Golf Ball Core Negative Hardness Gradient via Trans Content
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for a golf ball core that exhibits a soft-to-hard hardness gradient from the surface to the center, known as a 'negative' hardness gradient, which is challenging to achieve efficiently and inexpensively with existing methods.
Innovation Solution
The golf ball core is formed with a substantially homogenous rubber composition, featuring a casing layer and a cover layer, where the outer surface has a higher trans-polybutadiene content than the center, creating a negative hardness gradient, and can include a dual core structure with inner and outer core layers, each with specific hardness and trans content profiles to achieve desired spin and feel characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional hard-to-soft hardness gradient (positive gradient) is used in the core, then the manufacturing process is simple and well-established, but the ball exhibits limited spin control and feel characteristics
Solution Approach 1:
The patent applies local quality by creating distinct regions within the core with different hardness characteristics. Specifically, it implements a soft-to-hard gradient where the center is softer and the outer layers are harder, opposite to conventional cores. This localized variation in hardness properties enables improved spin control and feel while maintaining a feasible manufacturing process through controlled curing variations in different core regions.
2Adaptability or versatility
If a soft-to-hard hardness gradient (negative gradient) is implemented from surface to center, then unique spin and feel characteristics are achieved, but the manufacturing process becomes time-consuming and complex
Solution Approach 1:
The patent applies preliminary action by pre-configuring the core material with varying curing characteristics before the molding process. The core composition is formulated in advance with different regions having different crosslinking densities or curing rates, allowing the soft-to-hard gradient to form automatically during the standard curing cycle without requiring additional time-consuming steps or complex multi-stage manufacturing processes.
3Manufacturing precision
If multiple elastomer layers are molded together to create hardness gradient, then the gradient structure is achieved, but the process is time-consuming due to sequential layer creation
Solution Approach 1:
The patent merges multiple elastomer layers into a single integrated core structure that is molded and cured as one piece. Instead of sequentially creating separate elastomer layers and then assembling them, the invention combines all layers in a single molding operation with a unified curing process. This integration maintains the desired hardness gradient structure while dramatically improving production efficiency by eliminating sequential manufacturing steps.
Solution Approach 2:
The patent employs composite materials by formulating the core with multiple elastomer compositions that have different curing characteristics within a single homogeneous moldable mass. These composite elastomers are designed to self-segregate or form gradients during the curing process, creating the soft-to-hard structure without requiring separate layer-by-layer construction. This approach achieves precise hardness gradient control while maintaining high production efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the creation of golf balls with unique combinations of compression, feel, and spin, offering improved performance by precisely controlling the hardness and trans content gradients across the core layers.
Implementation Method 1
the outer surface has a higher trans-polybutadiene content than the center, creating a negative hardness gradient
Data Source
AI summary
A golf ball includes a ‘dual core’ formed from an inner core layer and an outer core layer. The inner core has an outer surface and a center and is typically formed from a substantially-homogenous rubber composition such that the center of the core has a hardness of about 72 Shore C to about 78 Shore C and a trans content of about 5% to 9%, and the outer surface of the inner core has a trans content of about 5% to 9%. The trans content of the outer surface and the center of the inner core are preferably within 2% of each other and, more preferably are substantially the same to define a zero trans gradient along a radius of the inner core.