When brand owners design custom flexible packaging, their focus is usually on shelf appeal. They spend weeks choosing colors, refining the logo, and selecting the perfect finish. But there is a critical factor that is often overlooked until it is too late: machineability.
Machineability refers to how well a packaging structure performs on an automated filling line. If a pouch is difficult to open, doesn’t fit the filling nozzles, or slips on the conveyor belts, the entire production line can grind to a halt. A jammed line costs money. It wastes materials, delays shipments, and frustrates the production team.
This article explores the hidden factors that affect machineability and what brand owners need to know to ensure their packaging design does not become a production bottleneck.
The Invisible Forces: Friction and Stiffness
Two of the biggest culprits behind machineability issues are friction and stiffness. Both are determined by the packaging material structure.
Flexible packaging needs a certain amount of stiffness to stand upright and feed cleanly into the filling machine’s grippers. If the film is too soft or flimsy, the pouch may buckle, causing the machine to misfeed it. This is why many high-speed filling lines require a minimum material thickness or a specific lamination structure to provide adequate structural integrity.
Conversely, friction, specifically the coefficient of friction (COF), affects how the packaging slides against the machine’s metal parts and against other packages. If the COF is too high, the pouches will stick together, leading to misfeeds. If the COF is too low, the pouches will slide around and may not be positioned accurately. The outer layer of the packaging film must have a carefully calibrated COF to work seamlessly with your specific filling equipment.
Design Features That Hinder Automation
Beyond the material properties, the physical design of the pouch itself plays a massive role in machineability.
The placement of the zipper is a common design flaw. If the zipper is placed too close to the top seal, the filling machine may struggle to open the pouch wide enough to insert the filling nozzle. Similarly, if the zipper is too thick, it can interfere with the sealing jaws.
Another issue is the shape of the seal. While unique, curved seal shapes can be difficult for standard filling machines to handle. V-shaped or rounded bottom seals are generally more machine-friendly than sharp angles.
Even the artwork can affect machineability. If the print registration marks (the small eye-marks used by the machine’s sensors to cut and seal the bags) are obscured by dark ink or placed on a highly reflective surface, the machine’s optical sensors may fail to read them. This causes the machine to cut the bags in the wrong place.
How to Ensure Your Packaging is Machine-Ready
The key to avoiding these issues is early and clear communication with your packaging manufacturer.
First, provide the exact specifications of your filling equipment. The manufacturer needs to know the model, the type of grippers, the nozzle size, and the sealing jaw configuration. With this information, they can recommend a material structure and design that is optimized for your specific machine.
Second, request a “run trial” or machine trial. Before mass production, ask the supplier to produce a small batch of finished bags and run them through your actual filling line. This is the only way to guarantee that the packaging will perform as expected. If you cannot run a full trial, at least request a sample roll of the material to test the film’s COF and feeding characteristics.
Third, use standard eye-mark placement. Unless your machine requires something custom, stick to standard registration mark placements that are easily readable by optical sensors.
The most beautiful packaging in the world is worthless if you cannot fill it efficiently. By prioritizing machineability during the design phase, brand owners can avoid costly downtime and ensure their products reach the market smoothly.