When making PVC masterbatch, additional fillers may be added to the mix. These fillers can change the composition, colour and properties of the end product.
Many fillers contain some inherent moisture them. This can lead to problems in the production of masterbatch. Innovox products can be used to remove this moisture problem.
These problems may manifest themselves in different ways.
One of the manifestations of moisture issues is the creation of porosity in products made from the masterbatch. This is particularly prone to happen where there are higher filler and additive content levels present (>25%). This porosity is usually formed during heating and moulding of the end components when inherent moisture turns into steam bubbles and escapes toward the surface of the component being formed. This can therefore lead to end components failing quality and creating weaknesses. For masterbatch producers the presence of moisture can lead to breakout on extruders during formation of the masterbatch. This breakout happens when moisture reaches the heated die of the extruders and then vaporises to steam. This vaporisation can split the extrusion and cause the uncontrolled breakout.
The addition of Innovox calcium oxide to the batch can remove the moisture present in the fillers and in turn stop extruder breakout. The way the Innovox calcium oxide works is it reacts with the moisture present, hydrates and then becomes additional inert filler in the mix.
We produce both a undamped calcium oxide and a damped calcium oxide for these applications.
Due to the specific requirements of masterbatch for end user food contact applications, we also produce a calcium oxide which is damped and with material which is approved for food contact applications, this is Innovox 95F.