Polyurethane Urea Elastomer Lacrosse Ball Hardness Control
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Solution Overview
Problem
Lacrosse balls tend to increase in hardness with age, leading to potential injuries during gameplay, and existing solutions fail to meet both safety and performance specifications, particularly in terms of control and manipulation.
Innovation Solution
A polyurethane/urea elastomer composition is developed, comprising a prepolymer and curative components, such as carbodiimide modified diphenylmethane diisocyanate and polypropylene glycol diols, which forms a molded spherical ball with controlled compression and coefficient of restitution, and is free or substantially free of plasticizers to maintain consistent hardness and facilitate ease of manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rubber lacrosse balls are used, then the ball meets weight and volume specifications, but the ball increases in hardness with age causing potential injuries
Solution Approach 1:
The patent changes the chemical composition parameters of the ball material by using polyurethane/urea elastomer instead of conventional rubber, and by controlling the ratio of polyols with different molecular weights. This chemical parameter change allows the ball to maintain consistent hardness over time while meeting safety requirements, resolving the contradiction between safety and hardness stability.
Solution Approach 2:
The patent employs composite material formulation by combining multiple polyols with different molecular weights (2000, 3000, and 6000 Daltons) in specific ratios within the polyurethane/urea elastomer system. This composite approach enables the material to achieve both safety performance and consistent hardness over time, eliminating the hardening issue of conventional single-composition rubber balls.
2Ease of operation
If the ball surface is made smoother to reduce friction, then the ball is easier to manipulate, but the ball slips during gameplay reducing control
Solution Approach 1:
The patent adjusts the coefficient of friction parameter of the ball surface through controlled composition of the polyurethane/urea elastomer. By optimizing the ratio of polyols with different molecular weights, the surface friction is tuned to provide sufficient grip for control during gameplay while maintaining ease of manipulation, resolving the contradiction between ease of operation and slipping prevention.
3Ease of operation
If plasticizers are added to the ball composition, then the ball is softer and easier to manipulate, but the ball increases in hardness as it ages
Solution Approach 1:
The patent extracts and eliminates plasticizers from the ball composition entirely. Instead of relying on plasticizers to provide softness and ease of manipulation, the invention achieves these properties through the intrinsic molecular structure of the polyurethane/urea elastomer system, specifically through the combination of polyols with different molecular weights. This extraction of the problematic component (plasticizer) resolves the contradiction between ease of operation and hardness consistency over time.
Solution Approach 2:
The patent changes the compositional parameters by replacing plasticizer-based softening mechanisms with a polyol ratio-based approach. By controlling the proportions of polyols with molecular weights of 2000, 3000, and 6000 Daltons, the material achieves consistent softness and ease of manipulation without the hardening problem associated with plasticizer degradation over time.
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 composition results in a Lacrosse ball that maintains consistent hardness over time, meets athletic equipment specifications, and provides improved control during gameplay by adjusting the coefficient of friction, thus reducing the risk of injury and enhancing player performance.
Implementation Method 1
a prepolymer and a curative. The prepolymer can comprise a carbodiimide modified diphenylmethane diisocyanate having a functionality of about 2.2 combined with a polypropyleneglycol diol having a molecular weight of about 2000 Daltons to form a 14% isocyanate prepolymer
Implementation Method 2
A polyurethane/urea elastomer material for game ball applications... exhibiting a ball compression of from about 180 pounds to about 210 pounds or from about 90 pounds to about 210 pounds when tested in accordance with ND 049-12m12 Section 5.3 Ball Compression
Data Source
AI summary
Disclosed herein is a composition for use in the preparation of a Lacrosse sport ball, the composition comprising a prepolymer, the prepolymer comprising a multifunctional polyisocyanate and one or more polyols having a molecular weight of from about 1000 Daltons to about 5000 Daltons, and a curative comprising an amine or an additional polyol or a combination thereof. A Lacrosse ball formed from the composition exhibits a ball compression of from about 180 pounds to about 210 pounds or from about 90 pounds to about 210 pounds when tested in accordance with ND 049-12m12 Section 5.3 Ball Compression, and wherein the molded spherical ball exhibits a ball coefficient of restitution COR of from about 0.60 to about 0.70 or from about 0.50 to about 0.75 when tested in accordance with ND 049-12m12 Section 5.4 Ball Coefficient of Restitution COR.