1. What is Injection Molding Machine Tonnage?

Definition: This calculator determines the clamping force required for an injection molding machine based on part geometry and process parameters.

Purpose: Helps manufacturers select the appropriately sized injection molding machine for their production needs.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — Required tonnage (tons)
• \( A \) — Projected area of part and runners (in²)
• \( P \) — Injection pressure (psi)
• \( SF \) — Safety factor (typically 1.5-2)

Explanation: The projected area multiplied by injection pressure gives the total force, which is then adjusted by a safety factor and converted to tons.

3. Importance of Tonnage Calculation

Details: Proper tonnage calculation ensures the machine can keep the mold closed during injection, preventing flash and ensuring part quality.

4. Using the Calculator

Tips: Enter the projected area (including runners), typical injection pressure (default 5000 psi), and safety factor (default 1.5). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is projected area?
A: The total area of the part(s) and runner system as seen from the direction of mold opening.

Q2: Why divide by 2000?
A: This converts pounds-force (from psi × in²) to tons (1 ton = 2000 lbs).

Q3: What's a typical injection pressure?
A: Most processes use 3000-8000 psi, with 5000 psi being a common default value.

Q4: When would I increase the safety factor?
A: For complex parts, high precision requirements, or materials with high flow resistance.

Q5: How do I find the projected area?
A: Use CAD software or calculate manually by summing all part and runner areas in the mold.