Approach to Expanding the Pad Printing Area on Golf Balls Through the Selection of an Appropriate Silicone Pad Structure

In Thailand's manufacturing environment, where strict quality control is required, pad printing on materials with curved surfaces presents a significant challenge. This is particularly true when attempting to expand the printable area on golf balls, where ink smearing and incomplete pattern transfer can occur. These issues often lead to positional errors and increased production time. This article explains how to select the structure and hardness level of a silicone pad to address these problems and correctly increase the contact area.

Table of Contents

• Why increasing compression limits the printing area on golf balls
• How soft silicone pad structures reduce printing accuracy
• K1 and K4 hardness levels: differences seen in the printing area
• Conditions for a two-layer pad that balances accuracy and expanded printing area
• How Tokuabe (Thailand) can help
• Frequently Asked Questions
• Key terms for understanding this article

■　Why increasing compression limits the printing area on golf balls

Golf balls are spherical, which makes it difficult to print a pattern across a wide area of the side surface. Operators may try to solve this problem by increasing the compression stroke to widen the pad's contact area. However, this approach creates limitations and can lead to other problems. Increasing the compression stroke by an additional 5mm beyond the appropriate compression level causes the silicone pad to deform excessively.

As a result, the contact surface can slip, causing positional errors and ink smearing. These defects are particularly noticeable at the center of the printed pattern. Increasing compression to expand the printing area therefore has limitations and cannot maintain consistent pattern quality. The deformation behavior of the pad must also be considered as an important condition during evaluation.

■　How soft silicone pad structures reduce printing accuracy

Selecting a low-hardness pad, such as K4, is another method often used to improve conformity to the shape of a golf ball. Although a soft pad can increase the contact area, an excessively flexible structure makes it difficult to maintain the shape of the printed pattern. The pressure transmitted through the pad is not distributed evenly, which can cause dents or incomplete ink transfer at the center where the highest pressure is applied.

In addition, when special structures such as hollow pads or tunnel-type pads are combined with soft silicone, the direction of force distribution becomes unstable and the sequence of surface contact can be disrupted. This can result in missing sections of the pattern and areas where the ink spreads unevenly. These structures therefore need to be checked for compatibility with the shape of the workpiece in order to reduce uncontrolled deformation.

■　K1 and K4 hardness levels: differences seen in the printing area

When pads with different hardness levels are compared under the appropriate compression condition of 0mm, clear differences can be seen in both the printing area and pattern quality. The harder K1 pad provides excellent shape retention, enabling highly accurate pattern transfer, but the printing area is limited to 706.5 square millimeters.

In contrast, the softer K4 pad can expand the printing area to 881.0 square millimeters, but it carries a higher risk of ink smearing and pattern deformation. These figures are important when assessing the balance between printing accuracy and area coverage.

Relationship between hardness and printing area under the appropriate compression condition

■　Conditions for a two-layer pad that balances accuracy and expanded printing area

To address the limitations of a single-layer pad, switching to a two-layer pad structure can expand the printing area while maintaining accuracy. A structure that provides a balanced result uses K2 silicone in the upper section that contacts the workpiece and K4 silicone in the lower section.

The harder upper section helps maintain the pattern shape and prevents distortion, while the softer lower section absorbs compression and allows the pad to wrap around a wider area of the golf ball. This two-layer structure can achieve a printing area of up to 803.8 square millimeters while maintaining uniform ink transfer. Checking the hardness arrangement of each layer is therefore an important point when selecting equipment for printing on curved surfaces.

■　How Tokuabe (Thailand) can help

Tokuabe (Thailand) can help analyze and supply silicone pads with hardness structures suitable for spherical and curved workpieces. Options include standard shapes, K1 hardness for applications requiring high accuracy, and two-layer designs intended to provide a balance between accuracy and coverage. Selecting the correct structure helps control contact behavior and reduce ink smearing.

The conditions used for assessment are the curvature of the workpiece, the type of ink, and the compression stroke of the printing machine. If these conditions are not yet complete, please contact us for further evaluation.

※For more details, please download the PDF file attached to this article or contact us by completing the form below.

■　Frequently Asked Questions

Q1：Can increasing the pad compression stroke solve the printing-area problem on golf balls?
A1：Increasing the compression stroke causes excessive deformation of the pad structure, which can make the contact surface slip and create ink smearing at the center of the pattern. It is therefore not a suitable method for maintaining print quality.

Q2：What are the advantages of a two-layer pad compared with a conventional pad for printing on curved surfaces?
A2：A two-layer pad with harder rubber at the contact surface and softer rubber at the base helps maintain a clear pattern shape while distributing the compression force. This allows printing over a wider curved area without sacrificing accuracy.

Q3：Is a hollow structure suitable for expanding the printing area on golf balls?
A3：A hollow structure can make the distribution of compression force and the direction of deformation uneven. When high compression is applied, parts of the pattern may fail to transfer, so the force distribution conditions must be evaluated carefully.

■　Key terms for understanding this article

• Silicone Pad : An intermediate component that picks up ink from the printing plate and transfers it onto the workpiece
• Compression Stroke : The distance the silicone pad is pressed against the surface of a spherical workpiece during the printing process
• Two-layer Structure : A structure created by molding together two materials with different hardness levels to balance force distribution

※For more details, please download the PDF file attached to this article or contact us by completing the form below.