Shenhua Printing: Performance Testing and Acceptance Standards for Ejection Rubber
Many printing and packaging companies struggle to evaluate the quality of ejection rubber before purchasing, leading to the use of inferior products that cause production problems. While professional laboratory testing provides the most accurate results, there are several simple tests that can be performed on-site to quickly assess ejection rubber quality. Shenhua Printing shares these practical testing methods and outlines the key acceptance standards that all high-quality ejection rubber should meet.
The first and most important test is the rebound resilience test. Simply press your finger firmly into the surface of the rubber and release it quickly. High-quality ejection rubber should rebound instantly and completely, leaving no visible indentation. Inferior rubber will rebound slowly and may leave a permanent depression. For reference, premium ejection rubber should have a rebound resilience of at least 90%, with top-performing products reaching 98%.
Next, perform the compression set test. Place a heavy weight (such as a 5kg block) on a small piece of ejection rubber for 24 hours. After removing the weight, measure the thickness of the rubber and compare it to the original thickness. The compression set is calculated as the percentage of thickness loss. High-quality ejection rubber should have a compression set of less than 3% after 24 hours of compression. A compression set greater than 5% indicates that the rubber will quickly lose its shape and performance during use.
The hardness test is also essential. While a durometer provides the most accurate measurement, you can get a good idea of hardness by comparing the rubber to known samples. The hardness should be uniform across the entire surface of the rubber. If some areas feel significantly harder or softer than others, the rubber has poor quality control and will cause uneven pressure distribution during die cutting.
Dimensional accuracy is another critical acceptance standard. Use a micrometer to measure the thickness of the rubber at several different points. The thickness variation should be no more than ±0.05mm for standard ejection rubber and ±0.03mm for high-precision applications. Also, check the width and length of the rubber sheets to ensure they meet the specified dimensions.
Finally, inspect the appearance and smell of the rubber. High-quality ejection rubber should have a smooth, uniform surface with no bubbles, cracks, or foreign particles. It should have a mild, non-irritating odor. Strong, pungent odors indicate the use of low-quality raw materials and harmful additives, which can be harmful to workers and may cause product contamination.
Shenhua Printing adheres to strict quality control standards, and every batch of ejection rubber undergoes comprehensive testing before leaving the factory. We provide detailed test reports with all our products, giving our customers complete confidence in the quality and performance of our ejection rubber.