Threadless Insert Sheet Bonding for Secure Book-Like Documents

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Solution Overview

Problem

Existing methods for producing book-like documents, such as passports, are complex and prone to tampering due to the use of sewing threads, which are difficult to implement with certain materials like PC layers and increase the risk of manipulation.

Innovation Solution

A method involving an insert sheet with open-edged recesses forming flap sections that are connected to inner pages and a book cover using thermoplastic materials and closure elements like welding or lamination, eliminating the need for sewing threads.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If sewing thread is used to connect the insert sheet to the book cover, then the connection strength is improved, but the device complexity and tampering risk increase

Engineering Contradiction:
Improveconnection strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent removes the sewing thread from the connection system entirely. Instead of using thread to sew the insert sheet to the book cover, the invention uses a flap made from the same PC material as the data page, which is directly laminated or welded to the book cover, eliminating the need for separate sewing components and processes

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical sewing system with a thermal bonding system. The flap is connected to the book cover through lamination or welding processes that use heat and pressure rather than mechanical needle and thread, simplifying the manufacturing process while maintaining connection strength

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If PC layers are used for the data page area, then the security and durability are improved, but the ease of manufacture deteriorates due to difficulty in sewing

Engineering Contradiction:
Improvesecurity and durabilityVSAvoidease of sewing
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces mechanical sewing with thermal bonding processes (lamination or welding) that are suitable for PC materials. The flap made from PC material is bonded to the book cover using heat and pressure, avoiding the need to pierce or sew through the rigid PC layers

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the connection method from mechanical (sewing) to thermal (lamination/welding), utilizing the thermal properties of PC material to achieve bonding. This parameter change in the connection process enables the use of PC materials without the manufacturing difficulties associated with sewing

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a flap extending completely along the long side of the data page is used, then the connection reliability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the flap with the data page by forming the flap from the same PC material as the data page itself. This integration eliminates the need for separate components and assembly steps, reducing manufacturing complexity while maintaining the connection reliability provided by the full-length flap

Inventive Principle:
Principle #5Merging (Combining)

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

Facilitates a simple, cost-effective production of threadless book-like documents with enhanced security features, allowing easy opening and closing without slamming shut, and reducing the risk of tampering.

Implementation Method 1

at least one layer or at least one further layer of the insert sheet is made of a thermoplastic material... the individual materials can be combined to create a specific layer structure

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 2

The at least one first layer or the at least one further layer of the insert sheet can consist of one or more individual layers that are joined together by lamination, bonding, or welding

Methodology Applied
Scientific EffectLamination: Lamination

Data Source

PatentEP3259139B1Insert sheet, book block and book-like document, and method for producing an inlay sheet, a book block and a book-like document
Publication Date: 2026.04.01 BUNDESDRUCKEREI GMBH
  • EP3259139B1 patent drawingFigure 1~3
  • EP3259139B1 patent drawingFigure 4~6
  • EP3259139B1 patent drawingFigure 7~11

AI summary

The invention relates to an insert sheet, a book block and a book-like document, in particular a value or security document, and to a method for producing them, wherein a structure without sewing thread is provided.