Natwood, established in 1945 and registered as Natural Wood Products but trading under the name of Natwood, produces a range of wooden lifestyle products including wooden bathroom accessories and toilet seats in various colour washes, wooden cabinets and mirrors and other bathroom furniture. Painted bathroom cabinets and vanities, housewares such as ironing boards, airers and laundry bins, wooden storage and shelving, wooden frame mirrors and picture frames also form part of their product range. They're also the importers of the Duraline range of glass shelves, wooden shelving and decorative brackets and clips. Natwood supplies large DIY shed type stores as well as hardware chains, house stores and sanitary ware merchants. Their sales and warehousing structure is spread throughout South Africa and Namibia. Natwood also has a significant offshore footprint with exports of Natwood's products going to amongst others Ireland, Australia, New Zealand and Cyprus.

Solid pine with a certain amount of MDF constitutes the bulk of the raw material used by Natwood. Finishes for solids includes dip staining (mahogany and cherry) and acid catalysed lacquers - sealer coat and final finish. Dip staining works well for solids but not so for MDF.ln terms of MDF, a primer coat is applied and thereafter the final white topcoat lacquer. Given the segment of the market serviced by Natwood, margins are under tremendous

pressure with process efficiency therefor of tantamount importance. Prior to the Venjakob's installation, finishing was the major production bottleneck that Natwood struggled with and where they had most trouble keeping costs in check. At the time, all the finishing was performed by hand with three day shift and three night shift spray painters handling all of the finishing on solids and two spray painters handling the day and night shift on MDF.

The duplication of spray painters, the relative inefficiency of them (40% transfer efficiency typically achieved when hand spraying), the inability to recover overspray and the nature of Natwood's product range that negates against the acquisition of a roller coater lacquer system, motivated Natwood to investigate the viability of acquiring the Venjakob system. The efficiencies realised through the Venjakob is impressive. In the first instance labourforce size and the associated costs are substantially reduced. Natwood reduced its spraypainter team to one x dayshift and one x nightshift spraypainter with the rest redeployed to different sections of the their production facility. Given the ability of the Venjakob to recover overspray, Natwood now achieves a 30% recovery of material previously lost (50% transferred onto product; 30% recovered if solvent is added back in; 20% of volatiles lost through chute). Going hand in hand with the recovery of materials is the control that the Venjakob allows for during the spaying process.

Typically, by hand, no control over the amount of material landing on the product is possible and no control exists to limit spraypainters from covering a given area twice. With the Venjakob, the amount of material eventually deposited onto products can be controlled to enable exact delivery of material quantities onto wood, eg 80 g/m2.

Productivity in terms of the finishing processes at Natwood has improved significantly as a consequence of the Venjakob's installation. In fact, the limiting factor at Natwood, if productivity is considered, now revolves around the length of their drying tunnel. Once product has exited the Venjakob, it passes through a flash-off tunnel. The flash-off system has a positive pressure with 10% more air being sucked in than expelled which then clears the solvents with the noxious parts extracted by the Venjakob. After passing through the flash-off tunnel, product is racked and ready for the drying tunnel or oven. Once in the drying tunnel which varies in terms of temperature from 30 - 47° C and is 14 m long, drying trolleys containing product ratchets forward plus minus every two minutes by 0,5 m/ratchet which translates into product being in the tunnel for approximately 50 minutes depending on
the coating and the baking requirement of that. Given the volumes that the Venjakob generates, the drying tunnel needs to be managed extremely well to cope with
the volumes.

A further factor thar has slightly inhibited the Venjakob's performance has been the quality of the raw material received from suppliers. Through no fault of the Venjakob, this has caused downtime to correct the difficulty with the suppliers, which they then promptly attended to. Quality of finishing has been a further contributor to the net increase of Natwood's productivity. The Venjakob can handle both acid catalysed and water based lacquers with the latter being of special significance to Natwood. Legislation is currently in the pipeline that when passed, will dictate that all finishes on wood products use water-based lacquers. When that happens, Natwood can accomplish the changeover given the through the functionality provided by the Venjakob, they will have the ability to change. Secondly, should Natwood wish to expand export volumes, the use of water-based lacquers is the trend abroad and by acquiring the Venjakob, Natwood would be in a favorable position to deliver product with the appropriate finish.

