More than sustainable: PVC proves its environmental credentials through use of recycled material
Dr. Jeff Ryan, Technical Director at Dugdale Ltd, discusses why PVC is proving it sustainability credentials, as well as why recycling PVC makes good business sense.
Anyone visiting the world’s triennial plastics fair, K 2016 in Düsseldorf last year can have been left in no doubt that the PVC sector is more than pulling its weight environmentally.
Clearly identifiable and clearly labelled, PVC-based products enjoy one of the highest rate of recyclability among plastics. The building and construction trades have led the way; the packaging sector continues to make progress and niche markets such as medical are also making great strides in collecting, recycling and finding second life uses for the material.
Organisations such VinylPlus, Recovinyl and the Vinyls Group of our own British Plastics Federation have also done much to establish a robust and sustainable circular economy for the future. As an independent PVC compounder we are wholly committed to these developments. Dugdale sees clearly that PVC recycling and reprocessing both make good business sense.
Opportunity in waste
There is no argument against second-life production taking wastage out of industry and society – both for post consumer (PCW) and post industrial (PIW). The environmental and business cases for both are as one.
There is, moreover, plenty of opportunity in both types of waste: typical PCW volumes consist of old windows, cable, flooring and other building products and PIW volumes consist of manufactured scrap or secondary operation scrap such as fabrication.
Each kind of waste presents different recycling issues, commercial and technical: PCW, for example, can be heavily contaminated and contain not only brick dust, plaster, glass, silicon sealant, metal, nylon spacers and hardware (such as handles, hinges etc) and but also non-PVC based gasket materials such as EPDM or TPE's which are not compatible with PVC. In addition, some older PCW products contain "legacy" additives such as cadmium or lead (Pb), which, under current REACH legislation, are problematic.
Normally the purchase price of PCW is lower due to the potential contamination. Second life applications, therefore, need to be carefully chosen as fit for purpose, such as unseen surfaces, products that are not surface critical, or those which use a capstock, either co-extruded or foiled.
In the window industry, PIW can be carefully managed and is invariably much cleaner and normally free from most contaminants, although some PIW sources can still contain quantities of non-PVC based gasket materials. However, PIW is typically free from "legacy" additives.
As PIW is normally a clean, more controlled waste stream, building system companies normally re-use it in their own manufacturing processes where possible. PIW’s relatively clean status and often single shade commands a price, of course, and recyclers, keen to get hold of a clean source, tend to bid it up.
Obviously, there are further streams of PVC-based materials that can be combinations of recycled material that have a varied and sometimes unknown source. It can contain various “contaminants”, i.e. metal, non-PVC polymer, paper or fabric, depending on the manufacturing process, application and end product.
It may also contain further contaminants such as floor sweepings and general waste, depending on how well the waste stream has been managed. It may also include a variety of colours and contain combinations of different PVC formulations which can be rigid and/or flexible in nature. For these materials, individual assessment is required and only worth considering if there is a regular supply source and a specific application can be found which can cope with the level of variability and contamination.
Quality control is key
Strict quality control over all incoming recycled materials, to ensure that the quality of the feedstock has a controlled level of contamination that is considered acceptable to the process and its intended use, is imperative. For Dugdale, this involves working in partnership with the recyclers but does restrict our supply sources. We also take our customer manufacturing waste and re-process this back into a consistent re-usable form – a service that is increasingly in demand due to the cost and environmental impact of disposal.
Our work with various kinds of PVC recyclate is, in truth, part and parcel of the 50 plus new compounds/colour variations we are developing across the board every month and have been enabled through our £3 million plus investment in capital plant and laboratory equipment since 2014.
The PVC industry’s continuing embrace of recycling and second-life production continues to be inspired and driven by economics and good business sense as much as environmentalism. At Dugdale we are more than happy to play our part in facilitating these important changes.