Golf Ball Core Hardness Gradient Reduces Spin
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Solution Overview
Problem
Existing golf balls struggle to achieve a lower spin rate and improved durability while maintaining high rebound properties, particularly in designs that increase the hardness difference within a single-layer core.
Innovation Solution
A golf ball core formed from a rubber composition containing a base rubber made from polybutadiene and unneutralized ethylene-unsaturated carboxylic acid copolymer, with specific acid content and metal oxide neutralization, along with water or lower alcohol, and organic peroxide, to create a large hardness gradient without compromising rebound or durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the hardness difference between the surface and center of the core is enlarged to reduce spin rate, then the spin rate on full shots is reduced, but the durability of the ball to impact decreases
Solution Approach 1:
The patent applies local quality by creating a hardness gradient within the core where the surface hardness and center hardness differ by a specific range (5-20 Shore D). This gradient is achieved through controlled vulcanization processes that create different crosslinking densities at different locations within the core, allowing the surface to be harder for reduced spin while the center remains softer for maintained durability.
Solution Approach 2:
The patent utilizes parameter changes by precisely controlling the vulcanization temperature, time, and pressure parameters to achieve the desired hardness difference. By adjusting these processing parameters, the crosslinking degree is optimized to create the specific hardness gradient that simultaneously reduces spin rate and maintains impact durability.
2Object-generated harmful factors
If the hardness difference between the surface and center of the core is enlarged to reduce spin rate, then the spin rate on full shots is reduced, but the rebound of the ball decreases
Solution Approach 1:
The patent applies local quality by creating a hardness gradient within the core where the surface hardness and center hardness differ by a specific range (5-20 Shore D). This gradient is achieved through controlled vulcanization processes that create different crosslinking densities at different locations within the core, allowing the surface to be harder for reduced spin while the center remains softer for maintained durability.
Solution Approach 2:
The patent utilizes parameter changes by precisely controlling the vulcanization temperature, time, and pressure parameters to achieve the desired hardness difference. By adjusting these processing parameters, the crosslinking degree is optimized to create the specific hardness gradient that simultaneously reduces spin rate and maintains impact durability.
3Shape
If a two-layer rubber core structure is used to increase hardness difference, then the hardness gradient is achieved, but the number of manufacturing operations increases
Solution Approach 1:
The patent merges the advantages of multi-layer construction into a single-layer core by using a homogeneous rubber composition that develops a hardness gradient during vulcanization. This eliminates the need for separate manufacturing steps to create multiple layers, reducing manufacturing complexity while achieving the desired hardness distribution through controlled crosslinking.
Solution Approach 2:
The patent utilizes parameter changes by precisely controlling the vulcanization temperature, time, and pressure parameters to achieve the desired hardness difference. By adjusting these processing parameters, the crosslinking degree is optimized to create the specific hardness gradient that simultaneously reduces spin rate and maintains impact durability.
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
The solution effectively reduces spin rate and enhances durability while maintaining high rebound, achieving a balance in golf ball performance by optimizing core hardness distribution.
Implementation Method 1
the core is formed of a material molded under heat from a rubber composition containing... an organic peroxide
Implementation Method 2
the base rubber is a rubber obtained by mixing together (a-1) a polybutadiene and (a-2) an unneutralized ethylene-unsaturated carboxylic acid copolymer, and subsequently neutralizing the copolymer with (a-3) a metal oxide
Data Source
AI summary
In a golf ball having a core and a cover of one or more layer, the core is formed of a material molded under heat from a rubber composition containing(a) a base rubber,(b) water and/or a lower alcohol having a specific molecular weight,(c) an α,β-unsaturated carboxylic acid and/or a metal salt thereof, and(d) an organic peroxide.The base rubber (a) is a rubber obtained by mixing together (a-1) a polybutadiene and (a-2) an unneutralized ethylene-unsaturated carboxylic acid copolymer, and subsequently neutralizing the copolymer with (a-3) a metal oxide. Component (a-2) has a specific acid content and accounts for a specific portion of the combined amount of components (a-1) and (a-2). The core surface and center have a specific JIS-C hardness difference therebetween.This ball achieves both a lower spin rate and excellent durability while maintaining a high rebound.