Clean-out Block

The clean-out block is used to remove the oxide aluminium layer on the liner at every alloy change or every shift change.

A proper operating dummy block will leave an aluminium layer of 0.25 mm thickness on the liner surface after each pressing.

A fully success is achieved at cleanings performed after heating up the liner. The inner surface of the liner must be measured in the full length prior to ordering a clean-out block. Whilst the container should be used long terms without any problem, there may incur problems like expansion of the diameter when hard alloys are used. Both the dummy block and the clean-out block cannot be used efficiently at deformed containers. A liner replacement or precise machining processes should be performed at containers in such situations.


Continuing metal cast and recovery techniques development works improve the aluminium alloy billet quality. But the oxidation of the billet surface can still not be prevented. And this leaves the quality in shade in form of small inclusions. It is important to prevent the progress of the faulty billet residual towards the die.


The inner part of the billet flows towards the die during the extrusion. The oxidized billet shell accumulates in the dead zone at the end of the container. The extrusion must be stopped before the contaminated alloy leaves the die. And finally, the butt, adhered to the die, is cut by the shear blade and disposed.


The container and the dummy block have a critical importance for the temperature controlled extrusion. There is no more need to cool down the dummy block thanks to the conical heating. The expansion of the dummy block is carefully calculated in order to leave a thin film layer on the liner surface during the pressing. This left oxidized layer mixes with the next billet. This situation may affect the surface quality and internal features of the product.


Damatool Clean-out Block

The Damatool clean-out block is designed to provide maximum cleanness on the liner wall.

The clean-out block has a long structure in order to fit on the loader and enough to move freely along the liner. The size change control of the clean-out block, designed to be used at room temperature, is able to be performed easily. The block is lightened by manufacturing this with a hole centre and converted flexible by a precise channel cut.


Upon indication of the minimum liner diameter at room temperature and the operating temperature by the customer, Damatool calculates the effect of the heat on both the liner and the dummy block and manufactures the cold clean-out block at the most appropriate size.

The size of the Damatool clean-out block needs to be calculated separately for each container and maximum aluminium film layer needs to be removed without harming the liner wall.