ODOUR AND EMISSIONS | TECHNOLOGY


Right: Odour- absorbing masterbatches enable


post-consumer recycled material to be used in applications where smell is critical


for use with a broad range of recycled polymers. Ampacet says OdorClear grades can also be used in combination with its R3 Sustainable Solu- tions products, including ThermProtect BlueEdge and ReVive. This allows formulators to ameliorate issues such as thermal degradation, inconsistent colour or product uniformity, all of which can occur when using high quantities of recycled material.


Physical solutions Additives are not the only way to tackle unwanted odour; various equipment-based solutions are also available or under development. One area of interest is in multilayer film recycling. While monolayer solutions are beginning to replace coextrusions in some packaging applications, quantities of multilayer barrier films entering the waste stream are still significant and likely to remain so. Italian extrusion machinery maker Bandera has developed solutions using its RevoTech Twin system that are said to be capable of recycling barrier film material with high percent- ages of EVOH and PA (up to 30% PA, for example). The company says in-house tests using post- industrial scrap from high-barrier film production


have shown the suitability of the use of the recyclate in various types of films — even thin films — at levels up to 100%. Smell is practically absent from the new film, it says, despite the presence of EVOH and PA. It puts this down to the high degassing and process- ing capabilities of the RevoTech Twin equipment. For companies regularly recycling packaging


Bandera’s RevoTech VOC and Odour Removal system uses microwave technology to reduce odours in batches of granules after granulation


film, Bandera has supplied RevoTech “VOC and Odour Removal” systems. These use a patented and highly energy-efficient microwave technology to reduce odours to levels that it says production using traditional single-screw or high-speed twin-screw extruders fails to reach. The purification process typically takes a couple of hours and can be performed on batches of granules that have been cooled after granulation. Various technology solutions to remove unpleas- ant odours from recycled plastics are also available from Coperion, including systems to remove odour from bulk materials downstream of the extrusion process. The company recently developed a mobile unit, allowing odour reduction trials to be carried out on freshly produced recyclate products at the customer’s site under real production conditions. “There is no need to spend a great deal of time


A cascade pelletising process for recycled polyolefins by Bandera incorporating venting for VOC removal


62 COMPOUNDING WORLD | March 2022


and effort on reproducing production set-up in Coperion’s Test Centre,” says the company. “The Coperion mobile deodorisation test unit can be integrated into real production. The customer thus obtains the test results in the fastest possible way – without loss of time and without loss of quality.” Coperion uses the mobile unit to determine the optimum odour reduction parameters necessary to achieve the quality desired by the customer. The degassing medium can be varied (air, steam, wet air with high moisture) and the temperature at which odours are most effectively removed can be adjusted — temperatures up to 150°C are possible. Deodorisation can be performed with very small amounts of product (as little as 10 litres per test run) using the mobile unit. Product samples can be taken


www.compoundingworld.com


IMAGE: BANDERA


IMAGE: BANDERA


IMAGE: AMPACET


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78