Looking at the present advancement of technology, we see the evolution of industrialization. The production of computers and automobiles is proof of man’s capacity to venture towards continuous development.

However, as we date back before these inventions, the use of stones, metals, and down to plastic for advanced engineering plays an important role. The Discovery of new materials for industrialization has now become a trend.

Modern technological devices came from the discovery of a technique that uses injection mold to make shapes and various styles. Depending upon the desired outcome, injection molding machines will provide the needed design with high precision.

Thus, the birth of automobiles, computers, smartphones and other objects alike is greatly influenced by the use of injection molding. The cost-effective, quality solutions are now used in a variety of applications depending upon their purpose. Its high level of durability is what makes injection molding special.

The art of injection molding involves the use of host materials like metals, elastomers, glasses, confections, and mostly thermosetting and thermoplastic polymers. Molted materials are fed inside a heated barrel and mixed using a helical screw where it is then injected into a mold and cooled until it hardens inside the cavity.

Industrial engineers make the product design and manufacture the molds with high precision. The advancement of 3D printing technology helps engineers to make the blueprint of the desired product and move on with the molding process. The basic parts of an injection machine involve three parts: the injection unit, mold, and the clamp. 

History of Injection Molding

In 1872, American inventors John Wesley and Isaiah Hyatt made the first injection molding machine. Like a hypodermic needle, the simplicity of this machine uses a plunger to inject molten material into a mold through a heated cylinder. As the company grew big, the production of collar stiffeners, buttons, and hair combs progressed slowly. 

The first material used in injection molding was cellulose nitrate. However, because of its flammable property, people continued to develop a new way to find a better material for injection molding. By 1903, two german chemists invented a less-flammable material. Arthur Eichengrun and Theodore Becker formulated the first soluble forms of cellulose acetate, much better material than cellulose nitrate. 

In 1946, a more precise injection molding machine that uses screw injection was made. American inventor James Watson Hendry made a machine that allows more precise control and better quality in the molding process. An advantage of this machine is the ability to pre-mix the materials prior to injection, making the colored and recycled plastic could be mixed properly before molding.

Although steel production was famous due to its durability, plastic production overtook its place by 1979 and in the 1990s, the development of aluminum molds also became popular. From comb and button production to the development of automotive parts, medical, toys, hardware products, and construction materials, plastic injection molding evolved over time. 

Injection Process

By using a ram or screw plunger, injection molding forces molten material (usually rubber or plastic) into a mold cavity. As the material solidifies, it forms the distinctive shape of the mold contour. Thermosetting and thermoplastic polymers are widely used as injection materials having thermoplastic polymers as the more common ones. 

The ease of access and versatility for an array of uses makes the thermoplastic polymer more highly suitable for DIY injection molding. Its ability to soften and flow during the heating process and element of safety over thermosets makes it more appropriate to use. 

With a high-pressure injection of raw materials, the injection molding process involves the shaping of polymer material into its desired form. There are two types of cavities to make a mold: a single cavity or multiple cavities.

Multiple cavity molds enable the manufacturer to produce the same product design simultaneously or make different shapes depending on each mold design in a single cycle. Hardened materials are then refined and sold in the market depending on the consumer’s choice. However, these are very intricate processes which is why manufacturers require their workers to always wear gloves and proper PPE equipment for maximum protection.

Injection Molding Material

Polymer materials, or sometimes referred to as resins, are widely used in injection molding along with thermosets, thermoplastics, and other elastomers. With the constant increase of production, molding materials increased at a rate of 750 per year since 1995 which became approximately 18,000 materials at present.

The use of alloys with other materials blended together also became a trend to better enhance material quality and consumer preference. Cost-effectiveness, strength, and function are some qualities that need to be considered in choosing the right material. Parameters also include the material’s ability to be bent without damage, water absorption, and heat deflection.

Thermoplastic materials include polyethylene, nylon, and polystyrene while epoxy and phenolic are common thermosetting materials. The production of plastic springs was not materialized because of its issues in pliability but the advancement of polymer properties solved this problem.

ABS Injection Molding

A special type of injection molding that uses thermoplastic polymer has now become a common trend.

ABS injection mouldings use ABS (Acrylonitrile Butadiene Styrene) as a molted material with properties that fit perfectly with the injection molding process. In fact, most consumer products nowadays use materials made from ABS injection molding.

With properties of a low melting point of just about 100 C, ABS plastic makes the injection molding process cheaper and easier. The thermoplastic property of ABS enables it to be reheated and recycled again. The ability to respond well with glue fixing and polishing also makes ABS more suitable as a molding material. Nevertheless, ABS injection molding is now one of the leading injection molding processes.


As a final takeaway, injection molding shows that technological advancement is inevitable in all industries.

Not only does this make the creation of products easier, but it also does it in a very cost-efficient manner. All it takes is the right creativity and proper tools and gear such as wearing gloves and using well-maintained equipment to ensure the utmost quality in the product it’s intended to create.