10 Interesting Facts About Custom Injection Molding

Abtec, Inc. is a custom injection molding service provider serving customers across the globe. Equipped with over 100 years of combined experience in the design, development, and manufacture of custom plastic injection molds and support tooling, we have the knowledge and skills to deliver solutions for unique product production needs. Our team employs both established and innovative mold making technologies and techniques, including a variety of CAD software formats, to answer and address customer needs effectively and efficiently.

Plastic injection molding is a manufacturing process that enables us to create custom plastic parts in prototype to production volumes. Compared to other methods, it offers superior design flexibility (even for complex parts), cost-efficiency (especially in high volume runs), and scalability. Due to these advantages, among others, it finds application across industry in a wide range of part and product manufacturing operations. 

Our Top 10 Favorite Facts About Plastic Injection Molding

Since its initial introduction in the late 1800s, the plastic injection molding process has been utilized for the production of countless components. It has played and continues to play a critical role in the manufacturing sector. Here are just a few of our favorite facts about the process:

1. When John Wesley Hyatt patented the first plastic injection molding machine, his initial motivation was optimizing billiard ball production.

In the late 19th century, billiards companies began searching for replacements to ivory billiard balls. The challenge attracted inventor John Wesley Hyatt, who eventually discovered a new material—celluloid—that could be melted and injected into a mold and hold the ball-shaped form once cooled. In addition to introducing a material suitable for injection molding, along with his brother, he also patented various use cases for the material and the first injection molding machine. 

2. LEGO® block sets, the creative inspiration for young minds of many generations, are manufactured using the plastic injection molding process.

Originally, the LEGO company made its titular blocks from wood. However, by the late 1940s, the company grew in size to the point that the founder sought a way to expand production operations to meet rising customer demand. His solution was to invest in a plastic injection molding machine, which forced him to make the switch to plastic material but allowed him to make consistent toy pieces in large quantities. While at the first, the machine employed only produced 12 blocks at a time, eventually injection molding technology developed to the point where machines could accommodate larger production outputs in shorter cycle times. 

By turning to plastic injection molding, the founder was able to turn his small toy company into a household name. Today, the LEGO company produces approximately 75 billion individual bricks in over 3,700 different styles each year. 

3. The injection molding process accommodates almost 100,000 different types of plastics and other materials.

Given the number of material options available, it may be challenging to choose an appropriate plastic for a particular application. When selecting a material for an injection molding operation, some of the factors to consider include:

  • Hardness. Sometimes referred to as its Shore hardness, the hardness of a material is how much it resists indentation. A material is classified as either type A or type D and given a number from 0 to 100 to specify its exact hardness. 
  • Flexibility. The flexibility of a material refers to its ability to withstand bending under stress. Flexible materials are less likely to break when bent, while stiff materials are more apt to break when bent. 
  • Weight. The weight of a material relates to its density, with less dense materials being lighter and more dense materials being heavier. 
  • Cost. The above properties, among others, affect how the end product will perform. However, when choosing a material, it is also important to keep in mind the budgetary constraints of the project. 

4. As an environmentally friendly manufacturing process, injection molding facilitates the minimization of material utilization and material waste generation. 

The push for sustainability has driven injection molding companies to optimize molding operations to minimize their environmental impact. In addition to reducing material usage and waste generation by using only the amount of plastic needed to produce the desired parts and products and recycling any excess plastic, they may also utilize more eco-friendly packaging and shipping options. 

5. During World War II, the demand for inexpensive, mass-produced parts led to the soaring popularity of injection molding among manufacturers.

The injection molding industry expanded significantly due to the demand generated by war efforts. In 1946, James Watson Hardy, an American inventor, revolutionized the industry with the introduction of the first screw injection machine. The new machine gave manufacturers better control over the process speed and production quality and enabled them to mix colored and recycled plastics with new materials before creating their final molds. It was the perfect solution for an economy that required high product volumes at affordable rates.

6. Bottles are the most common product manufactured using plastic injection molding. Billions, in varying shapes and sizes, are produced each year.  

The plastic injection molding process is highly versatile, resulting in its employment in the manufacture of many parts and products. In addition to finding use in the production of bottles, it is regularly used for automotive parts, commercial construction supplies, consumer goods, electronic housings, recreational items, and toy components. 

7. Acrylonitrile Butadiene Styrene (ABS) is the most common material used in plastic injection molding operations.

ABS is a thermoplastic polymer used in many molded products, including automotive parts, kitchen appliances, recreational equipment, and toys (e.g., LEGO bricks). The material inherently demonstrates low material weight and flexibility and can be modified to exhibit heat resistance, impact resistance, and enhanced strength and toughness, depending on the expected performance of the end product. 

8. Custom plastic injection molded parts often demonstrate enhanced strength, which means more versatility.

When designing an injection molded part or product, manufacturers need to determine the various flexibilities or rigidities required in the end product. These characteristics affect what design features they may need to integrate to achieve the desired performance. If necessary, they can strengthen the end product by using fillers in the molds resin to reduce increase the density and increase the  durability of the molded plastic. 

9. Modern yo-yos, including those from household names like Duncan, Throw Down, and Death by Yo-Yo, feature many plastic injection molded components. 

When it comes to yo-yo production, injection molding is an ideal solution. The process is highly versatile, enabling designers to create yo-yos of varying shapes and colors. For example, plastic injection molded yo-yos can be clear, holographic, or, like those trademarked by Sprite, filled with bubbles. Additionally, they are easily adapted for different uses, such as advertising. 

Some of the yo-yo companies that use the injection molding process for their products include: 

  • Alchemy Yo-Yos (e.g., The Silk)
  • Born Crucial (e.g., Milk)
  • Death by Yo-Yo (e.g., Gung Du)
  • Throw Down (e.g., Lucha Libre)
  • YoYoJam (e.g., KickSide and Lyn Fury)

10. Abtec, Inc. is a trusted global partner for all custom plastic injection molding needs.

Located in Eastern Pennsylvania, Abtec, Inc. has over 100 years of combined experience in the design, development, and manufacturer of custom injection molds and support tooling. From mold and part design to prototyping to full production, our team aims to deliver the highest quality injection molding products and services at the best possible price. 

Contact the Plastic Injection Molding Experts at Abtec, Inc. Today

Injection molding finds use in manufacturing operations across industry. If you need assistance with your next custom injection molding project, turn to the experts at Abtec, Inc. We are fully committed to working closely with each and every one of our customers so that we can meet—and exceed—all of their expectations. Let us help you design and create your next molded part or product—contact us today.