Unvulcanized Rubber Strip Stickiness Reduction via Electron Beam Pre-Crosslinking

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Solution Overview

Problem

The stickiness of unvulcanized rubber strips with reinforcements leads to material wastage during the production of spool bandage material, as they tend to adhere to each other when wound or unwound from spools, causing inefficiencies in tire manufacturing.

Innovation Solution

A method involving continuous production of tape-shaped spool bandage material with electron beam irradiation, applying a radiation dose of at least 40 kilo Gray to reduce the surface stickiness by pre-crosslinking the uppermost material layer, allowing for efficient winding and minimizing material waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If unvulcanized rubber strips with reinforcements are used for spool bandage material, then the material can be easily processed and assembled, but the stickiness of the rubber surface causes unwanted adhesion and material wastage during winding and unwinding operations

Engineering Contradiction:
Improveease of processingVSAvoidmaterial wastage
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent applies preliminary electron beam irradiation to the unvulcanized rubber strips to create a pre-crosslinked surface layer before the winding operation. This preliminary action modifies the surface properties of the rubber to reduce stickiness, allowing the material to be wound and unwound without adhesion problems while maintaining the ease of processing of unvulcanized rubber during assembly operations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical-chemical parameters of the rubber surface by applying electron beam radiation with specific energy levels (500-1500 keV) and doses (40-150 kGray). This parameter change creates a pre-crosslinked surface layer that fundamentally alters the surface properties, reducing stickiness by at least 10% while preserving the bulk properties of the unvulcanized rubber for easy processing.

Inventive Principle:
Principle #35Parameter changes

2Loss of substance

If electron beam irradiation is applied to reduce surface stickiness, then material adhesion is prevented, but additional equipment and process steps are required

Engineering Contradiction:
Improvematerial wastageVSAvoidprocess complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent replaces potential mechanical solutions for preventing adhesion (such as release films, surface coatings, or mechanical separation devices) with an electron beam irradiation system. This substitution uses electromagnetic radiation to achieve surface modification, eliminating the need for additional mechanical components and simplifying the overall process despite the sophisticated nature of the electron beam equipment.

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

Solution Approach 2:

The patent optimizes the irradiation parameters (energy 500-1500 keV, dose 40-150 kGray, exposure time based on transport speed) to achieve the minimum effective treatment. By carefully controlling these parameters, the process achieves adequate stickiness reduction with minimal radiation exposure, reducing the complexity and cost of the irradiation system required while maintaining effectiveness.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If high radiation dose is applied to reduce stickiness, then adhesion is effectively prevented, but the processing time and energy consumption increase

Engineering Contradiction:
Improveadhesion preventionVSAvoidprocess speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent identifies and applies the minimum effective radiation dose (40-150 kGray) required to achieve stickiness reduction. By optimizing this parameter, the process achieves reliable adhesion prevention (reducing stickiness by at least 10%) while minimizing the exposure time and energy consumption. The transport speed through the irradiation device is adjusted to deliver this optimal dose efficiently.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements continuous electron beam irradiation during the transport of rubber strips through the irradiation device. This continuous process eliminates interruptions and maintains high production speed, ensuring that the material receives the required radiation dose without stopping the production line, thereby maintaining productivity while achieving reliable adhesion prevention.

Inventive Principle:
Principle #20Continuity of useful action

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

Significantly reduces surface stickiness, preventing unwanted adhesion and material loss, while maintaining high process speed and ease of integration with existing manufacturing processes, ensuring optimal radiation dose for minimal material wastage.

Implementation Method 1

Passing the tape-shaped spool bandage material through an irradiation device and continuous irradiation of the spool bandage material with an electron beam scanner

Methodology Applied
Scientific EffectElectron beam irradiation: Electron Beam

Implementation Method 2

Adsorption of the electron beam energy by the spool bandage material, whereby a pre-crosslinking of the uppermost material layer of the spool bandage material is achieved

Methodology Applied
Scientific EffectAdsorption of electron beam energy: Absorption (EM radiation)

Data Source

PatentEP2774737B1Method for reducing the adhesive properties of unvulcanized rubber strips with reinforcing elements
Publication Date: 2016.10.12 CONTINENTAL REIFEN DEUTSCHLAND GMBH
  • EP2774737B1 patent drawingFigure 1~2

AI summary

The method comprises preparing strip-shaped bandage material (1) by a continuous process and providing reinforcing elements on a top and a bottom of a rubber material, introducing the bandage material to an irradiation device and then continuously and simultaneously irradiating the material using an electron beam scanner (3), and adsorbing electron beam energy by the material such that a stickiness of a surface of the material is reduced to 10% of an initial value while pre-cross linking of a top layer of the material with an electron beam (2). The method comprises preparing strip-shaped bandage material (1) by a continuous process and providing reinforcing elements on a top and a bottom of a rubber material, introducing the bandage material to an irradiation device and then continuously and simultaneously irradiating the material using an electron beam scanner (3), adsorbing electron beam energy by the material such that a stickiness of a surface of the material is reduced to 10% of an initial value while pre-cross linking of a top layer of the material with an electron beam (2), continuously and simultaneously winding the material on a bobbin to form a coil, and providing the material on the winding bobbin for the manufacture of vehicle tires. The bandage material is introduced relative to a movement of the scanner, and is irradiated with a dosage of 70-150 KiloGray. The electron beam dosage is adjusted via a transport velocity. The irradiation device generates the electron beam with an energy of 500-1500 kilo-electron-volts. The material is present in the form of strips that are arranged parallel to each other. The strip-shaped bandage material is prepared by an extruder and a gear pump.