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The Hard Case Manufacturing Process: From Design to Production

Published on

April 12, 2025

Small Injection Molding

The Hard Case Manufacturing Process: From Design to Production

In many industries, hard cases protect sensitive instruments. The selection of the case's materials, form, and assembly process is crucial to ensuring that the case provides the required level of service. The hard case manufacturing process consists of several key steps:

1. Material Selection

2. Case Design

3. Molding

4. Assembly

5. Quality Control

Step 1: Material Selection

The determination of the choice of materials establishes the durability, heft, and resistance characteristics of a hard case. The materials most used to manufacture hard cases include:

Polypropylene (PP) - This is lightweight, impact-resistant, and most often used for hard cases that are injection-molded.

Acrylonitrile Butadiene Styrene (ABS) - This material provides high-impact resistance and is often used for hard cases that contain tools and are protective enclosures.

Aluminum - This metal provides resistance to corrosion and gives a professional look and feel to hard cases, which is why it’s often found in industrial and aerospace applications.

Fiberglass or Carbon Fiber -These materials are strong yet light and are optimal for military and high-performance hard case applications.

Step 2: Case Design and Prototyping

After choosing materials, engineers use CAD software to develop a 3D model of the case. Design Factors:

Dimensions - Cases fit specific pieces of equipment.

Thickness - The case’s rigidity and resistance to impacts derive from its wall thickness.

Fasteners - Hinges and latches must close securely and help resist wear.

Foam -Cases can be customized with foam and dividers that protect equipment and organize the interior.

The case is then prototyped and tested.

Step 3: Molding and Fabrication

The most challenging cases are made using the following common methods:

Injection Molding

High precision, durable hard cases, typically made from plastic.

Plastic is melted, under high pressure, then injected into a mold to create seamless, robust cases.

Frequently used for military, industrial, and medical applications due to mold-ability into rigid, impact-resistant enclosures.

Blow Molding

Produces lightweight hollow cases—those that have smooth, impact-resistant shells.

Plastic is heated and formed into a parison, a tube-like shape, then expanded into a mold using air pressure.

Creates cases with integrated hinges and uniform wall thickness.

Often seen in applications like portable equipment enclosures and travel cases.

Roto molding

Produces strong, durable, hollow cases with seamless, uniform walls ideal for rugged use.

Plastic resin is heated inside a mold that rotates on multiple axes, evenly coating the interior to create a consistent shape without seams.

Allows integration of complex features, such as reinforced corners, molded-in handles, and threaded inserts.

Commonly used in heavy-duty applications like military gear cases, rugged outdoor equipment enclosures, and industrial protective cases.

Thermoforming

A very cost-effective method for producing semi-rigid plastic cases.

Utilizes a sheet, not a mold, and so does not have the ability to create encasing with high wall thickness or internal ribs, as is done with injection molding.

A lightweight but strong shell can be formed—in a style that is ideal for custom case designs and low production runs.

Step 4: Adding Features and Assembly

After the formation of the outer shell of the hard case, other parts are assembled inside:

Hinges and Latches -Either metal or reinforced plastic for durability, depending on the case's intended use. Secure, color-coded locking latches, often with customizable TSA-approved locks, for travel cases.

Sealing and Waterproofing - Rubber gaskets or pressure valves ensure waterproof and airtight protection. Under the most rigorous use, many cases are still expected to last for 30 years.

Internal Organization- Custom-cut foam holds equipment securely and absorbs shock. Available dividers and compartments make it easy to organize.

Wheels and Handles - Rolling cases include wheels. Lightweight cases have handles that allow for carry.

Step 5: Quality Control and Testing

Every single instance is subjected to strict, thorough testing to see that it conforms to the industry's very tough standards. In a nutshell, we put them through their paces. They are dropped and hit and are allowed to skid across a rough surface. They are submerged in water, exposed to steam, and forced to endure low and high temperatures. They are stuffed with heavy stuff and dragged around. And they are subjected, also, to the elements—rain, snow, and sunshine—to see just how good these cases are at keeping their contents under wraps. For military cases, the standards are even tougher.

Conclusion

The process of making hard cases is one that requires choosing materials with care; it demands not only good engineering but also precision in implementing that engineering; and, not least, it requires quality testing to make sure that the finished cases do what cases are supposed to do: protect valuable equipment.

Royal Case Company specializes in making custom hard cases that serve not one but several industries, including the military, medicine, and optical research. If you need a hard case, we will be able to help you. Contact us today to learn more!