What Are The Problems With Remodeling A Rotomolding Mold? Is It Recommended To Remodel It?

1. Potential problems of rotomolding mold modification

Cost issues

High costs: Mold modification involves redesign, processing, testing and other links, which are costly, especially for complex or large molds.

Production delays: The mold modification cycle is long, which may affect order delivery, leading to customer dissatisfaction or economic losses.

Technical risks

Structural stability: Mold modification may destroy the original strength of the mold, especially the welding parts are prone to embrittlement, deformation or cracking.

Precision deviation: Processing errors may cause uneven wall thickness, increased flash or dimensional deviation of the product, which requires repeated debugging.

Heat distribution changes: Local changes to the mold may affect the uniformity of heating and cooling, resulting in abnormal product shrinkage or residual stress.

Process adaptation issues

Parameter reset: After the mold modification, the process parameters such as rotation speed, heating temperature, cooling time, etc. need to be readjusted, which increases the cost of mold trial.

Equipment compatibility: If the mold modification does not fully consider the equipment limitations (such as oven size, rotating arm load capacity), additional equipment modification may be required.

Quality consistency risk

If the mold processing accuracy is insufficient or the design is not fully verified after the mold is changed, it may cause quality fluctuations between batches (such as color difference, bubbles), increasing the cost of quality inspection.

2. Is it recommended to change the mold? Decision-making by scenario
Situations where mold change is recommended
The product has functional defects

Such as insufficient structural strength, assembly interference, key size deviation, etc., which must be solved by mold correction.

Market demand changes

Added functions (such as buckles, threads), appearance upgrades (texture/Logo) or regulatory compliance requirements (such as wall thickness safety standards).

Long-term cost optimization

If the change can significantly improve material utilization, shorten the molding cycle (such as optimizing reinforcement ribs to reduce material usage), and the production batch is expected to be large enough, the long-term benefits will cover the cost of mold change.

Situations where mold change is not recommended
The problem can be solved by process adjustment

For example, adjusting the heating time to improve fluidity, optimizing the release agent to solve sticking, etc., give priority to process optimization.

Small batch or short-term demand

If the order volume is small, consider post-processing (such as machining to correct the size) or accept minor defects to avoid mold change investment.

The mold life is approaching the end

The cost-effectiveness of remodeling old molds is low, and it is more cost-effective to directly make new molds (especially when compatible with future product iterations).


3. Alternative solutions for remodeling
Local mold repair

For small defects (such as local flash), temporary repairs are made by welding, grinding, etc., but durability needs to be evaluated.

Use inserts or adjustable structures

Add replaceable inserts (such as threaded core molds) to the mold to flexibly adapt to design changes and reduce overall changes.

Sacrificial molds to adapt to new processes

For example, accelerate cooling through external cooling tools instead of modifying the internal cooling channels of the mold.

4. Key steps before remodeling
Simulation verification

Use CAE software to simulate the molding process after remodeling, predict wall thickness distribution, shrinkage, etc., and reduce the number of mold trials.

Prototype testing

3D printing or CNC to make simple molds, and then formally remodel after verifying the rationality of the design.

Supplier collaboration

Select an experienced mold factory, clarify technical requirements (such as tolerance ±0.1mm), and sign acceptance terms.

Zusammenfassung
Rotational mold modification requires weighing costs, cycles, risks, and benefits. If the modification is critical to product competitiveness or functionality and there are sufficient resources to support it, it is recommended to modify the mold; otherwise, process adjustments or alternatives should be given priority. Be sure to reduce technical risks through simulation and prototype testing, and work closely with professional suppliers to ensure success