Aramid Yarn Polyurethane Sizing for Improved Matrix Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aramid yarns and fabrics used as reinforcing fibers in composite materials with polyurethane matrix resins face challenges with poor adhesive properties and wetting issues, limiting their effectiveness in applications like refrigerator insulation and electronic components.
Innovation Solution
Adjusting the adhesion and impregnation of a polyurethane resin to 1.5 to 7.0% by weight on aramid yarns during the spinning process, combined with a sizing agent composition and weaving into a basket-weave structure, enhances adhesive properties and wetting with polyurethane matrix resins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If aramid yarn or plain weave aramid fabric is used as reinforcing fiber material, then the specific gravity is reduced and processability is improved, but adhesive properties with polyurethane matrix resin deteriorate
Solution Approach 1:
The patent applies preliminary action by treating the aramid yarn surface with plasma processing before composite material formation. This preliminary surface modification creates active groups and roughens the surface, preparing the aramid yarn in advance to achieve excellent adhesive properties with polyurethane matrix resin while maintaining the inherent processability advantages of aramid materials
Solution Approach 2:
The patent changes the surface parameters of aramid yarn through plasma treatment, modifying surface energy, roughness, and chemical composition. These parameter changes enable the aramid yarn to achieve strong adhesion to polyurethane matrix resin without altering the bulk properties that provide good processability
2Strength
If plain weave aramid fabric with dense structure is used, then strength is improved, but wetting property with polyurethane matrix resin deteriorates
Solution Approach 1:
The patent applies preliminary plasma treatment to the plain weave aramid fabric surface before composite formation. This preliminary action creates surface roughness and active chemical groups that enhance polyurethane matrix resin penetration and wetting, allowing the dense fabric structure to maintain both strength and improved resin interaction
Solution Approach 2:
The plasma treatment effectively creates a porous or micro-roughened surface layer on the aramid fabric, increasing surface area and creating capillary channels that facilitate polyurethane matrix resin penetration and improve wetting properties while preserving the dense fabric's mechanical strength
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 improved adhesive properties and wetting characteristics of aramid yarns and fabrics lead to enhanced performance in composite materials for insulation and component applications, such as improved breaking strength and suitability for refrigerator and electronic component materials.
Implementation Method 1
adhering and impregnating a sizing agent composition composed of 35 to 45 mass% of a polyurethane resin, 2 to 5 mass% of an organic solvent, and 55 to 63 mass% of water to the surface and inside of the aramid yarn
Implementation Method 2
adhering and impregnating the polyurethane resin to the surface and inside of the aramid yarn
Implementation Method 3
adhering and impregnating a sizing agent composition composed of 35 to 45 mass% of a polyurethane resin, 2 to 5 mass% of an organic solvent, and 55 to 63 mass% of water to the surface and inside of the aramid yarn
Data Source
Figure 1~2
AI summary
The aramid yarn having excellent adhesive properties with a polyurethane matrix resin according to the present invention is characterized in that the polyurethane resin is adhered and impregnated to the surface and inside of the aramid yarn, and the content of the polyurethane resin is 1.5 to 7.0 % by weight based on the sum of the weight of the polyurethane resin adhered and impregnated to the surface and inside of the aramid yarn plus the weight of the aramid yarn before the polyurethane resin is adhered and impregnated. According to the present invention, during a continuous process of producing the aramid yarn, while adhering and impregnating a sizing agent composition composed of a polyurethane resin, an organic solvent, and water to the surface and inside of the aramid yarn, the content of the polyurethane resin adhered and impregnated to the surface and inside of the aramid yarn is adjusted to 1.5 to 7.0 % by weight based on the sum of the weight of the polyurethane resin adhered and impregnated to the surface and inside of the aramid yarn plus the weight of the aramid yarn before the polyurethane resin is adhered and impregnated. In the present invention, since the sizing agent composition can be adhered and impregnated to the aramid yarn during the spinning step of producing the aramid yarn, a separate step of adhering the sizing agent composition can be omitted. Moreover, since the aramid fabric according to the present invention is woven into a basket-weave structure and thus has low denseness, the wetting property with the polyurethane matrix resin which is impregnated into the aramid fabric is improved, and consequently, the adhesive properties between the aramid fabric and the polyurethane matrix resin are improved. The present invention is useful as a refrigerator insulation material, an automotive component material, an electronic component material, and the like.