With over 60 years of manufacturing in New Zealand, Marley is a household name particularly for rainwater and spouting products. However its origins lie in vinyl floor manufacturing, in Manurewa Auckland, where on the same site, the extensive PVC and pipe fittings plant still operates today.
Marley has always focused on quality, innovation and long-lasting customer relationships and is one of New Zealand’s largest manufacturers in the plastics industry. Involved with extruded and injection moulded products, Marley’s manufacture processes use PVC, Polyethylene and Polybutylene, following Best Environmental Practice ( BEP), and Marley continually strive to minimise how their operations negatively affect the environment.
PVC is an environmentally smart choice because it takes a small amount of energy to make, lasts a long time and at end of life can be 100 percent recycled. With high Quality Control procedures, during processing any ‘seconds’ are removed from the line, shredded and re processed again – the lack of wastage being economic and environmentally friendly.
However when stringent QC checks mean a percentage of extruded pipe is rejected, the pipes are shredded so they can be re-melted and formed again, resulting in minimum wastage. The recycling is a good example of the environmental policies in operation however the re processing causes dust issues.
Neil Bell, Site Services and Project Engineer at the Manurewa plant says, “ We had an issue with a dust collector that was supplied as OEM equipment. The filters blocked frequently and required replacing. The filters could only be sourced from overseas and changing them was a dirty, difficult job.
NZDuct+Flex came up with a solution that was sized correctly and since installed in mid 2020 the filter has been doing a good job for us, reducing down time and saving the cost of replacement filter bags. Our fitters are particularly happy with this result.”
A traditional 3 modular baghouse filter was installed by one of the two install teams who are permanent employees at NZDuct+Flex. Driven by a JKF35D 11kW fan, the dust is collected in a custom built bin via a 1000mm Rotary valve also from Danish based JKF Industri.
Geoff Ebdon from NZDuct+Flex says, “As all the components i.e. the fan, filter, filter bags and ducting all come from JKF, compatibility and performance of the whole system is assured. The filter units, made of Swedish finely galvanised steel, can be enlarged by removing the end panel, adding another module and bolting the ends on again. Servicing these units is minimal and consists of oiling the fan shaft occasionally.
“The secret to long lasting dust removal, with minimal maintenance, is sizing up the filter, fan and the needs of the customer’s machinery correctly, and it is the filter area, not only the fan power, that is key,” says Geoff Ebdon.
“If you ask too small a filter unit to handle too much air and dust, instead of the dust cake forming gently on the surface of the filter material, it gets driven deep into the pile of the material and starts to clog. Once this happens it’s a downhill slope of poor filtration and constant filter replacement is costly, leaves dust in the work area and creates dangerous issues, (potential fire risk) in the ductwork. When it comes to filters (commonly called bag houses) a good ‘big’ one will always beat a good ‘little’ one’ for longer life and less problems,” says Geoff.
Modular Bag Houses may be one of the older filter methods, but they are still often a very cost efective solution for high air volumes and heavy dust loads in not only the wood working industry but others also. NZDuct+Flex offers a range of filters from 1000 m³/h to well over 100,000m³/h if it’s required.
Neil Bell confirms the company are very pleased with the solution provided: “The installation was carried out in a safe and efficient manner in the time stated. We are currently looking at another application with NZDuct+Flex where fumes and dust are our concern.”
For more information for a dust extraction solution visit
www.nzduct.co.nz or call 0508 69 38 28
