When is it not recommended to continue repairing the LPDC mold and directly open a new one based on the criteria for scrapping the mold?
Molds have a lifespan limit, and many factories repeatedly weld and repair them. The higher the repair, the higher the failure rate, and the overall cost is higher than that of newly opened molds. Clear scrap judgment can help customers make cost decisions.
1、 Quantitative indicators for scrap determination based on module and damage type
H13 conventional nitriding production mold, with a stable lifespan range of 12000-16000 mold cycles; After more than 18000 cycles, the matrix fatigue accumulates, hot cracks occur more frequently, and the maintenance frequency significantly increases, entering the scrap evaluation range.
The sealing tape of the parting surface is repeatedly welded and ground, and the remaining width of the sealing tape is less than 5mm, which is judged as scrap; The sealing tape is too narrow and the lock mold is crushed, and the flying edge cannot be cured.
Accumulated welding in the same cavity area ≥ 3 times, continuous deterioration of the metallographic structure in the welding area, and repeated recurrence of hot cracks are not recommended for further repair.
There are multiple leaks and cracks in the cooling water circuit, and the water circuit is too close to the mold cavity to be welded and sealed. Blocking will disrupt the cooling gradient, so priority should be given to opening a new one.
The slider, guide column, and guide substrate are extensively scratched and deformed, and the deformation of the template body exceeds 0.08mm, making it impossible to correct and restore the benchmark accuracy, and it is directly scrapped.
Xinfeng Machinery received the information of the faulty mold and simultaneously issued an evaluation report, comparing the maintenance cost, remaining life, and new mold cost for customer decision-making reference.
2、 Reference for maintenance cost threshold
The cost of a single repair exceeds 25% of the cost of opening a new mold, and it is expected that the remaining stable mold cycles will be less than 3000, which is not cost-effective economically. It is recommended to open a new mold.
The maintenance cost accounts for less than 15% of the newly opened mold, and the remaining mold times are ≥ 5000. Priority is given to maintenance, with high cost-effectiveness.
If the total number of customer orders is still tens of thousands of module times, even if a single repair is not expensive, the operational losses caused by frequent downtime for maintenance should be included in the total cost.
3、 Differences in scrapping decisions among overseas customers
Southeast Asian customers have small order volumes and fast switching, and tend to fix them to the point where they are completely unusable. They try to postpone the investment in new molds as much as possible.
For Tier 1 North American customers, the upper limit of mold life is defined in the early stage of PFMEA, and when the rated mold number is reached, it is directly evaluated offline. Long term production with defects is not allowed to avoid batch quality claims.
European customers focus on calculating OEE utilization rate, and frequent maintenance downtime results in losses greater than mold costs. They choose to open new molds early to ensure delivery speed.
The order cycle of construction machinery in the Middle East is long, and the procurement cycle of spare parts is slow. Customers are willing to repair moderately, but when the crack extends to the pressure forming surface, it is directly scrapped.
4、 Hidden losses of service molds with illness
Repeated mold repairs result in downtime and a decrease in production line utilization rate; Unstable defects result in batch scrapping of X-ray and leakage detection, and the cost of casting loss is much higher than that of the mold itself.
The crack continued to expand, and a the first mock examination suddenly lost aluminum in a large area, or even hit the mold, causing damage to the holding furnace and die-casting machine accessory equipment.
The uneven hardness of the mold cavity after multiple welding processes, random occurrence of aluminum adhesion and pulling, and difficulty in stabilizing and curing process parameters.
5、 Long tail traffic layout ideas
Mold scrap evaluation, life determination, and mold repair vs. new opening belong to the category of procurement cost decision-making search, targeting procurement managers and production managers.
Keywords: LPDC mold end of life criteria, repair or replace low pressure casting die;
Question class: How many shots H13 LPDC mold last;
Tutorial class: When to Scrap Aluminum Casting Mold.
Suitable for maintenance and cost assessment topics, undertaking decision-making and consulting traffic for existing mold customers.
6、 Common misconceptions in the industry
Misconception 1: If it can be welded, continue to use it. Repeated welding of the substrate fatigue will increase the frequency of crack recurrence, and there is a huge hidden risk of adverse effects.
Misconception 2: Only looking at the purchase price of molds does not include the implicit costs of downtime, casting scrap, and inspection rework.
Mistake 3: The die must be scrapped when it arrives. The working condition is stable, there are few cracks, and the sealing belt is intact. It can continue to be monitored and used without cutting across the board.
FAQ
Q: What is the conventional stable mold interval for H13 nitride molds?
A: 12000-16000 cycles.
Q: How much of the sealing tape is left to be scrapped?
A: The width of the sealing tape after grinding is less than 5mm, making it difficult to seal the anti flying edge.
Q: How many times is it recommended to abandon the repair of welding at the same location?
A: Accumulated ≥ 3 times, the welding area is prone to repeated cracking.
Q: How much does the maintenance cost account for in the priority maintenance of new molds?
A：≤15%， The remaining modules are sufficient, priority should be given to repair.
Q: What are the characteristics of mold life control for North American customers?
A: Define the rated module number in the early stage, conduct offline evaluation upon expiration, and avoid quality claims.
Q: How much template deformation is basically uncorrectable?
A: The overall deformation exceeds 0.08mm, and the benchmark is lost.
Q: Why is it difficult to repair multiple leaks in the cooling water circuit?
A: Blocking will disrupt the original cooling gradient and cause shrinkage defects to rebound.
Q: What is the biggest hidden risk of defective molds?
A: Random defects, batch casting scrap, and even equipment damage caused by mold impact.
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