Description:

• Film hardness is an important physical properties of coating, which directly affects the coating of some important properties, such as wear resistance, wear resistance performance, frictional resistance, scratch resistance, impact resistance and film conventions and cleaning ease, so the coating hardness evaluation of coating performance measurement indicators. With the instrument can be easily measuring film hardness.

Working principle:

• The instruments are mainly made up of pencil and test-bed aircraft, pencils and column is composed of four-bar structure, ensure that the weights of the weight perpendicular to the pencil and test-bed on the intersection points, and pencil and test-bed to a 45 ° angle, and remains unchanged. Test bench can be horizontal, vertical, and used it to fix the paint sample and sample sliding towards the scratches, pencil in, try and draw the corresponding track. Swap with a different pencil to draw the different traces, which can determine the hardness of coating.

Requirements:

• Test piece: according to customer requirements, making samples, make it fixed on top of the sliding table.
• Application environment: normal temperature and humidity.

Operation and usage:

Prepare

• GB1727-70 asked 120*50* (0.2-0.3) product requirement for smooth plate of tinplate or substrate prepared by coating.
• Using a pencil knife front-cut wooden parts of each pencil, exposing the 5-6mm cylinder refills (note that the lead pencil is not loose or cut injuries), hand holding a pencil, the pencil is always 90 ° angle with the No. 400 sandpaper, sand paper rubbing lead end, until you have smooth edges sharp pen at one end (the edge without a break or gap)
• Insert a pencil sharpened pencil rack. Adjust the pencil, pencil end coinciding with the weight of gravity (lead 25mm end with a pencil), and then use the screw, so pencil in position.
• Loosen the clamping nut, into the required determination of coating film, and then tighten the nut, so try fixing.
• Loosen the set screw, adjust the counterweight, so balance (pencil is just touching the test piece), and then tighten the set screw, pencil face left coated test piece.
• Rack weight lightly in pencil.

B test

• Loosen the set screw, make pencil gently lowered to the coating on the specimen to be measured.
• Turn the handwheel, so that coating scratches direction around 5mm (hand wheel clockwise), and observe the surface is cut.
• Remove the weight, replace the pencil, try rotating knob, tester, vertical distance replaced film scratches, repeatedly preparing the operation, then do the next test, in turn, each type of hardness a plow out of the five marks.
• Starting from the hardest pencil with this method, when the identification of five marks, if there are two or more plows when hurt, change level pencil until five marks, only plow once hurt coating pencil (or no damage). Pencil hardness values this level represents the hardness of the coating under test.

Routine maintenance:

• Operation of this instrument is to flexible rotation, after a period of use, screw and rotating parts such as bearings into the oil.
• After a period of use of this instrument, set screws, nut is tightened, so as not to loose.