Injection moulding is a process that enables us to produce parts in vast quantities. It is often used in mass production when the same part needs to be made thousands or millions of times. In this guide, we will take an in-depth look at injection moulding to explain how it can be of benefit to you. We will talk about the various uses for injection moulding, who uses it, what they use it for, how it works, which machines are used and how it has been used throughout the years.
During the plastic injection moulding process, material is fed into a heated barrel before it is mixed and placed in a mould cavity. The cavity is used to shape the material, and it is during this part of the process that it hardens into the end product. Plastic injection moulding is renowned for its accuracy. It offers accuracy within 0.0005 inches, and it’s possible to fabricate pretty much any kind of plastic part via the process.
Another key benefit of opting for plastic injection moulding is that it is an incredibly quick process. The gap between cycle times is normally 15-30 seconds. The actual speed will depend on the mould’s complexity. This is one of the reasons why it has become one of the most popular technologies for large manufacturing runs. You can also reduce labour costs by opting for plastic injection moulding. Automatic tools keep machines running with minimal supervision, freeing up staff to focus on other duties safe in the knowledge that the production process is running effectively.
The manufacturing companies of today are tasked with making their operations as sustainable as possible. Plastic injection moulding is ideal for manufacturers seeking to reduce their carbon footprint and make a better contribution to the environment thanks to the way excess plastic can be ground up and recycled, and how we only need to use the necessary amount of material to produce the part. This minimises waste considerably.
Plastic injection moulding is also highly regarded for its flexibility. It’s relatively easy to change the kind of material whenever we wish to, and it’s also straightforward to switch colours whenever required. We can also make parts more robust by adding fillers to components during the process. This reduces the density of liquid plastic and boosts the strength of the part. If you do need to produce tough parts that will stand the test of time, plastic injection moulding may well be the solution you have been looking for.
The benefits of injection moulding don’t end there. Injection moulding is also ideal for those seeking products that require little or no finishing. This is because parts leave the mould with a finished or almost finished appearance, with a smooth surface. Again, this can speed up the production process and keep costs down.
Although the production of the initial mould may not be cheap, once this is created it’s possible to create a huge volume of components from the mould for a very modest fee. This makes plastic injection moulding a much more affordable alternative to plastic machining in the long run. Plastic injection moulding is one of the most popular and dependable plastic producing processes available to you and is used by some of the world’s most renowned and prestigious brands. Chances are you encounter scores of items that were produced via the process every single day. The more parts you produce, the more production costs are lessened.
Let’s take a quick look at the history of plastic injection moulding. In 1847, Jons Jacob Berzelius unveiled the first condensation polymer. This was polyester, and it was made from tartaric acid and glycerin. Fourteen years later, Alexander Parkes invented the world’s first manmade commercial plastic, showing this off at the International Exhibition in London. He called it ‘Parkesine’, and it could be heated and moulded yet retain its shape after the cooling process was completed.
The US inventor John Wesley Hyatt developed a plastic material called celluloid in the late 1860s. This was first used to replace ivory in billiard balls. Hyatt collaborated with his brother Isaiah in 1872 to make and patent the first injection moulding machine. This was a rather primitive machine which injected melted plastic via a heated cylinder into a two-part mould. Over the ensuing years, new innovations were used to make goods like combs and buttons.
Phenol-formaldehyde plastic was discovered by Belgium’s Leo Hendrik Baekeland in 1909. This material was originally branded ‘bakelite’. A host of major vinyl thermoplastics emerged in the 1930s, and these included PVC, polystyrene and polyolefins. Perspex first came into use during this era. During WWII, the need for affordable mass-produced materials rose substantially, with nylon being used as a moulding material from 1941. In the mid-20th century, it became cheaper to produce a range of plastic materials. These weren’t just used instead of costlier plastics – they also replaced materials including glass, leather, metal and wood in various applications.
Polycarbonate was first marketed by General Electric in 1955, around a decade after US manufacturing pioneer James Watson Hendry created the first extrusion screw injection machine. This gave workers more control over injection speed, allowing the calibre of items to be enhanced considerably and enabling recycled and coloured materials to be added to virgin materials. The way that the screw worked helped the heater bands to heat plastic and therefore reduce energy use. It’s estimated that 19 out of 20 injection moulding machines in use today are screw machines.
