Injection Molding. Fault injection, engineering plastic

How Plastic Injection Molding Is Performed

Before plastic injection molding can be performed, a mold must first be created. Common materials used to make molds for plastic injection molding include stainless steel, high-carbon steel, and aluminum. For high-volume applications, though, steel is preferred because of its superior strength and resistance to wear to that aluminum. Steel molds can easily last for hundreds of thousands of applications, making them a cost-effective solution for manufacturing companies that produce large volumes of plastic products.

Once the mold has been created, thermoplastic material in the form of small pellets is fed into a large drum-like barrel where they are heated and pushed sideways towards the mold. As the injection molding machine’s screw pushes the liquefied material, the material eventually reaches a nozzle that further pressurizes and pushes the thermoplastic material into the mold.

Next, the liquified thermoplastic material is cooled — typically at room temperature — until it hardens. Depending on the type of injection molding machine used, it may feature a platen that opens after the material has cooled, allowing for the removal of the newly created plastic product.

A brief history of fault injection

Fault injection originated as a technique for simulating failures at the hardware level. Engineers exposed devices to various harmful conditions and observed the devices to determine how well they continued functioning. These tests involved shorting connections between pins, creating electromagnetic interference, disrupting the power supply, and even bombarding circuits with radiation. The goal was to see how stressors like these affected the device’s operations, determine at what point the device would fail, and redesign the hardware to be more resilient.

Over time, engineers developed tools for introducing faults using other methods. Devices started including specialized debugging ports such as JTAG, which allowed for injecting controlled faults directly into circuits. With the development of software fault injection, software engineers could simulate faults in their applications, test error, and exception-handling functions, alter source code to inject simulated faults (known as a compile-time injection), and trigger faults on actively running systems (known as runtime injection).

Runtime fault injection became especially popular among companies managing large, complex, distributed systems. In 2011, Netflix open sourced Chaos Monkey, a tool that terminated compute instances running in their cloud infrastructure. Chaos Monkey helped Netflix validate that their workloads could tolerate sudden and unexpected failures by randomly shutting down running systems. Netflix would later introduce its Failure Injection Testing (FIT) platform in 2014, which was a more sophisticated solution for orchestrating failure on a larger scale and across multiple teams. These tools laid the groundwork for Chaos Engineering as we know it today.

Why fault injection is useful

1.  We can thoroughly test our applications and systems.

2.  We can better identify the nature and cause of production failures. 

3.  We can better identify the nature and cause of production failures. 

   
   

 hOW DO I SELECT THE BEST ENGINEERING PLASTIC?

The wide range of engineering plastics on the market makes selecting the right one for your engineering plastics components application difficult. It depends on a variety of factors, all of which are related to your intended use of the mold. Here are some of the questions you need to consider:

• What is the primary function of the part?

• What is the maximum continuous use temperature?

• What is the load or stress on the part?

• Is FDA or other agency compliance required?

• Will the part come into contact with chemicals, humidity, and strong sunlight?

• Is toughness or impact resistance critical during use?

• Should the part be flame-resistant?

Then there are questions regarding the size and shape of the part, its paintability, and color. Further considerations are the type of molding you will need for your end product, as well as countless options for additives and customization. The answers to all these questions will direct you to the right engineering plastic for your application.

WHAT ENGINEERING PLASTICS CAN YOU RECOMMEND?

Below are some engineering plastics used by Permian for specific injection-molded applications: