Thermoplastic Composites

Lingol Corporation today specializes in Thermoplastic Composite Laminates. Thermoplastic composites consist of a resin matrix and reinforcement material combined to provide specific performance characteristics. Thermoplastic composites have better properties than conventional engineering materials. On a pound for pound basis they are 10 – 20 times stronger and several times stiffer than metals. Thermoplastic composites are up to 10 times tougher than thermoset structures. They provide easier manufacturing and can be Reprocessed and Recycled. Superior solvent/chemical resistance and low moisture absorption make them a good choice for use in hostile environments.

Resins

Thermoplastic resins used for composite structures are divided into two types: Amorphous and Semi-crystalline. Resin selection is typically based on cost and specific performance requirements.

Amorphous resins soften over a wide range of temperatures. This makes them good for conventional processing methods like thermoforming or compression molding. They provide superior toughness yielding good impact resistance and damage tolerance. Typical amorphous resins are:

RESIN	Tg	PROCESSING TEMP.	SERVICE TEMP.	ADVANTAGE
(PC) polycarbonate	305°F 152°C	565°F 296°C	265°F 129°C	Good strength, stiffness and impact resistance
(PES) polyethersulfone	430°F 221°C	555°F 291°C	355°F 179°C	Excellent heat stability, high strength and toughness
(PPSU) polyphenylenesulfone	428°F 220°C	675°F – 720°F 357°C – 382°C	392°F 200°C	Good hot wet properties, toughness and impact resistance
(PEI) polyetherimide	423°F 217°C	670°F – 710°F 354°C – 377°C	390°F 200°C	Excellent thermal properties, flame retardancy, chemical resistance

Semi-crystalline resins have a sharp melt point and lower melt viscosity than amorphous resins. Crystallinity provides higher stiffness and strength to composite structures. Lingol Corporation’s processing technology provides very specific control of cooling rates. This allows appropriate recrystallization which provides Optimum Performance. Typical semi- crystalline resins are:

RESIN	Tg	PROCESSING TEMP.	SERVICE TEMP.	ADVANTAGE
(PP) Polypropylene	HDT 315°F 157°C	385°F – 425°F 196°C – 218°C	194°F 90°C	Low cost, tough and chemical resistant
(HDPE) High-Density Polyethylene	HDT 250°F 121°C	355°F – 395°F 180°C – 202°C	–	Very good strength with chemical and wear resistance
(PET) Polyethylene- terephthalate	165°F 75°C	510°F – 555°F 266°C – 291°C	265°F 129°C	Good strength and stiffness, wear and chemical resistance
(PA) Polyamide, (PA6, Nylon 6)	105°F 41°C	475°F – 525°F 246°C – 274°C	250°F 121°C	Excellent mechanical properties at higher temperatures with good solvent and impact resistance
(PPS) Polyphenylene sulfide	194°F 90°C	610°F – 650°F 321°C – 343°C	430°F 221°C	High performance resin; superior mechanical, chemical, fatigue properties at high temperature; Low Flame, Smoke & Toxicity
(PEEK) Polyetheretherketone	289°F 143°C	700°F – 735°F 371°C – 390°C	480°F 249°C	High performance resin; superior mechanical, chemical, fatigue properties at high temperature; Low Flame, Smoke & Toxicity
(PEKK) Polyetherketoneketone	310°F 155°C	670°F – 705°F 354°C – 374°C	445°F 229°C	High performance resin; superior mechanical, chemical, fatigue properties at high temperature; Low Flame, Smoke & Toxicity

Reinforcements

Reinforcements used for composite structures are typically continuous or chopped fibers. These fibers are Carbon, Fiberglass and Aramids.

Fiber Type

Carbon Fiber is light weight, stiff and very strong in tensile. It is also a relatively expensive option.

Fiberglass is economical, good in compression and provides fatigue resistance. It is the heaviest reinforcement choice.

Aramid is the lightest of the reinforcements. It has high elongation, high tensile strength and good wear resistance. It is also an expensive material.

