Shrink tunnel

Types of shrink tunnels

Shrink tunnels are the critical component of shrink label and wrap packaging systems. Products are first introduced into a shrink tunnel after being conveyed by an infeed conveyor belt or system. In the shrink tunnel, the product will be subjected to hot air, steam, or water—enough heat to cause the label or film to shrink tightly around the product.

• Standard or generic shrink tunnel

  Usually, when people refer to shrink tunnels, they refer to standard shrink tunnels with no bells or whistles. Standard shrink tunnels do the job, i.e., they transfer heat to shrink film or labels. They come in a variety of sizes and shape configurations to accommodate different kinds of products.

• Conveyor shrink tunnel

  Conveyor shrink tunnels have an inbuilt conveyor belt. The conveyor belt transports products through the tunnel, and hot air then sprays them from different angles. The good thing about conveyor shrink tunnels is that they can be integrated into existing production lines. They also handle products of different shapes and sizes easily.

• Noiseless shrink tunnel

  As the name suggests, shrink tunnels that operate without noise are considered noise-less shrink tunnels. They work the same as conveyor-style shrink tunnels. Unfortunately, shrink tunnels are often very loud and can be damaging to the hearing of people working around them. Noise-reduced shrink tunnels strive to solve this problem by providing a softer, more tolerable operating noise.

• Airstream shrink tunnels

  Airstream shrink tunnels use hot air to shrink labels or films. They are versatile shrink tunnels that work with various films. Airstream shrink tunnels are usually energy-efficient because they only use the amount of heat required to do the job.

• Fire shrink tunnels

  As the name suggests, these tunnels use flames to shrink films or labels around products. They offer the fastest label-shrinking rates, but their use is limited to heat-resistant films or materials because of the intense heat they generate. Fire shrink tunnels are used in specialized packaging applications.

• Cross link shrink tunnel

  Cross link shrink tunnels are fire shrink tunnels with an X-shaped conveyor system. This X-shaped system ensures that products are evenly exposed to heat, regardless of their initial position. As a result, they shrink faster than their conveyor tape counterparts.

• The continuous shrink tunnel

  Tunnels that use a continuous process instead of intermittent operation are referred to as continuous shrink tunnels. They are usually integrated into automated production lines, offering a higher level of output than shrink tunnels that don't use a continuous process.

• The semi-automatic shrink tunnel

  These types of shrink tunnels require manual feeding of products but automatically shrink the film around the product.

Specifications and maintenance of shrink tunnels

Different types of shrink tunnel machines have different specifications. Here are some common shrink tunnel specifications and their maintenance requirements.

• Tunnel size

  The shrink tunnel's height and width must be large enough to accommodate the packages that will be passed through it. Additionally, the length needs to be adequate for the completion of the shrink packaging process. For maintaining the shrink tunnel, it's essential to inspect it regularly for damage or sign of wear and conduct cleaning of the tunnel regularly to prevent the accumulation of residue or dirt from the shrinks.

• Conveyor system

  It includes dimensions, speeds, alignment, and functioning. They should be examined intermittently, and the conveyor belt should be cleaned to prevent any blockage affect the smooth running of the machine. Also, maintain the right conveyor speed for optimum shrink results. The belt tension and alignment should be checked frequently so as to avoid jams or bottlenecks.

• Heat source

  It is the kind of heating mechanism used to shrink the film, such as infrared, steam, or hot air. The heating element temperature needs to be calibrated frequently for consistent shrink results, and the heat setting should be adjusted according to the film and package materials. Besides, during operation, operators should monitor the heat source carefully to avoid overheating or underheating.

• Voltage

  Shrink tunnels come in different voltage specifications, such as single-phase 220V - 240V/50Hz and three-phase 380V - 440V/50Hz. When maintaining the machines operators, they should refer to the manufacturer's instruction and ensure the correct voltage is used for the shrink tunnel so as to avoid power surges and electrical issues.

• Tunnellized film

  It refers to shrink film material that is compatible with the shrink tunnel. Typically, shrink tunnels are designed to work with specific types of shrink films, such as PVC, POF, or PE. For maintaining the tunnels, regular inspection for damages or holes on the film should be done. Also, operators should adjust the tunnel settings to fit the film type and package size for optimal shrink results.

