1. What is Injection Molding Machine Tonnage Calculator?

Definition: This calculator determines the required clamping force (tonnage) for an injection molding machine based on the mold's projected area, injection pressure, and safety factor.

Purpose: It helps manufacturers select the appropriate injection molding machine size for their molds to ensure proper part formation and prevent defects.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( T \) — Required tonnage (tons)
• \( A \) — Projected area of the part (in²)
• \( P \) — Injection pressure (psi)
• \( SF \) — Safety factor (typically 1.5-2)
• 2000 — Conversion factor from pounds to tons

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 molding machine can keep the mold closed during injection, preventing flash and ensuring part quality.

4. Using the Calculator

Tips: Enter the projected area in square inches, 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 maximum area of the part (including runners) as seen along the direction of mold opening.

Q2: What's a typical injection pressure?
A: Most materials use 3000-8000 psi, with 5000 psi being a common average value.

Q3: When would I change the safety factor?
A: Increase for complex parts (up to 2.0) or decrease for simple parts (as low as 1.2).

Q4: How do I find the projected area?
A: Use CAD software to measure or calculate length × width for simple parts.

Q5: Does this include runner systems?
A: No, you must include the projected area of runners in your total area calculation.