Composite Doctor Beam Stiffness and Weight Reduction
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Solution Overview
Problem
Existing doctor beams in pulp and paper mills are heavy, difficult to install and maintain, and expensive, with composite construction attempts failing to adequately address stiffness and cost-effectiveness.
Innovation Solution
A composite doctor beam constructed from pre-preg materials using autoclave moulding technology, featuring angled flanges and pre-tensioning rods made from composite materials, allowing for customizable thickness and orientation of fibres for enhanced strength and installability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If massive steel beams are used to ensure strength and stiffness, then the beam achieves sufficient structural performance, but the weight and installation difficulty increase significantly
Solution Approach 1:
The patent applies composite materials by combining a steel profile with a composite material layer (such as fiber-reinforced plastic) to create a hybrid beam structure. This composite construction reduces the overall weight compared to solid steel beams while maintaining the required strength and stiffness through the synergistic properties of the combined materials.
Solution Approach 2:
The patent implements local quality by applying the composite material layer selectively to specific regions of the steel profile where strength and stiffness are most needed. This allows optimization of structural performance in critical areas while minimizing material usage and weight in less demanding regions.
2Weight of moving object
If composite construction beams are used to reduce weight, then the beam becomes lighter, but the stiffness is insufficient
Solution Approach 1:
The patent uses composite materials with high stiffness-to-weight ratio (such as carbon fiber or glass fiber reinforced plastics) bonded to the steel profile. This combination provides the necessary stiffness while keeping the beam lightweight, overcoming the limitation of pure composite constructions.
Solution Approach 2:
The patent merges the high strength properties of steel with the high stiffness-to-weight ratio of composite materials in a hybrid structure. The steel profile provides foundational strength while the composite layer enhances stiffness and reduces weight, creating a beam that outperforms either material alone.
3Strength
If massive steel beams are used to ensure structural integrity, then the beam maintains performance, but the manufacturing cost increases
Solution Approach 1:
The patent employs composite materials that allow for optimized material usage, reducing the amount of expensive steel required while maintaining structural integrity. The composite layer can be manufactured more cost-effectively and applied in a controlled manner, lowering overall manufacturing costs.
Solution Approach 2:
The patent applies composite material reinforcement only where structurally necessary, rather than using solid steel throughout. This localized approach reduces material costs and manufacturing complexity while maintaining the required structural integrity in critical areas.
4Ease of manufacture
If composite construction beams are used to reduce material cost, then the beam becomes more cost-effective, but the stiffness and vibration resistance deteriorate
Solution Approach 1:
The patent selects composite materials with high damping characteristics and stiffness properties (such as fiber-reinforced plastics) that inherently provide vibration resistance. The steel-composite hybrid structure leverages the damping properties of both materials to reduce vibrations while maintaining cost-effectiveness.
Solution Approach 2:
The patent applies composite material layers with specific fiber orientations and thicknesses in regions where vibration resistance is critical. This localized optimization ensures adequate vibration damping and stiffness while controlling manufacturing costs through targeted material placement.
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 results in a lighter, more installable, and cost-effective beam with improved stiffness and vibration resistance, enabling easier fitting and maintenance while maintaining performance across varying conditions.
Implementation Method 1
The components 2 and 3/4 are manufactured particularly from a so-called pre-preg material using moulding technology in an autoclave.
Implementation Method 2
The prepreg material is a pre-impregnated so-called B-fabric, in which the impregnating agent is typically an epoxy resin
Data Source
AI summary
A beam construction, particularly a so-called doctor beam, for use mainly in pulp and paper mills to carry blade holders (7) intended to hold doctor blades. The beam (1) is a composite-construction hollow beam, which also includes at least one composite construction pre-tensioning rod (9, 10, 12). The construction has an essentially triangular cross-section.