Construction of molds for plastic materials: definition and typologies

The construction of molds for plastic materials is a production process used to start a mass production of plastic objects.

Mold construction for transparent polycarbonate

This is a rather complex operation, made up of numerous steps that require very specialized skills: from 3D CAD design, to in-depth knowledge of plastic materials, to the technical and performance characteristics of the injection molding production process and much more.

To all this, in the process of manufacturing molds for plastic materials, there is added the need to satisfy:

Functional requirements of the product in relation to other components;
Mechanical and structural performance
Quality of the finished product in relation to the surface finish and characteristics of the molded piece;
Dimensional checks on printed parts with analysis reports and global deviations compared to the CAD;
Lead times requested by the customer;

Thanks to the construction of molds for injection molding, it is possible to produce numerous components in thermoplastic materials in a short time, guaranteeing the dimensional repeatability of the pieces and reducing production costs.

Plastic molding is used in all sectors of the manufacturing industry for large and medium productions.

The phases of the construction of molds for plastic materials

Before starting the production and molding of polymeric materials, it is essential to collect the project specifications and listen to the customer’s needs.

The phases of building a mold for plastic materials are as follows:

Feasibility study

The feasibility study for starting an injection molding production includes the analysis of the reference context, the regulations and the reference market.

In addition to the analysis of the external elements, it is necessary to analyze the technical characteristics of the plastic object to start the production of a properly designed mold that guarantees the project specifications.

Co-Design

Collaboration with the customer is essential for the success of production.

For this purpose it is essential to define the material, the characteristics of the mold and the type of molding.

All these activities are fundamental to arrive at the final project and produce efficient and durable molds that do not require subsequent redesign interventions.

Design based on production volume

Before starting the construction of the mould, it is essential to follow an accurate design of the equipment using CAD/CAM/CAE software such as SolidWorks and molding simulation systems.

Design and construction of molds for plastic materials

This phase requires very specialized expertise on the part of engineers in order to optimize production.

First of all, optimize the thickness of the walls which must be constant in order to obtain good quality molded parts.

Construction of molds and molding for plastic materials

Construction and testing

Once the design of the molds for plastic materials has been completed, it is possible to start the construction of the steel or aluminum molds.

The material used for the production of the molds is chosen based on the expected runs.

For short production runs we use aluminum or hardened steel, for very large runs we use steel and often multi-cavity moulds.

Production of prototypes and prototype moulds

Before starting mold production it is very useful to produce prototypes to validate the 3D geometry of the part.

For the production of prototypes we can rely on numerous rapid prototyping technologies or CNC milling processes.

Alternatively, before starting a definitive mold we can produce a prototype mould, ideal for quickly testing a new product from both a technical and commercial point of view.