Shanghai Huale Industrial

Designing Changeover Schedules for Mixed-Size Tube Filling Runs

Mixed-size tube filling runs are common where one production line serves several products, pack volumes, and customer channels. A 15 ml dermatological tube, a 50 ml toothpaste tube, and a 100 ml sunscreen tube may use the same filler, yet each format can require different tooling, dosing settings, sealing temperatures, coding positions, and inspection criteria.

A workable schedule must account for more than the time needed to exchange a set of format parts. Operators also need time to clean product-contact areas, confirm the correct laminate or plastic tube, load recipes, complete line clearance, and release the first acceptable packs. Treating these activities as a single generic “changeover” often creates unrealistic production plans.

Australian manufacturers face additional planning pressure. A contract packer supplying pharmacies in Melbourne may handle shorter campaigns than a high-volume producer serving supermarkets in Sydney. Seasonal demand for sunscreen before summer, increased cold and flu products during winter, and long freight routes to Perth or Darwin can all change the best sequence of tube sizes.

The most effective approach combines equipment knowledge with production data. It uses standard changeover windows, groups compatible products, protects quality checks, and leaves enough capacity for normal variation. The result is a schedule that supports reliable output without asking operators to rush safety, hygiene, or documentation.

Map the Sources of Changeover Time

The first step is to separate the elements that change from one format to another. Tube diameter and length may require new holders, star wheels, guides, crimping components, or sealing jaws. Fill volume can affect pump settings, piston stroke, dosing speed, and the time needed to stabilise the product feed. Closure style, shoulder shape, and cap geometry may introduce further adjustments.

Product differences can be just as important as pack dimensions. A pharmaceutical ointment may need careful temperature control and slower filling to prevent stringing, while a free-flowing cosmetic gel may run at a faster rate. Fragranced personal-care products can also require stronger cleaning and odour-control measures before the next SKU is introduced.

Record each activity with a start and finish point. “Change parts” is too broad to support a dependable schedule. Break it into format removal, cleaning, replacement, adjustment, dry cycling, trial filling, inspection, and quality approval. A line may be mechanically ready in 35 minutes but require another 25 minutes for documentation and first-off testing.

The schedule should also recognise downstream effects. A tube filler may restart before the cartoner, case packer, or palletiser is available. If operators have previously found recurring faults downstream, cartoning wear guidance can help connect packaging-line observations with the wider changeover plan. A short interruption at the filler can otherwise become a much longer stoppage across the complete line.

Build the Sequence Around Practical Constraints

Mixed-size production is usually easier when campaigns are sequenced by the amount of physical and hygienic disruption involved. Start by listing all orders, their due dates, estimated quantities, product families, tube specifications, and required cleaning levels. Then identify which jobs can follow each other with minor adjustments and which require a full strip-down.

A simple sequencing rule is to group the same tube diameter together, then arrange products within that group by formulation and fill volume. For example, several 30 mm tubes may run consecutively, with low-risk products scheduled before products that contain strong colours, oils, actives, or fragrances. This reduces unnecessary tooling changes and limits the number of intensive cleans.

Due dates still matter. A smaller order for a hospital supply contract may need to run before a larger retail order, even if the sequence is less efficient. Australian producers should also consider public holidays, carrier cut-off times, and regional distribution. A batch bound for Brisbane may have different dispatch priorities from stock being consolidated for Adelaide, especially when temperature-sensitive goods are involved.

Use a forward-looking schedule rather than filling every available minute. A practical plan includes time for line clearance, pre-start checks, QA sampling, minor faults, and material delivery. If a shift is planned at 100 per cent utilisation, one delayed component or missing batch record can push every later job into overtime.

Information to confirm before sequencing

Choose the Right Changeover Pattern

There is no single best method for every mixed-format line. The right choice depends on product risk, equipment design, operator capability, and the cost of lost production. Three common patterns are useful starting points for planning.

Scheduling approach Best fit Main advantage Main limitation
Same-size campaign Several SKUs share tube diameter and tooling Minimises mechanical adjustments May increase product or colour cleaning between jobs
Product-family campaign Products use similar formulations and hygiene controls Reduces cleaning risk and validation effort Can require extra format changes
Due-date priority Orders are arranged around customer or regulatory deadlines Protects urgent supply commitments Often creates more changeover time and lower line efficiency

Same-size campaigns are often effective for personal-care and over-the-counter products where the tube body and sealing arrangement remain consistent. Product-family campaigns may be preferable for pharmaceutical products with strict cleaning controls. Due-date priority should be reserved for genuine service, regulatory, or supply reasons rather than used as the default for every order.

