Bi-standard Smart Card Frangible Clip Design

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Solution Overview

Problem

The production of bi-standard smart cards made from paper or cardboard faces challenges in achieving a clean and strong detachment of the mini-card from the card body, often resulting in delamination, irregular tears, and burrs, which can violate ISO standards and affect card operation.

Innovation Solution

A microcircuit card design featuring a fibrous material with an adhesive layer for mechanical retention and easy detachment, including a frangible clip formed by thinned regions with notches and a junction layer of starch-based resin for elasticity and clean breakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a pre-cut is made in paper or cardboard material to allow mini-card detachment, then the mini-card can be separated from the card body, but the separation produces delamination, irregular tears, and burrs instead of a clean break

Engineering Contradiction:
Improvemini-card detachmentVSAvoidseparation quality
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies composite materials by combining fibrous material (paper or cardboard) with a thermoplastic polymer layer to create a bi-standard card. The thermoplastic layer is applied to the fibrous material and then the card is heat-treated to fuse the layers, creating a composite structure that maintains mechanical retention while enabling clean separation along the pre-cut region when heated during mini-card detachment.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the card is made exclusively from fibrous material, then it is recyclable and cost-effective, but it lacks elasticity and produces poor detachment quality with burrs and irregular tears

Engineering Contradiction:
Improvematerial cost and recyclabilityVSAvoiddetachment quality
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent combines fibrous material (providing recyclability and cost-effectiveness) with a thermoplastic polymer layer (providing elasticity and clean detachment). The thermoplastic layer is applied to the fibrous material and heat-treated to fuse the layers, creating a composite structure that maintains mechanical retention while enabling clean separation along the pre-cut region.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the physical state of the thermoplastic polymer layer through heat treatment. During normal use, the thermoplastic layer remains solid and provides mechanical retention. During mini-card detachment, heating the card causes the thermoplastic layer to soften and become elastic, allowing clean separation along the pre-cut region without producing burrs or irregular tears.

Inventive Principle:
Principle #35Parameter changes

3Strength

If the pre-cut region is made strong to prevent untimely detachment, then mechanical retention is improved, but the detachment process becomes difficult and may cause delamination

Engineering Contradiction:
Improvemechanical retentionVSAvoiddetachment process
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent changes the physical state of the thermoplastic polymer layer through heat treatment. During normal use, the thermoplastic layer remains solid and provides mechanical retention. During mini-card detachment, heating the card causes the thermoplastic layer to soften and become elastic, allowing clean separation along the pre-cut region without producing burrs or irregular tears.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent makes the mechanical properties of the card dynamic by incorporating a thermoplastic polymer layer that changes its state based on temperature. At room temperature, the thermoplastic layer provides strong mechanical retention. When heated during detachment, the thermoplastic layer softens and becomes elastic, facilitating clean separation. This dynamic property resolution allows the card to exhibit different mechanical behaviors under different thermal conditions.

Inventive Principle:
Principle #15Dynamics

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

Ensures a frank and clean detachment of the mini-card with regular edges, maintaining mechanical retention and compliance with ISO standards, while being recyclable and cost-effective.

Implementation Method 1

Unlike a card formed exclusively with fibrous material, such a card has very good elasticity

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the junction layer of adhesive material ensures good retention of the clip while allowing easy detachment without burrs

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2423857B1Microcircuit card including a mini-card
Publication Date: 2016.05.25 OBERTHUR TECH SA
  • EP2423857B1 patent drawingFigure 1~3

AI summary

The card (10) has a mini-card (22) detachable from a card body (20) and carrying a microcircuit that is connected to the body by a fragile attachment (30), where the attachment is formed by a thin region of the body. The body comprises two fibrous material layers and a junction layer that connects the fibrous material layers, where the fibrous material layers are made from fibrous material e.g. natural and/or synthetic fibers. The thin region is extended partially in the thickness of the junction layer, where the junction layer is made from adhesive material e.g. starch based resin.