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Differential scanning calorimetry for coating curing
Via the DSC technique it can be verified if the coating is sufficiently cured or not. The DSC is a technique verifying how much energy is needed to have no temperature difference between the substance in test phase and the referential material, determined in according to time and temperature, when two specimen are submitted to identical temperature conditions in a controlled warm or cooled environment. First of all, the thermal history of the material is disturbed by the fast coolRead More …
Test Standard for weathering resistance of powder coatings
Resistance to mortar According to the standard ASTM C207. A specific mortar will be brought in contact with powder coating during 24h at 23°C and 50% relative humidity. Accelerated ageing and UV durability (QUV) This test in the QUV-weatherometer consists of 2 cycles. The coated testpanels are 8h exposed to UV-light and 4h to condensation. This is repeated during 1000h. Every 250h the panels are checked. Herewith the coating is tested on colour- and gloss retention. Saltspraytest According to theRead More …
General Mechanical properties of powder coatings
Cross-cut Test (adhesion) According the standards ISO 2409, ASTM D3359 or DIN 53151. On the coated test panel a cross-cut (# : indentations in the form of a cross and parallel to each other with a mutual distance of 1 mm or 2 mm) is made on the metal. A standard tape is put on the cross-cut. The cross-cut is valued through the quantity of the detached film after removing the tape. Flexibility A coated standard test panel is foldedRead More …
Production process of powder coatings
Premix The different dry raw materials (resin, hardener, pigment, additive, filler) are weighed in exact quantity and put in a container. This container will be tumbled or mixed during a determined time so that the raw materials are well mixed. A rather homogeneous distribution is obtained. The container is brought to the extruder, after control on homogeneity. Extrusion In the extruder, ingredients are warmed up to a sort of paste, mixed and kneaded. On molecular scale resin and hardener willRead More …
Five categories of additives in the compostion of powder coatings
This collective name for a big group of additives, to realise determined properties of the coating.5 categories exist : Accelerators (to accelerate the reaction of the curing system) Degassing additives (to let escape enclosed gases through the pores of the coating by opening them longer) Thixotropic additives (to resist sagging outs = viscosity regulator) Flow-control agent (to improve the flow on the surface) Matting agent (to reduce the gloss of powder coatings)
Chemical stripping solutions for removing powder coating
Chemical stripping solutions is an common and efficent way for removing powder coating and e-coatng. Benefits. A chemical stripping process can be done in-plant at considerably less expense than the burn-off and the abrasive-media blasting methods, which require higher equipment, energy, and media costs than chemical stripping requires. Chemical stripping operates at moderate temperatures, usually 150°F to 200°F, which keeps energy costs down. Chemical stripping also leaves the original surface of the racks intact and very clean after a freshwater rinse.Read More …
How to remove powder coating and electro-deposition coating
Many methods have been used to remove powder coating and electro-deposition coating from production hooks,racks,and fixtures. Abrasive-media blasting Benefits. Abrasive-media blasting is a common method used in the finishing industry to clean electro-deposition and powder coatings deposits from racks. Abrasive-media blasting provides adequate cleaning and coating removal. One of the benefits of rack cleaning with abrasive media is any rust or oxidation that may be present is removed with the coating, and this is accomplished at ambient, or room, temperature. Concerns. Using abrasive mediaRead More …
Some ingredients may influence the antibacterial performance
Presence of some ingredients in the formulation may influence the antibacterial performance of silver additives.Some antioxidants, imdidazole derivatives and fillers like calcium carbonate may influence the antibacterial performance of powder.One more suspect is barium sulphate which might spoil the activity of silver because sulphur has a feature which reacts with silver easily. As silver ions have a tendency to react with atmosphere sulphur and exchange the ions it may have some impact. However our present experiments show good performance withRead More …
Coating thickness and silver addivtive dosage effect the antimicrobial performance
Dry film thickness of coatings Silver additive is necessary to expose appropriately on the top surface of the coated components for better antibacterial performance. Migration of antibacterial agent to the surface of the coatings is most important to achieve the best antibacterial protection. However this migration depends on number of factors such as thickness of the coatings, binder content, recipe of formulation, dosage level of antibacterial agent, degree of cross linking, cross reaction of antibacterial agent with other ingredients(i.e. disturbanceRead More …
Mechanism of silver technology used in antibacterial powder coating
For the present study inorganic antibacterial agent silver type is used. Five different types of silver additives are tried. The silver additives used is a composite of active silver ions, sodium ions and other ions (e.g. Zn). In some additives silver is embedded into a base material such as zeolite & glass matrix etc. Silver ion is a natural inorganic antibacterial agent which is effective in fighting against bacteria, fungi& moulds. Silver ion is generally preferred for its a. BacterialRead More …
D5 Creation