A wide range of new thermoplastics were made available between 1955-1965. A new reciprocating screw plasticator was issued by W.H. Willert in 1956. In these systems, screws move backwards and forwards. Screws stop turning after the mixing process and pushed forwards to inject material into moulds, with the screw moving backwards during plastication. The first gas-assisted injection moulding process was unveiled by James Watson Hendry in the 1970s, enabling the production of quickly-cooling, hollow and complex items. This process is credited with boosting the strength and finish of parts considerably, reducing production costs and time. It also vastly reduced waste. In 1972, parts removal robots were used in the injection moulding process for the first time. Plastic production levels overtook steel production for the first time in 1979, with the first wholly-electric moulding machine being unveiled in 1985. Five years later, aluminium moulds gained vast prominence in injection moulding processes.
The first step of the plastic injection moulding process is to fill a mould cavity with plastic. Once the material is cooled and therefore hardened, the mould is opened to expose the part to air. Pins are used to release the product from the mould before the mould re-closes so new material can be added to it and the process can be completed until all the required parts are produced. The process is frequently used to create intricate parts with incredible detail. This is why it’s so important that the actual moulds are designed carefully. Any waste generated during the process can easily be processed, making injection moulding one of the most eco-friendly manufacturing processes available to us.
It’s even possible to combine different materials to create one product. This process is known as co-injection moulding. The technology used for injection moulding in all its forms, including plastic moulding and more, is evolving over time. It’s estimated that more than 400 billion Lego elements have been produced via injection moulding over the past 70 years, with 35,000 pieces being manufactured every minute. Items frequently produced via the injection moulding process can include everything from toys to small pieces of furniture, storage containers, car parts, parts for electrical appliances, bottle tops and many more.
When designers create moulds, they need to think carefully about the various features of the part, the moulding machine’s features and the materials of the mould. Moulds are often made from metal. It’s very important that the design meets the requirements at the first time of asking, as the mould production process can be somewhat costly and time-consuming. Injection moulding is more likely to be the right option for you if you require a substantial number of parts. The higher the quantity, the more cost-effective and viable the option will become.
At Regina, we have been offering plastic injection moulding services for a number of years. We have more than 70 years of design and manufacturing experience to draw upon and can be counted on to deliver the results that you are looking for. We do all we can to ensure the production process and materials sections are the right match for your requirements, with all the products that we manufacture having ISO9001:2015 approval. This enables us to provide the peace of mind that you deserve and the assurances that you’re receiving the quality that you are seeking.
We are adept at working with a host of materials, including commodity polymers such as polystyrene, polypropylene and polyethene. We can also work with engineering polymers like polycarbonate, acetal and nylon. Our base plays host to 26 moulding machines, with weights ranging from 22 to 150 tonnes. Our machines offer less than 1gm to 300gm shot weights, and we can help you whether you have a new requirement or wish to resource a pre-existing one. We are only happy when you are totally satisfied with the service that you have received, and we do everything in our power to meet or even surpass your expectations.
We use various complex processes to meet the most complex demands in terms of geometry and detail. A number of suitable polymers are available to heighten strength. All results are fully repeatable, with colour and surface finish being built in. Low volume production solutions are available when required, and we can offer swifter lead times than many of our competitors. We only ever use the latest and most efficient 3D CAD software. This enables you to see what the end-product will look like once the process is complete and allows you to confidently give us the green light to finish the process. Precision machining, too-making and product development are also available from Regina.
Our company was first founded back in 1950, with our history stretching back to 19th century Germany. The father of our company founder pioneered the Schuller Updrawing glass tubing process during this era. We are a Newcastle-under-Lyme company serving clients across the UK and beyond, with an expanding catalogue and an outstanding reputation amongst our customers. We have vast experience in designing and manufacturing bespoke moulded components for a diverse pool of clients. Should you wish to view a copy of our ISO9001:2015, you can download this from the website. If you wish to find out more about the injection moulding process and how it can benefit you, feel free to contact us at your earliest opportunity. If you ever require tubular glass containers, you can opt for our services and benefit from our many decades of experience in working with this material. As our company was founded in glass, you can feel confident you are enlisting the services of a key market leader.
We are waiting to hear from you right now if you are ready to learn more about plastic injection moulding or any other service offered by Regina. You can reach us today by calling us on 01782 565 646 or by sending a message to sales@regina.co.uk. We can also be found on a wide range of social media networks such as Facebook, Twitter, YouTube and LinkedIn. It’s also possible to upload your drawings via our website.