Injection molding - large series in thermoplastics
Over 600 injection molding machines in our system - 2K, 3K and 4K - with a pulling force from 6 to 4,000 tons. We produce parts from 0.01 g to 41.5 kg in materials such as POM, PE, PP, PS, PC and PMMA, as well as other special materials. Factories in Denmark, Finland, Poland, Slovakia, USA and China.
Over 600 injection molding machines - 2K and 3K - pulling force 6 to 4,000 tons
Details from 0.01 g to 41.5 kg in POM, PE, PP, PS, PC, PMMA and special materials
Factories in Denmark, Finland, Poland, Slovakia, USA and China - competitive in price, quality and delivery time
TECHNOLOGY
What is injection molding?
Injection molding is the most widely used industrial method for producing plastic parts in large volumes. The process begins with thermoplastic in granular form being melted in a heated cylinder. The molten plastic is then forced into a closed precision tool (mold) under high pressure.
The mold is usually made of hardened steel or aluminum and contains a negative impression of the finished part. As the plastic cools and solidifies, the mold opens and the finished part is automatically ejected. This makes injection molding a highly efficient process for high-volume production where repeatability, dimensional accuracy, and low unit cost are essential.
CAPACITY
What we can deliver.
MACHINES
600+
ATTRACTION
6 – 4,000 tons
RETAIL WEIGHT
0.01g – 41.5kg
MACHINE TYPES
2K, 3K and 4K
POM (acetal)
Wear resistance, dimensional stability and low friction – pumps, valves, gears.
PE (polyethylene)
Chemically resistant, lightweight and flexible – pipes, tanks and packaging.
PP (polypropylene)
Lightweight, chemically resistant and hygienic – packaging, food and farming.
PS (polystyrene)
Rigid, easy to process and cost-effective – packaging and consumer products.
PC (polycarbonate)
Extreme impact strength and good temperature resistance – covers, windows and protective equipment.
PMMA (acrylic)
Optical clarity and UV stability – displays, signs and lighting.
Special materials
Other more complex materials adapted to demanding applications and specifications.
AREAS OF USE
Plexx has supplied injection molded elements to:
Technical components
Gears, housings, bearings and valves in POM and PA – for industry, pumps and machinery.
Subsea and offshore
Components in PEEK and glass-filled materials that withstand pressure, chemicals and temperature.
Cleantech and energy
Plastic parts for heat pumps, ventilation and renewable energy – optimized for function and durability.
Food and farming
Hygienic, chemically resistant plastic parts in PP and PE – produced efficiently in large volumes.
Electronics and electronic products
Vertical rotary tables for embedding metal components, connectors and sensors.
WHEN TO USE INJECTION MOLDING
Choose injection molding when…
You will produce from a few thousand to many millions of identical parts
Tolerances, repeatability and low unit price are critical
The geometry is complex – multiple functions in one part
You need materials such as POM, PE, PP, PS, PC or PMMA
Production requires traceability and regulatory compliance
You want multi-component casting (2K/3K) or overcasting in the same cycle
THE PROCESS
How does injection molding work?
STEP 01
Plastic granules are melted
Thermoplastic in granulated form is fed into a heated cylinder where it is melted into a homogeneous mass at a controlled temperature.
STEP 02
Injection under pressure
The molten plastic is pressed into a closed precision tool under high pressure.
STEP 03
Cooling and hardening
The plastic cools in the mold and solidifies to the final geometry. The cooling time depends on the material type and wall thickness.
STEP 04
Expulsion and control
The mold opens and the part is ejected automatically. Visual inspection and quality control ensure that each part meets specifications.
BENEFITS
Why choose injection molding at Plexx?
Injection molding provides a unique combination of precision, efficiency, and scalability that few other manufacturing methods can match.
Micrometer precision
Critical for medical, hydraulic and technical components with strict tolerance requirements.
Multi-component and overmolding
Hard/soft combinations, liquid silicone rubber (LSR) and metal inserts in the same process.
Scalable economics
From pilot series to million-piece series with the same team, tools and processes.
Quality and environment
ISO 9001 and ISO 14001
Factories in six countries
Production in Denmark, Finland, Poland, Slovakia, the USA and China provides competitive price, quality and delivery time.
TOOL
Tool development and quality assurance
We source, test and qualify steel and aluminum tools globally – providing customers with the optimal balance between lead time and life measured in shots. The tools are designed in close collaboration with the customer’s engineers to ensure that geometry, tolerances and surface quality meet the required specifications.
Automation cells with integrated vision inspection, laser engraving and packaging provide a high OEE (Overall Equipment Effectiveness).
FAQ
Frequently Asked Questions About Injection Molding
Injection molding provides high precision, good repeatability and is suitable for complex geometries and detailed components. Vacuum forming typically has lower tooling costs and is well suited for large, relatively simple parts, especially in small and medium-sized series.
Since the tooling cost is spread over the number of parts produced, injection molding is normally most cost-effective from a few hundred units upwards. For simple parts, it can pay off at lower volumes, while complex products often require larger series before the investment pays off.
Multiple materials or colors are sprayed in the same cycle — for example, a hard core with a soft grip zone — without the need for post-assembly.
Typically 4–16 weeks depending on complexity, material and whether the tool is made in Europe or Asia.
Yes. We offer DFM (Design for Manufacturability) analysis early in the project and can create prototypes in 3D printing. We can also create prototype tools in aluminum for injection molding.