Additive masterbatches are used in plastic manufacturing to improve processing or to enhance the properties of moulded components. A blowing agent can be included within an additive masterbatch.
The active ingredient can create a foaming effect within the polymer during the plastic moulding process. As the material hardens, fine, regular bubbles of gas form within the structure; this reduces the density of the material without reducing the strength or rigidity of the end component. As the pockets of gas weigh less than the polymer, this process reduces the weight of the moulded component. The moulding in the image above features large bubbles to demonstrate the effect, but under optimum moulding conditions, the bubbles would not be perceived by the naked eye.
Encapsulating the blowing agent within a masterbatch offers an easy way for the moulder to incorporate the additive within their moulding process. As the masterbatch is provided in pellet form, it also allows the addition rate to be closely controlled for the plastic moulder to achieve the optimal result.
Why is it beneficial to use a blowing agent masterbatch?
In the competitive world of plastic manufacturing, a blowing agent masterbatch can offer multiple benefits to moulders and their customers. These include weight savings in the moulded component and cost savings resulting from reducing the amount of polymer required for the production run. Improved cycle times can be a further benefit for the moulder, delivering time and energy savings.
Using less polymer is beneficial both from an environmental and commercial perspective. Plastic taxes, such as the UK Plastic Packaging Tax are typically based on the weight of polymer processed. Therefore, by reducing the polymer required, polymer costs are reduced and (in relevant applications) so is the tax bill.
In which applications might a blowing agent masterbatch be used?
Lightweight plastic items will offer benefits for various market sectors. In the construction industry, there are advantages to lightweight components, such as plastic window profiles, without reducing strength. A blowing agent offers a favourable approach as it allows for weight reduction without lowering the thickness of the profiles. Furthermore, blowing agents have been proven to create improved thermal insulation properties. This is highly beneficial given the ever-increasing demand for energy-efficient materials within the construction industry.
In automotive and aerospace applications, lightweight components will improve performance and fuel efficiency. In packaged consumer goods, tax benefits will often apply and weight reduction is beneficial for transportation. Any plastic moulding in which cost and weight savings are desirable may benefit from the introduction of a blowing agent masterbatch.
How does a blowing agent masterbatch work?
Broadway’s blowing agent is an endothermic CFA (Chemical Foaming Agent). Endothermic CFAs are chemicals that take heat away from the chemical reaction. Endothermic CFAs tend to give off less harmful gases than exothermic ones, which release heat energy. The fact they take in heat energy, rather than releasing it means the chemical reactions for endothermic CFAs are easily controlled. There’s less risk of a ‘runaway’ reaction where too much heat is generated. Absorbing heat energy lends itself to reduced in mould cooling times, which in specific circumstances has been known to reduce mould cycle times dramatically.
Who would use a blowing agent masterbatch?
Anyone creating a coloured plastic item will tend to require a masterbatch. Masterbatch manufacturers such as Broadway can develop custom colours for plastics in the form of masterbatches. They can also develop additive masterbatches, including blowing agent masterbatches. Additive masterbatches are used to improve processing or enhance the properties of the moulded component.
Plastic moulders will purchase masterbatches from the supplier to use in production. However, brand owners, packaging technologists and product developers can benefit from working directly with a masterbatch manufacturer to develop and approve their colour and additive masterbatches. Broadway has an on-site colour matching suite specifically designed to host customers wanting to develop and approve new masterbatches for their products.
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