Scenarios of shrink tunnels

Shrink tunnel machines are popular because of their versatility and ease of use. These machines work on various packaging materials, making them an essential tool in many industries.

One of the significant advantages of shrink tunnel machines is their ability to package products of different shapes and sizes. The tunnels are adjustable, meaning business owners can quickly fit them for various products. This feature makes shrink tunnel packaging tunnels crucial in food, beverage, cosmetics, and household product industries, to name a few.

Shrink tunnels also work well with various packaging materials, including polyolefin, PVC, and PP. Once heated, these materials contract tightly around the product, providing a tamper-evident, secure, and sturdy packaging. The shrink tunnels ensure the packaging process is efficient and streamlined, giving end products a professional look.

Using shrink tunnel machines can enhance the flow-wrapped product's shelf life. Many shrink tunnel machines use FDA-approved shrink film, making them suitable for products that need food-grade packaging. The films protect products from dirt, dust, and damage. They also offer light, moisture, and air protection, thus prolonging the product's shelf life.

The shrink tunnel's ability to apply a tamper-evident seal is a safeguard for end-users. Once heated, the shrink film tightly contracts around the product. This makes it hard for anyone to open the package without damaging it. This feature ensures products are packed securely and helps reduce the risk of contamination.

Businesses that require high-volume packaging can also benefit from shrink tunnels. The machines work by transferring shrink film over a product. Once heat is applied, the film shrinks and conforms around the product. This automatic process is faster than manual packaging, thus increasing productivity and efficiency in high-volume packaging operations.

Finally, shrink tunnels can package multiple products together, such as bulk items, multipack bottles, and kits or tandem sets. The shrink tunnels tightly package several products with shrink film together, providing a secure and attractive packaging solution. This also reduces product damage during transit.

How to choose shrink tunnels

Choosing a shrink tunnel requires careful consideration of various factors to ensure that the selected tunnel meets specific packaging needs and operational requirements.

• Packaging Needs: Assess the type and size of products that need to be packaged. Consider the shape, size, and material of the item and the shrink film's compatibility. Determine if any special requirements, such as visibility or tamper-evident packaging, need to be addressed.
• Production Volume: Consider the required production speed and throughput. Shrink tunnels are available in different sizes and configurations to accommodate varying production volumes. Ensure that the selected tunnel can handle the anticipated output without causing bottlenecks in the packaging line.
• Conveyor System: Consider the type and dimensions of the conveyor system used in the packaging line. Ensure that the shrink tunnel's conveyor system is compatible with the existing setup and can smoothly integrate into it.
• Operating Costs: Consider the energy consumption and operating costs of the shrink tunnel. Look for tunnels with efficient heating systems and insulation to minimize energy usage during operation. Evaluating the long-term costs associated with operating the tunnel can help make a cost-effective choice.

By carefully considering these factors, businesses can select a shrink tunnel that meets their packaging needs, integrates with their production line, and provides reliable performance. It is also helpful to consult with packaging equipment experts who can provide guidance and recommendations based on specific requirements.

Q&A

Q1: Which types of products use shrink tunnels?

A1: Shrink tunnels are used for various products in different industries. In the food and beverage industry, they are used for packaging bottles, cans, jars, and other food products. In the pharmaceutical and cosmetics industries, shrink tunnels are used for packaging bottles, jars, and other products that require tamper-evident seals. Household products such as cleaning products, detergents, and other liquids also use shrink tunnels for packaging. Moreover, electronics toys, hardware, and stationery products may also use shrink tunnels for packaging.

Q2: What are the benefits of shrink tunnel packaging?

A2: One of the benefits of shrink tunnel packaging is improved product protection. Shrink tunnels provide a tamper-evident seal, making it difficult for anyone to open the package without damaging it. This feature gives consumers and retailers added confidence in the product's integrity. Shrink tunnel packaging also offers stackable and shelf-ready packages. The tightly consolidated packages are easier to stack and take up less shelf space, which is advantageous for retailers with limited shelf space.

Q3: How fast can a shrink tunnel packager run?

A3: The speed of a shrink tunnel packager can vary depending on the specific machine and its features. Generally, shrink tunnel machines can operate at speeds ranging from 10 to 150 cartons per minute. Some high-speed models may even exceed 200 cartons per minute.