Water-Soluble Polymer Coating for Tennis String Roughness

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing solutions for maintaining the rough surface of tennis, badminton, and squash racket strings are either complex, expensive, or ineffective in prolonging the duration of string roughness, which is crucial for generating spin and power, especially for frequent players.

Innovation Solution

A combination of a crystalline marble-based filler, such as crystalline calcium carbonate or calcium-magnesium carbonate, mixed with a higher-melting maleic resin binder, creates a durable and long-lasting anti-slip coating that maintains string roughness, using a process involving mixing with water and adhesion promoters like Erkamar to form a liquid varnish for application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If existing coating agents (resins in organic solvents) are applied to maintain string roughness, then the strings can be coated, but the production is complex and expensive, and the effect does not last long

Engineering Contradiction:
Improveduration of string roughnessVSAvoidcomplexity of coating production and application
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The patent changes the chemical parameters of the coating agent by using water-soluble polymers (carboxymethyl cellulose, polyvinyl alcohol, polyacrylamide) instead of traditional organic solvent-based resins. This parameter change enables water-based application, simplifying the coating process and reducing complexity while maintaining durable roughness effect through multiple washes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite coating material by combining water-soluble polymers with abrasive particles (silicon carbide, aluminum oxide, emery powder). This composite structure provides both the adhesive binding layer and the roughening abrasive elements, achieving long-lasting roughness while simplifying application to a single washable coating process

Inventive Principle:
Principle #40Composite materials

2Reliability

If strings are frequently re-strung to maintain optimal performance, then string roughness is restored, but this is time-consuming and expensive for amateur players

Engineering Contradiction:
Improveplaying effectiveness of stringsVSAvoidtime for re-stringing
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies a preliminary roughening coating to the strings during the initial stringing process or before use. This preliminary action of coating the strings with abrasive particles embedded in water-soluble polymer creates immediate roughness for spin generation, eliminating the need for frequent re-stringing and allowing players to maintain optimal performance over extended periods

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The coating system allows strings to self-maintain their roughness through the durable polymer-bonded abrasive layer. The water-soluble polymer matrix holds abrasive particles in place during play, and the coating can be refreshed by simple washing rather than requiring complete re-stringing, enabling strings to serve themselves over multiple uses

Inventive Principle:
Principle #25Self-service

3Duration of action of stationary object

If abrasive particles are embedded in adhesive coatings, then string roughness is improved, but the production process becomes complex and expensive

Engineering Contradiction:
Improveduration of roughnessVSAvoidease of coating production
Core Design Contradiction:
Duration of action of stationary objectVSEase of manufacture

Solution Approach 1:

The patent changes the solvent parameter from organic solvents to water, creating water-soluble polymer-based coatings. This parameter change simplifies manufacturing by eliminating the need for specialized organic solvent handling, drying, and safety infrastructure, while the water-based polymer solutions effectively bind abrasive particles for durable roughness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses inexpensive water-soluble polymers (carboxymethyl cellulose, polyvinyl alcohol, polyacrylamide) as the binding matrix instead of expensive traditional resins. These polymers provide sufficient adhesion for the abrasive particles and can be applied as simple washable coatings, reducing manufacturing cost and complexity while maintaining effective roughness duration

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 extends the durability and playing effectiveness of racket strings by maintaining their roughness and power, allowing for repeated reapplication and improved resistance to moisture, benefiting both professional and amateur players.

Implementation Method 1

a binder with adhesive properties, namely a higher-melting, maleic resin as a dispersing resin

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

a liquid varnish for application

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2134429B1Product for roughening the strings of tennis, badminton and squash rackets and for keeping them rough and method for producing said product
Publication Date: 2015.08.26 SURMECI BUNYAMIN

AI summary

The product basically consists of Saxolith®, a crystalline marble-based filler, and Erkamar®, a binder having adhesive properties. The product preferably also contains dimethyl ethanol amine to improve the dissolution of resins and to stabilize the pH, as well as isopropanol as the diluent, Sipernat® to improve the flow properties, Agitan® as defoaming agent and coagulant, as well as Byk® to improve the flow properties and as a filler. The product is produced by adding Erkamar® to at least the same quantity of water, mixing it and stirring it for a few hours, cooling the mixture to room temperature, and adding at least the same quantity of Saxolith® as previously Erkamar® and stirring until a homogeneous mixture is obtained.