What is Flow Wrapping – Ultimate Guide
Flow wrapping is one of the most common packaging methods used by large companies and small start-ups. Due to its popularity, many people often wonder about how flow wrappers work and their benefits.
This post explains all the details of flow wrapping and how it compares against other packaging methods like overwrapping.
What is Flow Wrapping?
Flow wrapping is a packaging process where a product is placed on a polypropylene or polyethylene sheet, moved horizontally, and sealed at both ends.
The most common type is a horizontal flow wrapper. This process is also called horizontal bagging, fin seal wrapping, crimp seal wrapping, and pillow pouch wrapping.
In vertical form fill seal packaging, the movement of products is vertical not horizontal.
How Does Flow Wrapping Work?
The entire process of flow wrapping is accomplished with a flow wrapper machine. This machinery carries out various steps to produce a flow-wrapped product:
- Step 1: Pick and place products on a conveyor belt.
- Step 2: Move the products on the conveyor belt to the forming zone.
- Step 3: Package the product with automatically or manually-fed sealing film.
- Step 4: Align the sealing film edges.
- Step 5: Seal the aligned edges by applying heat and/or pressure.
- Step 6: Move the sealed product to a cutter to create incisions between two consecutive sealed items to separate them.
- Step 7: Offload the final flow-wrapped package from the machine to the output/storage area.
How Long Does a Flow Wrapping Process Take?
The speed of flow wrapping varies significantly based on the machine, packaging size, and other factors.
Lower-end flow wrapping machines commonly have working speeds of 50 to 150 packages per minute. High-end, high-speed flow wrapping machines with speeds of 300 to 1500 packages per minute are usual for packing large quantities of products.
How Much Does Flow Wrapping Cost?
Like the speed of a flow wrapping machine, the cost can also vary significantly depending on the specific flow wrap machine, model, and features.
The cost of a flow wrapper suitable for small start-ups might be $20,000 to $150,000 – depending on requirements. The main expense in the flow wrapping process is the machine itself. The cost of the flow wrapping material, typically a polypropylene film, is negligible in the packaging process.
What are the Benefits of Flow Wrapping?
Flow wrapping has many benefits, a few of which are:
Flow wrap packaging can be used on a wide range of products. For example, medical devices, baked goods, and other food products. Unlike overwrapping, it has no limitations on the shapes of manufactured items.
Flow wrapping is an airtight form of packaging. Removal of oxygen protects the product from contact with moisture and any form of airborne contamination, such as dust. This also helps preserve shelf life and better freshness.
Compatibility With Other Machines
Horizontal flow wrappers or horizontal bagging stations can be seamlessly installed in a food processing setup. It is easy to use other technologies with flow wrapping machines to increase the quality of the final packaging.
The film used in flow wrapping can be transparent or printed. Many brands choose to design printed bags or wrappers using a film that includes the brand name, artwork, and information to make the most out of the space.
What are the Applications and Uses of Flow Wrapping?
Flow wrapping solutions are used for the packaging of solid products. Liquid items aren’t suitable for this process.
The most common applications of flow wrapping machines are biscuits and cookies, chocolate bars, candy bars, packs of tissues, frozen meats, boxes of tea, and baked goods. Flow wrapping is also used for packing high-hygiene requirement products such as medicines and lipsticks.
What are the Different Flow Wrapping Machines?
Due to the demand in the industry, there are many types of flow wrapping machines. PWR provides some of the best flow wrapping integration solutions for horizontal form fill and seal machines. PWR packaging solutions are the industry gold standard chosen by customers looking for the most value for money.
What makes a PWR better than other alternatives?
- HMI 4.0 – a feature-loaded touch screen display gives the operator user-friendly control over the operation.
- Integration options such as Clear Vision 4.0 to scan packaged products to ensure consistent quality.
- Smart Control 4.0 – provides options to reject any defective products and remove them from the packing line.
- Solutions tailored to meet the design of the current packing line setup.
What are the Most Common Materials Used For Flow Wrapping?
Flow wrapping uses a variety of film materials to wrap different food products. The specific film to use depends on the food product being packed.
Heat Sealing Film
Heat sealing uses a film, typically Polyethylene (PE). The seals on the ends are created by applying heat and pressure, resulting in a sealed bag/pouch or wrapper. This is the cheapest option for creating flow wrappers to package food products. Differences in films require the optimal temperature for the type of film used for flow wrapping.
Cold Sealing Film
Cold sealing is suitable for heat-sensitive food items like chocolates and candy bars. Cold sealing uses adhesive instead of heat to seal the bag/pouch/wrapper.
The flow wrapping machine applies the adhesive where the seal is required. And the sealing mechanism then applies pressure to secure the seal of the finished package.
Cold sealing films are generally more expensive than heat sealing films by about 5% to 10%.
Composite film wrapping uses multiple layers of different packaging materials for their enhanced properties. For instance, composite layers are more robust, have improved wear and tear resistance, are impermeable, or may have a better visual appearance.
The composite film is typically made from materials like polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET). The film provides better protection for products than other flow wrap materials. However, composite films are made using different types of plastics, so they are the most difficult to recycle.
Mono film is one of the newer flow wrap materials. It consists of multiple layers of the same material. As a single plastic material, mono films are easily recyclable. However, using a single plastic can weaken the final packaging. Therefore, a hybrid additive of 5% is allowed to increase the robustness and quality of the package.
Paper-based wrappers are also made of plastic but with a coated layer of paper. Waxed paper packaging of bread is an example of this type of packaging.
Flow Wrapping vs Overwrapping
Let us briefly compare the two most common packing methods: flow wrapping and overwrapping.
Since the initial investment of both methods varies significantly, we’ll compare them based on operation costs.
- Flow wrappers create airtight seals on both ends of the item, forming a bag/pouch or other shapes of wrappers. The precise quantity of material required for the packaging is used, leading to minimal costs.
- Overwrapping uses excess material to wrap the food product (like gift wrapping); on average, 20% more film than flow wrapping.
The cost of the added material is negligible for an individual product. However, for large quantities of food items, the extra cost is significant and leads to a higher overall cost of packaging.
Each packaging method is best suited to different applications.
- Flow wrapping is the preferred choice for primary packaging in pharmaceuticals, bakery items, candy bars, chocolates, biscuits, and soaps.
- Overwrapping is suitable for covering cardboard boxes and cartons used as primary packaging with film. For example, a box containing tea, cigarettes, cosmetic items, etc.
Flow wrapping and overwrapping each have specific benefits.
- Flow wrapping provides an airtight seal, better use of packaging material, and easy size adjustments.
- Overwrapping offers greater versatility, a more attractive package, odor locking, and tamper-proofing.
Which Method to Choose?
When we consider flow wrapping vs overwrapping, flow wrapping is the better choice as a primary packaging material for a food item. However, overwrapping is the better method for secondary applications like odor-locking tea boxes.
Flow wrapping and overwrapping are two different types of food packaging. Flow wrapping is better for primary applications, while overwrapping is better for secondary applications. The main benefits of flow wrapping are higher speed and efficiency, increased hygiene, and more consistent results. The main benefits of overwrapping are greater versatility, better aesthetics, odor locking, and tamper-proofing. The cost of flow wrapping and overwrapping machines is similar.
If you are in the market for automated packaging solutions, check out PWR’s range of packing machinery that provides unmatchable features at a price point that might surprise you. Get in touch to learn more.