From Melt to Solid - Simplifying PSA Packaging!

KAISER’s new, revolutionary bag filling process allows for direct packaging of melt pressure sensitive adhesives from the reactor or buffer tank into bags. Thus eliminating the need for previously required silicone lined cartons.

The newly developed bag filling machine operates as a fully automated FFS (Form, Fill and Seal) unit accommodating between 0,25kg (250 g) and 2,5kg (2,500g) of melt pressure sensitive adhesive per bag based upon processing requirements

 

Save: 50%  Labor Costs   90%  Packaging Costs   100%  Packaging Waste

The Process

The pressure sensitive adhesive is prepared in your existing reactor. Once the product is ready for packaging, the product pump conveys the melt through the pre-filter and the fine-filter into a heat exchanger. In the heat exchanger the melt is cooled from the batch temperature down to the filling temperature. The filling temperature is determined by the melting range of the packaging film. From the heat exchanger the melt flows through the filling head into the bag which is then sealed and transferred into the cooling tunnel. Once through the cooling tunnel the bags enter a drying system which removes the excess moisture from the outside of the bags. Upon exiting the drying system the bags are ready for transport.

All elements of the cooling tunnel can be custom designed to accommodate space constraints. The construction of the cooling tunnel will be designed around the product’s physical properties, residence time and bag size.

A standard bag filling machine is supplied with two format tubes which determine the width of the bag. The smaller format tube produces bags 150mm in width and the larger format tube produces bags with a width of 230mm. Other widths are feasible and available upon request.

The length of the bags is controlled by the PLC of the machine and is only limited by the mechanical strength of the film. The PLC has memory capabilities to save the parameters of up to 100 recipes. Therefore, ideal process parameters only have to be evaluated once during the initial start-up of the machine.

The Advantages

The material from which the bags are formed contains either a component of the adhesive or an inert material within the adhesive that allows the bag to melt simultaneously with the melt pressure sensitive adhesive. KAISER’s new bag filling process for melt pressure sensitive adhesives has numerous advantages over the traditional forms PSA packaging.

Process Advantages:

• The pressure sensitive adhesive is directly filled from the reactor into the bags
• The film used to form the bags can be melted and mixed with the product
• The cost of the film is one tenth of the cost for the silicon coated cartons
• The bags are cooled to ambient temperature in the cooling tunnel
• Product can be shipped immediately after production as no additional cooling time is required
• Only one operator is required to produce the batches in the reactor and run the machine
• The machine allows for various bag sizes between 0,25kg and 2,5kg
• Production rates reach values up to 1,0t/h
• The bags are fully sealed eliminating leakage
• Elimination of manual unpacking
• Packaging waste is eliminated as the material melts with the product

The Process (continued)
The standard film thickness for the Bag Filling Process for Pressure Sensitive Adhesives is 50µm. Thinner films are harder to process at elevated production rates due to the limited mechanical strength of the film, especially at high filling temperatures. Thicker films are possible but increase the film concentration in the final product.

In the cooling tunnel the bags are directly cooled through means of cooling water spray. The cooling water runs in a closed circuit and is cooled through a heat exchanger. The heat exchanger is cooled by the client’s primary cooling water circuit. Strainers in the cooling water system ensure that the product will not enter the heat exchanger. The cooling tunnel consists of two conveyors. The responsibility of the first conveyor is to transport the bags from the bag filling machine through the first drying phase. This conveyor has pockets on its outer surface allowing the bags to stand upright and enabling any air bubbles that could have formed during the filling process to rise to the surface of the melt. Furthermore, the pockets give the bag a rectangular shape, for easier packaging and reduced packet size. The second conveyor is a mesh conveyor on which the bags lay during the second cooling phase. If desired, the first conveyor can be designed similar to the second conveyor allowing the bags to lie on the belt.

Investment Phases
To accommodate the growth of your business and to reduce initial investment costs the bag filling process can be divided into multiple investment phases.

1. Investment Phase

– Installation of bag filling machine (Z-101)

With the sole installation of the bag filling machine the correct temperature for the filling of the PSA into the bags would be achieved by cooling the product in the reactor or holding vessel. This eliminates the need for the product heat exchanger and the thermal oil cooling circuit. In this scenario the temperature of the PSA is below the melting point of the film thus eliminating the cooling and drying tunnel. For ambient air cooling the bags can be placed on a shelf similar to the traditional carton method.

2. Investment Phase

– Addition of the heat exchanger (W-101) and thermal oil cooling unit (Q-101)

Adding the product heat exchanger (W-101) and the thermal oil cooling circuit (Q-101) would free up the reactor or holding tank (used in phase 1 as the cooling source) and increase production.

3. Investment Phase

– Addition of the cooling tunnel (K-101/K-102) and cooling water system (P-101/W-102)

This addition would eliminate the labor cost of manually transporting the filled bags to the shelf and eliminate the shelf space necessary for cooling.

4. Investment Phase

– Addition of the drying tunnel

Incorporating the drying tunnel responsible for removing the excess water from the bags would eliminate the labor cost of the bag drying and/or the time required for the ambient air drying.

5. Investment Phase

– Fully automating the process

To fully automate the process packaging, palletizing and pallet wrapping systems can be added.

Test Center

In 2004, KAISER Steel Belt Systems GmbH completed the installation of a full production scale Bag Filling Machine in our test center in Krefeld, Germany. With this full production test unit we are able to run customer demonstrations, feasibility studies and scale-up tests.
To introduce this new process for packaging Melt Pressure Sensitive Adhesives we would like to offer you the opportunity to test your product compatibility with our Bag Filling Machine. The demonstration will yield high quality sample bags for you or your customers. Our standard PE-base film material with a thickness of 50µm will be used for the packing process or you may provide other film for the test. Format drawings outlining the dimensions for film rolls and testing/product conversion proposals are available upon request.

Preparing the test requires the following information:

• Desired film for packaging material and melting range
• Viscosity curves for each product being tested
• Desired capacity
• Batch temperature of the melt
• Desired core temperature of the bag upon discharge from the cooling tunnel