India Powder Coating

Lalaram Nagar, Indore, Madhya Pradesh

This collective name for a big group of additives, to realise determined properties of the coating. 5 categories exist : a. accelerators (to accelerate the reaction of the curing system) b. degassing additives (to let escape enclosed gases through the pores of the coating by opening them longer) c. thixotropic additives (to resist sagging outs = viscosity regulator) d. flow-control agent (to improve the flow on the surface) e. matting agent (to reduce the gloss of powder coatings)

Terephthalic acid is the organic compound with formula C6H4(COOH)2. This colourless solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several billion kilograms are produced annually. It is one of three isomeric phthalic acids. Properties Terephthalic acid is poorly soluble in water and alcohols, consequently up until around 1970 most crude terephthalic acid was converted to the dimethyl ester for purification. It sublimes when heated. Production Terephthalic acid is produced by oxidation of p-xylene by oxygen in air: The oxidation is conducted using acetic acid as solvent and a catalyst composed of cobalt and manganese salts, using a bromide promoter. The yield is nearly quantitative. The most problematic impurity is 4-formylbenzoic acid, which is removed by hydrogenation of a hot aqueous solution. The solution is then cooled in a stepwise manner to crystallize highly pure terephthalic acid.

Neopentylglycol (NPG) is a unique polyalcohol offering superior performance advantages in many end-use applications due to its high chemical and thermal stability. Neopentylglycol (2, 2-dimethyl-1, 3-propanediol) is a unique diol offering superior performance advantages in many end-use applications. These advantages are derived from its chemical structure. The location of the hydroxyl groups on primary carbon atoms allows rapid esterification. Additionally, the two methyl groups, instead of the usual two hydrogen atoms, on the alpha carbon atom are responsible for the high chemical and thermal stability of Neopentylglycol and it derivatives. Application Neopentylglycol (NPG), or 2, 2-dimethyl-1, 3-propanediol, is mainly used as a building block in polyester resins for coatings, unsaturated polyesters, lubricants and plasticizers.

When a manufactured part is coated there may be certain areas of the surface that must be free of coating. For example, threaded areas may not fit properly if they are coated. Bearing surfaces with close tolerance cannot be coated. Some parts may require a bare spot for electrical-grounding contact. It is important to select a mask that is effective, easy to use and reasonable in cost. Masking may be done by caps, plugs, tapes, stoppers etc. Masking parts will add additional labor to the coating process. It is important to understand the different types of masking products that can be used. Masking can be as simple as placing a plug in a single hole or it may require a specially made mask or fixture. One large hole in a large part will require very little labor while some smaller parts may have numerous spots that need masking and require a lot of labor. Selection of the right masking procedure will affect the cost of the part. The mask must be reasonable in cost and it must do an effective job of keeping the coating off the masked surface.

The purpose of scratch hard­ness tests is to determine the resistance of coating materials or lacquers to scratch effects on the surface. Generally, scratch hardness is measured by moving a sharp object under a known pressure over the test surface. Here is informative video on how to properly set up and use a pencil hardness tester, or scratch tester.