|
Definitions: Troubleshooting: the process of resolving issues and or causes to defects.
The act of troubleshooting and or solving problems for a project or process can at times be complex yet simple. The steps involved in troubleshooting are multiple and start with the easiest yet most forgotten one... watching the process, observing and then describing what the issue and or problem are. The other issue that is tied to this one is the frequency of the issue, how often the problem occurs and is it continuous, intermitted, occasional, and the list could go on. In injection molding it can be further compounded by the fact that tooling can produce one cavity, or 32 cavities or more.
In extrusion it is the same issue, but now one has to do some math, as is the issue every foot, 2 feet and then how fast is the extrudant running, as the author has been in plants that produce way over 1,000 feet a minute. Thus simple math equals 16 plus feet a second.
To resolve just this one question (what is the problem) one must slow down, and in some cases sit back and watch, document and understand not only the process at hand but the total process. This in most cases is the hardest part, only because time is money and with the current issue money is being lost. The longer the process operates at this condition bad product is produced and or cost is put into the product because it may have to be sorted or worst yet scrapped. The real issue may take time to understand, and maybe if we were to wait a while it goes away. Now the question to ask is what happens? Why did it go away what changed, material, temperature and or other things?
Too many times in troubleshooting everyone jumps to a conclusion or thought process and starts changing things only to have to come back moments later or hours later to fight a new issue, or in most cases the same issue and in the process the setup is changed, and keeps getting farther away from the norm. An overview follows, which in later installments shall be expanded.
*Note that in many cases one has the knowledge or experience to grasp the issue at hand and provide a solution which in and of itself is great. The possible downside to this is that that solution and or issue is not documented for others to learn from.
In defining the issue the following must be asked:
1- What is good about the parts?
2- What needs to be improved?
- Is it all parts and or cavities every single cycle
3- Can we label the issue
- Short shots
- Black spec
- Dimensional ....etc.
Now that we know what is good, needs improvement and have labeled the issue the following can be implemented.
- We can develop a plan of attack
- We can check our reference material that exist for if this than do that
- We may even test things such as eliminate additives, change lot numbers, move to another machine but these are all plans with outcomes to be monitored.
Now that there is a plan we move forward and implement the plan
- If there are process changes only one at a time and time is allowed for the change to take effect
- Temperatures are the last thing to try and change
- This is because the effects take so long to see
- If changes are made take big steps if it is possible.
- This speeds up the process as you are looking to see if that is the direction to go.
- Care must be taken to understand the process and what is being done so as to not damage the tool or machine by these steps.
- If the change does not result in anything change it back and give it time to stabilize prior to making another change.
- Too many times it is moved back and immediately another change is implemented and the result may be good or bad, but there is still the effect of the previous change.
- Basically one is not noticing the effect to that change but of the two together.
- This is where knowing when to impute the change and how long it takes for the machine to react comes into play.
- Should the change result in a successful elimination of the defect than great. Leave it alone and monitor it for a few shots to be sure it has stabilized.
Since the plan worked and or if it did not work it must be documented. The documentation does multiple things.
- It creates a history and record of what happened
- This is both a cause and effect or maybe only issue and correction to that issue.
-
It is a start of a trouble shooting guide for this mold.
- Though it must be recorded and then re-recorded into a form that allows future expansion, should someone else encounter this issue there now appears to be a resolution which can be tried.
- This troubleshooting guide is a living history for this issue.
- The documentations also show an understanding as to the cause and effect by the processor.
Troubleshooting in many plants is an art, though in fact it is an experiment in cause and effect. The key is to observe and then to react but only after one has thought it out and has a plan.
SLSILVEY
14072013.01
| 