Fiber Length

Continuous Fiber Reinforcement, (CFR), provides the greatest performance benefits in strength and stiffness. Long and short fibers, ( 1” to 0.25”), can also be used for cost effective improvements in performance over thermoplastic resin alone, (Neat resin sheets).

Reinforcement Forms

Woven fabrics made with carbon, fiberglass or aramid fiber in different weave patterns are used to achieve desired cosmetic and performance characteristics.

Stitch-bonded fabrics provide a cost effective way to provide multi-axial constructions for specific performance.

Non-woven veils can be used to provide short fiber reinforcement for cost effective performance improvement over neat resin sheets.

Knitted fabric is resilient and often needle stitched to provide improved shear strengths.

Uni-directional fibers heat bonded or stitched are used to achieve oriented strength and stiffness.

Processing

Unlike conventional thermoset composite materials, which are cured at temperatures between 250°F to 350°F (121°C to 177°C), Thermoplastic Composites are processed at much higher temperatures. For example, PP, polypropylene, a workhorse thermoplastic, is processed in a range from 375°F to 435°F (190°C to 224°C); PEEK, polyetheretherketone, one of the highest performance thermoplastics, is processed in a range from 700°F to 735°F (371°C to 390°C). This is usually managed using conventional radiant heating technology. Once the appropriate temperature range is reached, parts can be formed easily and cooled in a matter of minutes to yield a fully functional part. With thermoset materials, parts are formed and must be cured over much longer periods; up to hours for large parts.

Thermoforming
Lingol Corporation’s processing produces composite laminates with superior consolidation, (very low void content), and dimensional stability. These well consolidated sheets are critical for high speed thermoforming. Our products are geared to conventional thermoforming equipment, fast cycle times, (3-7 minutes), and typical tooling.Thermoforming non-reinforced thermoplastic sheets involves stretching of the materials to form parts. CFR sheets do not stretch. Lingol Corporation engineers CFR laminates to allow some stretch and inter-layer movement for uniform wall thicknesses and deeper draws.
Compression molding
Prepregs and Laminates are perfect for Compression molding applications, replacing conventional epoxy base prepreg. Much faster layup and cycle times are achieved with thermoplastic composite materials. They provide all the performance benefits of thermoplastics plus, lower cost processing and recyclability. Existing equipment can be used to achieve much higher production rates.
Machining
Thermoplastic composite panels are available from Lingol Corporation with most resin/ reinforcement combinations. These panels permit close tolerance and fine detail machining of parts such as gears, pump vanes, compressor vanes and fasteners.
Tube Rolling
Prepreg can be developed for specific customer performance requirements. Reinforcement and resin combinations are provided in rolls and/or sheets for processing convenience.
Over-molding/Co-molding
Laminates with specific properties can be provided for selective reinforcement of injection and compression molded parts. Compatible thermoplastic resins can be used with special reinforcements to provide sheets and/rolls of laminates for part development.
Roll Forming
Laminates are designed for performance characteristics in a finished part. These laminates are supplied in rolls or sheets for continuous processing/forming of parts such as C, T, and hat sections, beams and frames.
Vacuum Forming
Sheets of thermoplastic resin reinforced with short fiber vales can be supplied for simple vacuum bag forming, such as that used in the Orthotics and Prosthetics Industry. These materials can be easily formed into braces and other components.

Contact our Technical Department for help making the appropriate selection of Resin system, Reinforcement and Laminate construction.

Disclaimer

©2018 Lingol Corporation. Unauthorized use is strictly prohibited. All other trademarks, service marks and logos used herein are property of their respective owners. All rights hereto are retained by Lingol Corporation and any third party owners of such rights. All statements, technical information and recommendations contained in this publication are for informational purposes only. Lingol Corporation does not guarantee the accuracy or completeness of any information contained herein and it is the customer’s responsibility to conduct its own review and make its own determination regarding the suitability of specific products for any given application.