To achieve impurity-free thermoplastic film mixing virgin and recycled raw materials it is necessary to use a high-filtration screen changer that ensures top quality of end applications.
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High-quality thermoplastic applications
High-quality thermoplastic applications are achieved focussing on impurity filtration along plastic extrusion cycle. In particular, to rely upon an adequate filtration in plastic extrusion processes means to achieve valuable high-quality thermoplastic film applications, optical, medical and food applications included.
In such a backdrop, polymer characteristics and production process are essential.
Plastic extrusion with virgin and recycled raw materials
When manufacturing thermoplastic film intended for high quality applications, the use of virgin impurity-free polymers as raw materials is crucial. At the same time, it’s recommended – and sometimes required – to use recycled plastic materials as well.
There are two main reasons for mixing virgin and recycled plastic materials for the production of high-quality film:
- The exclusive use of virgin plastic materials would offer a smoother production of high purity film; however, the addition of a percentage of recycled plastic offers the chance of minimizing overall raw material procurement costs, thus resulting in economic benefit.
- To tailor production to environment protection rules and regulations in force in several countries, it is necessary to include a percentage of recycled plastic in plastic productions.
What virgin and recycled plastic mixing percentage is required? Mix ratio is highly variable and depends on 3 main factors:
- Type of applications
- Purity level of end applications
- End application intended use
High-purity plastic film production
To achieve plastic extrusion final outcomes of adequate purity and quality, recycled plastic must have minimized impurity levels. An adequate selection of recycled plastic to be mixed with virgin raw materials is therefore a key factor.
Therefore, the presence of a high-filtration continuous screen changer turns into a key factor.
The screen changer to be installed in a plastic extrusion system should preferably be continuous, i.e. it should operate in the production cycle without any process interruptions. And, most of all, the screen changer filtering capacity must be adequately high and efficient, in order to remove all impurities in recycled plastic materials as well as in virgin raw material.
High filtration with a continuous screen changer
A high-filtration screen changer ensures that the desired end application quality is achieved. According to the desired purity level and the plastic film intended use, the screen changer can be adequately set up to carry out the filtration required.
Since 1968, Cofit has been manufacturing self-cleaning continuous high-filtration screen changers, particularly suitable for the extrusion of high purity plastic film, BOPP and BOPET film included. Cofit AP series screen changers are the ideal solution for the screening of mixed virgin and recycled polymers, offering filtering levels exceeding 10 microns, i.e. filtering levels required for high quality application (food, optical grade, medical).
Cofit AP screen changers
AP series by Cofit has been designed for the production of high-quality thermoplastic film and they outstand for their sturdiness:
- They withstand over-500-bar
- They do not include motors, hydraulic or pneumatic components, which are subject to failures or tear and wear.
- They need minimized maintenance.
Moreover, AP screen changers require low investments at assembly and start-up stages and low management costs during service life. Compared to other screen changers with similar characteristics and equal efficiency, AP screen changer service life is definitely longer. Have a look at AP data sheet.
Contact us
Cofit deals with research, engineering, manufacturing, and distribution of continuous screen changers, either automatic or manual, intended for several industrial sectors and with the majority of plastic materials. Contact us to optimize your extrusion line with a continuous screen changer and manufacture high-quality film.
