What is Injection Moulding?

Injection moulding is a widely used manufacturing process that is often used to produce plastic products like chairs, toys and enclosures for electronic goods. The process allows even shapes of high-complexity to be produced extremely quickly from both thermoplastic and thermosetting polymers, making it a highly efficient and cost-effective manufacturing option. In addition to plastics, injection moulding can be used with other materials.

The mould inside the machine comprises of two halves, one half male and the other female. When the machine closes this enables molten plastic to inject into the mould and the cycle time also allows the moulding to cool. Inside the tool are water circuits to reduce the material temperature from about 200 degrees C to about 60 degrees C. When the mould opens the product is then ejected and a robot will then lift the moulding onto a conveyor belt.

Settings, temperatures and timings are very important factors in the process. BSA has an excellent quality control system, where production is checked every 1.5 hours.

Stages of Injection Moulding

Clamping: The first stage involves securing the mould with the clamping unit. This step is crucial for maintaining the mould’s shape and integrity during the injection phase.

Injection: During this stage, the injection unit melts the plastic pellets and injects the molten plastic into the mould cavity. The speed and pressure of the injection can vary based on the type of plastic and the complexity of the part being produced.

Cooling: Once the mould is filled, the plastic begins to cool and solidify. Cooling rates must be carefully controlled to avoid defects such as warping or shrinkage.

Ejection: After the plastic has cooled sufficiently, the mould opens, and the finished part is ejected. This stage often involves additional mechanisms to ensure the part is removed without damage.

How to produce High Quality Injection Moulds

Ensuring the quality of the final product is paramount. Various quality control measures are employed throughout the process, such as:

Dimensional Accuracy: Employing precision measuring instruments to verify the dimensions of the moulded part.

Material Testing: Conducting tests to ensure the plastic material meets specified standards.

Visual Inspection: Manually inspecting the part for surface defects or inconsistencies.

How is the environment impacted by injection moulding?

Given the growing concern for environmental sustainability, it is imperative to consider the ecological impact of plastic injection moulding. While the process itself is highly efficient, it does generate waste in the form of sprues and runners.

However plastic injection moulding offers the benefit of reduced waste, as it allows for the recycling of material. Excess plastic can be ground up and reused, thus minimising waste and promoting sustainability.

What is the cost of Injection Moulding?

Several factors influence the cost of plastic injection moulding, including:

Mould Complexity: The intricacy of the mould design directly impacts the cost.

Material: The type of plastic used can significantly affect the overall expense.

Production Volume: Higher production volumes generally lower the cost per unit.

Advantages of Injection Moulding

One of the most compelling advantages of plastic injection moulding is its efficiency. The process is highly automated, operated by machines and robotics, which can be controlled by a single operator. This level of automation allows for increased productivity and operational efficiency. Unlike traditional methods that require multiple stages and manual labour, plastic injection moulding streamlines operations, thereby reducing manufacturing time and increasing output.

Another significant benefit is the flexibility in material and design that this method offers. Various types of plastics can be used simultaneously, which allows for co-injection moulding and provides a broad spectrum of customisation options. The high pressure used in the moulding process ensures intricate designs and complex geometries can be effectively created.

How Strong is Injection Moulding

When it comes to manufacturing parts that require high strength, plastic injection moulding is an optimal choice. The technique allows for the use of fillers in the injection moulds. These fillers reduce the density of the plastic while adding enhanced strength to the finished part. This feature is particularly useful in industries such as automotive and aerospace, where component strength is crucial.

How Accurate is Injection Moulding

Accuracy is paramount in manufacturing, and plastic injection moulding excels in this regard. The method allows for high-precision moulds, which result in components with extremely tight tolerances. This level of accuracy is crucial for industries such as medical devices, where even a minor deviation can have significant consequences.

Consistency is another noteworthy advantage. Once the initial setup is complete and the moulds are prepared, you can expect uniformity across all produced units. This reliability is vital for maintaining quality standards and meeting regulatory requirements.