Common Molding Methods of Carbon Fiber Composites: RTM, Compression Molding, Hand Lay-up

Carbon fiber composites (Carbon Fiber Composites) are widely used in aerospace, automobiles, sports equipment, new energy and other fields due to their excellent specific strength, specific stiffness, corrosion resistance and lightweight performance. The realization of its performance depends not only on the fiber and resin itself, but also on the molding process. This article will systematically introduce the three common molding methods of carbon fiber composites: RTM (resin transfer molding), compression molding and hand lay-up, and analyze their respective characteristics, applicable scenarios and process requirements to help companies and engineers choose the most suitable molding solution.

If you need to purchase or wholesale carbon fiber materials, you can contact Revolve CF carbon fiber material supplier (email: HarveyXu@revolve-cf.com, official website: https://www.revolve-cf.com).

RTM molding process (Resin Transfer Molding)

Process principle and process

RTM is a closed mold process. The dry carbon fiber preform is placed in the mold cavity, and the liquid resin is injected into the mold cavity by pressure to make it penetrate and solidify to form a composite structural part.

The basic process of RTM process is as follows:

Prepare preformed fiber reinforcement material;

Close the mold;

Vacuum assisted exhaust;

Inject resin;

Heat up and solidify;

Demolding.

Process characteristics

Advantages:

Suitable for mass production of complex structural parts;

High surface quality, smooth on both sides;

Short molding cycle, high degree of automation;

Clean process, suitable for environmental protection requirements.

Disadvantages:

High mold cost;

Many process control parameters, and the resin flow path needs to be accurately calculated.

Compression Molding Process (Compression Molding)

Process Introduction

Compression molding uses prepreg (usually chopped fiber or fabric) placed in a heated mold, and quickly pressed and solidified under high temperature and high pressure conditions. Applicable to thermosetting and thermoplastic composite materials.

Process Advantages and Disadvantages Analysis

Advantages:

Fast molding speed, suitable for large-scale, standardized production;

High dimensional accuracy;

High mold reusability;

Low labor dependence, conducive to industrial automation.

Disadvantages:

Limited molding of complex shapes;

High initial mold investment;

Fiber laying and exhaust need to be strictly controlled.

Application Scenarios

Compression molding is particularly suitable for manufacturing high-strength structural parts, such as aviation sandwich panels, automotive structural parts (B-pillars, beams), rail transit seat frames, etc.

Compression Molding Comparison Table

Hand Lay-Up Process

Process Overview

Hand lay-up is the most traditional carbon fiber composite molding method. The operator manually lays dry fiber or prepreg cloth on the mold surface and manually coats or impregnates the resin. After stacking layers, it is naturally or heated to cure.

Feature Analysis

Advantages:

Simple process equipment and small initial investment;

Flexible molding, suitable for non-standard customized parts and small batch products;

Different structural properties can be achieved by adjusting the layering method.

Disadvantages:

Low production efficiency;

Poor surface consistency, post-processing required;

High technical requirements for operators, and difficult to control quality.

Application scope

Hand lay-up is often used in shipbuilding, wind turbine blades, pipelines, non-standard equipment shells, artistic modeling parts, etc., which do not require high dimensional accuracy and batch size.

Comparison and selection suggestions of three molding methods

From the perspective of production scale, product complexity, mold investment, environmental protection requirements and other dimensions, different molding processes have their own advantages:

Recommended application suggestions

Choose RTM: suitable for high-end structural parts with high surface quality requirements and medium batch production;

Choose molding: suitable for automobile and rail transit parts with high standardization and fast beat;

Choose hand lay-up: suitable for customization, sample verification, and single-piece production with complex shapes.

Conclusion: Reasonable selection of process to improve product performance and cost-effectiveness

Carbon fiber composite molding technology is constantly developing, from manual operation to intelligent manufacturing. Choosing the right molding method can not only effectively control costs, but also improve structural performance and product appearance. For start-ups or R&D projects, you can start with hand lay-up for quick verification; for mass production and high-performance requirements, RTM or molding process should be given priority.

If you need to purchase high-quality carbon fiber cloth, carbon fiber prepreg, demoulding materials and other raw materials, please contact Revolve CF carbon fiber material supplier, email: HarveyXu@revolve-cf.com, official website: https://www.revolve-cf.com, we will provide you with professional products and technical support.