Rexolite 1422 – CNC Machining

Rexolite 1422 is used for CNC machined components where RF and microwave dielectric stability and tight geometry control are required in precision polymer parts.

Its machining behavior is defined by rigid, low-ductility cutting response and sensitivity to heat buildup that can degrade surface integrity on fine features.

At ShvaveyMetal, Rexolite machining workflows are defined around sharp tooling, conservative thermal input, and finishing passes that preserve dimensional and dielectric intent.

Rexolite 1422 is a cross-linked polystyrene material selected for machined electrical and RF components where low dielectric loss and stable permittivity are design drivers.

Property Typical Value Units
Density ~1.05 g/cm³
Tensile Strength ~50–60 MPa
Elastic Modulus ~2.5–3.0 GPa
Elongation at Break ~2–3 %
Hardness ~120–130 Rockwell R

Mechanical response is relatively stiff for a polymer, with low ductility that influences edge handling and thin-wall design.

Thermal & Physical Properties

Property Typical Value Units
Glass Transition Temperature (Tg) ~95–105 °C
Continuous Service Temperature ~80–100 °C
Thermal Conductivity ~0.14–0.18 W/m·K
Coefficient of Thermal Expansion ~60–80 µm/m·K

Low thermal conductivity increases the importance of chip evacuation and controlled cutting parameters.

Electrical / Dielectric Properties (Typical)

Property Typical Value Units
Dielectric Constant (Relative Permittivity, εr) ~2.5 —
Dissipation Factor (Loss Tangent) Very low (order of 10−4 to 10−3) —
Volume Resistivity High Ω·cm
Dielectric Strength High kV/mm

Electrical performance depends on frequency, temperature, and part cleanliness after machining.

Rexolite machining behavior is governed by heat management, chip control, and surface integrity requirements for RF interfaces.

Key machining characteristics include:

  • Clean cutting with limited ductility, with increased risk of edge chipping on sharp geometries
  • Heat sensitivity that can introduce local surface damage if dwell or rubbing occurs
  • Good dimensional repeatability when tool wear is controlled and thermal input is minimized
  • Surface finish requirements that are often functional for RF contact surfaces rather than cosmetic
  • Sensitivity to burr formation on small features, requiring controlled deburring methods

Machining is typically performed with sharp carbide or polished tools, conservative surface speeds, and finishing passes designed to avoid heat buildup.

Benefit Description
Stable Dielectric Behavior Supports RF and microwave components where permittivity and loss must remain consistent
Dimensional Repeatability Enables precision geometry for waveguide and antenna features
Low Moisture Sensitivity Reduces drift compared to moisture-absorbing polymers in RF assemblies
Good Machinability for Precision Features Supports tight bores, steps, and interface faces with controlled processes
Electrical Insulation Suitable for insulating structures and electrical separation features

Rexolite 1422 is commonly used for CNC machined components such as:

  • RF and microwave insulators and spacers
  • Antenna supports and dielectric lenses
  • Waveguide components and inserts
  • Test fixtures and metrology parts for RF assemblies
  • High-frequency electrical isolation components

Application suitability depends on frequency range, thermal exposure, and geometry sensitivity.

Variant General Characteristics
Rexolite 1422 Common electrical and RF grade used for precision machining
Alternate dielectric polymers Selected when higher temperature capability, higher toughness, or different permittivity is required
Stock form differences Residual stress and stability can vary between forms and suppliers

Grade and stock form should be specified clearly when dielectric performance and tolerance are both critical.

  • Define functional RF interface surfaces and specify surface finish requirements on those faces
  • Avoid sharp internal corners and thin unsupported walls that increase chipping risk
  • Align tolerance and inspection temperature to the assembly operating range
  • Plan deburring methods that do not contaminate or smear dielectric surfaces
  • Control heat input during finishing to prevent local surface degradation

Early alignment between RF requirements, geometry, and machining route reduces rework risk.

FAQ

How is Rexolite machined?

Rexolite machines cleanly to fine tolerances and takes an excellent surface finish, which matters for RF-critical surfaces. It is, however, brittle and heat-sensitive, so sharp tooling, light finishing cuts and careful heat management are required. Certain solvents and coolants cause crazing, so fluid compatibility must be verified before production.

What is Rexolite 1422 and what makes it suitable for RF components?

Rexolite 1422 is a cross-linked polystyrene developed for radio-frequency applications. Its dielectric constant of approximately 2.53 remains essentially constant from low frequencies into the tens of gigahertz, and its dissipation factor is extremely low. This predictability is what makes it a standard choice for precision RF and microwave parts.

Can Rexolite rod and sheet be machined to tight tolerances?

Yes. Rexolite holds tight tolerances well and is routinely machined into lenses, insulators and waveguide components. Because it is brittle, workholding must support the part without inducing stress, and machining is normally staged with light finishing passes to avoid chipping at edges and thin sections.

What components are machined from Rexolite?

Typical applications include microwave and millimetre-wave lenses, antenna components, radome elements, coaxial connector insulators, waveguide windows and ultrasonic transducer delay lines, generally where predictable dielectric behaviour and low signal loss are the primary functional requirements.

Why does surface finish matter on machined Rexolite parts?

In RF and microwave components, surface irregularities and subsurface damage scatter energy and degrade electrical performance, particularly at higher frequencies. Meeting the specified electrical behaviour therefore depends on controlled finishing, dimensional accuracy and consistent surface quality, not on material selection alone.


Why Machine Rexolite at ShvaveyMetal

ShvaveyMetal machines Rexolite 1422 using CNC workflows focused on thermal control, edge integrity, and repeatable precision features for RF-driven designs.

This approach supports consistent machining outcomes for components where rexolite material properties are part of the functional specification.