Refrigerator Parts Silver Antibiotic Layer for Color Stability

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Solution Overview

Problem

Conventional zinc-based or copper-based antibiotic substances used in refrigerators degrade over time due to light and heat exposure, require high amounts for effectiveness, and are costly, leading to discoloration, carbonization, and increased manufacturing failures.

Innovation Solution

A silver-based antibiotic method involving a mixture of Ag oxide, zirconium phosphate, and zinc oxide, used in pellet form at 0.05-0.1% concentration with resin, forming a protective layer on refrigerator parts through extrusion or injection molding to maintain antibacterial and whitening effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If zinc-based or copper-based antibiotic substances are used to impart antibiotic and whitening effects, then the antibiotic capability is improved, but the parts are discolored into yellow with time under light and heat

Engineering Contradiction:
Improveantibiotic capabilityVSAvoidcolor stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical composition parameter from zinc-based or copper-based substances to silver-based substances (specifically silver oxide, silver chloride, or silver carbonate). This parameter change maintains the antibiotic capability while preventing the yellow discoloration that occurs with conventional substances under light and heat exposure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining silver-based antibiotic substances with specific resin matrices. The silver-based substance is dispersed within the resin to create a composite that provides both antibiotic protection and color stability, preventing the yellowing issue while maintaining effectiveness.

Inventive Principle:
Principle #40Composite materials

2Reliability

If inorganic zinc-based or copper-based antibiotic substances are added in large amounts (0.5 to 5% by weight) to maintain antibiotic capability and whitening, then the antibiotic effect is improved, but the manufacturing cost increases

Engineering Contradiction:
Improveantibiotic effectVSAvoidcost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the concentration parameter from 0.5 to 5% by weight to a much lower range of 0.01 to 0.1% by weight. This is made possible by using silver-based substances which provide equivalent or superior antibiotic effectiveness at lower concentrations, thereby reducing material costs significantly.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If organic antibiotic substances are used, then the antibiotic effect is maintained, but the substances are carbonized at high extrusion temperatures (210 to 250° C.)

Engineering Contradiction:
Improveantibiotic effectVSAvoidthermal stability
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent changes the chemical nature parameter from organic antibiotic substances to inorganic silver-based substances (silver oxide, silver chloride, or silver carbonate). This parameter change provides thermal stability at extrusion temperatures of 210 to 250° C., preventing carbonization while maintaining antibiotic effectiveness.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If antibiotic substances are mixed directly with resins for manufacturing parts, then the antibiotic effect is achieved, but gas is generated during processes causing corrosion on surfaces

Engineering Contradiction:
Improveantibiotic effectVSAvoidsurface corrosion
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent creates a composite material system where silver-based antibiotic substances are uniformly dispersed in the resin matrix. This composite structure prevents gas generation during processing, eliminating the surface corrosion problem while maintaining the antibiotic effect throughout the part.

Inventive Principle:
Principle #40Composite materials

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 silver-based antibiotic method prevents discoloration and maintains antibacterial capability over time, reduces material costs, and minimizes manufacturing failures by using a stable and accurately distributed antibiotic substance, ensuring freshness and hygiene within the refrigerator.

Implementation Method 1

a silver-based antibiotic substance comprising 60 to 80% by weight of an oxide of Ag ions, 10 to 20% by weight of zirconium phosphate, and 10 to 20% by weight of a zinc oxide

Methodology Applied
Scientific EffectAntimicrobial activity:

Implementation Method 2

forming a preform of the part to have a thickness relatively smaller than that of a finished product of the part through an extrusion process

Methodology Applied
Scientific EffectExtrusion: Extrusion

Data Source

PatentUS7781497B2Antibiotic method for parts of refrigerator using antibiotic substance
Publication Date: 2010.08.24 LG ELECTRONICS INC

AI summary

A conventional part of a refrigerator containing an antibiotic substance has problems in that discoloration occurs with time, a surface of the part of the refrigerator is corroded during a manufacturing process, or the whitening effect is degraded, and production costs increase.The present invention relates to an antibiotic method for processing a part of a refrigerator using a silver-based antibiotic substance. The antibiotic method comprises the steps of forming a preform of the part to have a thickness relatively smaller than that of a finished product of the part through an extrusion process; mixing 0.05 to 0.1% by weight of the silver-based antibiotic substance in the form of pellets with a resin based on the total weight of the resin; and forming an antibiotic layer on a surface of the preform of the part using the resin with the antibiotic substance mixed therewith. The antibiotic layer may be formed by laminating a film made of the resin with the antibiotic substance mixed therewith, or formed on the surface of the part of the refrigerator through multi-extrusion. Further, the silver-based antibiotic substance may comprise 60 to 80% by weight of an oxide of Ag ions having diameters of several dozen to hundred nanometers, 10 to 20% by weight of zirconium phosphate, and 10 to 20% by weight of a zinc oxide. According to the present invention, there are advantages in that the production costs of the refrigerator are reduced, and the antibiotic and whitening effects are improved.