Binder Composition for Lignocellulose Moisture Tolerance
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Solution Overview
Problem
Existing binders for composite lignocellulose products have short pot lives and are ineffective with lignocellulose substrates having high moisture content, leading to compromised adhesion and increased waste due to the need for frequent preparation and potential process upsets.
Innovation Solution
A binder composition comprising 30-40% urea-modified aldehyde-based resin, 0.1-3% isocyanate-based resin, 0.1-12% extender, and 50-62% liquid medium, with a sodium hydroxide equivalent weight alkalinity of 3-9%, which maintains viscosity stability for extended periods, allowing for longer pot life and effective bonding of substrates with higher moisture content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If typical binders are used, then bonding function is provided, but pot life is short (a few minutes to 2-3 hours) requiring frequent preparation
Solution Approach 1:
The patent modifies the chemical composition parameters of the binder by incorporating specific resins (urea-modified aldehyde-based resin at 30-40 wt% and isocyanate-based resin at 0.1-3 wt%) and additives (extenders and liquid mediums in specific ratios) to extend the pot life from 2-3 hours to significantly longer durations, allowing batch preparation and storage without significant viscosity increase
2Adaptability or versatility
If lignocellulose substrates with high moisture content are used, then material availability and processing flexibility improve, but adhesion is compromised and bond failure occurs
Solution Approach 1:
The patent creates a composite binder system combining urea-modified aldehyde-based resin with isocyanate-based resin, where the isocyanate component specifically addresses moisture sensitivity by reacting with water to form stable urea linkages, thereby enabling reliable bonding of substrates with up to 40% moisture content while maintaining bond strength
Solution Approach 2:
The binder composition parameters are specifically adjusted to include 0.1-3 wt% isocyanate-based resin and 0.1-12 wt% extenders, which chemically interact with moisture to prevent adhesion failure, transforming the binder's response to moisture from harmful to beneficial
3Ease of manufacture
If binders with short pot life are used, then initial viscosity is manageable, but binder is wasted when process upsets prevent timely use
Solution Approach 1:
The patent enables preliminary preparation and storage of binder batches before actual use by extending pot life significantly, allowing the binder to be prepared in advance, stored properly, and used when needed without significant viscosity increase or degradation, thereby preventing waste from process upsets
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 binder provides extended viscosity stability, enabling longer batch preparation and storage, and allows for effective bonding of lignocellulose substrates with up to 40% moisture content, reducing waste and improving manufacturing efficiency.
Implementation Method 1
a binder for making composite lignocellulose products can include about 30 wt % to about 40 wt % of solids that include a urea-modified aldehyde-based resin; about 0.1 wt % to about 3 wt % of solids that include an isocyanate-based resin
Implementation Method 2
heating the resinated furnish to a temperature of about 60° C. to about 300° C. to at least partially cure the binder
Data Source
AI summary
Binders, methods for making same, and methods for making composite lignocellulose products therefrom. The binder can include about 30 wt % to about 40 wt % of solids that include a urea-modified aldehyde-based resin; about 0.1 wt % to about 3 wt % of solids that include an isocyanate-based resin; about 0.1 wt % to about 12 wt % of an extender; and about 50 wt % to about 62 wt % of water, where all weight percent values are based on a total weight of the binder. The binder can have a sodium hydroxide equivalent weight alkalinity of about 3 wt % to about 9 wt %.