PROFESSIONAL BLOG
JANUARY 10, 2023 • 9 MIN READING
About injection molding
Injection molding is a production method for thermoplastics that is well suited for products with complex geometry and larger production runs.
Geir Bergh
Head of Office, Plexx
What is injection molding?
Injection molding is a production technology for thermoplastic products. It has many applications – the method is particularly well suited for articles with complex geometry and for larger production runs.
In an injection molding machine, plastic granules are melted and processed by a piston in a cylinder. The piston forces a measured amount of material into a cooled mold. After the injected plastic has cooled and hardened, the mold is opened and the part is removed.
Areas of application
Injection molded products range from everyday items to advanced technical components:
Automotive parts
Mobile phones
Packaging
Furniture
Lamps
Electrical installations
Medical equipment
Sports items
Materials
A wide range of materials are used for injection molding, from inexpensive bulk plastics to higher-quality technical materials and more expensive specialty materials.
Volume Plastics
PE, PP, PS — affordable materials for large series and simpler applications.
Technical plasters
POM, ABS, PMMA, PC, PA — higher mechanical and thermal properties.
Special materials
PEEK and fibre-reinforced materials for extreme demands on strength and temperature.
"Injection molding is particularly well suited for items with complicated geometry and for larger production runs – where precision and repeatability are crucial."
The history of injection molding
The process was invented in the late 19th century. Over the past 150 years, developments – particularly in machinery and computer technology – have contributed to increased efficiency and lower production costs.
1872
First patent
The Hyatt brothers patented the first injection molding machine. Simple items such as combs and buttons could now be mass-produced in plastic.
1946
Modern machine
James Watson Hendry built a more modern injection molding machine with precise control of injection speed and the ability to mix materials before injection.
1951
Screw injection
The United States developed the first screw injection molding machine – a principle that is still in use today.
FROM
1970
Gas-assisted casting
Hendry developed the first gas-assisted injection molding process. Complex, hollow products could be cooled quickly – and flexibility, strength and efficiency were drastically increased.
in
DAY
Computerized precision
The combination of machinery and computer technology makes injection molding the standard method in the automotive, aerospace, defense, electronics and consumer industries.
Injection molding with Plexx and SP Group companies
We have extensive experience in injection molding in our companies, and have over 500 machines in our machine park - with a pulling force of 25 to 1800 tons. We can deliver parts from 1 to approx. 2000 grams. Our factories are spread over 3 continents and 12 countries, with the main focus in Europe. The types of materials used by us are e.g. POM, PE, PP, ABS, PS, PC, PMMA, as well as other more complex special materials such as PEEK and fiber-reinforced materials.
We are happy to provide tips and advice on which materials are most appropriate to use for your respective projects. We are competitive in price, quality and delivery time, and we are also happy to assist in the process of making tools. We cooperate with skilled tool manufacturers in Asia and Europe.
Questions and answers
Injection molding is a production method for thermoplastics in which plastic granules are melted and pressed into a cooled mold by a piston in a cylinder. Once the plastic has solidified, the mold is opened and the part is removed.
The method is particularly well suited for items with complex geometry and for larger production runs — from automotive parts and packaging to medical equipment and electrical installations.
A wide range: affordable bulk plastics such as PE, PP and PS, technical materials such as POM, ABS, PC, PMMA and PA, and special materials such as PEEK and fiber-reinforced plastics.
We have over 500 machines in our machine park, with pulling power from 25 to 1800 tons. We deliver parts from 1 to approx. 2000 grams, from factories spread across 3 continents and 12 countries — with the main focus in Europe.
Yes. We are happy to assist in the process of making tools, and collaborate with skilled tool manufacturers in both Asia and Europe.
We are competitive in price, quality and delivery time, and are happy to provide tips and advice on material selection for each project. All of our subsidiaries and sister companies are ISO certified.
Do you have a challenge you would like to discuss?
We advise you so that together we can find the optimal solution – from material selection to finished product.