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Shrink Wrapping Machines:

What You Need to Know

By: Michael Gertin

A shrink wrapping machine provides a fast and effective solution for securing pallets and protecting inventory. With an outer layer of plastic, you hold the load together and prevent damage to the items inside.

If you are moving a lot of inventory through a warehouse, then a shrink wrapping machine can be an excellent investment. This equipment is efficient and cost-effective, helping to optimize the productivity of your team, save costs on material waste, and ensure a safe and secure load.

What is Shrink Wrap?

Shrink wrap, sometimes known as shrink film, is a thin, often-transparent polymer material. Individual items can be shrink-wrapped to hold objects in place and ensure they’re ready for shipment or movement within a warehouse. More commonly, however, companies use large shrink wrapping machines to secure a number of individual items to a pallet.

The plastic film is placed in the desired location on the product. Then, the shrink wrapper applies heat, causing the film to shrink tightly around the item inside. The heat causes a change in the molecules of the shrink film sheet. When it cools, these molecular characteristics are set, so the plastic stays in this stretched state.

The final result: a durable, clear layer of plastic protection around a single or set of stacked items.

Types of Shrink Wrapping Machines

Various machinery has been developed to make it easier for users to apply shrink wrap. Since there isn’t a one-size-fits-all solution, it’s essential to learn about your options before investing in a shrink wrapping machine. In a warehouse setting, large machines offer automatic, semi-automatic, and rotary arm features:

Automatic Shrink Wrappers

The benefit of an automatic machine is that the shrink wrapper can run independently, without an operator intervening with each cycle. The most advanced and innovative of these these automatic machines include conveyor belts that move the pallet into position, and then the shrink wrapper begins wrapping automatically.

Many automatic wrappers have the ability to customize each wrap using sensors to determine the height and weight of each load. After the film is cut and sealed, conveyorized wrappers will move the pallet so other loads can enter the wrapping cycle; non-conveyorized automatic wrappers require an operator using a forklift to move the load and place a new one. Businesses that move high volumes of pallets each hour benefit most from these automated features.

Wulftec WCA Twin

The WCA-Twin is an example of a conveyorized automatic shrink wrapper, offering up to 100 loads per hour.

Semi-Automatic Shrink Wrappers

Semi-automatic functions require an operator to run the machine and are an excellent solution for medium to low-volume applications. The operator places a pallet load on the shrink wrapper and positions the shrink wrap film tail for the process to initiate.

Then, the machine's automated features take over to wrap the plastic film on the pallet load. The operator must remove the pallet to make space for the next load.

Rotary Arm Shrink Wrappers

A rotary arm machine is a type of automatic shrink wrapper. Since the arm moves around the pallet, it eliminates the need to rotate the pallet during wrapping. In addition, because the load itself sits on the floor and not on top of a turntable, there is virtually no limit to the weight of the load that can be wrapped by a rotary arm shrink wrapper. Rotary arm machines are preferred for unstable or heavy loads and are commonly used on packing lines.

Wulftec WRTA 150

Rotary arm shrink wrappers, like the WRTA-150 pictured here, have no weight limits as the load sits on the ground while the arm travels around the item or pallet.

Specifications to Consider

Learning about the functions and features of shrink wrap machinery is an essential step before you purchase equipment for your warehouse. As you compare these specifications, you can find the optimal systems to accommodate your standard workflow.

Production Rate

How many loads are you moving through the line each hour? Your production rate is a good indicator to help you determine the type of stretch wrapper you need. Keep in mind that fully automated machines tend to be more expensive compared to semi-automated stretch wrappers. These automated features require more moving parts and equipment to achieve maximum efficiency.

But the investment in an automated shrink wrapping machine is worth the cost when you are moving a lot of product. Small- to mid-production might be better suited with a cheaper, semi-automatic shrink wrapping system. Investing in a semi-automatic shrink wrapper is recommended if you expect to wrap 10 to 20 loads per hour on a single machine.

Weight Capacity

Consider the weight of your load to ensure the conveyor belt and/or turntable can handle each pallet. Both automated and semi-automated equipment can handle heavy loads, but you’ll need to check the machine specifications to ensure the shrink wrapper can meet the daily demands. If the product(s) you’re wrapping are very heavy, then consider a rotary-arm shrink wrapping machine as these do not have weight limits.

Maximum Load Size

Automated features are ideal for companies with limited products and large runs of these goods. When there is consistency and repeatability in the load size, then your organization can really capitalize on the speed and efficiency of an automated shrink wrapper.

On the other hand, varying runs and different configurations makes it more expensive to automate the system. Some automated machines require downtime and operator involvement for changeovers when load sizes vary drastically. So, semi-automatic might be a better solution for those with small runs and/or varying pallets sizes.

Pneumatic and Electrical Requirements

shrink wrapped pallet

Finally, you will need to make sure your warehouse is equipped with sufficient electrical connections and air compressors to run the machinery. Electric stretch wrappers tend to be a bit cheaper compared to wrappers with pneumatic features. Since the machine runs on electricity alone, you don’t need an air compressor to run the equipment.

Pneumatic stretch wrappers must have industrial-level air compressors to run. This compressed air powers the clamps that power different parts of the machine, such as the top platens (for load stabilization) and power clamps for grabbing the film. While these machines are often more expensive, they also offer greater strength and capacity for heavy or oversized loads.

Regardless of your needs, be sure to check the electrical and pneumatic requirements before making a purchasing decision.

Investing in a Shrink Wrapping Machine

When you are ready to optimize productivity and improve your warehouse systems, then a shrink wrapping machine can be a great investment. This durable equipment can last for years, giving you a long-lasting solution for securing pallets and protecting inventory, which will result in a high ROI as time goes on.

Our team at Gertex Solutions provides the hands-on support you need when designing the optimal fulfillment strategies for your business. Not only do we offer a variety of shrink wrappers, but we also have all the shipping materials you require to run said machines.

We specialize in packaging automation to help your shipping management. If you’d like to learn more about this equipment, then contact us to schedule a free consultation.

Michael Gertin