Pad printing heads are the core component of pad printing process, and head quality directly affects printing results and production efficiency. Many customers encounter various defect problems when using pad printing heads, not knowing where the cause lies or how to solve them. Hongye Silicone, as a professional manufacturer with 25 years of
Pad Printing Silicone R&D and production experience, today summarizes the 6 most common pad head defects and solutions.
Defect 1: Pores on Pad Head Surface
Pores appearing on the pad head surface is one of the most common defects, causing white spots or missing print in patterns.
Cause Analysis: The main cause is insufficient vacuum degassing after silicone mixing, leaving residual bubbles inside. Secondly, pouring into the mold too quickly entrains air. Additionally, dust or impurities on the mold surface can cause pits on the pad head surface.
Solutions: Ensure sufficient vacuum degassing time, generally 5-8 minutes until no more bubbles rise to the silicone surface. Pour slowly from one side of the mold allowing natural flow. Clean the mold surface before use to ensure no dust or impurities. If there are many pores, try secondary degassing by placing the poured mold in the vacuum chamber again.
Defect 2: Pad Head Cracking or Breaking
Pad head cracking or breaking during use seriously affects service life.
Cause Analysis: The main cause is insufficient tensile and tear strength of the silicone with substandard physical properties. Secondly, internal pores or defects in the pad head become stress concentration points. Additionally, improper operation such as forceful pulling or sharp object scratches can cause cracking.
Solutions: Choose silicone models with high tensile and tear strength such as HY-902 high wear grade with tensile strength ≥4.0MPa and tear strength ≥18kN/m. Ensure sufficient degassing for dense internal structure without pores. Handle carefully during demolding and installation, avoiding forceful pulling. Prevent pad head contact with sharp objects. Regularly inspect pad head condition and replace promptly when small cracks appear.
Defect 3: Blurry Printed Patterns
Blurry printed patterns is a common problem affecting printing quality.
Cause Analysis: The main cause is oil or dust on the pad head surface affecting ink adhesion. Secondly, insufficient pad head resilience causes slow recovery after pressing, leading to pattern smudging. Additionally, inappropriate ink viscosity, excessive or insufficient printing pressure can also cause blurry patterns.
Solutions: Clean the pad head surface with a lint free cloth and special cleaner before use. Choose silicone models with good resilience such as HY-912 multi color universal grade. Adjust ink viscosity to appropriate range. Adjust printing pressure to ensure uniform and moderate pressure. Regularly clean pad heads and clichés, maintain clean printing environment.
Defect 4: Uneven Ink Transfer
Uneven ink transfer manifests as some areas dark and some light in the printed pattern.
Cause Analysis: The main cause is inconsistent surface smoothness of the pad head, with some areas absorbing ink and some not. Secondly, uneven pad head hardness causes uneven printing pressure distribution. Additionally, inconsistent cliché etching depth or insufficient ink stirring can also cause uneven transfer.
Solutions: Choose silicone with fine texture and smooth surface such as HY-902 with viscosity 15000mPa.s and fine texture. Ensure uniform silicone mixing to avoid local hardness differences. Check cliché etching depth consistency. Stir ink thoroughly before use. Adjust pad head angle to ensure uniform contact.
Defect 5: Pad Head Deformation
Pad head deformation during use causes printing position offset.
Cause Analysis: The main cause is low pad head hardness with insufficient support, deforming after prolonged pressing. Secondly, insecure pad head installation causes shifting during printing. Additionally, high ambient temperature causing silicone softening can also lead to deformation.
Solutions: Choose models with higher hardness and good support such as HY-902 with hardness 28 Shore A. Ensure secure pad head installation using dedicated fixtures. Control ambient temperature between 15-35°C, avoiding high temperature environments. If the pad head is already deformed, replace with a new one promptly.
Defect 6: Short Pad Head Service Life
Short pad head service life with frequent replacement increases production costs.
Cause Analysis: The main cause is insufficient silicone wear resistance causing rapid pad head wear. Secondly, improper pad head surface cleaning using corrosive solvents. Additionally, excessive printing speed or pressure accelerates pad head aging.
Solutions: Choose high wear long life models such as HY-902 with service life more than double standard models. Use dedicated pad head cleaner, avoiding strong corrosive solvents. Adjust printing speed and pressure to reasonable ranges. Regularly maintain pad heads, clean and store properly after use. Establish pad head usage records and replace aging heads promptly.
Conclusion
The above are the 6 most common pad head defects and solutions. When encountering problems, do not panic. Follow the above methods to troubleshoot one by one, and most problems can be identified and resolved. Choosing stable quality silicone raw material is fundamental to preventing defects. Hongye Silicone full series pad printing silicone products undergo strict inspection before shipment with COA reports provided, ensuring stable and reliable quality. Welcome to consult and purchase.
Shenzhen Hong Ye Jie Technology Co., Ltd
