HANATEK FRICTION TESTER. MODEL 6010 (Obsolete) INSTRUCTION MANUAL. Replaced by:

Transcription

1 HANATEK FRICTION TESTER MODEL 6010 (Obsolete) INSTRUCTION MANUAL Replaced by: March 2004

2 2 CONTENTS SECTION No. Page No. 1 Contents 2 2 Introduction to Friction Testing 3 & 4 3 Installation Instructions 5 4 Sample Preparation 5 5 Set Up 6 6 Test Method 7 & 8 7 Calibration 9 8 To set Clock Range selection and PC interface Short cut to testing 12 & Peel/ Block/ Tear Tests Spares Service 16 2

3 3 2. INTRODUCTION TO FRICTION TESTING The frictional force, F, opposing motion of an object is given by the simple formula: - F = u x N (Where N is the force exerted by the object in the direction of gravity and u is the coefficient of friction) There are two methods of measuring the coefficient of friction: - a) Flat Plane Method This involves moving a sled of known mass (and hence known N value) along a flat horizontal plane and measuring the force to move it along a set distance. This measurement will give the F value in the above formula and hence the coefficient of friction can be calculated. The test gives two values of coefficient of friction: - Static and Dynamic values. Both values give information about the frictional characteristics of the material, which may relate to the movement of that material through a machine or process. Static coefficients relate to a stop/start process, whereas Dynamic will be of more interest to a continuous motion in a process. Static friction is the measured force, which starts the sled in motion. This is shown by the initial peak force value seen when beginning the test. After this initial peak, the force value stabilises (usually) at a lower force value as the sled moves across the surface at the selected speed of motion. The mean value of the force is taken as the dynamic force and hence is used in calculating the dynamic coefficient of friction. b) Inclined Plane Method This test involves placing a sled of known mass on a horizontal flat plane and then increasing the slope of the plane until the sled slips down the plane. The tangent of this angle is then taken as the coefficient of friction. No measurement of the dynamic friction coefficient is possible. Both methods involve measuring the material when in contact with it and hence the same face of each material should be upwards from the plane as is facing down from the sled. Equally the direction of the sample on the plane should match the direction of the sample on the sled. This arrangement then follows the requirements of a number of Standard Test methods such as ASTM D1894 or BS 2782:8:824A. (A TAPPI Inclines plane methods for paper sack materials have the material on the plane at right angles to the direction of the sample on the sled - see relevant standard). 3

4 4 There are thus four possible combinations: - face A MDvsMD, face A CDvsCD, face B MDvsMD and face B CDvsCD. Various aspects of the test are controlled to ensure repeatability and these are laid down in various standards. The latest version of British Standards tests stipulates the need for two different connections between the sled and the load cell in order to measure the static and dynamic coefficients of friction (COF). The static COF is the initial force required to just start the sled into motion and here a spring is used to approach the required force gently, thus giving a peak value which can be recorded by the data acquisition system. Should the test be continued with a spring, the dynamic force can become a series of peaks as the sled slips then stops (known as "Stick/Slip" action). The dynamic test is thus measured using a rigid support. BS 2782 Part 8 Method 824A: 1996 & ISO 8295:1995 Refers. All tests should be made at known conditions of Temperature and Relative Humidity to ensure repeatability. Personnel should not handle surfaces, as the grease from the fingers will affect the frictional characteristics. Equally the same surface should not be re-measured for standard evaluations as this previous use may affect the surface characteristics. The test can be conducted in a number of ways but consideration should be given to the effect of dwell at the beginning of the test. As the test measures the interlocking of the two surfaces and as plastics creep to accommodate loads then a static COF measured immediately after placing the sled on the flat plane will often give lower values than one measured after allowing a "settling time". This equipment has a built-in countdown clock, which is triggered, at the start of each test automatically to ensure compliance with this requirement. The choice of Standard used relates to the final end use and all the above parameters are laid down in the various standards. It is recommended that the user familiarises ones-self with the relevant standard and calibrates the equipment at regular intervals to ensure continuing confidence in the function of the machine. Requirements of the equipment are given in the Standard and this should be used as the basis for calibration. Even an annual calibration may need further checking if the instrument is used excessively by a range of people. This check is known as a "Calibration Check Service" or "Round Robin". Here the equipment is checked using a consistent and known material. The results are compared with a group of other users and the variation from an acceptable mean value can thus indicate a loss of accuracy. This loss may be a loss of calibration or may be due to misuse of the equipment and indicate a need for training to enable the operative to improve his technique. 4

