With the Gardner test you can test critical drying of the paint. The Gardner wheel combines the exposure of UV light with cold hydrolysed water. What happens is that the wood panel will exhibit shrink and swell behavior much faster than in a real building.
This allows us to test the elasticity of the paint very well. It also provides good insight into whether the paint formulation can withstand extreme climates with rapidly changing temperatures. The wheel turns with a certain speed and in one direction for several weeks.
This type of testing is one of the most extreme tests for polymers.
Accelerated weathering testing (video example here) is similar to the Gardner wheel but here is a constant exposure of UV-light. To simulate outdoor weathering, the QUV accelerated tester exposes wooden panels with paint finishes to alternating cycles of UV light and moisture at controlled, elevated temperatures.
It simulates the effects of natural sunlight and artificial irradiance using special fluorescent UV lamps in the UVA, UVB, and UVC portions of the spectrum.
All our exterior coating systems, includeing Hydrolux, Ankolux and Aplex Aqua have been exposed to this test method and achieved great results.
Outdoor exposure racking
On different locations across the Netherlands (in Gorredijk, located 50 kilometres from the North Sea) and United Kingdom (Peterborough), we expose our products to the natural influence of the climate. We also have a cooperation exposure racking with Accoya, located in Arnhem, the Netherlands.
In these racking we follow the EN927 procedure, meaning that the wooden panels are faced south. All products of Anker Stuy Coatings are exposed to this testing method which gives a real and honest result of the performance of our coating systems and the specific type of wood.
Each six months a inspection is being done and logged in our database. In this way we have a real expectation of outdoor durability and maintenance indication.
Water uptake tests
Our exterior coatings systems are tested following the KOMO water uptake standards.
- The coating system is applied by Airless/Airmix spraying system on 5 Norway spruce panels.
- The film build up is controlled by weighing the amount of applied paint for each panel per layer.
- The coating system is dried according to ‘Quick Scan conditions’ as indicated by the manufacturer.
- The paint system is tested in the colours RAL 1013 and RAL 7026.
After drying the panels are weighed, placed in fresh demineralised water for 72 hours and afterwards 48 hours in a fridge with -5 degrees and then weighed again.
Then the water uptake and (directly) adhesion are determined. Finally, the panels are evaluated according to ISO 4628-4, -5 and –2 (degree of cracking, flaking and blistering).
Monitoring of raw materials following a certificate of analysis
Paint formulations have about 10 to 20 ingredients. All these ingredients must meet the standards that you have agreed with the supplier. We work according to a certification of analysis.
This means that the specifications of each raw material are determined in advance. Each delivery is inspected and checked to see whether the raw material meets the pre-agreed specifications. This allows us to guarantee our quality and the customer is assured of an optimal end product.
Depending on the raw materials, different methods are used. For example, PH value is one of them. By working with this system, we also put our suppliers on edge and such delivery errors have already been prevented and thus potential complaints in the future.
Quality assurance for each produced batch
All of our produced batches are subject to quality checks before they are allowed to leave the factory. For paint products, this quality assurance consists, for example, of measuring drying, PH value, solids content, gloss and fineness of the product.
Our inspection lab consists of two employees who are responsible for the quality inspection. They have the authority to approve or, where necessary, adjust batches produced before they can be processed further. By applying this system we can guarantee the quality of our products.
100% total and complete product
Did you know that Anker Stuy produces its own colour pigment pastes? Most paint manufacturing companies buy them elsewhere, because this is a labor intensive process and something that deserves continuous attention.
Pigments are available on the market from cheap and low quality (for instance for paint for kids) up to exclusive high quality pigments, such as the automobile industry. As we select our own pigments from suppliers, we determine what quality they must meet.
The colour pigments have an enormous influence on the colour fastness of the product in combination with outdoor durability. In addition, the pigments also influence the gloss reduction and craters that might appear over time.
The photo is a good indication and shows the difference between 8 years outside exhibition with a standard pigment paste (on the left left) and a sample with our own colour paste (on the right). You can see that the colour fastness of our pigments perform better.
Besides all these testing methods mentioned above, we conduct even more tests when we start to formulate or work with new raw materials.
Depending on the purpose and application of the product we might conduct testings such as bend and flex testing, creep and stress rupture testing, impact testing, shear testing, tear testing, fracture toughness testing and more.