Composite Materials are made when two or more materials with different chemical and physical properties combine to form one new material. Composite Materials have unique properties different from those individual materials. For example, composite materials can be harder, softer, or more resistant to electricity or harsh environmental conditions than individual materials. Most of the materials we work with at Spaulding Composites are called Fiber-Reinforced Polymer (FRP) Composites.

Some examples of FRP composite materials are:

• Fiberglass Epoxy: Fiberglass, which is a hard yet lightweight material, is a combination of glass fibers and resin. This composite material is used for boats, cars, and pipes.
• Aramid Phenolic: Aramid is a synthetic fiber commonly referred to as Kevlar. Kevlar® is the trademarked brand name for the aramid fiber made by DuPont™. Aramid fibers encased in Phenolic Resin can be used for applications that require high impact strength, high wear resistance, or improved strength-to-weight performance compared to metals.
• Cotton Phenolic:  A mixture of cotton fabrics with phenolic resins, this material has excellent insulating properties and good stiffness and bearing applications.  Cotton Phenolic composites are used in diverse industries and applications globally.

Challenges of Machining Composite Materials

FRP composites can often possess reinforcing constituents with very high abrasiveness.  While these properties provide strength to FRP composite materials, the trade-off is that machining composite materials can be complex and challenging.

Some of the challenges associated with the machining of FRP composite materials are as follows:

• The hardness and abrasiveness of composite materials require special processing equipment and machining tools.
• Random wear and tear on machining tools.
• The delamination of the composite material layers.
• Incompatible materials result in a poor surface finish.
• Uncut or torn out fibers on machined surfaces.
• Low thermal conductivity of composites results in high local temperatures, which can damage and melt the matrix.
• Unstable cutting conditions and vibration.

Tackling the Challenges

There are several ways to tackle the challenges involved in machining composite materials. The major ones are as follows:

• Know your composite materials: You must know the unique properties of the composite materials and their components before machining them.
• Dust removal:  Use the right dust removal systems to protect your health and prevent the contamination of the workpiece and the machine.
• The right choice of machining tools: You must use the right combination of machining tools for the specific composite material and machining process.
• Maintain the sharpness of the tool: Dull machining tools can cause delamination, fiber fraying, thermal damage, and burr formation in the composite material. The only solution is the frequent replacement or resharpening of the tools.
• Use appropriate parameters: You must adjust the parameters as per the fibers’ type and orientation and the composite material’s thickness. For example, high spindle speeds and low feed rates can reduce heat generation and cutting impact.
• Ensure adequate cooling: Air or water mist cooling reduces heat generation and extends the life of machining tools. You must avoid using oil-based coolants, which can contaminate the composite material.  Many of these materials are Hydroscopic, which means they grow or shrink with water absorption, making it difficult to maintain precision while cutting fluids.

How Spaulding Composites Can Help

Spaulding Composites is a global leader in the manufacturing and fabricating of engineered thermoset composite materials and components for various markets, such as aerospace, defense, research, industrial, and energy.

We have over 100 years of expertise in composite technology and innovation. We can handle any challenge associated with machining composite materials using advanced technologies and automation to provide the ideal solution.

Contact us today if you are looking for a trustworthy and knowledgeable partner for your composite materials and component needs, and discover how we can help you achieve your goals.