Easypure by PiovanGroup: The revolution in odour elimination

Odorless post-consumer resins

The main problems that emerge, with the growing demand for plastic products that contain a non-negligible component of recycled material, are:

• the availability of good quality recycled raw materials;
• the impact in qualitative terms of the recycled material on the finished product.

At present, the supply chains of polyolefins such as rHDPE , rLDPE , and rPP , are unable to satisfy all the market demand for recycled material with related compromises on quality and origin. This very often translates into recyclates with non-specific properties which, in addition to having low mechanical characteristics, present problems in terms of odor and emissions.

The compounder or recycler generally works skilfully in the formulations and obtains compounds with the characteristics required by the injection molder. The use of suitable fillers such as talcs and glass fibers allows obtaining composites with acceptable performance. But the problem of the smell and the VOCs present remains. Generally, the extruder degassing systems only partially extract these substances which remain trapped in the molten mass inside the granule produced and are then released during the molding phase and during the life of the finished product. It, therefore, becomes necessary to install downstream of the extrusion lines systems capable of stripping gases and vapors which contribute to the formation of unpleasant emissions to obtain a quality finished product and protect the end user's health.

Easypure is the system that Piovan offers to support the world of extrusion and molding in general, to treat all those polyolefin compounds containing recycled materials and more, which have emission and odor problems.

The main benefits are:

• Higher quality compounds
• Possibility of penetrating particularly demanding markets
• Greater use of recycled
• Energy saving and protection of the working environment
• Smart deodorization system
• Contribution to the achievement of FDA specifications for recycled materials

Higher quality compounds

Easypure exploits the phenomenon of desorption of volatile substances following the heating of the granule. The heat supplied also accelerates the diffusion processes of the substances previously absorbed by the finished product, in the granule these substances now migrate towards the surface and are then released. Heating takes place through a constant flow of air that crosses the entire column of material contained in the deodorization hopper. The air flow not only has the function of transporting the heat and transferring it to the granule but becomes the carrier for the stripping of the volatile substances.

The deodorization treatment is extended over time until a concentration known as the odor threshold is reached, below which the odorous substances can no longer cause unpleasant odours. The achievement of this threshold, without an adequate deodorizer such as EasyPure, is difficult to achieve with only the hot washing of the recycled material.

Possibility of penetrating particularly demanding markets 

In the past, post-consumer materials were used to produce items without particular organoleptic requirements, such as vases, pipes, and agricultural plastic film. With the aim of recycling as much material as possible, many companies in the sector have identified new applications but the problem of emissions and odors remains a strong limitation.

The role of the compounder becomes key. In fact, it can treat the granule with the deodoriser and supply an ecologically acceptable product that is also comparable to products developed with first-choice resins. To date, for example, the automotive interior and HVAC sector already select thermoplastic compounds that comply with standards where clearly is indicated the maximum concentration of permitted substances; the intensity of the odor, and the effects that these substances can have in the passenger compartment such as yellowing of the surfaces and patinas on the crystals ( fogging ). The compounds produced with the first choice could be treated with Easypure to easily overcome these limitations. This process becomes necessary if non-negligible percentages of recycled resin are introduced.

Greater use of recycled

Adopting a deodorization process such as EasyPure facilitates the use of higher quantities of recycled resin in the final compound and this translates into commercial leverage because it allows the introduction of new products on the market, increasingly ecological and comparable to those produced with virgin resin alone . The same recycler that produces its compound entirely with recycled material becomes more attractive if the quality in terms of emissions and odor of the granule can be improved with low process costs.

Energy saving and protection of the working environment

The EasyPure system not only helps to improve the quality of the compound but if suitably equipped with the insulation kit limits the heat dissipation during the transport of the granule from the extruder to the deodorization hopper and therefore considerably reduces the energy costs charged to the heating unit of the hot air flow.

In general, deodorizers work in an open cycle and the process air, loaded with volatile and odorous organic substances, is released into the surrounding environment. For this reason it is recommended to equip the deodorizer with Condenso, the fume condenser that Piovan offers to retain and collect the substances released during the deodorization phase. The optimal condensing temperature is managed by a controller that modulates the water flow in the heat exchangers, reducing energy costs for the chiller and limiting water consumption. Condenso can also operate with activated carbon filters for further reduction of substances that are not condensed.

Smart deodorization system

The Advance version of Easypure offers the advantage of PLC control of the entire deodorization cell. The HMI interface is a state-of-the-art touchscreen display that easily guides the operator during monitoring and setting of the main parameters such as optimal deodorization temperature; residence time of the granule inside the hopper; air flow and alarms that allow timely intervention with clear identification of the possible problem. The version Advance also adopts an odor monitoring system - the Odor minder - or better known as an electronic nose for smart deodorization.

The Odor Minder Thanks to a series of specific sensors, is able to monitor the deodorization phase and guide the operator in the correct optimization of the process. In fact, the sensors are set to identify specific substances which are the basis of unpleasant odours, therefore by monitoring their presence over time it is possible to define the optimal deodorisation parameters and the deodorisation cycle time without having to  extend it more than necessary. This determines the excellent working point which guarantees deodorization and energy saving.

Easypure Advance is ready for the “Smart Deodorization ” function, i.e. intelligent integration with Odor Minder in order to automatically adjust the process parameters according to the real state of deodorization.

Contributes to meeting FDA specifications for recycled materials

According to the guidelines provided by the FDA “Use of Recycled Plastics in Food Packaging ( Chemistry Considerations ): Guidance for Industry” the recycled resins to be admitted to food contact must comply with certain limits regarding the content of dangerous substances. Therefore the recycler must not only demonstrate the suitability of its marketed resins but also adopt production systems that allow achieving these objectives. Easypure becomes to all intents and purposes a tool to improve the quality of the regenerated as it helps to eliminate all those volatile substances which can very often be harmful to the final customer.