Understanding Radome Manufacturing Processes: A Guide To Key Composite Molding Techniques

Radomes—those protective covers for radar and communication systems—require not only excellent electromagnetic transparency, but also durability in extreme environments. Behind every high-performance radome lies a carefully chosen composite molding process, tailored to the specific application. In this article, we’ll walk you through the main radome manufacturing methods, including hand lay-up with vacuum bagging, compression molding, autoclave molding, filament winding, and Resin Transfer Molding (RTM).

1. Hand Lay-Up with Vacuum Bagging: Proven and Versatile

The hand lay-up vacuum bag method is one of the earliest and most widely used techniques in radome manufacturing. This process involves applying a release agent on a mold surface, then manually layering resin and fiberglass fabrics. Technicians use rollers to remove air bubbles and excess resin between each layer. After reaching the desired thickness, the part is sealed with a vacuum bag and subjected to vacuum pressure. This enhances fiber compaction and resin distribution. Once cured, the radome is demolded and finished.

Why use it?

• Low tooling cost

• Suitable for large or custom-shaped radomes

• Good fiber wet-out and strength

2. Compression Molding: Efficient for Medium-Sized Radomes

Compression molding is commonly used for small to medium radomes. Pre-cut fiberglass fabrics are first impregnated with resin and partially dried. They are then layered onto a coated male mold, with the number of layers depending on the required wall thickness. A matching female mold is then pressed down, and pressure (and sometimes heat) is applied to cure the part. Once fully cured, the mold is opened and the radome is trimmed and finished.

Key benefits:

• Fast cycle time

• Consistent thickness and finish

• Good dimensional accuracy

3. Autoclave Molding: High-Performance Composite Forming

For high-performance or aerospace-grade radomes, autoclave molding is preferred. Similar to hand lay-up and vacuum bagging, this process involves sealing the laminate inside a vacuum bag. However, instead of ambient curing, the entire assembly is placed in an autoclave—where controlled heat and pressure ensure optimal fiber compaction and resin flow. This results in excellent mechanical properties and surface quality.

Ideal for:

• Aerospace radomes

• Structural integrity-critical components

• Precision tolerances

4. Filament Winding: Precision through Automation

Filament winding is a process in which continuous fiberglass rovings pre-impregnated with resin are wound onto a rotating mandrel (typically the positive mold). Winding patterns are computer-controlled, ensuring consistent fiber angles and structural strength. After curing, the mandrel is removed to reveal a strong, lightweight radome.

Best suited for:

• Cylindrical or dome-shaped radomes

• High-volume production

• High axial and hoop strength

5. Resin Transfer Molding (RTM): Closed Mold Precision

RTM is an advanced closed-mold technique. A rigid mold cavity is filled with dry fiberglass preforms, and then liquid resin is injected under pressure. The resin saturates the reinforcement and cures within the mold. RTM offers excellent dimensional control and a smooth surface finish on both sides of the radome.

Advantages:

• High-quality surface finish

• Good production repeatability

• Cleaner working environment

Choosing the Right Process for Your Radome

The choice of molding process depends on several factors: radome size, mechanical requirements, production volume, and cost targets. Whether you're looking for aerospace-grade RTM radomes, custom hand lay-up solutions, or filament-wound designs, choosing the right process ensures optimal performance in demanding environments.

Looking for custom radome solutions? Contact our composite manufacturing experts for tailored support and high-performance products built to your exact specifications.