5 -5-3. INSTALLATION INSTRUCTIONS 3.1 Packaging: - corrugated box with end caps in Etha foam. 3.2 Contents. Friction Tester Unit, complete with adjustable feet, load cell, tray with Edding cutting mat for sample preparation, 200gm sled, sled to load cell Link, 2 magnetic strips for sample clamping, Calibration pulley, calibration cord, sample template, scalpel, spirit level, mains lead and operating manual. Integral printer fitted with paper roll holder and paper roll, which is clamped down for protection during transit. N.B. Remove all packaging material from printer before use. 3.3 Remove unit from packaging and place where required. Adjust feet for level operation using spirit level provided. N.B. While adjusting feet ensure free movement of tray when adjustment is Complete. Re-adjust if necessary. 4. SAMPLE PREPARATION 4.1 If the test material is plastic it should be conditioned for 40 hours, if paper/board for 24 hours. In both cases the conditions should be 23 +/- 1 deg C, 50 +/- 2% rh. 4.2 Using the template provided cut out test pieces for attaching to the sled. The Test Bed samples should be at least 250 x 130mm (no template is available but size is not critical). The long direction of the test pieces should be cut in the direction of the test. Machine and cross direction of the material being tested must be marked along the edge of each sample. (On the surfaces, which do not come into contact). Press Reverse button to position load cell near the start point for a test. 5

6 6 5. SET UP 5.1 Plug in mains lead, switch "on" and leave for 15 minutes for temperature to stabilise. Meanwhile, after switching on, the instrument will display "software version for 5 seconds only. (It is important to note this information, as it will be required in the event of any failure). The display then switches to "Print, No, or "Test". 5.2 If Print is pressed. A copy of the last test results will be printed. No will offer a selection of tests. Test will start a new series of the present test. 5.3 To set-up pre programmed tests. (Max 10) 5.4 Press Custom 5.5 Scroll test types using "No" button and "Yes" to select required test. Test Available Go To Friction 5.6 Peel 90 degrees Page 14 Peel 180 degrees Page 14 Block Page 14 T Peel Page 14 Trouser Tear Page Select sled weight (sled supplied 200 gms) 5.7 Select speed (mm per minute) 5.8 Select test distance (mm) 5.9 Press Enter after each digit selection of 5.6, 5.7, and Press Test No. (1-10) using +/- keys to store these settings in the Memory Confirm storage location and press Enter to see programme To see any of the Customised programmes, press Select and the Programme No. 6

7 7 6. TEST METHOD 6.1 Place the large sample on the Test Bed with machine direction along the length of the Bed For Film Magnetic strips are provided for securing film, located a) on the top right-hand side of the Bed and b) just over the top edge of the left-hand side. Two black bars identify the position of each magnetic strip. Position film until right-hand edge covers black bars on right-hand side of Bed. Place magnet to secure film. Tension film by pulling gently over left-hand edge of Bed and secure using magnet to black metal strip. Alt. method: - Secure, using Bulldog clip and clamping left hand side of Sample only For Paper/Board Secure sample (both left and right) on Bed along centre line of load cell using masking tape. Check that the sled and foam is undamaged. Secure the test sample to the sled length-wise using masking tape, ensuring that the sample remains completely flat over the contact area. Care being taken to avoid contact with both samples over their respective test areas. 6.2 Position sled on Test Bed in line with load cell pick-up point, approximately 30mm from left-hand edge. 6.3 Connect sled to load cell using rigid link provided ensuring that the link is parallel to the front edge of the Friction Tester. Use forward/reverse momentary buttons to achieve this. 7

8 8 7 To Conduct Multiple Static Tests. (Max 5) 7.1 Use +/- keys to select the number of tests required. Press Yes to commence testing. 7.2 Press Yes to continue testing as the Test No. increments. 7.3 Press Batch to print Batch statistics. 8.0 To Conduct Dynamic Tests. (Max 10, or a combination of Static/ Dynamic tests max. 10) NB. each Dynamic test will also include a Static Result. 8.1 At Dynamic Friction Screen, enter Number of Dynamic Tests Required using +/- keys. 8.2 Press "Go", display indicates the test is running. Sled will dwell for 15 seconds. Indicated by a countdown clock. 8.3 The motor will then draw the cell and sled along. 8.4 As the tension is taken up the display will indicate Static Friction. 20 measurements will be taken in the test distance selected and on completion; the display will indicate dynamic friction. 8.5 If you wish to keep the results press "Print" and the system will print the results. If you do not wish to keep the results, press "No" and the unit will ask you to redo the test. 8.6 After a series of tests have been completed (minimum of 3), if no further tests are required press "Batch" to obtain Printed Batch results with statistical data. 8.7 An interrupt button Stop is available to stop printing or to stop a test and return to Custom/ Select Screen. 8.8 The Time and Date is displayed for 4 seconds at the start of a new series of tests. 8

9 9 9.0 CALIBRATION. 9.1 On switch On, Calibration is displayed for 4 secs. Press Yes within the 4 secs to initiate calibration. 9.2 Screen will display Input or Speed. Select INPUT. 9.3 Press +/- keys to Select 0.0 with nothing connected to the load cell. 9.4 Press Enter to Read Press Exit. Place a known weight over the pulley provided and connect via the cord to the Load Cell. 9.6 Press +/- keys till Set on display = known weight. 9.7 Press Enter and read displays Set value on Display 9.8 Press Exit then take the weight off To calibrate output speed Press +/- keys till speed reads Press Enter To measure distance: Drive the Load Cell to the extreme left as start point, note and press Yes to start run Count Down clock starts timer for 1 Minute. If Back is pressed, then restart from At the end of the minute, note the distance run and Enter this distance in mm. at the Set figure. Press Enter firmly Note no change of screen Press Exit 10.7 Set ramp time. Ramp rare set will read 5 change for set = Press Enter Read should now = 1.0 Press Exit 10.9 Unit displays Communication screen for information only Press Skip 9

