Composite Sewing Thread for Thermoplastic Resin Impregnation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The production of composite parts with thermoplastic resin impregnation faces challenges such as fraying, maintaining three-dimensional shape, and deformation during high-temperature molding due to the limitations of existing sewing threads, which are either fragile or lack thermal resistance, leading to inhomogeneous reinforcement and increased stress.
Innovation Solution
A sewing thread comprising a group of high-tenacity filaments with a melting temperature higher than the processing temperature and a thermoplastic fraction miscible or soluble in the resin, assembled through comélage, twisting, or covering, ensuring mechanical strength and compatibility with the resin, reducing fraying and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a temperature-resistant sewing thread (e.g., glass) is used to maintain mechanical strength during high-temperature molding, then thermal resistance is improved, but the thread becomes fragile and causes excessive wear on sewing heads
Solution Approach 1:
The sewing thread is constructed as a composite material combining high-tenacity polyethylene filaments (providing thermal resistance with melting point above 160°C) and aramid filaments (providing mechanical strength and abrasion resistance). This composite structure allows the thread to withstand both high temperatures and mechanical stresses during sewing operations without being fragile or causing excessive wear.
2Manufacturing precision
If high pressure is applied during molding to force reinforcement into a tight wringer, then fiber density is improved, but reinforcement deformation and thread displacement occur
Solution Approach 1:
The sewing thread performs preliminary action by mechanically interlocking the fibrous reinforcement layers together before the high-pressure molding process. This pre-bonding through stitching prevents fiber displacement and maintains reinforcement homogeneity during the subsequent high-pressure impregnation, allowing tight wringer to be achieved without deformation.
3Ease of manufacture
If parallel filament rovings are used for reinforcement, then manufacturing simplicity is improved, but fraying occurs at cut areas due to weak filament holding
Solution Approach 1:
The sewing thread utilizes phase transition (melting) of its thermoplastic polyethylene components at molding temperatures to create a bonding effect. This thermal bonding phase transition secures the parallel filament rovings together, preventing fraying at cut areas while maintaining the simplicity of using parallel filament reinforcement structures.
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 provides enhanced mechanical cohesion and reduced fraying during high-temperature molding, allowing for homogeneous resin flow and improved fiber retention, while the thermoplastic fraction melts into the resin, reducing the sewing thread's impact and facilitating preform shaping.
Implementation Method 1
a group of filaments made from a thermoplastic material, miscible or even soluble in the impregnation resin, and having a melting point lower than the processing temperature of said thermoplastic impregnation resin
Implementation Method 2
a group of filaments having a melting point higher than the processing temperature of said thermoplastic impregnation resin
Data Source
AI summary
The invention relates to a textile reinforcement suitable for being used in a method for impregnation by a thermoplastic impregnation resin, with a view to producing composite parts, including at least one set of substantially parallel high-tenacity yarns, and a sewing yarn sewn through the one or more sets, characterised in that the sewing yarn includes filaments which have a melting temperature higher than the melting temperature of said thermoplastic impregnation resin, and filaments made from a thermoplastic material, which can be mixed into the impregnation resin, and which have a melting temperature lower than the implementation temperature of said thermoplastic impregnation resin.