HOW OFTEN SHOULD INJECTION MOLDING TOOLS BE REPLACED
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Posted by Moorsel Bas - Filed in Arts & Culture - 893 views
It can be difficult to determine when your injection molding tooling needs to be replaced if there are no universally accepted guidelines in existence. The Plastics Industry Association (PLASTICS, formerly known as the Society of Plastics Industry or SPI) develops mold classification standards that can be used to estimate the tool life of plastic injection molders.
101, 102, 103, and 104 are the mold classifications used in PLASTICS, with Class 101 indicating the highest quality, cycle count and production level, and 105 representing the lowest quality, cycle count and production level. In order to account for the wear and tearinjection molding occurs as a result of mechanical processes, these estimates are based on {anchor} shots (the number of times a mold is filled and opened), rather than on the number of parts that are produced.
All in all, tooling does not reach its maximum capacity after one million shots is taken. We have tools{anchor} run over a million shots per year here at Junying, and some that have run over 20 million shots before needing to be repaired or replaced.
It is preferable to learn how to identify specific issues in advance{anchor} might indicate tooling replacement rather than relying on hard and fast rules based on shots or timelines, because the replacement schedule can be affected by a variety of factors, from material selection to program requirements and preventative maintenance schedules.
When any of the following issues are identified, you should begin to consider replacing your tooling.
PPM LEVELS ARE RISING.
One of the first signs that tooling needs to be replaced is when the trend in parts per million (PPM) starts to rise significantly. Because of a variety of factors, PPM numbers can be higher than expected in some cases, some of which are simply a normal part of the tooling process. In contrast, a sudden increase in PPM in a tooling process{anchor} has previously been trouble-free is usually caused by either tool conditions that cannot be improved or tool conditions that can be repaired temporarily but then fail again quickly.
AVERAGE RATES FOR ON-TIME DELIVERY
Due to increased maintenance requirements and rising PPM rates, tooling that is breaking down causes delays. The constant downtime that occurs when tooling reaches the end of its useful life makes fulfilling orders a burden. Downtime could be caused by a variety of factors such as waiting for tool repair lead times, increased scrap rates, or non-value-added post-production operations such as flash trimming and part sorting.
COSTS ARE GOING UP.
It is common for program costs to begin to rise when tooling reaches the end of its lifecycle. Watch out for costs associated with scrap rates, tool repairs, labor for sorting or other operations, and the chaos that results from issues such as orchestrating returns, line downs, and vendor management, in addition to monetary expenses.
RISKY CIRCUMSTANCES
Your injection molder or toolmaker will be able to identify at-risk conditions with your tooling, and you should be aware of these conditions throughout the operation to avoid any problems. The majority of the time, at-risk conditions are maintained through repairs, but most repairs can only be performed so many times before the tooling has to be replaced. The time to consider replacing your tooling comes when repairs no longer hold or when parts become worn down.
