Gunnable Silicone Adhesive Primerless Weather Barrier Bonding
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Solution Overview
Problem
Conventional sealants exhibit poor adhesion to low surface energy substrates like polyethylene and require primers or surface treatments, which increase labor and cost, and lack flexibility for thermal expansion, making them unsuitable for forming a continuous, robust weather barrier system.
Innovation Solution
A gunnable adhesive composition comprising a mixture of silicone resin and organopolysiloxane, with specific ratios and additives, that forms a primerless, flexible bond between weather barriers and substrates without the need for surface treatment, ensuring robust adhesion and movement capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional sealants are used to bond weather barriers to substrates, then adhesion is achieved, but the sealants require primers or surface treatments which increase labor intensity and cost
Solution Approach 1:
The adhesive composition contains adhesion promoters that enable it to bond directly to low surface energy substrates without requiring external primers or surface treatments. The formulation self-provides the necessary adhesion enhancement through its built-in chemical components, eliminating the need for separate surface preparation steps.
Solution Approach 2:
The sealant is formulated as a composite material combining silicone resin, adhesion promoters, and other components that work together to provide both bonding capability and flexibility. This composite formulation integrates multiple functions (adhesion, flexibility, sealing) into a single material, eliminating the need for separate primer and surface treatment steps.
2Strength
If conventional sealants are used to bond weather barriers to substrates, then adhesion is achieved, but the sealants lack flexibility to allow for joint movement during thermal expansion
Solution Approach 1:
The adhesive composition uses silicone resin with specific viscosity characteristics and incorporates plasticizers or flexible components that change the material's physical parameters to provide both strong adhesion and the flexibility needed for thermal movement. The formulation adjusts the balance between bonding strength and flexibility through careful selection of resin molecular weight and additive composition.
3Reliability
If primers or surface treatments are applied to low surface energy substrates, then adhesion is improved, but labor intensity and cost increase
Solution Approach 1:
The adhesive composition contains adhesion promoters that enable it to bond directly to low surface energy substrates without requiring external primers or surface treatments. The formulation self-provides the necessary adhesion enhancement through its built-in chemical components, eliminating the need for separate surface preparation steps.
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 adhesive composition provides a strong, flexible bond with high peak peel strength to low surface energy substrates and structural substrates, reducing air leakage and enabling a continuous weather barrier system that meets energy efficiency standards without the need for primers or surface treatments.
Implementation Method 1
adhering the construction membrane to the structure through the adhesive product
Data Source
AI summary
A gunnable adhesive composition includes a silicone resin and an organopolysiloxane, or a reaction product thereof; as well as a filler and a solvent. The silicone resin and the organopolysiloxane are present in amounts to provide a resin/polymer ratio ranging from 58 % to 64 %. The gunnable adhesive composition may be applied to low surface energy substrates at ambient temperatures without primer or other surface treatment. The gunnable adhesive composition and adhesive product thereof are useful in weather barrier applications, such as building wraps.