Circular Drying Time Recorder

Do you like watching paint dry? No, of course not, but when developing a paint or coatings system it is imperative to know just how long the process takes for it to dry or cure. That process is known as drying time and establishing one is an essential parameter for Research and Development (R&D) and Quality Control (QC) as it determines when a painted or coated part can be put into use.

Our GARDCO Ultracycle Circular Drying Time Recorder (DTR) is a simple and practical tool for use in the laboratory or a QC environment and provides a robust and inexpensive method to control drying time. The GARDCO Ultracycle Circular Drying Time Recorder can be used on any type of flat substrate, such as wood, glass, plastic, metal or even drawdown charts. Which makes the DTR a very suitable instrument for many applications as it can be to be used with a myriad of substrates and allows the flexibility to make tests directly on your finished product.

It is also important to note that drying time can be affected by environmental factors like temperature and humidity, and by using the GARDCO Ultracycle Circular DTR valuable drying behaviors can be measured and quantified. It automatically records these conditions with its built-in temperature and relative humidity sensor and eliminates the need for the user to have other instrumentation to document the environmental conditions.

Just apply the paint or coating to your substrate using an applicator such as Microm Film Applicator, Mayer Rod or Bar Type Applicator. Immediately after application the DTR can be placed directly on the coated substrate, and the testing can begin. The DTR uses a 10mm (3/8”) diameter Teflon ball stylus that is dragged through the coating, and as this is happening the stylus leaves a track in its wake. This track is later used to determine the drying time as outlined in Standard Test Method ASTM D5895. Drying time can be recorded from 1 minute up to 99 hours.

On/Off Button - This button operates from any mode. When pressed, the unit will display the Temperature or, "Press Start" and the Green L.E.D. power indicator will light. Pressing the button again will turn the unit off and interrupt any test in progress, including any changes being made to the configuration data.

Menu Button - Pressing this button will take you into the configuration menus. This can only be done with the unit on and no test running. The new configuration will be stored in memory when this button is pressed so that the display returns to the start test screen. Operating Instructions

Scroll Button - This button only works in the configuration mode. Pressing this button will advance through the hour range. In the operation mode, pressing this button will display relative humidity with min max values of current test.

Start Button - This starts the test. The motor will continue to run, and the elapsed time will be displayed until the stop or on/off button is pressed. The Red L.E.D. Motor Run indicator will also light. When the Unit is first powered up, the display will show "Drying Time Recorder" for 5 seconds and then show "Unit Off Press Start".

Stop Button - This stops the test. The motor will stop and the L.E.D. will go out. The elapsed time of the test will be reset. Center timer on test panel making sure the arm is counter-rotated eliminating any play in the clockwise motion of the arm. Make sure the Teflon® ball stylus impinges the painted surface. This is done by adjusting the counterweight at rear of stylus arm to a balanced position. The 12 gram weight is then mounted on the stylus spindle extending above the rotating arm to give a calibrated weight load. Weight load on the ball can be adjusted by operator so that results will closely coincide with the finger touch method of determining drying time.

Program Cycle - Program the desired cycle in minutes via the scroll menu.

After drying stage is completed, place the clear, plastic template provided over the circular area scribed by stylus and note appropriate scale number degree required for the film to cure hard dry. Calculate the drying time using the following formula:

• DT = (Tc/360) (D)
• DT = Drying Time in minutes
• Tc = Time Cycle in minutes
• D = Degree on template

The character of the marks by the ball stylus relate to the drying of the film. Record the results and if desired, record the temperature and the wet film thickness as these factors are important in considering the drying time of films.