DIRECT-TO-SHAPE DIGITAL PRINTING USING UV INKJET TECHNOLOGY

Many brands are seeking greater product differentiation, shorter development cycles and more sustainable packaging solutions. As a result, DTS digital printing is becoming an important manufacturing process. UV-inkjet systems enable decoration directly onto finished objects. These range from beverage cans and glass bottles to reusable drinkware, cosmetics packaging and industrial containers. DTS printing eliminates the need for labels, sleeves or traditional printing plates.

Advances in printhead technology, UV-LED curing and specialist ink formulations have transformed DTS printing from a niche capability into a viable production solution. The result is a technology that offers manufacturers and brand owners greater flexibility, reduced inventory risk and new opportunities for consumer engagement. 
At the same time, DTS printing meets increasingly demanding performance requirements. This trend has been observed across metal packaging, reusable drinkware and other direct-to-object (DTO) applications. This is because personalisation, short runs and rapid design changes are becoming commercial priorities. 

Traditional decoration remains highly effective for certain applications and for high-volume production runs. However, they often require dedicated tooling, plates or screens. These aspects create costs and lead times that can limit product agility.

Digital DTS printing removes many of these constraints. Images are generated directly from a digital file. As a result, manufacturers can seamlessly produce limited editions, regional variants, promotional campaigns and variable-data details without interrupting production. Artwork changes that may previously have taken weeks, can be implemented in hours – even on the fly – increasing efficiency.

This flexibility supports several strategic advantages:

• Mass customisation and variable-data printing
• Reduced inventory and packaging obsolescence
• Faster time-to-market for promotional and seasonal campaigns
• Elimination of labels, adhesives and associated waste streams

For many brands, the ability to print only what is required, when it is required, reduces both operational risk and working capital while supporting more responsive supply chains. There is a growing popularity for reusable cup programmes, personalised beverage packaging and premium cosmetics decoration. All of these demonstrate how DTS printing is increasingly becoming a strategic marketing tool rather than simply a decoration process. 

“DTS digital printing is becoming an important manufacturing process”

UV inkjet has become the dominant technology for DTS applications. This is because it combines high image quality with immediate curing and excellent durability. Unlike solvent or water-based systems – relying on drying through evaporation – UV inks cure almost instantly when exposed to ultraviolet energy. As a result, a durable crosslinked polymer film is produced that can be handled immediately.

The advantages are significant. Instant curing enables higher production speeds, reduces manufacturing footprint and eliminates lengthy drying stages. The adoption of UV-LED curing has further accelerated growth. It offers lower energy consumption, reduced heat generation and longer operational life, compared with conventional mercury lamps. These attributes are particularly valuable when decorating heat-sensitive plastic substrates.

However, developing inks that perform reliably in industrial-inkjet systems comes with challenges and trade-offs. Inkjet printheads require precise viscosity control to generate consistently sized droplets at high frequencies. UV inks should be designed to remain sufficiently low in viscosity for jetting. At the same time, they still need to deliver the crosslink density needed for adhesion, chemical resistance and durability. Balancing these requirements is one of the most technically demanding aspects of UV ink development.

“DTS printing eliminates the need for labels, sleeves or traditional printing plates”

Metal containers typically incorporate protective coatings and undergo demanding downstream processes. These include filling, lidding, handling and transportation. The printed image must maintain adhesion while resisting scratching and mechanical damage. 

Glass presents a different challenge. Its smooth, chemically inert surface can make adhesion difficult. This is particularly the case in applications exposed to condensation, repeated handling or aggressive cleaning chemicals.

Rigid plastics introduce further complexity because material composition and surface energy can vary significantly. Polypropylene, polyethylene, PET and polycarbonate all behave differently during printing and curing. Therefore, surface preparation is often critical. Flame, corona and plasma treatment are frequently used to increase surface energy and improve ink wetting. In many cases, specialised primers are applied to create an optimised bonding layer between substrate and ink.

Geometry also creates challenges. Unlike flat-sheet printing, DTS systems must accurately place microscopic droplets onto curved, tapered or irregular surfaces. Maintaining image quality at production speeds requires highly accurate part handling, machine-vision systems and sophisticated software. Together they must be capable of compensating for object geometry and positioning tolerances.

One of the most important developments supporting growth in packaging applications has been the evolution of low migration UV-ink technology. Much of the adoption of DTS printing – in beverage-related applications – has coincided with advances in low migration, UV-ink systems. 

Traditional UV formulations often relied on relatively low molecular weight monomers and photoinitiators to achieve rapid curing. While effective from a processing perspective, these materials can potentially remain mobile if curing is incomplete.

Modern, low migration formulations are designed to minimise this risk through careful raw-material selection and curing optimisation. Higher molecular weight components, improved photoinitiator systems and enhanced curing efficiency help reduce residual extractable species. At the same time, they maintain the performance characteristics required for industrial production.

The challenge is that migration performance cannot be optimised in isolation. Increasing crosslink density may improve chemical resistance and migration properties, but can also increase brittleness. Conversely, increasing flexibility may reduce resistance performance. Successful DTS inks therefore require a carefully engineered balance between adhesion, flexibility, durability, cure response and regulatory compliance.

This balance is particularly important for reusable drinkware, beverage packaging and other applications. Demanding performance requirements must co-exist with increasingly stringent regulatory expectations. Low-migration technology has become a key enabler in these markets. 

While the ink is a critical part of the final printed item, the complete decoration system often depends on the interaction between primer, ink and topcoat varnish.

Primers promote adhesion on difficult substrates and help compensate for variations in surface chemistry. On glass, they enhance moisture resistance and bonding. 
On plastics, they can improve adhesion to low-surface-energy polymers. On metals, they contribute to durability during handling, filling and sterilisation processes.

Topcoat varnishes are equally important in many applications. Clear UV varnishes provide an additional protective layer that improves abrasion resistance, chemical resistance, lip-contact safety and long-term appearance retention.

In reusable cups and drinkware, varnishes are often used to improve wash resistance and to support lip contact where a separate lid is not part of the construction. In metal packaging, they protect graphics during transportation and filling, while enhancing gloss and visual impact. Premium packaging applications may also employ speciality varnishes to create matte, tactile or high-gloss finishes.

In some systems, the topcoat can also serve as an additional barrier layer, supporting overall migration performance and helping protect the printed image throughout the product lifecycle.

“UV inkjet has become the dominant technology for DTS applications”

Durability testing is essential before any DTS system can be commercially deployed. Cross-hatch adhesion testing remains a fundamental assessment, but it represents only one part of a comprehensive validation programme. Most applications also require abrasion testing, impact resistance evaluation and chemical resistance testing against substances such as ethanol, detergents and cleaning chemicals.

Together, these tests verify that the complete primer, ink and varnish system can withstand the real-world conditions encountered throughout manufacturing, distribution and consumer use.

DTS UV-inkjet printing is transforming the decoration of metal, glass and rigid plastic products. By combining mass customisation, rapid changeovers and inventory reduction with durable, high-quality graphics, DTS technology offers compelling benefits for both manufacturers and brand owners.

The success of these applications depends upon sophisticated engineering. This is essential from surface preparation and printhead technology to low migration UV formulations, specialised primers and protective topcoats. As these technologies continue to advance, DTS printing is increasingly positioned not merely as an alternative decoration process, but as a strategic platform for flexibility, sustainability and consumer engagement in modern packaging production.