Industry News

Flexo printing machine has become the preferred printing equipment for packaging in industries such as food packaging, pharmaceutical packaging, luxury packaging, beverage packaging, and personal care products, thanks to its high efficiency, eco-friendly performance, and high-quality printing. It delivers vivid colors and sharp graphics on kraft paper, coated paper, and corrugated paper. Common drying methods of flexographic printing machine include hot air drying, infrared drying, UV curing, and LED UV curing. Do you know how to choose the right one? Mengji will analyze them from four aspects: working principle, suitable materials, advantages and disadvantages, and selection logic.

Label Printing Machine for Beverage Labels

Hot Air Drying

Hot air drying uses high-speed air nozzles to blow heated air, removing moisture and solvents from the surface of the substrate, which are then exhausted through a ventilation system.

Suitable Materials

Hot air drying is ideal for printing paper and nonwoven products using water-based ink, such as paper cups, shopping bags, and medical masks, as well as film packaging using solvent-based ink, such as shrink sleeve labels and plastic film pouches.

Advantages and Disadvantages

Hot air drying offers strong versatility, low cost, mature technology, and easy maintenance. However, it also has drawbacks, including high energy consumption, risk of thermal deformation for films like fresh food packaging film and courier bags, and limitations in increasing printing speed.

Flexo Printing Machinery for Coffee Packaging Bags

Infrared Drying

Infrared drying uses infrared radiation to directly heat the ink layer. Moisture in the ink is absorbed first, accelerating the evaporation process.

Suitable Materials

Infrared drying is highly suitable for water-based inks, delivering excellent results on paper products such as coffee paper cups, ice cream paper bowls, and cigarette paper boxes. It is also commonly used as an auxiliary system for hot air drying.

Advantages and Disadvantages

Infrared drying features rapid heating and a compact footprint. However, it has limited penetration depth, and when used alone, it may cause uneven drying in thick ink layers. Therefore, it is often combined with hot air drying.

Flexographic Press for Beverage Paper Cups

UV Curing

UV curing uses ultraviolet light to activate photoinitiators, instantly polymerizing and curing the ink layer.

Suitable Materials

UV curing is highly suitable for UV inks, widely used for labels and flexible packaging such as wine labels, cosmetic labels, pharmaceutical labels, and barcode labels.

Advantages and Disadvantages

UV curing produces no VOC (Volatile Organic Compounds) emissions, delivers sharp dots and high print quality, and achieves instant curing speeds of 200–400 m/min. However, it has drawbacks, including short lamp lifespan, high energy consumption, potential heat impact on films, and ozone and UV radiation.

Flexo Press for Salad Paper Bowls

LED UV Curing

LED UV curing uses LED light sources with a narrow wavelength to cure specially formulated UV inks.

Suitable Materials

LED UV curing is suitable for films and heat-sensitive materials such as decorative film, thermal labels, and vacuum packaging film, as well as high-end labels and flexible packaging products like luxury labels, perfume labels, and jewelry labels.

Advantages and Disadvantages

LED UV curing offers low energy consumption, low heat output, no ozone emission, and long service life. However, it has higher ink costs and requires a higher initial equipment investment.

Flexographic Printer for Skincare Labels

Selection Logic

In flexographic printing machine production lines, drying systems are often used in combination. Hot air + infrared improves drying efficiency for water-based inks, ideal for paper bags, fast food packaging paper, chocolate wrapping paper and burger wrapping paper. Hot air + UV is suitable for products using solvent-based inks for base colors and UV coating on the surface. UV + LED hybrid systems balance high speed and energy savings. Multi-stage hot air drying by color separation helps prevent ink set-off and smudging.

Flexography Machine for Reusable Shopping Bags

Material Heat Resistance

PE and PP products such as hygiene packaging film, disposable packaging bags, and biscuit packaging film are prone to deformation, so LED UV curing or low-temperature hot air drying is recommended.

PET products such as waterproof labels, skincare labels, and barrier film have better heat resistance, making UV curing or hot air drying suitable choices.

Paper products like bakery packaging paper, paper plates, and sandwich wrapping paper have no strict temperature limitations, so hot air drying or infrared drying can be used.

Nonwoven products such as wet wipes, nonwoven shopping bags, and isolation gowns tend to shrink when exposed to heat, so LED UV curing is the preferred option.

Flexographic Machine for Vitamin Labels

Printing Speed Target

If the target printing speed of the flexographic printing machine is ≤100 m/min, choose hot air drying. For speeds between 100–200 m/min, select hot air + infrared drying. For speeds ≥200 m/min, choose UV curing or LED UV curing.

Product Added Value

For low value-added packaging such as garbage bags and kraft paper bags, choose hot air drying.

For mid-range products such as chocolate packaging boxes and zip lock food bags, select optimized hot air drying or LED UV curing.

For high-end products such as shampoo bottle labels, skincare labels, and whiskey labels, choose UV curing or LED UV curing.

Energy Consumption and Long-Term Cost

Hot air drying has a low initial equipment cost but high long-term electricity consumption. UV drying consumes a large amount of energy and also involves lamp replacement costs. LED UV curing requires a higher initial investment but offers the lowest long-term operating cost.

Flexo Printer for Medical Mask Pouches

Today, flexo printing machines are widely favored by manufacturers of ice cream paper cups, pet food paper bags, adult baby diapers, and QR code labels. By considering factors such as material heat resistance, target printing speed, product added value, and energy consumption with long-term cost, and by properly combining hot air drying, infrared drying, UV curing, and LED UV curing, it is possible to improve print quality while maximizing efficiency, supporting brand building and upgrading.