about 1cm in size, with stroke thickness around 1mm. However, the stamping plate processing method limits precision, and even with embossing plates, there are few improvements possible. Micro-nano stamping plates achieve micro-nano-level precision, allowing the main text and logos to incorporate patterns or texture variations, such as embossing, platinum, or lens-like photolithography effects, making the text brighter, more transparent, three-dimensional, and more refined. In Figure 1, the main text 'Cloud End (Medium)'' on the cigarette package uses micro-nano hot stamping, with a stroke thickness of 0.5mm, and employs Fresnel embossing photolithography technology to achieve an exceptionally strong three-dimensional and transparent effect.Figure 1: Micro-nano hot stamping relief effect of the main text on the 'Cloud (Medium Filter)' cigarette pack
Solving the registration issue of aluminized laser paper
The materials commonly used in the development and production of new cigarette packs are aluminized laser paper. The main text can achieve a hot stamping effect by printing first and then embossing. With the application of lithography technology in the packaging industry, lithographic positioning paper has gained popularity, and lithographic patterns combined with printed colors have become common product processes. However, in actual production, issues such as stretching deformation during pressing, unstable paper slitting, and paper deformation during printing often lead to inaccurate registration of the main text and logos. By using micro-nano hot stamping for the text and logo, effects such as three-dimensional text and logo relief can be achieved, solving the problem of precise registration in production. In Figure 2, on the 'Liqun (Premium Medium Filter)' cigarette pack, the 'Liqun' main text and English letters use micro-nano hot stamping over a lithographic background plate overlay, achieving accurate registration and a strong embossed text effect.
Figure 2: 'Liqun (Zun Zhong branch)' cigarette pack 'Liqun' main text micro-nano hot stamping relief effect
Solving the cost problem of holographic positioning stamping
Traditional holographic positioning stamping involves transferring the designed graphics and patterns onto a holographic positioning stamping film through photolithography and then stamping it onto the surface of the printed product using the equal-length step principle. Although positioning stamping has always been favored by consumers for its aesthetic appeal and anti-counterfeiting properties, it has remained expensive. Moreover, the alignment for positioning stamping is limited by equipment precision and the stretching deformation of the stamping film itself. In the new tobacco bidding environment, how can we meet customer requirements while reducing costs and increasing efficiency?
Micro-nano hot stamping is undoubtedly a powerful tool. It can not only achieve high product quality but also solve cost problems and even partially replace holographic positioning stamping. Micro-nano hot stamping replaces holographic positioning stamping in two steps: first, a standard aluminum-coated film is used for flat stamping, then a micro-nano plate is pressed to produce the graphics and images. Micro-nano hot stamping can perform flat stamping followed by reverse pressing on dual-machine setups, producing embossed, platinum, and laser effects, while achieving precise alignment.
Therefore, micro-nano hot stamping using a standard aluminum-coated film can achieve the effects of holographic positioning stamping with a simple process, low equipment requirements, and effectively reducing the cost of holographic positioning stamping. In Figure 3, the 'Golden Leaf (Tianxiang)' cigarette pack uses micro-nano hot stamping instead of holographic positioning stamping to achieve embossed images and multiple shimmering effects, while also achieving 1:1 precise alignment.
Solving the issue of material processing with stamping before printing
Cigarette pack substrates are generally divided into aluminum-coated paper and non-aluminum-coated paper. As tobacco demands for packaging quality and grade continue to increase, lithography technology combined with packaging materials has made customized lithographic paper a trend in the development of some new products. Combining lithographic patterns with offset printing can express designs in more dimensions, especially the use of embossing and lenses, which can bring a strong sense of space and visual impact. Aluminum-coated paper can directly have lithographic patterns embossed on it, and UV embossing can be used to improve paper registration accuracy. However, in the development of new cigarette pack products, for processes involving high-brightness white or bright yellow colors, even creating a white base on aluminum-coated paper cannot effectively solve the problem of grayish base color. On the other hand, non-aluminum-coated paper, especially white card paper and medium paper, cannot achieve the effects that aluminum-coated paper can.
Micro-nano stamping can achieve a metallic texture for local lithographic patterns. On non-aluminum-coated paper, using micro-nano stamping to produce the effects of aluminum-coated paper involves stamping before printing, first embossing the lithographic pattern onto the paper using a micro-nano plate, and then aligning it 1:1 with offset printing to reproduce the colors. This ensures the brightness of the base color while making the local patterns more refined, with clearer and more dynamic detail reproduction.
In Figure 4, the large leaf on the "Golden Leaf (Tianye Soft)" cigarette pack uses micro-nano stamping combined with CMY three-color printing, stamped before printing, presenting the dynamism and embossing effect of the large golden leaf.
Figure 4: 'Golden Leaf (Tianye Soft)' Cigarette Pack Large Leaf Micro-Nano Hot Stamping and KMY Three-Color Printing Effect
Solving the Anti-Counterfeiting Issue
Hot stamping can be divided into two types according to the way the image information layer is transferred: one is the transfer of graphic image information from the hot stamping film, and the other is the copy transfer of graphic image information on the hot stamping plate. The process of transferring graphic image information from the hot stamping film involves transferring the graphic image information onto a hot stamping film with a release layer through lithography-coating-embossing, and then heat-transferring it onto paper using a hot stamping plate. This method is limited by lithography equipment and produces relatively simple effects.
Micro-nano hot stamping, on the other hand, mainly involves the copy transfer of graphic image information from a micro-nano plate. By combining, splicing, and overlaying plates, multiple microscopic structures are realized to present the structural sense, layering, and visual effects of images. Therefore, the multiple processing methods of the micro-nano plate become the technical core of the micro-nano plate.
For example, in the micro-nano plate manufacturing process, special microscopic structures machined by precision planing machinery can be integrated with lithography effects. By changing the material and the direction of light reflection, the image contrast is enhanced, the layers are richer, and the anti-counterfeiting effect is stronger. In Figure 5, the crown combines multiple lithography techniques, such as embossed borders, pearl-like micro-lenses, and laser micro-particles, making the overall effect more luxurious and highly secure against counterfeiting. In Figure 6, the Yunyan Ruyi pattern combines Finier embossed lithography techniques with CNC machining technology, presenting different optical microstructures on the same plate. The strong contrast of materials provides an excellent anti-counterfeiting effect.
Figure 5 Crown micro-nano hot stamping (embossed, lens, dot pattern)
Figure 6 Yunyan Micro-Nano Hot Stamping (Phenyl Embossed Lithography CNC Machining)
Micro-nano hot stamping represents a new hot stamping method, which enhances the finesse of text and logo stamping. It not only resolves registration issues during the production process but also offers significant advantages in terms of cost and anti-counterfeiting. Additionally, micro-nano hot stamping imposes high requirements on both the stamping film and stamping adaptability. Therefore, during the stamping process, different stamping films should be selected based on different stamping surfaces to ensure that micro-nano hot stamping is "both flat and bright," and to accurately replicate the complete microstructure in the back-pressure process, delivering high-quality stamping. Micro-nano hot stamping involves the interdisciplinary intersection of graphic image processing, optics, material chemistry, and CNC machining, offering immense potential for exploration in every technical aspect. With the continuous improvement in the quality of life, people's demands for packaging quality are increasingly high, and it is believed that micro-nano hot stamping will be applied more widely in new products.