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University of Delaware December 10, 2007 Senior Design Team 15 Anthony Brazen IV Nick Hirannet Sam Holland Megan Keenan.

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Presentation on theme: "University of Delaware December 10, 2007 Senior Design Team 15 Anthony Brazen IV Nick Hirannet Sam Holland Megan Keenan."— Presentation transcript:

1 University of Delaware December 10, 2007 Senior Design Team 15 Anthony Brazen IV Nick Hirannet Sam Holland Megan Keenan

2  To improve the robustness and reliability of the tablet feeding process. ◦ This can be done through prevention and detection

3  The tablets are moved along the tracks with the aid of a linear vibrator creating backpressure

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5  The tablets drop through the holes and chutes into the flex  Sensors are currently placed at the top of the chute to detect that a tablet has fallen

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7  What? ◦ A flex does not receive a tablet ◦ Entire lot must be opened and inspected  Happens 45 out of 8 million tablet drops

8  Why?  Tablet breaks top sensor and may get stuck in the chute ◦ Tablet bounces off side walls causing delayed drop ◦ Tablet never exits the chute  Possibility for erroneous test result  Loss of time and money due to product re-inspection ◦ Hand inspection is currently used to ensure that the correct amount of tablets are in each flex  Expensive  Time consuming

9 The tablets exit the chute at a 90 degree angle from entrance into chute The drastic turn could cause the tablet to hit the side walls, delaying exit from the chute

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11 Top 10 Wants Final Ranking Wants Rate of Importance 1Quality control37 2Reliability18 3Robustness15 4Ease of Integration13 5Justifiable Cost9 Constraints Size Cleanable Removable Compatibility

12 PreventionDetection

13  Too many modifications to the chute would cause Siemens to redesign the entire process ◦ Too expensive and time consuming  New Feature: Add sensors to the bottom of the chute ◦ Sensor detection in current process is placed at the top, which provides knowledge of the tablet entry, but problem arises upon tablet exit MetricsPerformance Value Process Time>= 1.1 tablets per second Impact <= a one second greater process time Cost Less than $60,000 for one working line

14  Holes will be drilled into the sides of the chutes and the lowest point where the chutes and Lexan meet  Twelve sets of visual sensors will be attached to the bottom surface of the Lexan guard  Will utilize same communication software that Siemens currently uses

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16  Met with Keyence Sales Rep.  4 sensors were ordered  Two were able to be eliminated immediately based on visual inspection  FU-12 and FU-51TZ  The FU-50 and FU-59 were tested

17  Test station set-up

18 Diameter of ALL tablets = 0.2185 in. Large tablet height = 0.1510 in. Small tablet height = 0.0835 in. Red = Strength of beam Green = Threshold setting FU-50 worked well for large tablets, but was quickly eliminated after missing several small tablets in the first two trials Due to large beam aperture, which causes a decrease in sensitivity

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20  2000 tablets were dropped  Eight trials of 250 tablets were tested  ALL tablets were detected SMALL TabletsLARGE Tablets Diameter of ALL tablets = 0.2185 in. Large tablet height = 0.1510 in. Small tablet height = 0.0835 in. Red = Strength of beam Green = Threshold setting

21 Diameter of ALL tablets = 0.2185 in. Large tablet height = 0.1510 in. Small tablet height = 0.0835 in. Red = Strength of beam Green = Threshold setting

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23  4 modes of failure for detection have been identified ◦ 2 create undesirable risk levels  Sensor gets blocked by an object  Sensor becomes unaligned ◦ Both potential effects are that sensor detects a non-existent tablet ◦ HMI and PLC controls will identify a blocked beam or misalignment

24  Cutting an existing tablet track and adding a 90° turn Desired chute drops tablets straight down Eliminates current chute  2 ways to achieve this 2- 45° straight angle turn Curved radius turn Current State Desired State MetricsPerformance Value Probability of Error0 Errors for 250 Tablets Impact <= a one second greater process time Time Less than 2 mins configuration time on chute change Cost Less than $60,000 for one working line

25  2 aluminum tracks were milled  Tracks were mounted on linear vibrator ◦ Test to determine what prototype allows:  Tablets to reach the end of the track  Tablets get to end of track fastest Vibration

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27  Tracks without flipper mechanism

28 Radius Track has ability to move tablets faster Current system rate = 1.1 tablets/sec Both new designs exceed this rate Angle track moved Large tablets faster

29  If Siemens decides to replace their current tracks with our 45 degree turned tracks ◦ May not allow required space for vacuum mechanism  Alternative to vacuum – flipper mechanism

30  Full circle rotation

31  Half rotation

32  Aluminum cylindrical flipper placed at end of track ◦ Six slots cut along the cylinder to receive tablets from track ◦ Upon loading, cylinder will rotate CW allowing tablets to be released

33 Cost Justification: 1 bad flex = $25,000 in lost productivity, re-packaging, and labor 10 bad lots per year = $250,000 Detection at the bottom of chute pays for itself

34 MetricsPerformance ValueAchieved Value Process Time>= 1.1 tablets per second up to 3.5 tablets per second Impact Does not perform slower than current systemUp to 350% Faster Cost Less than $60,000 for one working line$18,353.84 Detection MetricsPerformance ValueAchieved Value Probability of Error0 Errors for 250 Tablets 0 Errors for 2000 Tablets Impact Does not slow down current system by > 1 secNo extra process time Time Less than 2 mins configuration time on chute changeAutomated on Computer Cost Less than $60,000 for one working line$12,840 Tracks

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36  0 defects in a sample of 250 tablets is considered acceptable by Siemens statistical analysis ◦ We tested 8 samples of 250 tablets to validate this acceptance

37 The number of samples (n) to be taken can be calculated by the following expression:  Z(A) = standard normal variant value for  error  Z(B) = standard normal variant value for β error  = AQL (Average Quality Level)  = LTPD (Lot Tolerance Percent Defective) 2

38  The acceptance number (c) (number of “defects” per sample permitted) can be determined by the following expression:   = Producer’s Risk   = Consumer’s Risk  = AQL (Average Quality Level)  = LTPD (Lot Tolerance Percent Defective)  n = Required Sample Size  c = Acceptance Number (Number of Defects Permitted in Sample) 2 c =


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