Sheet in PEEK GF30 3000x300 mm beige

Glass fiber reinforced PEEK in sheet form gives stiffness and dimensional stability without losing the electrical insulation. The glass fiber stiffens the material. It raises tensile strength and compressive hardness compared with pure PEEK, but unlike carbon fiber, glass-filled PEEK stays insulating. The sheet takes 260 degrees continuously and short peaks toward 300 degrees. That makes it an option when you want the stiffness of the reinforcement but are not allowed a conductive material in the design.

Tensile strength is around 113 MPa and ball indentation hardness around 280 N/mm², which keeps a part in shape under compressive and bending load. The impact strength of about 52 kJ/m² is good for a fiber-filled plastic, so the material takes some shock load without chipping. Density is about 1.53 g/cm³ and water absorption negligible, around 0.03 percent, so parts barely move in moisture and keep their fit. The flammability rating is V0. The specific volume resistivity around 10^14 ohm·cm means the material insulates, even reinforced. Thermal conductivity is around 0.35 W/mK. Chemically the resistance is broad against oils, acids, bases, hot water and solvents.

The sheet format is the stock for stiff, dimensionally stable parts that you mill out of a block. Load-bearing mounts and brackets in hot machines where an unreinforced plastic would have given way under load. Insulating structural parts that have to hold their geometry despite load and temperature. Valve components and seal supports in chemical process equipment that meets aggressive media. Fixtures and supports where low thermal movement and electrical insulation are required at the same time, for example in test and measuring setups. The high stiffness and low thermal expansion are often the whole reason for the choice, since the part then holds its dimensions from cold start to full operation.

The glass fiber wears on the tools, though less than a ceramic filler. Run sharp carbide inserts, moderate feeds and speeds and good cooling. Expect more frequent edge changes than with pure PEEK and plan for it. The material mills and turns to fine tolerances and holds its dimensions well over time. Clamp the blank securely and avoid point load against thin sections that can otherwise crack. Thick parts can be stress relieved before finish milling for the best dimensional stability, so that they do not move once the material has been exposed. Drill in stages and clear the chips in between.

Stiffness is what the glass fiber adds above all. A GF30 part bends less under load and keeps its geometry better than unreinforced PEEK, which shows most clearly in load-bearing and supporting functions. The glass fiber also lowers the thermal expansion, so the part moves less when the temperature swings between cold start and hot operation. Creep under constant load is low, so a tightened joint keeps its preload over time. For brackets and mounts that have to sit dimensionally stable through years of thermal cycling, this is often exactly what decides the choice.

Unlike carbon fiber, the glass fiber does not make the material conductive, so GF30 insulates electrically and works in places where a conductive part would cause trouble. The color is typically bone white to light gray. The glass fiber wears on the tools, but less than a ceramic filler, so ordinary carbide inserts go a long way if they are kept sharp. For bonding, the surface should be pretreated since PEEK is chemically unreactive, and mechanical fastening with threads or metal inserts is often more reliable. If the part needs even higher stiffness and is allowed to conduct current, carbon fiber filled PEEK is an option, and we will help you choose the right one.

A practical advantage of the low thermal expansion is that tolerance chains become easier to hold over a wide temperature range. A part that moves little between cold and hot operation makes the designer's job easier, since fits and clearances do not have to be calculated with large margins. That is especially valuable in assembled units where several parts in different materials have to work together. Choose a sheet thickness close to your final geometry, so that you do not mill away more of the expensive material than necessary.

Sheets come in several thicknesses and are cut to blanks per drawing, so you do not pay for material you mill away. Unsure whether glass fiber gives the stiffness you need, or whether carbon fiber suits your part better? Glass-filled insulates, carbon-filled conducts and is stiffer still. Describe the requirements and we will help you choose the right grade.

Beige GF30 in 3000 x 300 mm is enough for many stiff, dimensionally stable small units out of one and the same narrow sheet.