Roofing Membrane Barrier Layer for Bitumen Migration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing roofing and sealing membranes face issues with migration of plasticizers and bitumen oils, leading to brittleness, discoloration, and reduced durability when in contact with bitumen, which complicates the use of non-bitumen sheets on renovated areas and direct application over insulation like EPS.
Innovation Solution
A multi-layer system comprising a migration-inhibiting barrier layer and a fleece, bonded using a reactive plasticizer-resistant adhesive, which prevents the migration of volatile components and ensures adhesion without reacting with bitumen or water, thereby maintaining membrane integrity and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If plastic membranes (PVC-P-NB) are used for roofing, then flexibility and durability are improved, but plasticizers migrate into bitumen layers causing brittleness and shrinkage
Solution Approach 1:
A barrier layer made of polyethylene terephthalate (PET) is introduced between the plastic membrane and bitumen layer to prevent direct contact. This intermediary layer blocks the migration of plasticizers from the PVC membrane into the bitumen, while also preventing bitumen oils from penetrating to the membrane surface, thus resolving the harmful interaction while maintaining both flexibility and durability.
Solution Approach 2:
The roofing system is designed as a composite structure consisting of multiple layers: the plastic membrane layer, the PET barrier layer, and the bitumen layer. This composite material approach combines materials with complementary properties - the plastic membrane provides flexibility, the PET layer provides migration resistance, and the bitumen layer provides waterproofing, achieving both durability and preventing harmful migration.
2Use of energy by stationary object
If light-colored membranes are used to reduce roof heating, then energy efficiency is improved, but bitumen oils migrate to the surface causing discoloration and impaired aging behavior
Solution Approach 1:
The PET barrier layer serves as a protective intermediary between the light-colored membrane and the bitumen layer. It prevents bitumen oils and flux oils from migrating through the plastic sheeting to the surface, thereby maintaining the original light color and appearance of the membrane while still allowing the membrane to reflect sunlight and reduce roof heating.
Solution Approach 2:
A thin film barrier layer of PET is used to provide protection against oil migration. This thin film is sufficient to block the harmful substances while being transparent or translucent enough not to interfere with the light-reflecting properties of the membrane, thus maintaining both the aesthetic appearance and energy efficiency.
3Ease of operation
If self-adhesive plastic roofing membranes are used, then ease of installation is improved, but direct contact with cold self-adhesive layers causes interactions and plasticizer loss
Solution Approach 1:
The PET barrier layer is positioned between the plastic membrane and the cold self-adhesive layer, preventing direct contact and the associated harmful interactions. This allows the membrane to maintain its self-adhesive properties for easy installation while the barrier layer protects against plasticizer migration into the adhesive compound.
4Productivity
If direct installation on EPS insulation is performed, then construction time is reduced, but interactions between membrane and insulation cause volatile component migration
Solution Approach 1:
The PET barrier layer acts as a protective intermediary when installing directly on EPS insulation. It prevents volatile components and plasticizers from migrating between the membrane and the insulation material, allowing direct installation for construction efficiency while protecting against harmful chemical interactions.
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 solution effectively prevents the migration of plasticizers and bitumen oils, maintaining the membrane's flexibility and durability, and allows for the use of light-colored membranes without discoloration, ensuring a stable and long-lasting roofing solution.
Implementation Method 1
a first layer running towards the element in the form of a barrier layer or film, which is migration-inhibiting towards at least one material from the group consisting of bitumen, expanded polystyrene, and plasticizers
Implementation Method 2
either the first layer is bonded to the second layer by means of a reactive plasticizer-resistant adhesive
Data Source
Figure 1~4
Figure 5~8
AI summary
The invention relates to a covering such as a roof laminate or layer system (10) comprising at least - a first layer (14) extending towards the covering side in the form of a barrier layer or film that inhibits the migration of bitumen, plasticizers and/or EPS and - a second layer (12) extending away from the covering in the form of a first nonwoven fabric, wherein either the first layer is connected to the second layer by means of a reactive plasticizer-resistant adhesive (16) or, if the first layer is designed as a thermoplastic hot melt adhesive film, by means of this.