Lignocellulosic Composite Material Production via Pre-Impregnation
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Solution Overview
Problem
Current methods for producing lignocellulosic composite materials face challenges such as difficulty in preparing masterbatches, adhesion issues between hydrophilic cellulosic fibers and hydrophobic polymers, high viscosity leading to equipment clogging, differential shrinkage, homogeneity and repeatability issues, aesthetic problems, and complex recycling processes.
Innovation Solution
A method involving impregnating lignocellulosic materials with a filling element, grinding the impregnated material into chips, and using these chips to create a composite material reinforced from the outside, which allows for improved adhesion, reduced viscosity, enhanced mechanical and physicochemical properties, and simplified recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the masterbatch method is used to produce lignocellulosic composite materials, then the material can be manufactured with polymer and cellulose fibers, but the preparation process becomes lengthy and complex requiring grinding wood into discrete fibers followed by mixing with polymer
Solution Approach 1:
The invention applies preliminary action by pre-impregnating lignocellulosic material with polymer before processing. This reverses the conventional sequence where polymer and fibers are mixed after fiber preparation. The pre-impregnated material is then ground into chips that already contain distributed polymer, eliminating the need for separate fiber grinding and mixing operations. This preliminary impregnation step simplifies the overall manufacturing process and reduces preparation time.
2Strength
If hydrophilic cellulosic fibers are mixed with hydrophobic polymer in masterbatch form, then composite material is formed, but adhesion defects occur due to moisture level control difficulties and hygroscopy of lignocellulosic reinforcement
Solution Approach 1:
The invention applies inversion by reversing the conventional approach to adhesion. Instead of trying to control moisture in hydrophilic fibers before mixing with hydrophobic polymer, the method impregnates the lignocellulosic material with polymer first, then grounds it into chips. This reverses the sequence of operations and fundamentally changes how the hydrophilic-hydrophobic interface is managed, eliminating adhesion defects caused by moisture control difficulties.
3Quantity of substance
If the proportion of fibers is increased to improve environmental performance, then the mixture viscosity increases and equipment clogs, but if fiber proportion is decreased to reduce viscosity, then shrinkage coefficient increases and geometry deviates from expected
Solution Approach 1:
The invention applies parameter changes by transforming the physical state and distribution of the fiber-polymer system. Instead of mixing discrete fibers with polymer to create a high-viscosity mixture, the method impregnates lignocellulosic material with polymer and grounds it into chips. This changes the parameters of fiber distribution, size, and polymer-fiber integration, allowing high fiber content (improving environmental performance) while maintaining low viscosity and preventing equipment clogging.
4Quantity of substance
If the proportion of fiber is decreased to reduce viscosity, then the shrinkage coefficient of the material increases causing problems of stripping and soiling, but increasing fiber proportion improves environmental performance
Solution Approach 1:
The invention applies composite materials principle by creating a integrated lignocellulosic-polymer chip structure through impregnation before grounding. This produces a homogeneous composite where polymer and lignocellulosic components are intimately combined at the chip level. The resulting composite material maintains dimensional stability (controlled shrinkage) even at high fiber proportions, while improving environmental performance. The composite structure prevents stripping and soiling issues associated with low fiber content.
5Manufacturing precision
If discrete fibers are ground and mixed with polymer to ensure homogeneous dispersion, then uniform characteristics are achieved, but the method produces large amounts of production rejects and industrial waste
Solution Approach 1:
The invention applies preliminary action by pre-impregnating the lignocellulosic material with polymer before grounding into chips. This preliminary step ensures homogeneous distribution of polymer within the lignocellulosic matrix at the chip level. When these pre-impregnated chips are processed further, the homogeneous dispersion is already established, eliminating the need for extensive mixing operations that generate production rejects and industrial waste.
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 method produces lightweight, cost-effective composite materials with excellent mechanical and physicochemical properties, improved aesthetic appeal, and facilitates recycling, addressing the limitations of existing techniques by creating a composite material that is reinforced externally and can be recycled as a monomaterial.
Implementation Method 1
a step of impregnating a lignocellulosic material with at least one filling element so as to obtain an impregnated lignocellulosic material
Data Source
AI summary
The present invention relates to a method for producing a lignocellulosic composite material, a lignocellulosic composite material that can be obtained with this method, and the use of said lignocellulosic composite material.