Security Sheet Insert Fusing for Uniform Quality

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Solution Overview

Problem

Current methods for manufacturing plastic security sheets for personal data display are inefficient due to uneven fusing and quality issues caused by temperature and pressure distribution during the lamination process, and they struggle to incorporate certain security features like watermarks.

Innovation Solution

A semi-continuous method involving inserts with security elements is used, where plastic layers are fused with inserts containing security elements detectable by the naked eye or machine, and the insert substrate is registered to the security element, allowing for improved security features and uniform quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If thin plastic layers are placed between laminating plates and heated for fusing, then the plastic layers fuse together to form a plastic sheet, but the heating and cooling cycle lasts around thirty minutes making the method time inefficient

Engineering Contradiction:
Improvefusing qualityVSAvoidmanufacturing speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent divides the plastic sheet formation process into multiple stages: initial heating at lower temperature to start fusion, then progressive heating at higher temperatures to complete fusion. This segmented temperature approach allows faster processing while maintaining quality, reducing the total cycle time from 30 minutes to a more efficient duration.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies a preliminary low-temperature heating stage before the main high-temperature fusion stage. This preliminary action initiates the fusion process and prepares the plastic layers, allowing the subsequent high-temperature stage to complete the fusion more quickly and efficiently.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If heat is applied to the top and bottom of the stack during lamination, then the thinner plastic layers fuse together, but uneven temperature and pressure distribution causes varying quality due to laminating plates closer to top and bottom being hotter or colder

Engineering Contradiction:
Improvefusing uniformityVSAvoidquality consistency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent introduces intermediate heating elements positioned between the laminating plates and the plastic layers. These intermediate heaters provide localized heating to specific regions of the plastic stack, compensating for the temperature variations caused by the top and bottom plates. This ensures more uniform heat distribution and consistent fusion quality throughout the entire stack.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The intermediate heating elements act as mediators between the external heat source (top and bottom plates) and the plastic layers. These intermediaries distribute heat more evenly across the plastic stack, preventing the temperature extremes that occur at the edges of the stack and ensuring uniform fusion throughout.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If plastic security sheets are manufactured using traditional lamination methods, then the sheets are durable and resistant to delamination, but it is not possible to include certain security features like watermarks

Engineering Contradiction:
Improvedelamination resistanceVSAvoidsecurity feature incorporation
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The patent segments the plastic sheet into multiple thin layers that are laminated together. Certain layers can be selectively removed or modified to create apertures, windows, or transparent regions while maintaining the overall structural integrity and delamination resistance of the composite sheet. This allows incorporation of security features like watermarks in specific layers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses composite construction with multiple plastic layers having different properties. Some layers are designed to be transparent or removable to accommodate security features, while other layers provide structural support and delamination resistance. The combination of different material properties in a composite structure enables both durability and security feature incorporation.

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

This method enhances the security of the plastic sheets by making it difficult for counterfeiters to reproduce and ensures uniform quality, while allowing for the incorporation of various security features like windows and biometric data storage.

Implementation Method 1

heating devices (54, 55) located within the first and second continuous belts (45, 46) are operable to heat and pressurise a region of the laminar structure (32) therebetween

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

heating devices (54, 55) located within the first and second continuous belts (45, 46) are operable to heat and pressurise a region of the laminar structure (32) therebetween

Methodology Applied
Scientific EffectPressure increase: Pressure Increase

Implementation Method 3

cooling devices (56, 57) located within the first and second continuous belts (45, 46) between the heating devices (54, 55) and the outlet drums (49, 52) are operable to cool and pressurise the plastic substrate (14)

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3359389B1A method for manufacturing a security sheet and an insert for incorporation into a security sheet
Publication Date: 2020.03.18 DE LA RUE INTERNATIONAL LTD
  • EP3359389B1 patent drawingFigure 1~2
  • EP3359389B1 patent drawingFigure 3~5
  • EP3359389B1 patent drawingFigure 6~7

AI summary

The present invention is directed towards a method for manufacturing a security sheet (11) for displaying personal data comprising a plastic substrate (14). The method comprises inserting an insert (61) into an aperture (41) in at least one plastic layer (34, 35, 36, 37, 38, 39, 40). The insert (61) comprises a plastic insert substrate (66)and at least one security element (72) located within and/or on the insert substrate (66). The at least one security element (72) is detectable by a naked eye and/or a machine. The method further comprises arranging plastic layers (34, 35, 36, 37, 38, 39, 40) over opposing surfaces of the insert (110) and fusing at least the insert substrate (66) and plastic layers (34, 35, 36, 37, 38, 39, 40) together to form a plastic substrate (14). The present invention is further directed towards an insert (61) for incorporation into such a security sheet (11), a security sheet (11)comprising the insert (61), a security document (10) comprising the security sheet (11) and a method of manufacturing the insert (61).