Is the new rubber head 'oily' or 'not oily'? Full analysis of root causes and solutions

In pad printing production, the newly replaced rubber head sometimes has the troublesome "oil leakage" or "no oil" phenomenon. This is not because the quality of the rubber head itself is not up to standard, but rather the result of the combined effect of material formula, process parameters and usage habits.

1. Why does the rubber head "emit oil"?

The root cause of "oil leakage" is improper addition of silicone oil or use of inferior oil. In order to adjust the hardness of the rubber head, silicone oil needs to be added during production. The more silicone oil, the softer the rubber head will be. But the problem lies in two aspects:

Poor oil quality: In order to reduce costs, some manufacturers use petrochemical products such as white mineral oil to replace or compound silicone oil. White mineral oil is incompatible with silicone and will precipitate from the inside of the rubber head over time, causing "oil leakage" on the surface.

Excessive addition of silicone oil: Even if high-quality silicone oil is used, if the addition ratio exceeds 50%, it will destroy the molecular structure of the silicone, resulting in a decrease in hardness and oil analysis.

2. Why is the new rubber head "not oiled"?

"No oiling" is often misunderstood as the rubber head does not absorb ink, but in fact it means that the hardness of the rubber head is too high. When the rubber head is too hard, it cannot fully absorb the ink in the steel plate graphics and text, especially for small English letters or precise patterns. In addition, if the release agent on the surface of the new rubber head is not cleaned, it will also hinder the ink transfer.

3. Targeted solutions

1. Source control: choose high-quality materials

Prioritize the use of pad-printing silicone brands that are permanently anti-static and do not emit oil. Be sure to use pure silicone oil to adjust the hardness and avoid adding petroleum-based diluents such as white mineral oil. The amount of silicone oil added is recommended to be controlled within 50%.

2. New plastic head activation: standard preprocessing

Before using a new rubber head, the surface must be wiped with industrial alcohol, white oil or facial cleanser to completely remove the release agent. Do not use strong corrosive solvents such as Tianna water and net washing water. This will destroy the molecular structure of the surface of the rubber head. Although it is temporarily "oiled", it will greatly shorten the service life.

3. Routine maintenance and emergency treatment

Regularly cleaning the surface of the rubber head with alcohol can improve minor "oil leakage". For rubber heads that have become oily, you can use detergent and water to clean them and dry them before continuing to use them. At the same time, avoid soaking the rubber head in solvent or ink for a long time, and clean and dry it in time after printing.