As mentioned, a major benefit that the Venjakob brings to the table is the recovery of overspray. Being a fully enclos wet-spray booth finishing system, every droplet that is sprayed inside the booth gets directed to the product by the push and pull spray action of the air assisted airless sprayguns with particles emitted that do not go onto the product through spraying, down drafted onto product by the supply air stream or settling on the special polyster type belt. Material landing on the belt is recovered and finally washed off the belt in a two-phase process. The first phase - material recovery - is situated underneath the outfeed side table and consists of a crossbelt unit that wipes the overspray off the belt whereafter it's collected in a collection bin. During phase two - belt cleaning - the conveyor belt passes between a set of four offset rollers, placed over and under the belt that wash the remaining material off the belt with cleaning solvents whereafter it passes through a rubber drying blade to remove final cleaning solvent still left on the belt. The PVC belt itself is temperature resistant up to 90° C and is driven through a frequency inverter variable speed drive.

The Venjakob "reads" what is placed on the infeed table through a photoelectric transistor bridge. Light sensors at the entrance of the sprayer send precise material shape and size information to the EPS-CNC electronic gun control unit that allows for the precise position of the guns as to where spraying should start and end. The fully enclosed, linear, reciprocating-type gun carrier can be fitted with up to four spray guns. Push and pull spraygun positions allow for the total coverage of the component being sprayed. Airless air assisted nozzles contribute towards the precise delivery of material to product. The supply air filter is integrated into the top of the booth with full width out-blow area for even and controlled input of air. The "dry" exhaust system contains a three-stage filter, one x paper Andrea filter and two x mesh fine dry filter element located on either side of the conveyor with an exhaust fan mounted under the conveyor.

The spray booth itself is equipped with double folding doors with windows at the servicing end of the booth and large observation windows on the non-service end. The interior of the booth is illuminated through a fluorescent lamp. Above the service doors, the servicing panel contains all the elements for operating the machine including amongst others pressure regulators, monometres and gun test buttons. The menu guide on the Windowsbased controller includes process visualisation, parameter listing, surface programming and gun and machine control, selfdiagnostic system which displays a picture of any element of the machine that may have caused the stoppage.

The flash-off tunnel and the drying tunnel were designed and constructed by Allen Connolly himself to meet budgetary demands.

To conclude, the Venjakob installation brought distinct benefits to Natwood. The most important of those are the ability to recover oversprayed material, the quality and efficiency of the spraying process as mediated by the Venjakob and the commensurate improvement of overall productivity. Sounds like it's still paying for itself.

	The four sprayguns mounted on the fully enclosed linear reciprocating-type gun carrier with four guns mounted thereon. Each gun is wrapped in silk stockings to enable easy cleaning. Note the angle of the guns and, when combined with the pull-push action of the four guns, maximum coverage of l! /(' product is achieved. The product in view passes through the Venjakob twice (01 top and bottom coverage. The supply air filter is viewed at the top of tl1 booth and the dry exhaust system on either side of the conveyor
	The Venjakob unit viewed from the service end. The double folding doors which interlock allow for maximum viewing of the spray proces. In the background, the high peressure pump that delivers raw material to the spray guns.
	The control panel of the Venjakob with in the background, the photoelectric transistor bridge over the infeed table. Light sensors at the entrance of the sprayer send precise material shape, position and size information to the EPS-CNC electronic gun control unit that allows for the precise positioning of the guns where spraying shauld start and end
	The first phase of the material recovery process where a cross belt unit wipes the overspray off and finally delivers into a container. Once solvents are added back in, the material is ready for yet another round .
	Phase two - belt cleaning. The conveyor belt passes between a set of four offset rollers, placed over and under the belt that wash the remaining material off the belt with thinners whereafter it passes through a scraping blade to remove final material residue still left on the belt