• by MEOT
• visits
• 2026/3/6

On-Site Maintenance Guide: 24-Cavity PET Preform Mold – Fixed Half

METO Machinery is a leading manufacturer and supplier of high-precision preform molds for the global packaging industry. Specializing exclusively in the design and production of advanced PET preform tooling, we provide comprehensive, customized solutions for manufacturers worldwide. With years of technical expertise and a strong commitment to research and development, we offer state-of-the-art molds that enable customers to produce high-quality preforms efficiently and cost-effectively.

On-Site Maintenance Guide: 24-Cavity PET Preform Mold – Fixed Half 

At METO Machinery, we understand that proper mold maintenance is essential for maximizing production efficiency and extending mold life. A well-maintained 24-cavity PET preform mold can deliver millions of high-quality shots, while neglect leads to defects, downtime, and costly repairs . Here is a professional overview of the on-site maintenance procedures for the fixed half (cavity side) of a 24-cavity PET preform mold.

Why Focus on the Fixed Half?

The fixed half contains the critical cavity inserts that shape the outside of the preform and houses the hot runner system. It is subjected to high temperatures and pressures during each cycle . Proper maintenance here is essential for preform quality and dimensional accuracy.

Daily On-Site Maintenance Checklist

1. End-of-Shift Cleaning
After each production shift, the mold must be cleaned thoroughly:

• Action: Open the mold fully. Use dry, oil-free compressed air (6 bar) to blow out any PET dust, additive residue, or debris from every cavity and neck ring area .

• Surface Wipe: Wipe the cavity surfaces with a clean, lint-free cloth lightly moistened with alcohol to remove oily residues .

• Visual Inspection: Check for any plastic leakage around the hot runner manifold sealing surfaces .

2. Cooling System Check

• Action: Visually inspect the cooling channel outlets for white calcium deposits or signs of corrosion .

• Clean: Cooling water should not be left in the channels. Clean regularly to prevent rust and blockages .

3. Hardware Check

• Action: Verify that all bolts, screws, and mounting plates securing the fixed half are tight and properly torqued before starting the machine .

Regular Maintenance Tasks

1. Deep Cleaning and Descaling

• Frequency: Every 3-6 months, depending on water quality.

• Action: Clean the cooling channels thoroughly to prevent rust and blockages that affect cooling efficiency .

2. Hot Runner System Inspection

• Frequency: Quarterly.

• Action: Check all electrical connections, verify thermocouple function, and check heating element grounding to prevent temperature abnormalities .

3. Surface Protection

• Frequency: Before storage.

• Action: After cleaning, spray all steel surfaces with anti-corrosion oil (LPS2 or LPS3) to prevent rust during downtime .

Storage Protocol for the Fixed Half

If the mold needs to be stored:

1. Clean and dry the fixed half thoroughly 

2. Apply anti-corrosion spray to all steel surfaces 

3. Close the mold tightly to prevent dust entering the cavities 

Proper on-site maintenance of the fixed half ensures that your 24-cavity PET preform mold operates at peak performance, producing consistent, high-quality preforms with minimal unplanned downtime .