Tool manufacturing is an important part of the plastics industry. The tools are used to shape plastic materials in various processes, such as injection molding, extrusion and vacuum forming. They affect both the product's design, tolerances and how efficient the manufacturing is.
In this text, we review different types of tools, with particular focus on molding tools and extrusion tools – two areas in which MK Plastteknik has extensive experience.
The role of tools in plastics manufacturing
Tools in the plastics industry are designed to shape and process thermoplastics and thermosets in various processing steps. They must withstand high temperatures, pressures and cyclic loads, while maintaining tight tolerances over long runs. Material selection, geometry and surface treatment are critical factors in tool performance.
The two most common types of tooling in plastics processing are molding tools and extrusion tools. Both require advanced design, often in 3D CAD, as well as manufacturing techniques such as CNC milling, wire sparking, and hardening.
Forming tools
Molds usually consist of a fixed and a moving part (core and cavity), as well as channels for injection, cooling and sometimes even vacuum systems. The tool must be dimensioned for both mechanical stability and thermal balancing. Common types of molds are:
- Injection Molding Tools: Used to produce parts with complex geometry. They often include release angles, gate systems (hot runners or cold channels), and built-in cooling coils for short cycle times.
- Vacuum forming tools: Often have simpler geometries, but require careful management of air flows and often micro-drilled holes to facilitate forming of thin materials.
- Multi-component molds: Used for two-component (2K) molding where multiple materials are combined in the same tool, often with rotating plates or indexing systems.
Extrusion tools
Extrusion tools (also called dies or extruder heads) shape plastic by forcing the material through a profile or opening, where the geometry defines the final product. The design of the tool affects flow characteristics, pressure drop and dimensional stability.
There are several technical challenges in extrusion tool design:
- Flow optimization: The viscosity and temperature profile of the plastic must be evenly distributed to avoid defects such as surface damage, edge pulls or swelling.
- Geometry: Profiling tools must take into account both the rheological behavior of the material and subsequent shrinkage.
- Tool temperature control: Some tools require active cooling or heating to maintain the process window.
Technical features of special tools
Toolmaking for the plastics industry often involves functions that require both expertise and specialized machinery. Below are examples of technical solutions found in advanced tools:
- Segmented cooling for zoned temperature control
- Integrated vacuum channels in vacuum forming tools
- Interchangeable inserts for product variations in the same tool
- Optimized sluice systems for homogeneous melt feeding
- Wire-spark-formed cavities with µm precision
- Hardened tool steels such as 1.2343 (X38CrMoV5-1) for dimensional stability
Summary
Toolmaking is a highly specialized discipline where every detail in design and manufacturing affects the end result. We offer complete solutions in toolmaking with molds and extrusion tools – from CAD development to finished production-ready units. With modern machinery, in-house expertise and a focus on quality at every stage, we are a partner for industrial companies with demands for precision and reliability in their plastic processing.
