How to Properly Maintain and Repair Molds?

In precision mold manufacturing such as injection molds, die-casting molds, and stamping molds, molds are the core tools for achieving efficient production and high-quality forming. However, during long-term operation, molds are exposed to wear, corrosion, and thermal fatigue, which, if not properly maintained and repairs molds, can lead to product defects, increased downtime, and higher production costs.

So, how should molds be maintained and repaired to keep them in optimal condition? This guide provides a comprehensive overview of mold maintenance and repair methods.

Maintain and Repair Molds During Mold Installation

Before installation, clean the upper and lower surfaces of the mold to ensure the mounting surface and press table are free from damage and maintain parallelism during production.

After installation, open the mold and clean all parts, especially the guiding components. For surface-critical molds, ensure the cavity surfaces are thoroughly cleaned to guarantee product quality. Lubricate all sliding components with grease.

Inspect all safety components such as safety side pins, safety screws, side plates, and scrap channels.

Maintain and Repair Molds During Production

Regularly apply oil to critical areas, such as:

• Drawing dies: blank holder rings and radii.
• Trimming dies: cutting edges.
• Flanging dies: block sections.
• Regularly clean the scrap channels of trimming and piercing dies.

Maintain and Repair Molds After Production

• Conduct a comprehensive inspection of the mold.
• Thoroughly clean the mold to ensure cleanliness.
• Remove all scrap from the mold and clean the scrap box.
• Record the mold’s usage status and post-production condition on the mold log sheet.

Component Maintain and Repair Molds

1. Drawing Dies (Punch & Die)

• Common issues: galling and surface dents.
• Solution: polish the rounded corners where galling occurs. If dents are present, perform welding repair followed by re-machining.

2. Guiding Components (Guide Pins, Bushings, Plates)

• Common issues: scratches caused by dirty lubricant or improper clearance.
• Solution: polish with a fine oilstone and repolish as needed.

3. Trimming Cutting Edges

• Common issues: chipping or edge collapse.
• Solution: weld and regrind damaged cutting edges.

4. Springs and Elastic Components

• Common issues: breakage or deformation (most vulnerable parts).
• Solution: replace with identical specifications based on color, outer diameter, and length—all three must match before replacement.

5. Punches & Punch Sleeves

• Common issues: punch breakage, bending, or wear; sleeve wear.
• Solution: replace with standard parts of the same specification. Punch parameters include working section size, mounting section size, and overall length.

6. Fastening Components

• Common issues: loosening or damage of screws, bolts, and clamps.
• Solution: replace with identical standard parts.

Mold maintenance and repair are essential for improving production efficiency, extending mold life, and ensuring product quality. Through proper daily maintenance, scheduled preventive repairs, and professional management, companies can effectively reduce production costs and minimize unexpected downtime.

Whether it is a plastic injection mold, die-casting mold, or stamping mold, adhering to a standardized maintenance process ensures longer service life and higher production efficiency.