When one of the most important manufacturers of pens in the world asked us to solve the problem of cooling of thorns that create cavities in the pens, the most obvious thought it was to provide a chiller beside the machine that, with a great pressure, could flow great amount of water in the small passage (around 5 mm) that was divided in two parts by a separator-sheet in order to allow the flow of water.

This solution did not solve the problem because the small passage created in thorn was easily blocked even using treated water. In this way the cooling capacity decreased more and more day by day, and then it was necessary to  dismantled frequently the mould and replace the separator-sheet full of limestone deposits, with high costs due to stopping production and maintenance.

It was obvious that in order to avoid the problem of rapid obstruction of the passage was necessary to flow the liquid in the passage without the separator-sheet.

In agreement with the customer we studied a radical modification of the mould, replacing the thorns that were obviously blind with thorns with tube form, with free passage. It was modified the fixed part of the mould by creating a collector who was in communication with each terminal parts of the thorns. In this way, whit closed mould, the water could pass freely through the thorns from the fixed part of mould to the other part.

In this way it was possible to use the complete inner diameter available, reducing considerably the loss of load. But another change was necessary : the way of circulation of water need to be changed in suction way instead of pressure way. In fact by suction of water, it was possible to open the mould without any loss of liquid and keep the matrix perfectly dry.

This was possible because DEGA always offers its customers machines (Chiller or Thermo-regulator) for the control of temperature of the mould, with pumps that can work either in pressure or suction, with almost equal yields.

By adopting this technology, it was increased cooling of the mould, lowering in this way the production cycle. In addiction it was possible to eliminate stopping of machine for replacing of thorns full of calcium carbonate. The production was not stopped even when some O-Ring began to leak, since the fluid circulating by suction throughout the mould prevent any leakage.