RECYCLING | PVC
The PVC processing challenge
US compounding systems group Farrel Pomini says processing PVC can be a challenge as it is heat sensitive by nature, its processing temperature window is narrower than many polyolefins, and if exposed to extended residence time or overheat- ed will degrade quickly and release hydrochloride acid, which is toxic and highly corrosive to the processing equipment. “The degradation will affect the colour and mechanical properties of the product,” the company says. Processing recycled PVC is an even bigger challenge because of its unknown thermal history and the contaminant invariably carried by the recycled material.
Temperature control Farrel Pomini says its Compact Processor (CP) II series is designed with the Farrel Continuous Mixer (FCM) technology that maintains precise temperature control which results in lower temperature mixing and a wide processing window for
both rigid and flexible PVC. The precise temperature control also provides higher production rates and lower costs due to a reduced need for heat stabilisers. Its CP series, offered in six models and able to provide PVC compound- ing at nominal production rates from 170 to 3,000 kg/hr for rigid PVC, and rates from 250 to 4,700 kg/hr for flexible PVC, feature multiple tem- perature control zones and rotor cooling which allows for processing of PVC within its ideal temperature range and with less reliance on heat stabilisers. The units also feature energy-efficient atmospheric venting for removing air, volatiles, and moisture from the mixer. The FCM utilises a twin rotor design that compounds materials in a single step rather than a melt, add, mix, convey, repeat technology associated with twin-screw extruder technology, says the company. Mixing is achieved by repeated passage of the compound through
and sheet have to be used in a closed loop. As a result it means that from 29 May 2026 onwards, only lead-containing recyclate from rigid PVC pipes can be used for the production of new pipes. No derogation was granted to lead-containing
recyclate from soft PVC applications. Manufacturers using rigid lead-containing PVC
recyclates in new products must comply with a mandatory certification of origin of the rPVC used as well as a mandatory product marking. The new regulation does not cover the use of
lead-free recyclates from profiles and pipes. For more than a decade, profiles and pipes use a calcium zinc-based stabiliser. Lead-free recyclate from profiles and pipes can be used for new non-pressure rigid PVC pipes without any restric- tion, but subject to product standard specifications. TEPPFA members already set-up end-of-life
rPVC pipe collection schemes more than 30 years ago in some EU Member States such as the Netherlands, Belgium, Austria and Denmark. Due to the useful life time of the rPVC pipes from 50 up to 100 years, the volumes collected were mainly limited to installation waste.
28 COMPOUNDING WORLD | November 2024
the controlled shear region formed by the rotor tip and the inner housing walls, as well as the continuous splitting and recombination of the compound between the two rotors.
Good dispersion Large rotor tip to wall clearances and non-intermeshing rotors allow for processing of abrasive materials and contaminants without excessive wear to major machine components. The unit’s #15/7 rotor combination provides good dispersive mixing with excellent distributive mixing and yields decreased melt temperature with increased production rates. Farrel Pomini has presented several case studies in which various recycled PVC materials in the form of a clear film, Luxury Vinyl Tiles, window frame, vinyl siding or shredded carpet tile backing, and containing a high percentage of solids/fillers or mixed durometer materials could be pro- cessed into a homogenous compound. �
www.farrel-pomini.com
TEPPFA’s activities to support an increase in
rPVC collection as the restriction comes into force include a project to open up non-pressure product standards for an increased use of recycled content without compromising on quality, performance, and longevity. It also concluded a mass flow analysis with German association member KRV to find out the potential non-collected volume, which can help to set the baseline for future pilot collec- tion, sorting, and recycling projects for end-of-life plastic pipes at national levels from 2025 onwards.
Vinyl flooring The European Resilient Flooring Manufacturer’ Institute (ERFMI) is advancing projects relating to the recycling of PVC flooring and PVC from bulky urban waste. With the support of VinylPlus Italia, the group commissioned Phoenix RTO, a Padua, Italy-based optical instrument, and systems maker to design and build an industrial technology capable of separating PVC from other plastics in post-consumer waste. Phoenix RTO developed a handheld device that employs near-infrared (NIR) hyperspectral technol-
www.compoundingworld.com
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
