Ise 507 - Design and Analysis of Experiment

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ISE 507: Design & Analysis of Experiments

Mini Project 2

Instructions

This project is open-book, open-notes, and requires a computer.  You may work in groups and you may talk to classmates about your approach.  It is best to attempt the work on your own and then ask questions of your peers.  Try to focus on understanding the reasons for any differences between your answer and someone else’s approach. Please refer to the syllabus to determine when this mini-project is due.  Late mini-projects will not be accepted but you may hand it in early.

Provide your full name and student ID number on your submission.

Problem:[pic 2]

I have been designing a specialty medical device at UB and I am having trouble with the product cracking at extreme environmental temperatures.  This proprietary device must be stiff (but not rigid) under normal conditions of use, but must also remain stiff and not crack in cold environmental conditions.

The test method that I am using is called the “cold-crack resistance test” (or CCR).  The medical device is measured by means of a mechanically applied pressure to a prepared specimen after both the specimen and the pressure-device have been conditioned in a carefully controlled cold cabinet.  The pressure-device subjects the product specimen to a precisely controlled folding action at high speed in accordance with standard test methods and the resistance to this folding action is measured in inch-pounds.   Historical test results using this test method have been between 17 in-lbs. and 22 in-lbs.  Recent test results however have been marginal and are sometimes below specification (the lower limit to cold-crack resistance is 20 in-lbs. and there is no upper limit).  

A group of my R&D engineers and I met and we came up with 17 possible factors that could be studied to determine why recent test results have been marginal to below specification.  We chose 15 factors to study and they are (along with their levels):

Factors        Low Level (-1)        High Level (+)

A.        Temperature of coating rolls        115°F        125°F

B.        Solvent        Recycled        Refined

C.        Polymer X-12 preheat temperature        130°F        150°F

D.        Web Type        LX-14        LB-17

E.        Humidity of air feed to dryer        75%        90%

F.        Number of chill rolls after coating        2        3

G.        Temperature of drying roles        75°F        80°F

H.        Feed dryer temperature        60°F        100°F

J.        Tension of coating roles        30        40

K.        Mixer agitation speed        100 rpm        200 rpm

L.        Time between making formulation and coating it on the web        10 min        30 min

M.        Amount of dispersant in formulation        0.1%        0.2%