Over the last few years, one of the main growth areas in PVCu windows and doors has been the demand for colour. So, in the 3rd part of our ‘behind the scenes’ at Selecta Systems feature, we take a look at the foiling process. Lamination Manager, Dan Coton, takes us in to the colourful world of PVCu profile lamination.
It’s fairly obvious that colour remains high on the homeowner’s agenda as they look to windows and doors that are not only secure and thermally efficient, but that they also complement the style, period and location of their property. This is where colour choice comes in and opens up further opportunities. Consumer demand for coloured PVCu windows and doors has driven innovation in coloured foil options, whilst the development of lamination technology and machinery has seen Selecta invest in this key area.
The Selecta lamination process begins with a daily stock control and production planning meeting between Mark Roberts, Stock Control and Purchasing Manager, and myself. These daily meetings are key to our production planning, as stocks and orders fluctuate on a daily basis. It’s important that we keep an eye on this ever-changing landscape, to ensure that the process is as efficient and effective as is possible, whilst also forward planning any special orders that have been placed in the 24-hour period.
We laminate a range of coloured profiles to stock, not to order, so production planning within the department focuses on a number of factors that determine product runs. Stock levels are an obvious trigger, but it is also important to align this with existing planned production and what special colour orders are currently within the system. It’s easier to slot in a run of the same profile section, but different colour, than to plan it further down the line as this reduces set-up times. We would rather have the machines running consistently and efficiently, rather than stop starting, adding to set-up times, downtime and waste.
Planned runs can be brought forward or pushed back, dependant on the day’s circumstances, needs and demands. That’s why production planning meetings are such an important part of the process, so that these fluctuations can be factored in to daily and weekly plans. Production plans are forever changing and management of this is key.
Production planning also incorporates profile and foil stocking for each production run. Profiles are run to stock in the extrusion and it’s important that the coloured profile substrate is available for picking when required, with foils stocks sufficient to cover. Selecta has invested heavily in increasing the volumes and a range of foil stocks over the last couple of years.
Lamination of PVCu Profiles
A profile section and foil colour requirement is assigned to a particular lamination machine. There are three foiled section possibilities – foil on the bead side face, non-bead side face or both sides of the profile section. A single face profile section set-up on a machine, will very often follow with colour changes throughout the run. For instance, once set-up for a particular section has been completed it is far more efficient to run, let’s say, anthracite grey for the required stock run and then follow this with other stock colours or a special colour, than it is to change over to another section. This will happen even if stock is still available for that profile colour, but we will boost the stock levels further.
Lamination technology has improved considerably over the years with the new machines now all computerised in the respect of primer and adhesive application. The profile section face width is programmed in to the machines computer along with the adhesive weight and spread. The adhesive weight adjusts the thickness of the adhesive, whilst heater settings warm up the profile section and adhesive to make it ‘tackier’ and adjust its adhesiveness.
The set-up of the lamination machine takes on average between 30-45 minutes per side of a profile section. Each forming wheel, guide and cutter is manually adjusted and set to ensure that when the foil is fed on to the profile, each surface, chamfer, sculpture and lip is covered by the foil and formed in to the shape. The coloured foil is oversized to cover the face of the profile section, with the lamination machine cutters trimming the excess foil to the gasket and bead chamber. The correct size of protective tape is put on the feeding wheel, to cover the newly foiled profile section face. Profile section runners are used to fine tune the settings, before the required production quality is achieved and production is approved to continue.
The line speed is set accordingly to the profile section with an average of 15-16 metres per minute. However, this is sometimes determined by pack quantities, as we pack profiles on-line, whereas other lamination houses may pack offline and up line speeds. So, we effectively run, inspect and bag two and half lengths per minute of a one-sided coloured profile section. We see this as a more efficient and effective way of production and it also factors in on-line QC inspection as well as packing.
With each lamination machine approximately 18 metres in length, they require four operatives to be able to run efficiently and effectively. The lamination process starts with the feeder operative wiping the profile down to remove any contaminants, then feeding the profile section along the roller bed in to the machines wheels and guides. The profile section hits the machines priming station first, which contains a chemical cleaner and part adhesive, before heaters dry, warm and prepare the section for the foil. The machine applies the adhesive directly to the foil at the head of the machine, where a foil feeder wheel transfers the foil to the profile section.
The profile section meets with the foil and the wheels, guides and cutters ensure the surface is covered, whilst the machine operator / setter carries out the on-line QC inspection to ensure that there are no imperfections, foreign bodies under the foil and that it has adhered to the profile. Once the protective tape is applied by the machine wheels, the profile is fed on to the roller bed and two packers inspect, bag and lift the finished profile section in to the stillage.
Where two sides are required, the section may be moved on to another machine that is running a similar sized section face or await the second side to be run according to the production plan. The lamination process is repeated for the second side.
The finished coloured profiles are then transferred in to stock and special orders allocated to customers, awaiting picking for their next delivery. Regular external pull tests are carried out, where a weight is applied to the foil to check the adhesion strength of the foil to the profile sections and delamination.
Positive Investments and Environmental Impact
There is an ongoing investment in colour at Selecta with further plant, machinery and infrastructure plans afoot. The new lamination machines upgraded performance capabilities have improved efficiency and output quality, providing greater foil adhesion and a superior foiled finish.
This has also been a big part of our environmental and sustainability programme, with Selecta’s impact on the environment greatly reduced, with all of the solvent-based machines now replaced. The more environmentally friendly hot melt lamination machines have eliminated solvent emissions and improved waste stream management significantly. So, whether it’s standard white or foiled anthracite grey, black, cream or chartwell green, Selecta don’t believe it should be referred to as just a window, door or piece of plastic. To us it is and will continue to be that precision engineered product.