What a Turnkey Packaging Line Actually Includes
The definition of “turnkey” varies significantly between suppliers. A minimum definition includes the filling machine and a bag sealer connected by a conveyor. A full definition includes:
| Station | Function | Common Specification Gaps |
|---|---|---|
| Product infeed / silo | Stores and feeds bulk product to the filler | Silo capacity often undersized — should hold at least 4 hours of production to allow bag changes and refills without stopping the line |
| Filler / bagging scale | Weighs and fills bags to target weight | Throughput quoted on ideal product; confirm on actual product at actual ambient temperature |
| Bag placer / magazine | Feeds empty bags to the fill head automatically | Magazine capacity — how many bags before refill? 100-bag capacity means refilling every 10–15 minutes on a fast line; undersized magazines are a common throughput bottleneck |
| Inline checkweigher | Weighs each filled bag; rejects out-of-spec bags | Often omitted from base quotes to reduce price; should be treated as mandatory for declared-weight products |
| Bag sealer (heat seal or stitcher) | Closes the filled bag | Sealer speed is frequently the line bottleneck — confirm it matches filler throughput at your bag width |
| Labeller / printer | Applies batch code, weight, date | Print speed and label application speed must match conveyor speed; inkjet vs. thermal transfer vs. label applicator each has different uptime characteristics |
| Palletiser | Stacks filled bags onto pallets | Robotic vs. conventional palletiser: robotic handles more SKUs but costs 2–3× more; conventional is faster for a single bag size |
| Pallet wrapper | Wraps the completed pallet in stretch film | Wrap cycle time (60–120 seconds) must fit within the time to complete one full pallet layer |
When requesting a turnkey quote, specify which of these stations you need included. “Turnkey” without a defined scope produces quotes that are incomparable — one supplier includes everything above; another includes only the filler and sealer. Price comparison between the two is meaningless without the scope alignment.
The Throughput Bottleneck Problem
A turnkey packaging line runs at the speed of its slowest station. This sounds obvious, but it is regularly ignored in line specification — each station is specified to meet the target throughput, but the practical throughput of each station under real conditions is not equal to its rated throughput, and the margins are not equal.
A worked example: a target throughput of 400 bags per hour of 25 kg flour.
- Filler: rated at 480 bags/hour on free-flowing granule; on flour with agitator, realistic rate is 380 bags/hour
- Checkweigher: rated at 600 bags/hour; realistic rate at 25 kg bag weight and ±50 g tolerance: 520 bags/hour
- Sealer (stitcher): rated at 500 bags/hour; on a 500 mm wide bag with double stitching: 360 bags/hour
- Palletiser: rated at 600 bags/hour; with a 5-bag layer and manual pallet change: 380 bags/hour
The binding constraint in this example is the sealer at 360 bags/hour — 10% below the target. The fix is either a wider-throat stitcher or a single-stitch configuration. If this constraint is not identified before the line is ordered, it shows up at commissioning — where changing the sealer is a 6–8 week lead time problem.
The lesson: when reviewing a turnkey packaging line proposal, ask for the throughput figure of each station at your specific bag dimensions, product and fill weight — not the rated maximum of the station in isolation.
Single-Supplier vs. Multi-Supplier Integration
The advantage of a single-supplier turnkey line is a single PLC with all stations on one control network — one HMI, one alarm list, one support contract. The disadvantage is that no single supplier makes the best equipment in every station category. A supplier whose filler is excellent may use an average checkweigher and an undersized palletiser to complete the line scope.
A multi-supplier approach — best-in-class equipment at each station, integrated by a system integrator — gives better equipment but creates integration risk: who is responsible when the checkweigher and the palletiser communicate incorrectly? The answer to this question must be contractually defined before the equipment is ordered, not after the problem occurs at commissioning.
For most standard packaging applications (food, chemical, agricultural products), a single-supplier turnkey line from an established manufacturer is the lower-risk choice. For highly specific applications — pharmaceutical cleanroom, ATEX Zone 1, multi-product lines with rapid changeover — multi-supplier with a dedicated integrator is often necessary because no single turnkey supplier covers all the requirements.
Commissioning Risk: Where Turnkey Lines Run Late
Turnkey packaging line commissioning runs late more often than not. The three most common causes:
Site not ready. Utility connections (compressed air, electrical supply, drainage), foundation bolts and floor anchors, and access routes for equipment delivery are often not complete when the equipment arrives. Every day of site-related delay pushes commissioning back and — on fixed-price commissioning contracts — creates a cost dispute. Prepare a detailed site readiness checklist against the machine supplier’s installation requirements, signed off by your facilities team 4 weeks before the scheduled delivery date.
Product trials at commissioning. Running your actual product on the line for the first time at commissioning is the wrong time to discover that the product bridges in the bag magazine, or that the bag sealer temperature needs adjustment for your specific bag film. Product trials should happen at the factory — either a factory acceptance test (FAT) with your product and bags, or a series of sample bags run on a test machine. FAT adds cost; line commissioning delays cost more.
Spare parts not on site. A commissioning failure caused by a pneumatic fitting or a proximity sensor can halt commissioning for days if the spare part is not on site. Request a recommended commissioning spare parts kit from the supplier and have it delivered with the machine.
Frequently Asked Questions
What is the difference between a turnkey packaging line and an automatic packaging line?
An automatic packaging line refers to the automation level of the line — machines operate without continuous operator intervention. A “turnkey” packaging line refers to the procurement model — one supplier delivers a complete, integrated system ready to operate. A turnkey line is usually automatic; an automatic line is not necessarily turnkey (you might have purchased the stations from different suppliers and integrated them yourself).
How long does it take to commission a turnkey packaging line?
For a standard line (filler, checkweigher, sealer, palletiser): 5–15 days on a prepared site. A full line including silo installation, conveyor integration and automated pallet wrapping: 3–6 weeks. Pharmaceutical or ATEX-rated lines with validation requirements: 8–16 weeks including IQ/OQ documentation. These timelines assume a factory acceptance test has been completed before shipment — add 50–100% to these figures for lines shipped without FAT.
Can a turnkey packaging line handle multiple bag sizes or products?
Yes, but the changeover time between products or bag sizes is a specification parameter that most buyers do not confirm until after purchase. A “flexible” line that handles 10 kg to 50 kg bags may require 45–90 minutes of changeover including mechanical adjustment, product purging and fill accuracy recalibration. If you run multiple SKUs daily, this changeover time directly reduces productive capacity. Confirm changeover time for your specific size/product range — not the theoretical minimum — before accepting the line specification.