PVC Purge: effective carbon removal for PVC
PVC Purge will shift stubborn carbon deposits from injection moulding machinery.
Use it all the time, and it will shift all the carbon from your machine – just as you can see in this photo of a screw cleaned with PVC Purge.
Carbon deposits can cause problems in several ways:
- They can make internal machine surfaces rough, acting as a ‘key’ to which traces of the last batch of material can stick;
- They can show up as specks or streaks in finished products; or, traces of an ‘old’ batch can be moulded into a product, affecting physical properties
- They can act as a catalyst for further degradation – such as hydrochlorination of PVC;
- Continuous build-up can reduce screw throat depth. This alters the melting characteristics of the screw and barrel, leading to fluctuating processing conditions and splash marks.
Preventing carbon build-up is better than cure. But if a cure is needed, PVC Purge is the ideal solution.
For strip-down, empty the machine of its last batch of material. Then, increase back pressure to maximum and run the screw at 40% of its top speed. Then, dose Scrubber Freeze through the machine until the system is dear. Run the screw empty, and return back pressure and screw speed to normal.
PVC Purge should be used at normal PVC processing temperatures (160°C to
210°C). It is not suitable for machines with nozzle filters, mixers, screens or diameters smaller than 2.5mm, and should not be used with tools such as hot runners