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Myt Machining specializes in machining two exceptional high-performance thermoplastics: PEEK and PEI. These advanced materials work well in both CNC machining and injection molding processes, creating components that stay strong under extreme heat.
Polyetheretherketone (PEEK) Material Properties
PEEK parts show great mechanical strength and chemical resistance when temperatures get high. The material has tensile modulus values from 90-200 MPa and melts at 662°F (343°C). Some PEEK types can handle operating temperatures around 482°F (250°C).
This toughness makes PEEK popular for precise mechanical parts and medical devices. Aerospace, automotive, and chemical companies use PEEK a lot because it insulates well and doesn’t change shape when hot for long periods.
PEEK’s crystal structure gives it amazing dimensional stability – perfect for machined parts that need exact measurements. The material barely expands when heated, so it performs the same way across different temperatures. It also handles repeated stress really well, which means parts last longer. PEEK even resists radiation damage, making it useful in nuclear plants and spacecraft where other materials break down.
Polyetherimide (PEI) Material Specifications
Like PEEK, PEI (sold as Ultem) handles high heat well and stays strong and stiff while resisting chemicals. PEI has tensile modulus ranges of 96-190 MPa and melts above 420°F.
PEI comes clear or colored, with glass-filled versions that are even stronger. What makes PEI different from regular plastics is how well it holds together and resists cracking when exposed to fuel, alcohol, and acids. This makes these high-performance thermoplastics really valuable for car and plane parts.
PEI naturally resists flames and doesn’t make much smoke, meeting tough safety rules for transportation and electronics. Clear PEI works great for see-through parts and electronic cases where you need both visibility and electrical protection. The material also handles moisture really well, keeping its strength even in steamy conditions or when steam-sterilized.
Key Performance Advantages in Demanding Applications
Both PEEK and PEI beat regular engineering plastics in tough conditions. They resist creep well, meaning they hold their shape under constant pressure. They also don’t release much gas, making them good for vacuum systems and clean rooms.
These materials resist wear really well – sometimes you don’t even need lubricants for moving parts. PEEK works especially well in medical implants because the body accepts it. Both materials keep their strength across wide temperature ranges, performing consistently whether it’s hot or cold.
Neither material reacts much with chemicals, so they last longer in harsh environments where metal parts would need frequent replacement. Being lightweight is another plus for applications where weight matters but strength can’t be compromised.
Machining Considerations and Best Practices
Machining high-performance thermoplastics takes some know-how and the right approach. Both PEEK and PEI machine well with standard operations when cut properly. Sharp tools with positive angles help prevent overheating, which keeps the material’s good properties intact.
Good clamping methods matter because these materials don’t conduct heat well – this can cause hot spots if not handled right. Coolant or air helps control cutting temperatures and creates better surface finishes. Carbide tools usually work best for both rough and finish cuts.
Cutting speed and feed rate need careful balance to avoid heat buildup while removing material efficiently. Complex shapes might need heat treatment afterward to prevent warping during use.
Optimal Manufacturing Method Selection
Small batches (up to 200 parts) of PEEK and PEI can be machined and ready in 3 days. Larger quantities in the thousands work better with injection molding, which takes about 7 days for standard delivery.
The materials perform nearly the same whether machined or molded. Testing prototypes by machining first makes sense if the design might change later. Cost usually favors machining for small quantities, while molding becomes cheaper as numbers go up.
Part complexity also affects the choice. Machining handles design changes better and can create undercuts and internal features that molding might struggle with or can’t do at all.
Questions about high-temperature plastics or specific PEEK and PEI needs can be directed to Myt Machining customer service engineers. Technical specialists help with material selection and explain how high-performance thermoplastics work for specific applications.
Myt Machining goes beyond basic manufacturing, delivering precisely engineered solutions with high-performance thermoplastics that beat industry standards for heat resistance, chemical durability, and mechanical strength in the toughest applications.
