Continuous fiber-reinforced high-performance thermoplastic composites have gradually attracted the attention of the composite industry due to their unique advantages such as light weight, high strength, good impact resistance, short molding cycle, secondary molding, and recyclable scrap.
On June 20, 2019, Teijin Limited announced that Airbus’ next-generation ultra-wide-body midsize airliner A350 XWB aircraft using Teijin Tenax TPCL carbon fiber thermoplastic reinforced laminate was delivered to Japan Airlines on June 11 and arrived at Tokyo Haneda Airport on June 14.
This is another application of continuous fiber-reinforced high-performance thermoplastic resin matrix composites. Due to the shortcomings of thermosetting composites in aerospace and other high-tech manufacturing fields, such as poor heat resistance, poor environmental resistance, low impact and damage resistance, and high manufacturing costs, their application scope is limited to a certain extent.
Therefore, improving the comprehensive properties (toughness, functionality, etc.) of composite materials and reducing manufacturing costs have become the main research goals of resin matrix composites, and fiber-reinforced thermoplastic composites have become the research focus of material scientists, and their growth rate has gradually caught up with fiber-reinforced thermoset composites.
For the past half-century, advanced structural materials used in aerospace and other high-tech manufacturing applications have been dominated by continuous fiber-reinforced thermoset composites.
Also as an advanced structural material, the emergence of continuous fiber reinforced thermoplastic composites is an inevitable result of material development and molding process progress.
As a primary or secondary load-bearing structural part, continuous fiber-reinforced thermoplastic composites have the characteristics of lightweight, high strength, designability, fatigue resistance and integration of structure and function, and have also begun to be explored for application in aerospace and marine fields.
With the increase of fiber length, fiber reinforced thermoplastic composites can be generally divided into short fiber reinforced thermoplastic composites, long fiber reinforced thermoplastic composites and continuous fiber reinforced thermoplastic composites.
The main performance advantages of continuous fiber reinforced thermoplastic composites depend not only on the continuous fiber reinforcement, but also on the thermoplastic resin matrix. The high performance thermoplastic resin matrix has the comprehensive characteristics far superior to the traditional general thermoplastic resin matrix.
|Universal thermoplastic resin|
|Polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), phenolic plastic (PF), amino plastic (AP), polyamide (PA), polyformaldehyde (POM), polycarbonate (PC), polyphenyl ether (PPO), saturated polyester (PET / PBT), acrylic plastic (PMMA), etc|
|High-performance thermoplastic resin|
|Fluoroplastics, polysulfone (PSF), polyetherimide (PEI), polybenzene sulfide (PPS), polyether ether ketone (PEEK), polyimide (PI), liquid crystal plastic (LCP), etc|
High-performance thermoplastic composites often maintain excellent engineering characteristics and have better functional characteristics such as fatigue resistance, corrosion resistance, self-lubrication, etc., so they are favored by the high-end manufacturing field.
In the primary or sub bearing structures of aerospace and Marine fields, the four most commonly used high performance thermoplastic resin matrix of continuous fiber reinforced high performance thermoplastic composite materials are polyether ether ketone (PEEK), poly benzene sulfide (PPS), polyether imide (PEI) and polyether ketone (PEKK).
Among them, the most excellent comprehensive performance is PEEK resin, which is a crystalline polymer, which has excellent impact resistance, damage resistance (the highest in thermoplastic resin), excellent fatigue resistance and creep resistance (the highest in thermoplastic resin), high heat resistance (heat deflection temperature up to 300 °C after fiber reinforcement), environmental resistance (can be used in 200~260 °C steam), corrosion resistance (no solvent can corrode it except concentrated nitric acid and concentrated sulfuric acid), radiation resistance, flame retardant, good electrical insulation and other characteristics.
In addition, by designing the molecular structure, poly aryl ether ketone materials can be given different properties, such as heteraphthalene biphenyl poly aryl ether ketone as an amorphous polymer, with high temperature resistance and soluble characteristics.
High-performance thermoplastic composites also offer great advantages over primary or secondary epoxy or double-horse thermoset composites. Continuous carbon fiber reinforced PEEK thermoplastic (CF/PEEK) composites have excellent impact and damage resistance.
Therefore, CF/PEEK thermoplastic composites become the crown jewel of continuous fiber reinforced high performance thermoplastic composites. Of course, because PEEK resin has extremely high molding temperature (380~400℃), high melt viscosity (η > 300Pa.s), and small diameter of carbon fiber monofilaments, it will be a comprehensive test for equipment design and preparation technology to achieve good impregnation.