Ejection Rubber: A Complete Technical Guide for Die Cutting Operations

Ejection rubber, also referred to as die ejection rubber, stripping rubber or die cut rubber pads, is an essential consumable component mounted on die cutting boards. It plays a critical role in packaging printing, label production, carton converting and other paper converting industries by ensuring smooth material ejection after each die cut stroke.

Core Functions of Ejection Rubber in Die Cutting

The primary purpose of ejection rubber is to push cut substrates cleanly out of the blade gap, preventing material jamming and sticking. Beyond basic ejection, it delivers three key operational benefits:

• Blade protection: Absorbs impact force during die cutting, reducing blade wear and extending die tool service life
• Cut accuracy improvement: Stabilizes the substrate during the cutting cycle, minimizing material shift and edge burrs
• Production efficiency boost: Eliminates manual stripping work, enabling continuous high-speed die cutting production

Common Ejection Rubber Types by Hardness & Material

Selecting the correct hardness is the most critical factor for optimal performance. Ejection rubber is classified by Shore A hardness, each grade designed for specific substrate types:

1. Soft Ejection Rubber (20–35 Shore A) Ideal for thin paper, specialty films, fragile substrates and high-end printed materials. It provides gentle ejection without leaving indentations or damaging surface print quality.
2. Medium Ejection Rubber (40–50 Shore A) The most widely used standard grade, suitable for regular cardboard, coated paper and sticker die cutting. It balances good resilience with cost-effectiveness for daily production.
3. Hard Ejection Rubber (60–70 Shore A) Engineered for thick cardboard, corrugated board and rigid substrates. It delivers strong supporting force and maintains dimensional stability under high die cutting pressure.
4. High-Temperature Resistant Ejection Rubber Formulated for hot die cutting and high-speed continuous production lines. It resists thermal aging and retains resilience under prolonged cyclic compression.

How to Select the Correct Ejection Rubber

Follow these matching principles to ensure compatibility with your production setup:

1. Match to substrate thickness: Thicker and stiffer substrates require higher hardness rubber
2. Match to blade height: Ejection rubber should be 0.8–1.2 mm higher than the cutting blade edge to guarantee effective ejection
3. Match to machine speed: High-speed die cutters (10,000+ strokes per hour) require high fatigue-resistance rubber grades
4. Match to process requirements: For combined hot stamping and die cutting processes, use high-temperature resistant formulations

Proper Installation & Maintenance Best Practices

Installation Guidelines

• Clean the die board surface thoroughly to remove dust, residual glue and debris before application
• Apply adhesive evenly along both sides of the blade, maintaining a 1–2 mm gap from the cutting edge
• Stagger joints at stress points to avoid delamination during operation

Maintenance Tips

• Inspect rubber condition regularly; replace when resilience decreases or cracks appear
• Store unused die boards in a flat, cool place away from direct sunlight and oil contamination
• Release pressure on die boards during long downtime to prevent permanent compression set

Common Issues & Troubleshooting

About Shenhua Printing Equipment

Shenhua Printing Equipment Co., Ltd. is a specialized manufacturer and supplier of printing and die cutting consumables. Our ejection rubber products are made from premium virgin rubber materials, available in a full range of hardness grades and custom sizes. We deliver consistent quality, stable delivery and technical support for printing and packaging factories worldwide.

If you need assistance selecting the right ejection rubber for your die cutting line, or require custom dimensions, feel free to contact our technical team for a tailored solution.