Pad Printing Rubber Head, How To Match Soft And Hard?

In the pad printing process, the rubber head is the key intermediary for transferring the steel plate pattern to the surface of the workpiece. Whether the hardness of the rubber head is appropriately selected directly determines the quality of printing. As a professional brand deeply involved in the field of printing equipment, Oulette has developed a scientific method for matching soft and hard rubber heads based on years of technology accumulation.

1. Common ranges and applicable scenarios of rubber head hardness

The hardness of pad printing pads is usually expressed in Shore hardness, and the common range is between 15 degrees and 40 degrees:

Soft rubber head (15-20 degrees): It has good flexibility and can adapt to uneven or irregular workpiece surfaces. It is suitable for printing rough materials or workpieces with large curved surfaces. But the disadvantage is that the edges of the pattern are easily deformed and are not suitable for fine line printing.

Medium hardness rubber head (25-30 degrees): The widest range of applications, taking into account good mold release and moderate deformation ability, can cope with the printing needs of most ordinary flat workpieces and small curved surfaces.

Hard rubber head (35-40 degrees and above): minimal deformation, high degree of pattern restoration, suitable for printing high-precision line text, fine dots or flat hard workpieces.

2. Four core principles for selecting the hardness of the rubber head

According to the shape of the workpiece: the larger the curved surface of the workpiece and the more obvious the unevenness, the softer the rubber head should be selected to fully fit the ink pickup and transfer; for the flat workpiece, a harder rubber head can be used to ensure that the pattern is clear and not deformed.

Depending on the fineness of the pattern: For fine lines, tiny text or half-tone dots, a harder rubber tip (above 30 degrees) is required to reduce expansion and deformation; for large-area color blocks or bold patterns, a slightly softer rubber tip (20-25 degrees) is beneficial for even coverage.

According to the printing material: hard and smooth surfaces (such as metal, hard plastic) should use a medium-hard rubber head; rough or soft surfaces (such as leather, cloth, soft plastic) need a softer rubber head to cooperate with downward pressure deformation to fully contact.

According to the amount of ink taken up and down, the soft glue head takes up more ink and the ink down is thicker, which is suitable for scenes with high covering power requirements; the hard glue head takes ink accurately and has a thin ink layer, which is suitable for fine restoration.

3. Practical suggestions and precautions

Combined use: When the shapes of different areas on the same workpiece are greatly different, you can consider customizing special-shaped rubber heads instead of simply relying on hardness adjustment.

Proofing verification: Before mass production, it is recommended to use a rubber head with the same or similar hardness to confirm the effect on the trial print to avoid batch scrapping.

Regular replacement: The rubber head is a consumable item. It will gradually harden or crack as the number of uses increases. If the transfer is found to be incomplete or the pattern is blurred, it should be replaced in time.

Oulette provides a variety of original matching rubber heads, covering the full hardness range of 15-40 degrees, and the shape can be customized according to customer workpieces. If you need further technical support, please contact our technical team.