Principles of Injection Molding and Practical Analysis of Multi-Color Cup Component Production (Mold Technology Edition)

There are stories in cups, and warmth in life. Hello everyone, "Dong Dong's Cup Talk" is here.

In our previous discussions, we mentioned that our factory not only manufactures cups but also specializes in plastic mold production. http://www.umbottle.com/ProductsDetail-VB-10425.htmlAs plastic components are indispensable in cup manufacturing, our facility boasts a professional and well-equipped injection molding department. Today, based on years of hands-on experience and real-world cases, I'll share practical insights into injection molding principles and the production of multi-color cup components. Given the extensive content, this will be divided into multiple installments.

IV. Mold Design Defects and Solutions

1. Common Mold Issues

- Poor Venting:

- Solution: Add 0.02mm-deep venting grooves at the parting line of PP cup lids to eliminate burn marks.

- Uneven Cooling:

- Solution: Implement conformal cooling channels to reduce cup body cooling time from 25 seconds to 18 seconds.

- Ejection Deformation:

- Solution: http://www.umbottle.com/ProductsDetail-VB-10425.htmlFor thin-walled Tritan cups (1.2mm), switch to nitrogen spring ejection + large-area ejector plate structures.

2. Material-Mold Matching Principles

- High-Viscosity Materials (e.g., PC):

- Increase runner cross-section by 20% and adopt fan-shaped gates to reduce shear heat.

- Crystalline Materials (e.g., PP):http://www.umbottle.com/ProductsDetail-VB-10425.html

- Maintain mold temperature ≥80°C to enhance crystallinity and prevent post-molding shrinkage deformation.

V. Injection Molding Proverbs for Engineers

1. Material Certification First:

- FDA 21 CFR 177.1520 applies to PP for food contact, while AS materials must pass LFGB §30-33 migration tests.

2. Equipment Selection Formula:

- Clamping force (tons) = http://www.umbottle.com/ProductsDetail-VB-10425.htmlProjected part area (cm²) × Material pressure coefficient (0.3 for PP, 0.45 for PC).

3. Golden Rule for Multi-Color Molding:

- Second-color injection delay time ≤15% of first-color cooling time (to prevent interlayer separation).

Final Insight:

Injection molding is an art that blends materials science with precision mechanics. http://www.umbottle.com/ProductsDetail-VB-10425.htmlOnly by mastering every variable—from raw pellets to finished products—can one stay ahead in the competitive arena of cup component quality.

Would you like any refinements or additional technical details?