Shrink wrapping can provide a clear retail finish, group products into multipacks or add protection for storage and transport. The right result depends on more than buying a sealer and applying heat: the machine, film, product and required output must work as one system.

Severn Packaging’s shrink-wrapping range covers compact chamber machines, semi-automatic L-sealers and tunnels, automatic continuous sealers, sleeve wrappers and shrink tunnels. This breadth allows the equipment to be selected around the application rather than forcing every product through one machine format.

Start with the pack—not the machine

Before comparing models, define what the finished pack must achieve. A presentation pack around a printed retail box has different requirements from a collated tray of bottles or a large industrial product.

• What are the minimum and maximum product dimensions?
• Is the product stable, fragile, heat-sensitive or irregularly shaped?
• Is the aim presentation, protection, tamper evidence or collation?
• Which film type is expected: POF, PE or another compatible material?
• What sustained output is required—not just the fastest theoretical cycle?
• Will the machine operate independently or connect to an existing line?
• How much operator involvement and changeover flexibility is acceptable?

The main types of shrink-wrapping machine

Hooded chamber machines

A hooded chamber machine combines sealing and shrinking in one compact unit. The operator positions the product in film, closes the hood and the machine completes the seal-and-shrink cycle.

This format is well suited to lower-volume work, varied products and operations where floorspace and simplicity are important. It is less suitable when the process must deliver continuous high output or integrate directly into an automated line.

Semi-automatic L-sealers

An L-sealer creates seals along two sides of a centre-folded film. Semi-automatic systems increase consistency and reduce manual handling while retaining operator flexibility. They can be used as standalone sealers or paired with a shrink tunnel.

An L-sealer and tunnel combination separates the sealing and shrinking stages. This provides greater process control and can support higher, more repeatable output than a single chamber machine.

Automatic continuous side sealers

Continuous side-sealing machines are designed for automated production. Product length is not constrained by a conventional fixed L-seal, making this format useful for varied or longer packs. Servo-driven sealing, product detection and stored parameters can support fast changeovers and consistent operation.

The supplied machinery catalogue includes automatic systems with adjustable conveyors and multiple machine widths. Published maximum cycle figures are always subject to product dimensions, film type and configuration, so real output should be established using representative products.

Continuous-motion high-speed sealers

Where throughput is the dominant requirement, a continuous-motion sealer can maintain product flow while forming the pack. These systems require careful product spacing, film selection and line integration. They are most effective when upstream feeding and downstream shrinking can support the same sustained rate.

PE sleeve wrappers

Sleeve wrappers apply PE film around grouped or larger products, often for transport protection or multipack collation. Semi-automatic and fully automatic formats are available, including inline feeding and collation arrangements.

Because the film forms a sleeve rather than a fully enclosed presentation pack, the result and material requirements differ from POF shrink wrapping. Product stability and the opening orientation should be reviewed during trials.

Shrink tunnels

The tunnel is central to the quality of the finished pack. Controlled heat and airflow shrink the film after sealing. Tunnel dimensions, conveyor arrangement, temperature stability and airflow should be matched to the product and film.

A larger or more powerful tunnel is not automatically better. The objective is even, controllable shrink at the required line speed without unnecessary heat exposure or energy use.

Six decisions that shape the specification

1. Product size range

Specify the smallest and largest products expected on the machine. A system selected only around today’s largest product may be inefficient on smaller packs; a machine selected too narrowly can restrict future work.

2. Throughput and labour

Measure current sustained output, operator time and peak demand. Automation should address a real constraint. A compact semi-automatic system may be the right answer for frequent changeovers, while a continuous line is more appropriate when products and flow are consistent.

3. Film compatibility

Confirm the machine’s approved film types, thickness range, maximum width and roll diameter. The same film description can perform differently across sealing systems, so trials should use the intended production specification.

4. Seal and finished-pack quality

Define acceptable seal strength, excess film, corner appearance and shrink finish. These standards should be practical and repeatable, not based on a single carefully prepared sample.

5. Utilities and layout

Check electrical supply, compressed-air requirements, heat management, access, conveyor height and maintenance space. Include infeed and outfeed accumulation in the layout rather than measuring only the machine body.

6. Integration and future growth

If the machine may later connect to automatic feeding, labelling or inspection, plan the controls and conveyor interfaces early. Stored product recipes and adjustable settings can also reduce changeover time as the product range expands.

Why the film and machinery should be trialled together

A machine demonstration using a convenient film may not represent the production result. The most useful trial uses representative products and the intended film specification, then records line speed, sealing, tunnel settings and finished-pack quality.

The trial should also include awkward products, changeovers and realistic operator handling. This reveals whether the system is reliable outside the easiest demonstration pack.

Common selection mistakes

• Buying around a headline maximum speed rather than sustained output with the real product.
• Ignoring the smallest product and focusing only on maximum machine dimensions.
• Treating the shrink tunnel as a standard accessory rather than part of the process.
• Choosing film after the machine without validating the two together.
• Forgetting infeed, outfeed, operator access and maintenance space in the layout.
• Automating an unstable upstream process and transferring the bottleneck elsewhere.

Frequently asked questions

What is the difference between a chamber machine and an L-sealer with tunnel?

A chamber machine seals and shrinks in one enclosure and is typically compact and operator-led. An L-sealer and tunnel separate the processes, supporting more controlled and repeatable production at higher volumes.

When should I use a sleeve wrapper?

Sleeve wrappers are commonly used for PE collation packs, grouped products and larger industrial applications. They are a different format from fully enclosed POF presentation packs.

How fast is an automatic shrink-wrapping machine?

Speed depends on the machine, product dimensions, film, spacing and tunnel. Catalogue maximums are useful for initial comparison but should not replace a representative production trial.

Can a shrink wrapper integrate with an existing line?

Yes. Automatic systems can be configured for inline operation, but conveyor heights, controls, product spacing, guarding and upstream and downstream capacity must be reviewed together.

Build the right shrink process

The best shrink-wrapping machine is the one that produces the required pack consistently at the real operating rate. That requires a clear product brief, compatible film, an appropriate sealing method and a correctly specified tunnel.

Severn Packaging can assess products, output, layout and film requirements before recommending a shrink-wrapping system. Contact our team to discuss chamber machines, L-sealers, automatic continuous systems, sleeve wrappers, tunnels and matched shrink film.