In the process of extrusion blow molding, production efficiency depends on two key factors:

• the capacity and speed of mould cooling
• the time needed to move the carriages

Standard cooling system

To improve mould cooling capacity, and therefore to reduce cycle time, one step is to usually concentrate on assuring that the molds have a good heat dissipation on the extruded parison, which has a temperature of about 200°C or 392 degrees Fahrenheit when it comes out from the plasticizing head.

During the blowing stage the only part of the container which is in contact with the mold surface is the outer side and for this reason this solution proposed by some manufactures has two disadvantages:

• Plastics are heat-insulating by nature and therefore do not allow heat to dissipate from the inside of the container to the outside.
• The compressed air used to blow and form the container remains inside it, during the entire blowing phase, quickly reaching a high temperature.

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The need for a fast cooling system in blow molding machines is determined by the fact that the degree gap between outside and inside causes stress to the material. This can lead to significant damage in containers integrity, making them more likely to fail quality tests because of leaks or other issues.

What happens in that case, is that the manufacturer has to thicken the products’ surface and redo the tests; as a consequence, costs become remarkably higher and cycle times extend.

The need to use a more effective fast cooling system than the standard one thus emerges.

A more efficient Techne fast cooling system

To overcome the limitations highlighted, securing adequate heat dissipation, Techne has developed and patented a system that ensures recirculation of the compressed air used during forming of blow-molded bottles and containers.

In this way, heat can be efficiently transferred from the inside to the outside, improving output quality and process performance.

Shorten production times and make cycle time more economically sustainable for your business.

In order to deepen the topic and find out the main advantages to use the fast cooling system in the EBM process, download the brochure below.