Plastic moulds: differences between injection and blow moulding

Stampi plastica differenze iniezione e soffiaggio - Disegno tecnico stampo serbatoio - C.A. Stampi

Introduction to plastic moulds

In the plastics production sector, there are various technologies for creating components. Among the most common are injection moulds and blow moulds. Understanding the differences between these two technologies is crucial to selecting the most suitable method for your production needs.

Plastic injection moulds

Injection moulds are used to produce complex and detailed plastic components. This process involves injecting molten plastic material into a mould, where it cools and solidifies, assuming the desired shape. It is an ideal technology for producing parts with intricate geometries, smooth surfaces and precise details.


  • High precision and detail: Injection moulds allow parts with very fine details and close tolerances, making them perfect for parts requiring high precision.
  • Fast production cycles: Once the mould has been created, the moulding process is very fast, enabling high-volume production.
  • Material versatility: This technology is compatible with a wide range of plastic materials, offering flexibility in choosing the most suitable material.


  • Initial costs: The construction of injection moulds requires a significant initial investment, which can only be recouped with high-volume production.
  • Preparation time: The mould design and construction phase can be lengthy, requiring careful planning.

Plastic blow moulds

Blow moulds are used to create hollow objects such as bottles, containers and tanks. This process involves heating the plastic material until it becomes malleable, then blowing it inside a mould where it takes the desired shape. It is a technology suitable for light and strong products.


  • Perfect for hollow and lightweight items: Blow moulding is ideal for producing items such as bottles, tanks and containers that need to be hollow inside.
  • Relatively low production costs: Once the mould is created, the blow moulding process is relatively inexpensive, especially for large production volumes.
  • Good structural strength: Products made with blow moulding technology are often lightweight but robust, suitable for many industrial applications.


  • Limited to relatively simple shapes: Compared to injection moulding, blow moulds are less suitable for creating complex shapes with intricate details.
  • Lower accuracy: The accuracy of blow-moulded products is generally lower than injection-moulded products, particularly with regard to thickness control over the entire surface, making this technology less suitable for applications requiring tight tolerances.

Plastic moulds differences: comparison between injection and blow moulding

While injection moulds offer high precision and detail, making them ideal for complex components, blow moulds are excellent for the production of hollow, lightweight objects. The choice between the two technologies depends mainly on the type of product to be produced and the expected production volumes.

Final considerations

In summary, both injection moulding and blow moulding have unique advantages and disadvantages. The selection of the most appropriate technology must be based on a careful evaluation of the specific production needs and requirements of the end product. Understanding these differences makes it possible to optimise the production process and guarantee product quality.

At C.A. Stampi we are available to evaluate all project options together with the customer in advance, thanks to the experience and professional commitment of our technicians.