A hybrid approach usually works best. The planner can first protect fixed dispatch commitments, then group the remaining work by tube size and product compatibility. For example, a Melbourne facility might schedule an urgent 50 ml medical cream, follow it with other 50 ml products requiring similar cleaning, and then move to larger sunscreen tubes before the summer campaign reaches its final dispatch window.

The planned sequence should be tested against real line data. Optical inspection, code verification, and reject trends can reveal whether a format change is truly minor. Suppliers of inspection technology, such as inline vision systems, can also help manufacturers understand whether cameras, lighting, and product presentation need separate settings for each tube size.

Standardise the Work Without Removing Judgement

A standard changeover method should define what happens before the line stops, while it is stopped, and before production is released. Preparation can include staging labelled tooling, checking seals and gaskets, verifying the recipe version, confirming cleaning materials, and printing the documents required for the batch. These tasks reduce idle time and prevent operators from searching for parts during the main changeover window.

The line stop should follow a clear order. Operators can remove remaining materials, isolate the equipment where required, carry out line clearance, clean product-contact components, install the new format parts, and complete mechanical checks. A second person should verify critical settings such as pump stroke, tube orientation, sealing temperature, coding position, and recipe selection.

First-off approval must be treated as part of the changeover rather than an optional extra. Run enough tubes to check fill weight, seal integrity, crimp quality, print legibility, cap fit, appearance, and reject operation. For regulated products, the QA process may also include documented reconciliation and sample retention. The schedule should show this time explicitly.

Training is important because a fast operator is not necessarily a consistent operator. Supervisors should observe whether staff recognise abnormal noise, product build-up, loose tooling, distorted seals, and repeated rejects. A changeover checklist can guide the process, but experienced operators still need authority to pause the line when a condition falls outside the approved range.

Use Visual Controls and Two-Level Checklists

Visual management makes the schedule easier to follow during a busy shift. A board or digital dashboard can show the current SKU, next SKU, format parts required, planned stop time, actual restart time, and release status. Colour coding may distinguish mechanical changes, cleaning tasks, QA checks, and material shortages.

The following controls are useful for every scheduled transition:

Checklists should be divided into operator and verifier responsibilities. The operator can confirm assembly, adjustment, and cleaning steps, while a trained verifier checks the points where a wrong setting could affect product quality or batch identity.

A second checklist can focus on restart and early-run performance:

This two-level system avoids a common weakness in paper-based procedures: recording that a task was completed without proving that the result was acceptable. It also gives planners better information when standard times need to be revised.

Measure the Schedule and Improve the Next Run

After each campaign, compare planned time with actual time for every stage. Useful measures include mechanical changeover duration, cleaning duration, first-off approval time, time to reach target speed, startup rejects, and unplanned stops during the first hour. Separating these figures shows whether the main problem is preparation, tooling, quality release, or machine stability.

A Pareto review can identify the few causes responsible for most lost time. Frequent examples include missing format parts, inaccurate recipe selection, waiting for QA, difficult-to-clean product residue, and adjustments to tube presentation. Each cause should have an owner and a practical corrective action, rather than being left as a general note to “improve efficiency”.

Schedules should also reflect the cost of campaign length. A very long run may reduce changeovers but create excessive finished-goods inventory, especially for products with short shelf life or uncertain demand. Short campaigns provide flexibility but can consume capacity through repeated cleaning and format replacement. The best balance depends on forecast confidence, order size, storage space, and customer service requirements.

For Australian operations, review the plan before seasonal peaks and distribution changes. A producer supplying sunscreen through New South Wales and Queensland may need longer campaigns before summer, while a pharmaceutical packer may prioritise secure availability for hospital orders. When a line audit or equipment discussion is needed, contact the machinery team with actual tube dimensions, products, target speeds, and recent changeover records.

A mature changeover schedule remains a living operating document. Update standard times after tooling modifications, new tube suppliers, recipe changes, or operator training. When planning is tied to measured performance, mixed-size tube filling runs become easier to control, easier to cost, and more dependable for customers across Australia.