Industrial processes

Process by which variable or static information is generated and applied directly onto a packaging material, packaging component, or product surface using non‑contact or contact marking technologies such as inkjet, laser, thermal transfer, or embossing.

Creasing is the formation of a groove in paperboard by compression between tools, intended to facilitate folding without surface rupture.

During the operation, the paperboard is weakened along well-defined lines that then act as hinges for folding, since attempting to fold uncreased paperboard typically causes the surface plies to crack or the fold line to remain undefined. The crease is formed using a creasing rule, a thin steel strip with a round, smooth edge, which presses the paperboard into a matching groove cut into a make-ready (also called matrix or counter-die) positioned beneath it, producing a permanent deformation. The relationship between the crease's width and depth is critical to quality: a crease that is too shallow or wide makes folding difficult, while a deeper, narrower crease generally produces a cleaner, lower-resistance fold.

Grammage also affects the process: thin papers (below roughly 180 g/m²) are often folded without any surface preparation, whereas heavier paperboard (above roughly 600 g/m²) typically requires multiple creases or scoring prior to folding.

Extrusion coating is a process whereby molten plastic is applied to a thin substrate (paperboard, paper, plastic film, aluminium foil etc.) and subsequently chilled to form an extremely thin, smooth layer of uniform thickness.

The molten plastic can be used as an adhesive to laminate a plastic film or a metal foil.

In addition to lamination, extrusion coating is mainly used to provide protection against moisture, act as a barrier to gases (water vapour, oxygen, aromas, etc.), offer grease resistance, ensure heat-sealability and create an attractive appearance (glossy surfaces).

The process is carried out by extruding the molten polymer through a flat slot die directly onto the moving substrate, which is then pressed against a chill roll to rapidly cool and solidify the coating while defining its surface finish.

Low-density polyethylene (LDPE) is the most commonly used resin due to its good adhesion, sealability and processability, although other polymers such as polypropylene (PP) or ethylene vinyl acetate (EVA) can be used to achieve specific barrier or performance properties.

Because the coating is formed directly on the substrate in a single continuous pass, extrusion coating is typically faster and more cost-effective than conventional adhesive lamination for high-volume applications.

Filling is the packaging operation by which a liquid, semi-liquid, powdered, particulate or solid product is transferred with precision into the final container, such as bottles, sachets, jars, tins or bags. The process must ensure control, consistency, safety and quality preservation, preparing the packaging for the subsequent stages of sealing, handling and distribution.

Folding‑gluing is the converting process that transforms a flat, die‑cut, and pre‑creased carton blank into a finished folding carton by folding its panels along defined creases and bonding them with adhesive (typically hot‑melt or cold glue) in a continuous inline operation.

Blanks are fed individually into the machine and precisely aligned before critical creases are pre‑broken, or pre‑folded, to a partial angle in order to condition the board and ensure reliable, high‑speed folding downstream.

Adhesive is then applied to defined glue flaps in a precise pattern synchronized with blank position and machine speed, after which the panels and flaps are folded into their final position through a sequence of belts, rails, hooks and guides, bringing the glued surfaces into contact.

The folded cartons subsequently pass through a compression section that maintains pressure for a defined time to allow the adhesive to set and reach adequate bond strength before being discharged.

Finished cartons are then counted, formed into shingled streams or bundles, and made ready for packing, palletizing or direct feeding to downstream cartoning or case-packing equipment.

Form-fill-seal (FFS) is a process in which a flexible packaging stock is fed from a roll. The stock is folded to the desired package shape and stabilized by heat sealing. The product is placed into the formed package, and the remaining opening is sealed. Machines can be configured so that the stock travels horizontally through the machine (horizontal form-fill-seal) or vertically through the machine (vertical form-fill-seal)

Because forming, filling and sealing are carried out in a single continuous, integrated operation, FFS eliminates the need for pre-made packages, reducing material handling, storage space and overall packaging costs.

The process is compatible with a wide range of flexible materials, including plastic films, laminates and paper-based structures, allowing package properties such as barrier performance, printability and seal integrity to be tailored to the specific product.

FFS technology is widely used across the food, pharmaceutical, personal care and industrial sectors to package solid, liquid, powder or granular products into formats such as pouches, bags and sachets.

Heat sealing is the process of joining thermoplastic films by the application of heat and pressure for a specific period of time, causing the surfaces to soften or melt and fuse together into a continuous bond.

In-line digital printing in packaging is a process where digital printing units (i.e. inkjet printers) are integrated directly into the production or filling line. This allows for "just-in-time" printing of text, graphics, and variable data onto packaging materials as they move through the line, rather than using pre-printed stock.

Several digital printing technologies can be used depending on speed, resolution and substrate requirements, including continuous inkjet (CIJ) for high-speed coding, thermal inkjet (TIJ) and drop-on-demand (DOD) piezo inkjet for higher-quality text and graphics, and laser marking for permanent, contactless coding.

This approach enables late-stage customization, allowing the same packaging line to produce multiple product variants, languages or regional formulations without changeovers or the need for dedicated pre-printed stock.

Typical applications include printing batch numbers, expiry dates, barcodes and serialization codes for traceability and regulatory compliance, as well as region-specific text, promotional messages and personalized or sequential variable data. 

Induction sealing is a non‑contact process in which an alternating electromagnetic field induces eddy currents in a conductive layer, generating localized heat that activates a thermoplastic material. The softened polymer bonds to an adjacent substrate, producing a hermetic seal.

Because heat is generated directly within the foil rather than transferred through heated sealing bars and multiple material layers, the sealing temperature is reached almost instantly, giving the process very low thermal inertia

The process requires a metallic layer, typically aluminium foil, within the packaging structure: without it, no heating and no sealing can occur. As packaging shifts toward mono-material, recyclable structures, aluminium is being phased out of many laminates, so induction sealing will likely remain mainstream mainly in niche sectors such as pharma, where the foil also serves other functions (barrier, tamper-evidence) justifying its retention. 

Lamination process consists of bonding together two or more films of different materials (i.e. Al/Paper,  Al/Plastic, Plastic/Paper etc.).

By combining materials with complementary properties, lamination allows the resulting structure to achieve barrier performance, mechanical strength, printability and sealability that none of the individual layers could provide on their own, making it a key process for producing high-performance flexible packaging.

Several technologies can be used to bond the layers together, including

adhesive lamination, in which a wet or solvent-based adhesive is coated onto one substrate before the layers are pressed together and cured;

extrusion lamination, in which a molten polymer is extruded directly between the two substrates, acting simultaneously as the bonding layer;

and thermal lamination, in which heat and pressure are applied to activate a heat-sealable coating already present on one of the substrates, without the addition of a separate adhesive.

Sealing is a general term describing the process of joining two or more layers of packaging material by applying energy (typically in the form of heat) together with pressure for a defined period of time, without the addition of external materials such as adhesives. The specific energy source used to generate the heat (i.e. a heated bar, an electrical impulse, ultrasonic vibration, an induced electromagnetic field or a radio-frequency field) depends on the sealing technology employed, but the underlying process sequence remains consistent across methods:

Position & Align: the materials to be sealed are positioned and aligned by the handling system to ensure correct registration of the sealing area.

Apply Pressure & Activate Energy: the sealing tool applies a targeted force to the aligned layers while the energy source is activated, softening or melting the material at the interface.

Maintain Dwell: pressure is held for a defined dwell time, allowing the softened material at the interface to interpenetrate, forming a continuous bond as it consolidates.

Cool & Release: the energy source is deactivated, the joint is allowed to cool (or is actively cooled) under pressure to stabilize the bond, and the tool then opens to release the sealed package.