How To Identify Faults In Injection Molding

Update:19-08-2021
Summary:

  A logical and systematic method of handling failures […]

  A logical and systematic method of handling failures is the most desirable, and many actual mold manufacturers have their own operating plans. When preparing such a plan, it is important to ensure that all terms used are clear and understood by all relevant personnel. The failure should be clearly described and all possible causes should be checked.

 

  The impact of the failure should be considered, and after determining the cause, necessary measures should be taken to eliminate the failure and prevent its recurrence-the recommended seven-point plan is as follows:

 

  Naming failure.

 

  This may seem obvious, but some faults have multiple names. For example, "splash marks" are variously referred to as "mica marks", "silvered" or "silver stripes". It is recommended to decide which names will be used and stick to that decision.

 

  Describe the failure.

 

  When describing the failure, one possible cause may be included-for example, "short mold", ie. An incomplete molding may be described as "insufficient pressure to fill the mold, or" not enough material to fill the mold. It is useful to try to describe all common failures in the simplest terms without attributing any possible causes. In this way, any possible prejudice against the next phase of the plan is cleared from the mind, that is, looking for the cause of the failure.

 

  Find out the cause of the failure.

 

  This can be a long process because it requires consideration of materials, machines, molds and processes-the following guidelines are recommended:

 

  (a) Materials. Check the grade or type, check for contamination, and make sure it meets the manufacturer's specifications.

 

  (b) Machine. Check the functions of all parts of the machine according to the recommendations given, and consider any factors that may affect pressure, temperature, speed, and time.

 

  (c) Mould. Make sure that the mold is set up correctly and at the correct temperature, and all parts are functioning properly.

 

  (d) Process. Check whether the pressure, temperature, rate and time are set according to the recommendations of the material supplier

 

  Determine the impact of the failure.

 

  If a malfunction renders the component unusable or unsellable, it obviously must be corrected. If it is only of secondary significance, it may not be necessary to try to eliminate it completely.

 

  Determine where the responsibility lies.

 

  This may only be of academic interest, but if the failure occurs again, the operator and the materials, machines, molds and processes need to be checked.

 

  Take measures to avoid malfunctions.

 

  If proper measures are not taken, defective molds may be produced unnecessarily, which will adversely affect the profitability of the project.

 

  Take measures to prevent it from happening again.

 

  Make sure to keep a complete record of the situation after troubleshooting. Pay attention to any repairs and changes to the mold or machine, as well as any changes in material type, grade or quality. If you use rework (ie, re-ground waste), pay attention to proportions and quality.

 

  These troubleshooting steps may seem redundant, but unless all seven points are taken into account, no fault finding work is complete-making faulty molds, even if they can all be restored and reground and reuse the material, is very Uneconomical and is a shortcut to bankruptcy.

 

  Operators who make defective molds for whatever reason will not be satisfied with their work, and will not be able to get a satisfactory salary if a bonus plan is implemented. The pride in production quickly disappeared, and the mold shop personnel took a laissez-faire attitude, which was manifested in poor housekeeping, low efficiency and general dissatisfaction.

 

  Proper handling has boosted morale, the styling workshop has become more commercialized, and efficiency has also increased.

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