Roofing Element Manufacturing Plant Fiber Bitumen

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional methods for producing roofing elements using cellulose impregnated with bitumen are limited to developing only developable forms and struggle with producing elements that can withstand severe climatic conditions, require complex processes, and have high production costs, while also failing to achieve non-developable shapes and aesthetic adaptations for architectural environments.

Innovation Solution

A process involving hot molding of plant fibers under vacuum to concentrate dry matter, followed by impregnation with bitumen, allowing for the production of both developable and non-developable forms with high density and aesthetic appeal, using a multi-stage process that includes preliminary vacuum concentration, thermoforming, and impregnation with hot bitumen.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional continuous process methods are used to produce roofing elements, then only developable forms can be obtained, but the ability to produce non-developable forms and complex geometries is lost

Engineering Contradiction:
Improveability to produce different formsVSAvoidmanufacturing process simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by transforming the physical state of the plant fiber composition through controlled heating and pressing. The composition is heated to temperatures between 80-200°C and pressed at pressures of 0.1-10 MPa, causing the fibers to bind together and form both developable and non-developable shapes. This thermal and mechanical parameter control enables complex geometries that cannot be achieved through conventional continuous processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining plant fibers with binding agents and additives to create a moldable composition. The plant fiber composition includes cellulose fibers, hemicellulose, lignin, and binding agents that enable the material to be shaped into complex forms while maintaining structural integrity. This composite approach allows production of non-developable forms with high aesthetic value.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If plant fiber composition is pressed and heated in the mold until high dry matter content is achieved, then the element maintains its shape during subsequent operations, but the molding process requires precise control of temperature and pressure parameters

Engineering Contradiction:
Improveshape stability during processingVSAvoidmolding process control complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by achieving the desired shape and structural stability during the molding process itself, before subsequent operations like bitumen impregnation. The plant fiber composition is pressed and heated in the mold to reach a dry matter content of at least 60%, which locks in the shape and prevents deformation during later handling and processing steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements feedback control by monitoring and adjusting temperature and pressure parameters during the molding process to achieve consistent quality. The process controls temperature between 80-200°C and pressure at 0.1-10 MPa, with feedback mechanisms ensuring the plant fiber composition reaches the required dry matter content and shape stability before exiting the mold.

Inventive Principle:
Principle #23Feedback

3Reliability

If the element is impregnated with hot bitumen after molding, then the element gains water resistance and durability, but the presence of water in the element disturbs the impregnation process

Engineering Contradiction:
Improvewater resistance and durabilityVSAvoidimpregnation process quality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by removing water from the plant fiber element before bitumen impregnation. The element is dried to reduce water content to below 10%, and preferably below 5%, which prevents water from interfering with the bitumen impregnation process. This preliminary drying ensures complete and uniform impregnation, achieving the required water resistance and durability.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If the mold is placed under vacuum for preliminary concentration of dry matter, then the concentration efficiency is improved, but the production time for this preliminary phase is extended

Engineering Contradiction:
Improveconcentration efficiencyVSAvoidpreliminary concentration time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent applies pneumatics by placing the mold under vacuum during the preliminary concentration phase. The vacuum pressure of -0.1 to -0.5 bar removes water from the plant fiber composition, concentrating the dry matter content to at least 20% before the main pressing operation. This pneumatic water removal significantly improves concentration efficiency compared to passive drying methods.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 process enables the production of roofing elements with enhanced durability, aesthetic appeal, and adaptability to complex roof geometries, meeting climatic and architectural demands while maintaining cost-effectiveness and operational efficiency.

Implementation Method 1

a preliminary phase of concentration of the dry matter of said composition in the mold is carried out by placing the molding cavity under vacuum

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

by hot molding in a mold and under mold pressing pressure, an element made of plant fibers is produced... until said element has a dry matter content of at least 60%

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 3

after the element has left the mold, said element is dried to a dry matter content of at least 98% in said element

Methodology Applied
Scientific EffectDrying: Desiccation

Implementation Method 4

said element is thoroughly impregnated with a hot bitumen

Methodology Applied
Scientific EffectImpregnation: Absorption (physical)

Data Source

PatentEP2655742B1Method for manufacturing a roof-covering element made of plant fibres, and roof-covering element
Publication Date: 2014.08.13 ONDULINE SA
  • EP2655742B1 patent drawingFigure 1a~1b
  • EP2655742B1 patent drawingFigure 1c~1d
  • EP2655742B1 patent drawingFigure 2a~2c

AI summary

The invention relates to a method for manufacturing a covering element made of moulded cellulose impregnated with roofing bitumen. In a first step, an element, preferably made of cellulose, is manufactured by means of hot-pressing in a mould; in a second step, when the element has a dry matter content of at least 60% upon removal from the mould, said element is covered with pigmented varnish and dried; and in a third step, when the element has a dry matter content of at least 98%, said element is impregnated with a hot bitumen. Specific operational conditions are indicated. The covering elements include, in particular, a side ridge portion, a ridge cap, a ridge kit, a cant strip or skylight frame and a hip rafter.