For all processors and transformers involved in extrusion plastics, particularly in compound production, the use of correct process material is critical, and filtering is key.
Contaminated plastics means potential benefits
An extrusion line for thermoplastics fed with heavy-contaminated polymers, based on cheap reground plastics may be an attractive option and an obvious cost-effective choice. However, the use of reground plastic for your extrusion line need to deal with additional contamination issues, and this means higher processing costs.
The perfect balance between the use of cheap raw materials and additional process costs becomes a true challenge. And this the reason why the screen changer plays the major role – the selection of the most suitable screen changer is a key issue, aimed at obtaining the most from the use of chep raw materials and processing costs.
How about assembling a slide-plate screen changer?
The installation of an automatic and continuous screen changer can be the right choice – focus on cost reduction and throughput increase. This is mostly important if you process wide volumes of plastic.
The base solution (even not the smartest, although) to the issue may be the installation of a slide-plate screen changer to retain contaminants from the molten material inside the extruders. However, even a slight amount of contaminants can clog a slide-plate screen changer very quickly. As contaminants builds up on the screen, pressure increases to unacceptable levels until a screen change is needed.
Typical issues due to slide-plate screen changers
Why isn’t the above solution the smartest one? Because in this case operators are normally asked to attend the extrusion run with high level of attention, preventing them from taking care of more than one machine at a time. This involves increasing personnel costs as you increase your business.
Furthermore, contamination levels can sometimes get so bad that you have to stop processing your extrusion line to remove them, and store dirty regrind plastic inside a float-sink tank, additional cost and time.
A continuous screen changer is the right choice
The solution is certainly the replacement of the side-plate screen changer with a Continuous Filter Operation (CFO) melt-filtration system on your extruder, e.g. Gorillabelt T screen changer by Cofit.
If used in the above conditions, Cofit Gorillabelt T can help to increase extruder output rates by +10%, up to +20%. Moreover:
- Gorillabelt T helps to maintain a more consistent pressure inside the extruder barrel, thus resulting in more consistent operation
- Personnel costs are reduced, since no interventions are required during the extrusion run
- Filter replacement costs are reduced to the minimum
- Maintenance costs are reduced to the minimum
Saving time and money
Your extrusion line will effectively process less expensive feedstocks than before, will save time and money, and will maintain elevated the quality level of your extrudate.
Cofit deals with research, engineering, manufacture and distribution of automatic and continuous screen changers for post-consumer and post-industrial recycling materials, too.
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