Segmented Compression Ring for Fiber Pre-form Consolidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional injection molding techniques are inadequate for producing non-metallic fiber reinforced composite parts with long continuous fibers, which are necessary for achieving high strength and lightweight materials to replace heavy metal parts in aircraft applications, as they lack the tensile and shear strength required for high-speed and high-altitude conditions.
Innovation Solution
A mold system incorporating a segmented adjustable diameter compression ring and a tapered compression ring support is used, where loose compression ring segments are loaded around a fiber pre-form on a mandrel, and through a process of heating and axial pushing, the compression ring segments move from an open to a closed configuration, applying increasing compressive force to consolidate the fiber pre-form under heat and pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If conventional injection molding techniques are used to manufacture non-metallic fiber reinforced parts, then the parts can be produced with relatively lightweight characteristics, but the parts lack the tensile and shear strength required to withstand extreme physical forces
Solution Approach 1:
The patent changes the physical parameters of the molding process by implementing a two-stage process: first heating the mold to approximately 770°F to soften the resin and activate the fibers, then applying high compressive force (up to 100 tons) to consolidate the fiber pre-form. This parameter change enables long continuous fibers to be properly consolidated, achieving both lightweight and high-strength characteristics that conventional injection molding cannot achieve.
Solution Approach 2:
The patent uses composite materials consisting of long continuous fibers (such as carbon, glass, or aramid) embedded in a resin matrix. The fiber pre-form contains approximately 60-80% by weight of reinforcement material, creating a composite structure that provides both the lightweight properties of non-metallic materials and the high strength characteristics required for aircraft applications.
2Strength
If long continuous fibers are used to increase the ultimate strength of parts, then the tensile and shear strength improve, but conventional injection molding techniques become inapplicable
Solution Approach 1:
The patent segments the molding process into distinct stages: (1) heating the mold to soften the resin, (2) applying compressive force to consolidate the fiber pre-form, and (3) cooling and ejection. This segmentation allows long continuous fibers to be properly handled and consolidated without the limitations of conventional single-stage injection molding, making the manufacture of high-strength parts feasible.
Solution Approach 2:
The patent applies preliminary action by first heating the mold to approximately 770°F before introducing the fiber pre-form and applying compressive force. This preliminary heating softens the resin and activates the fibers, preparing them for proper consolidation. Without this preliminary thermal action, the long continuous fibers cannot be properly consolidated, and conventional injection molding remains inapplicable.
3Strength
If metal parts are used to ensure high strength characteristics, then the strength requirements are met, but the overall weight of the aircraft increases
Solution Approach 1:
The patent employs composite materials with high fiber content (60-80% by weight) that provide strength characteristics comparable to or exceeding metal parts while maintaining significantly lower weight. The long continuous fibers create a reinforcement structure that, when combined with the resin matrix, achieves the required strength-to-weight ratio for aircraft applications, enabling weight reduction without compromising structural integrity.
Solution Approach 2:
The patent changes the manufacturing parameters to enable the production of high-performance composite parts that can replace metal. By controlling the heating temperature (approximately 770°F) and applying high compressive force (up to 100 tons), the process produces parts with strength characteristics suitable for high-speed and high-altitude aircraft operations, achieving both weight reduction and strength requirements.
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
This method enables the production of high-strength, lightweight fiber reinforced composite parts that can withstand extreme physical forces, effectively replacing heavier metal parts without compromising strength or reliability, as demonstrated by the ability to maintain hydraulic connections under high pressures.
Implementation Method 1
The compression ring segments are urged radially inwards towards the heated mandrel such that a compressive force is applied by the segments against the fiber pre-form
Implementation Method 2
an oven is heated to a temperature of about 770 degrees F. and the mold is then placed into the heated oven for approximately 20 minutes
Implementation Method 3
The platen press applies an axial pushing force to the end cap to drive the heated mandrel and the compression ring downwardly through the compression ring support
Implementation Method 4
The platen press is permitted to cool to a temperature of approximately 450 degrees F. during which the combination of heat and pressure consolidates the fiber pre-form around the mandrel
Data Source
AI summary
A mold and a method for molding high strength, non-metallic fiber reinforced composite parts having a variety of (e.g., cylindrical) shapes that are lighter in weight than similar parts manufactured from metal. An unmolded non-metallic pre-form having long continuous fibers is placed around a mandrel, and a segmented, adjustable diameter compression ring is disposed in surrounding engagement with the pre-form at an upper position within an inwardly tapered compression ring support. The compression ring is formed from a plurality of loose compression ring segments that are initially spaced circumferentially from one another at the upper position of the compression ring support. The mandrel and the pre-form are first heated and then located in a press. The press is closed to push the compression ring and the heated mandrel from the upper position of the compression ring support, at which the compression ring has an open configuration and a wide diameter, to a lower position, at which the compression ring has a closed configuration and a narrow diameter. As the compression ring is pushed to the lower position, the compression ring segments slide along the inwardly tapered compression ring support so as to be moved end-to-end one another to apply a compressive force for consolidating and shaping the heated pre-form into the molded part.