10 To Set The Clock Start from 9.1 and press Skip Display shows Time and Date Press Yes. Back returns to the start of Calibration Set year using +/- keys Press Enter then Exit 11.5 Set Month using +/- keys Press Enter then Exit 11.7 Set Day using +/- keys Press Enter. then Exit 11.9 Set Hour using +/- keys Press Enter then Exit Set Minute using +/- keys Press Enter then Exit Press Skip to return to Start screen 10

11 11 The rear of the Unit has a plate fitted with two sockets and a selector switch. 9/way din socket for Comms. 3 /pin XLR plug giving 0-10 v chart recorder output. Selector Switch for the ranges : 0-500: : gms. The Instrument must be calibrated after each range switch change. In the event of over range being displayed, select the appropriate range and recalibrate the instrument If the local Printer is not fitted, then the Unit will have a 25-way connector for downloading the Printer information to a PC. Requirements: - IBM compatible PC with Windows 95. Select Start. Programme Accessories Hyper Terminal. Select Hyper term and give the Programme a Name. Select programme name and then Properties. Comms Port 2 and configure. Baud rate 9600 Bit 8 Parity - none. Stop bit 1 Flow control Hardware Press advance. Select settings Select windows key. Set auto detect. Set buffer for 30 lines for a single test. (Refreshes complete screen each time.) Set buffer for 140 lines for a 3-test batch print. Set buffer for 182 lines for a 4-test batch. Set buffer for 223 lines for a 5-test batch etc. All other settings remain unchanged. 11

12 12 TO PERFORM SINGLE STATIC AND DYNAMIC FRICTION TESTS OR SEVERAL WITH BATCH STATISTICS. Software Version 2V1 Action Display Operation Switch ON Friction Tester. Software version Calibrate? Displayed for 4 secs. Option to print last result or perform a test Press Test Custom/Select. Press Custom Sled weight? Enter 200gms. Custom offers the opportunity to Set up to a max. of 10 preselected tests in the memory. Select, offers the choice of any one of the 10 preset test parameters in the locations Or required weight. Enter 100mm/min Enter 100mm Sled speed? Test distance? or required speed. or required distance. This programme can now be set-up as preset number 1 in the stored memory. The next time this test is to be performed, press Select 1 and the test parameters will automatically be selected. 12

13 Dynamic Friction tests always include a Static result. 13 Press enter to confirm settings. If batch statistics are required, a minimum number of 3 tests must be carried out. Enter number of tests to be carried out, attach Sled and Press Yes to start Test. Display indicates 15-second timer countdown for dwell time. Action Display Operation Press next. Static friction at test end, refit sample Repeat till end of this test series. Press Next Press Print Press Batch Printer will print Independent test Results and Full Batch Statistics. +/- buttons will scroll through the Results. Press Print for copies of the results Press Back and Back to return to the start of the same test parameters. Press Back 3 times to set-up or select a new test from the pre-programmed List. 13

14 14 For Tests other than Friction. After switch on the start screen displays: - Friction Test. Test? Print? Test No Print Select No Display offers: - Friction: Block: Tear: Peel Select Test required. Press Test. Follow screen prompts. NB. In customer pre-programme These test parameters can be stored for use at any time. Test Standard Sample length Width Speed Distance Per min. Block test. Peel Test 90 deg. Peel Test 180 deg. FMT2 to suit 25mm 300mm to suit. FMT1 to suit 25mm 300mm to suit. T Peel Test ISO 11339/93 200mm 25mm 100mm 300mm Trouser Tear Test. ISO mm 50mm 200mm 150mm BS2782 Pt3. 14

15 15 Scalpel Spirit Level Template BS / ISO / ASTM Pattern 200 gms. Template BS Pattern for 700gm sled Sled 200 gms. Sled Foam Pad SPA102 SPA122 SPA169 SPA170 SPA171 SPA172 Fixed Link SPA195 Edding Mat SPA174 Load Cell 5N, 10N, 20N. Calibration Weight 100 gms SPA201 Calibration Pulley SPA197 Calibration Cord SPA189 Sample template for 180 deg.peel Test SPA194 Sample template for Trouser Tear Test SPA deg. wheel SPA deg. bracket SPA deg. bracket SPA deg. Hook (long) SPA deg. sample carrier plate. SPA202 T Peel Peg SPA203 T Peel/ Trouser Tear Hook (Short) SPA204 Trouser Tear positioning Bracket SPA205 Accessories Case SPA206 15

16 16 9. SERVICE In the event of a breakdown, or calibration required, call your local agent: - Hanatek Rhopoint House, Enviro 21 Park Queensway Avenue South St Leonards on Sea, East Sussex TN38 9AG, UK Tel. No. +44 (0) sales@hanatekinstruments.com Web: 16