Benchtop Injection Molding machine

The CE certified pneumatic Benchtop Injection Molding machine for thermoplastic molding was developed and manufactured in Italy by Robot Factory. The Benchtop Injection Molding machine is available in two options: a manual vice for mould clamping with a lever mechanism or a pneumatic vice for mould clamping with an automatic Ø 80mm piston mechanism.

The pneumatic vice can generate a force of up to 4000 Newton at 8 bar, which ensures that the molds are closed with adequate pressure even for very complicated molds. Furthermore, an automatic feeding system can be used with the pneumatic version of the injection molding machine. This automatic injection system allows you to manage both the timing of the closing vice and the timing of the descent of the piston for the injection, thus helping obtain the constancy of processing times and improve the quality of the work.

Video 1: The automatic injection system for timing management. Source: Robot Factory.

The capacity of its injection chamber is 32 cm3 (about 32 g by weight at 1.0 g/cm3 density) and the injection nozzle has a 6 mm diameter. The Benchtop Injection Molding machine weighs only about 14 kg and measures 260 (width) x 400 (length) x 700 (height) mm, which makes it ideal for any workshop or even a standard desk.

Image 1: The Benchtop Injection Molding machine by Robot Factory. Source: Robot Factory.

The Benchtop Injection Molding system by Robot Factory is based on the simple principle of injection molding where compressed air moves a Ø 63 mm piston to inject molten plastic into a mold placed in the injection chamber. Once the plastic is at its melting point, it is injected into a two shell mold and it assumes the shape of the mold, maintaining the new shape as it cools and solidifies. 

Image 2: Details of the Benchtop Injection Molding machine. Source: Robot Factory.

The materials tested and recommended for use with the Benchtop Injection Molding machine by Robot Factory are PE, PS, PMMA, TPV, EVA, PP, ABS and TPU/TPE. Those polymers can be used in the form of pellets or plastic shreds recycled from 3D printing waste, for example with the help of the Felfil plastic shredder or the ProtoCycler+. The Virtual Foundry 316 stainless steel Filamet pellets (80 % metal, 20 % PLA base) were also tested with the Benchtop Injection Molding machine with satisfying results. Materials that are not recommended are PC, PET, PVC and Nylon.

Video 2: Plastic injection molding with traditional aluminum molds. Source: Robot Factory.

While normally the mold is made of aluminum or steel, the pneumatic clamp in the Benchtop Injection Molding machine is also compatible with FFF or SLA 3D printed resin molds provided that they are designed to have a sufficient thickness and that the filament or resin used for making the molds is suitable for temperatures of up to 350 ºC. In the case of FFF molds, suitable mold materials would be PPS, PBT, Ultem or Peek, and in the case of resin molds, the High Temp Resin by FormLabs would be ideal.

Image 3:  3D printed resin molds. Source: Robot Factory.

The fact that 3D printed resin molds can be used with the Benchtop Injection Molding machine means that it is no longer necessary to make custom CNC machined aluminum molds for small scale production. This is a huge step towards making plastic injection molding accessible to all kinds of audiences. It should be kept in mind that molds produced with 3D printers have to be placed inside metal counter molds (provided by the manufacturer on request).

Video 3: Plastic injection molding with 3D printed resin molds. Source: Robot Factory.

Plastic injection molding is a decades old manufacturing method used to inject thermoplastic material into molds for the purpose of prototyping, production or research and development. Despite its popularity, traditional plastic injection molding is still relatively costly and only rentable for mass production. The Robot Factory Benchtop Injection Molding machine bridges that gap as it can be used at any scale by anyone, especially for the manufacturing of small and medium size electronics, jewelry pieces and medical devices.

Furthermore, to adapt to the constantly changing production practices, the Benchtop Injection Molding machine enables the user to produce parts with recycled material or from raw materials readily available on the market, for example pellets. This makes the Benchtop Injection Molding machine a user friendly and ecological manufacturing solution.

In addition to the injection system (timing control) you can also automate the entry of material. The new Automatic Material Feeding system is one more piece that adds to the universe of Pneumatic Injection Molding, making the system increasingly powerful and competitive in the market.

The use of Pneumatic Injection Molding with Pneumatic Clamp in combination with the Automatic Material Feeding system allows the material to be fed automatically before each injection cycle, giving the possibility of speeding up, facilitating and improving the quality of the work. The Automatic Material Feeding system manages the loading of the material using a microprocessor, feeding the injection chamber with the necessary amount of pellet.

Image 4: Automatic material feeding system. Source: Robot Factory.

Video 4: Automatic Material Feed tool. Source: Robot Factory.