Mineral Wool Binder Stability in Acidic pH
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Solution Overview
Problem
Mineral wool insulation products using carbohydrate-based binders face issues with mechanical property retention over time, especially at high humidity, leading to increased binder proportions and costs, and instability of phenolic resins in acidic environments.
Innovation Solution
A binder composition with a pH between 1.0 and 6.5, containing hydrogenated sugars, monomeric polycarboxylic acids, and aminated phenolic resins, which are stable in acidic conditions and improve mechanical properties without the need for high phenolic resin quantities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If carbohydrate-based binders (reducing sugars, non-reducing sugars, hydrogenated sugars) are used to bind mineral wool fibers, then formaldehyde emission is reduced and health safety is improved, but the products become relatively hygroscopic and lose mechanical properties over time, especially at high humidity
Solution Approach 1:
The patent uses a composite binder system combining carbohydrate-based binders (hydrogenated sugars, reducing sugars, non-reducing sugars) with phenolic resins (resols) and silane modifiers. This composite approach leverages the low formaldehyde emission of carbohydrate binders while the phenolic resin component provides enhanced mechanical stability and resistance to aging under humid conditions, resolving the contradiction between health safety and reliability.
Solution Approach 2:
The patent modifies the binder composition by adjusting the ratio of carbohydrate-based binders to phenolic resins, and by incorporating silane modifiers to change the hydrophobicity and crosslinking characteristics of the binder system. These parameter changes optimize both the low formaldehyde emission property and the mechanical property retention under humid conditions.
2Reliability
If the proportion of binder is increased to compensate for loss of mechanical properties after aging, then mechanical property retention is improved, but the cost of the final product increases and fire reaction properties are altered
Solution Approach 1:
The patent employs a composite binder system where phenolic resins (resols) work synergistically with carbohydrate-based binders. The phenolic resin component provides structural stability and resistance to aging with lower binder proportions, eliminating the need to increase binder quantity to compensate for mechanical property loss, thus avoiding increased cost and altered fire reaction properties.
Solution Approach 2:
The patent uses silane modifiers that provide long-lasting protective effects against moisture and aging. These silane-modified phenolic resin components create durable crosslinked structures that maintain mechanical properties over time without requiring excessive binder quantities, effectively replacing the need for high binder proportions with a more efficient, long-lasting binder system.
3Device complexity
If usual phenolic resins (PF resins or PFU resins) are used in aqueous binder compositions based on sugars and polycarboxylic acids, then binder composition is simplified, but the resins prove unstable and react/precipitate rapidly at room temperature due to acidic pH
Solution Approach 1:
The patent modifies the phenolic resin composition by using specifically formulated resols that are stable in acidic media. This parameter change in the resin type allows the binder composition to maintain simplicity while achieving stability at acidic pH, preventing rapid reaction and precipitation that occurs with conventional PF and PFU resins.
Solution Approach 2:
The patent introduces silane modifiers as intermediary substances that mediate between the acidic binder environment and the phenolic resin. These silane-modified resins act as stable intermediaries that resist rapid polymerization and precipitation in acidic conditions, enabling the use of simplified phenolic resin-based binders without the instability problems of conventional resins.
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 enhances the mechanical properties and resistance to aging of mineral wool insulation products, maintaining performance under humid conditions without increasing costs or altering fire reaction properties.
Implementation Method 1
a aqueous binder composition having a pH between 1.0 and 6.5, preferably between 1.5 and 5.0, and comprising: (a) at least one carbohydrate selected from hydrogenated sugars, reducing sugars, non-reducing sugars and mixtures thereof, (b) at least one monomeric polycarboxylic acid or an anhydride of such an acid, (c) from 1 to 35% by weight, based on the total weight of components (a), (b), and (c), of a water-soluble amino phenolic resin consisting essentially of phenol-formaldehyde condensates and phenol-formaldehyde-amine condensates
Implementation Method 2
heating the fibers sized by the aqueous binder composition so as to evaporate the volatile phase of the aqueous binder composition and to achieve thermal curing of the non-volatile residue
Implementation Method 3
heating the fibers sized by the aqueous binder composition so as to evaporate the volatile phase of the aqueous binder composition and to achieve thermal curing of the non-volatile residue
Data Source
AI summary
The present invention concerns a method for manufacturing an insulating product based on organic or mineral fibres, which comprises - applying an aqueous binder composition to organic or mineral fibres, preferably mineral wool fibres; - heating the fibres bonded with the aqueous binder composition so as to evaporate the volatile phase of the aqueous binder composition and to bring about the thermal curing of the non-volatile residue, or packaging the organic or mineral fibres bonded with the aqueous binder composition for the purpose of storage and/or transport, the aqueous binder composition having a pH of between 1.0 and 6.5, preferably between 1.5 and 5.0, and comprising: a) at least one carbohydrate selected from hydrogenated sugars, reducing sugars, non-reducing sugars and mixtures thereof, (b) at least one polycarboxylic acid or an anhydride of such an acid, (c) from 1 to 35 % by weight, relative to the total weight of components (a), (b) and (c), of a water-soluble, amine-containing phenolic resin consisting essentially of phenol-formaldehyde condensates and phenol-formaldehyde-amine condensates.