VR201.2 – IGP coating powder in the IGP-Effectives® process
Introduction
IGP-Effectives® is an innovative finishing process. This process gives effective powder coatings exceptional application reliability.
In contrast to conventional effect powder coatings, the application parameters or even the system configuration have only a minor influence on a perfect coating result. Processing parameters and reclaiming mode only lead to very small differences in colour and effect. Regardless of the system and the Application, IGP-Effectives® generally produces a uniform coating result.
This processing guideline VR 201.2 has been drawn up to draw the user's attention to the relevant processing characteristics of IGP-Effectives®.
In principle, IGP coating powders with effect agents are agglomerate-free and fulfil the requirements for problem-free and reproducible processing. There are five main processing categories for IGP effect powder coatings, ranging from * to *****. The products in the
IGP-Effectives® group are all labelled 5* and therefore do not place any higher demands on the coater than the processing of uni powder coatings.
Fundamentals
First and foremost, these effect powder coatings are application reliable, very stable in circulation and ideally suited for processing in reclaiming mode.
The otherwise very high demands on the processing of effect powder coatings are significantly reduced by the application of IGP-Effectives® technology. The user receives a product that is easy and safe to process while maintaining known quality criteria in the application process.
IGP-Effectives® technology is primarily used for weathering-resistant façade qualities of the product series 56, 57 and 59 (e.g. 5607U; 5703U, 5903U,) and is labelled with a "U" in the fifth position of the product key.
Order organisation
One batch - one application equipment
If the components are installed directly next to each other, we recommend determining the amount of powder required for coating the entire job, allowing for a certain reserve and coating the entire job with one finished batch of paint. This ensures colour and effect consistency when coating the entire order. For follow-up orders, we recommend only using powder coatings that have also been produced using IGP-Effectives® technology.
Processing
Processing of IGP-Effectives® powder coating products should always be carried out using corona guns with electrostatic charge in negative polarity. For this purpose, we recommend a high voltage setting of 60 to 90 KV.
With an electron flow of at least 2µA, the products can also be processed with tribo guns. We recommend spraying and curing a sample before starting production. This should be compared with an approved limit sample. Depending on the electron flow (µA), different nuances in brightness may occur when processing with tribo guns.
In order to produce a smooth, even surface, especially on large objects, the spraying distance from the gun should not be less than 180 mm. Further measures within the Application, such as optimising the movement sequences in long-stroke operation using sinusoidal programs, or adjusting the distances between the guns and the stroke height in short-stroke operation, ensure the best possible coating thickness distribution on the workpieces to be coated.
Ideally, any manual application required in semi-automatic operation is always carried out as a pre-coating. If this is not possible for technical reasons, IGP-Effectives® powder coatings can also be applied by hand as a follow-up coating. In this case, we recommend a spraying distance of at least 200 mm for the final coat. This also applies to Processing in pure manual coating operation.
For fine structure powder coatings, VR 214 "IGP fine structures" must also be observed.
Reclaiming
In principle, IGP-Effectives® effect powder coatings are very stable in circulation and ideally suited for processing in reclaiming mode.
The proportion of overspray that is reclaimed via the separation system can lead to an accumulation of fine powder particles (fines) during reclaiming using a filter. When processing IGP-Effectives® in reclaiming mode using a cyclone, fine powder particles (fines) are continuously removed from the powder coating. In both cases, there is a shift in the particle distribution.
In order to ensure the most consistent particle distribution possible when processing in reclaiming mode, we recommend the continuous addition of fresh powder.
Maintenance and Cleaning of the system
To ensure reducible coating results on the coating plants, the maintenance work recommended by the manufacturer to replace wearing parts must be carried out on the entire system at the intervals provided for this purpose. Various functional checks, such as checking the high voltage, must be carried out at regular intervals.
Mounting the parts
The mounting of the workpieces must be determined before coating (horizontal or vertical). The distances between the coating objects within the hanger as well as the distances between the hangers should be as small and even as possible. If the distances between the hangers are large, it is advisable to switch the guns on and off automatically via a parts detection system.
Curing
Different curing temperatures and heating speeds of the parts must be avoided, just as thick and thin-walled parts must not be coated at the same time. The recommended curing window must be adhered to.
Earthing
When processing coating powders with pearl mica effect, particular care must be taken to ensure sufficient earthing. This measure contributes significantly to a uniform consistency of the shade and effect formation.
Recommendations for Processing IGP-Effectives®
The values given here are recommendations. When processing IGP-Effectives®, we recommend adapting the processing parameters of the coating plants to the product to be processed.
| Equipment and processing parameters (equipment / accessories) | Setting (parameter) according to categorisation | Possible effect (comment) |
|---|---|---|
| ***** | ||
| High voltage setting (gun) | 60 - 90 kV | Setting range for Processing |
| Current limiter µA (gun) | 80 µA → < 10 µA → | → For normal operation → Reduces spray-back effects |
| Total airm3/h/ conveying + dosing air (inner diameter of powder hose) | 12 mm = 5m3/h 11 mm = 4m3/h 10 mm = 3m3/h | Prevents pulsation of the powder cloud, ensures optimum atomisation. |
| POE powder hose with integrated earthing (injector gun) | Injector grounding | Prevents electrostatic charge of the powder in the powder hose. |
| Nozzle (gun) with flat spray nozzles | Suitable | Good depth, even atomisation |
| Nozzle (gun) with baffle plate | Suitable | Reduced depth of atomisation |
| Processing with ion-leakage ring (gun) | Suitable with or without | Reduces spray-back effects, improves levelling properties with Film thicknesses > 120 μm. |
| Coating spraying distance (gun-workpiece) | >180mm | Uniform layer thickness distribution |
| Coating with tribo guns (guns) | Possible with tribosuitable products after checking the shade | Brightness differs in nuances compared to corona coating |
| Powder delivery with fluidised container | Well suited, fluidising air as required | Uniform powder feed and powder cloud |
| Powder delivery from the box | Suitable | Slightly irregular conveying in some cases. |
| Screening with US screen (screening machine) | Suitable with mesh size >140µm | Better fluidisation more slippery Application |
| Maximum proportion of reclaimed powder in recirculation mode without testing the shade | <90% | Risk of shifting the particle size distribution with a higher proportion |
| Document processing parameters (control unit programme) | Recommended, but not necessary | Facilitates reproducibility of the coating results |
| Limit sample in advance | Not necessary, incoming inspection sufficient | Prevents excessive colour deviations from being subsequently coated |
| Coating on different coating plants | Possible | The same batch should be used on all systems |
| Manual pre-coating of the workpieces in semi-automatic operation | Possible | With spraying distance >200mm |
| Manual follow-up coating of the workpieces in semi-automatic operation | Possible | With spraying distance >200mm |
| Manual coating only | Possible | With spraying distance >200mm |
