- March 10, 2022
- Posted by: admin
- Category: News & Atricles
Paint test equipment’s
The purpose of paint testing is to help and ensure that the minimum requirements for ingredients and material characterization are met by the manufacturer on a batch basis, and to help ensure that the formulated product will provide satisfactory performance in the environment.
In order to prevent defects in post-production or, at least, to determine the causes defects and failures that may occur on the products, It is important to verify the characteristics of the coatings with regard to thickness, hardness, adhesion to the substrate, color, resistance to corrosion and to climatic agents.
Hegman Gauge or Fineness of Grind Gauge
The fineness of grind is particularly important during the manufacture of pigmented products. Grind gauge is to indicate the fineness of grind or the presence of coarse pigment particles in sample. Grind gauge are used in controlling the production, and application of dispersion by milling in the paint, plastic pigment, printing, ink, paper and pharmaceuticals.
Fineness of Grind Gauge (Hegman Gauge) is a precision gauge manufactured from hardened stainless steel and has two ground channels giving scales of both microns and hegman scale. Grind Gauge is supplied complete with scraper blade.
ASTM D 333, BS 3900
0 – 25 Microns, (8 – 6)Hegman.
0 – 50 Microns, (8 – 4)Hegman.
0 – 100 Microns, (8 – 0)Hegman.
- Place the gauge on a flat, horizontal and non slip surface, with the zero mark on the scale closest to the user.
- Place a suitable amount of the material in the deep end of each groove.
- Place the scraper on the surface of the gauge behind the material. Use both hands to hold the scraper.
- Pull the scraper along the length of the gauge at a constant speed. Stop at a point beyond the zero depth this operation should take approximately 2 – 3 seconds.
- View the drawn out material within the next 3 seconds. This avoids inaccurate testing due to evaporation of the material. The material should be viewed at right angles to the length of the groove and at an angle of 200 to 300 with the surface of the gauge.
- Perform two more tests and calculate the visually value of the result. The average value is the fineness of grind of the material.
- Use a suitable solvent to clean the gauge and scraper.
Flow Cup Viscometer or B4 Cup
Viscosity Flow Cups are very easy to use instruments made of brass or anodized aluminum with a stainless steel orifice, for measuring the consistency of paints, varnishes and similar products. Measured value will get in seconds with digital watch multi-functional (1/100 sec.). For measuring time value.
IS 101, ( Part 1/ Sec 5 ) 1989 DIN 53211, ASTM D 1200
|Flow Cup||Orifice diameter|
The general test process is described as follows:
- Level stand using spirit level
- Place cup in the stand or in temperature control vessel
- Close nozzle
- Fill with fluid
- Wipe off surplus material across the edge of the cup with a glass plate, and close cup with finger or glass plate.
- Open nozzle
- Pull off glass plate horizontally and simultaneously set stop watch in motion
- At the first break off in the fluid flow stop watch and note time
Further details are described in the various standards. It is to be noted that the cups are only calibrated for the specified ranges and for the specified flow times.
In addition, it is particularly important to follow the instructions concerning temperatures carefully. Only a small difference could lead to considerable changes and hence wrong measuring results.
Of particular importance is to understand that it is not sufficient just to make sure that the fluid is at the right temperature: the Viscosity cup must also be at the correct temperature, if necessary by surrounding it with a temperature control cover so that the intended temperature is maintained. It is also essential to check the temperature of the jet of fluid coming out of the cup, since it is at this point that the actual temperature of the fluid being measured can be established. Comparable reproducible results are only possible if the temperature is kept fully under control.
Care and Maintenance
After making a measurement the flow cup particularly the nozzle must be carefully cleaned without, however, using any hard or sharp implements. If remnants of fluid (paint) remain in the nozzle the diameter of the orifice will be altered and the cup can no longer give accurate measuring results.