If you’re developing a new product, you’re likely trying to balance cost, quality, lead times, and risk, often without clarity on what a fair price looks like, or what should be included in a quote. 

If you’re already producing parts, you might be questioning whether your current supplier is delivering value for money, good quality parts, and reasonable turn around times. 

Plastic injection moulding is a technical process, but the biggest challenges are often commercial rather than mechanical. How much should a tool really cost? When is it better to modify an existing mould rather than build a new one? What affects part pricing? You need answers to these questions to set your project up for success.

This guide brings together the questions we are asked most often. It’s designed to give you clear, practical answers so you can make informed decisions, whether you are launching something new, or reviewing an existing production setup.

How much does injection moulding really cost?

The cost of plastic injection moulding varies greatly with the size, scope and duration of your project. It depends on two main areas – the tool and the parts. 

First of all, the mould tool is a large part of your upfront investment. This is the precision engineered steel tool that forms your plastic part. The cost varies depending on the size and complexity of the part, the type of material being used, the expected production volume, and the lifespan required. A simple, single-cavity tool for a small component will cost far less than a complex multi-cavity tool designed for high volume production. 

Secondly, part price plays a role in ongoing production costs. Once the tool is built, you’ll pay for the manufacture of each moulded part. Part pricing is influenced by cycle time (the time it takes to produce one part), the material cost, the weight of the component, and the number of cavities in the tool. Larger volumes generally reduce the unit cost because the initial tooling investment is spread across more parts. 

It’s also important to look beyond the headline figures. A lower tooling quote does not always mean better value. Consider what’s included – has the design been reviewed for manufacturability? Is sampling included? Who owns the tooling? What happens if modifications are needed later?

In many cases, modifying an existing tool can be more cost effective than starting from scratch. A good manufacturer will be open about this rather than pushing you towards a full rebuild if it’s not required. 
If you’d like to explore what influences the cost of your project in more detail, you can read our full guide on how much plastic injection moulding costs.

Why choose injection moulding over other manufacturing methods?

Plastic injection moulding is not the right solution for every product. However, when it fits, it offers clear commercial and practical advantages over many alternative processes such as machining vacuum forming, or 3d printing.

One of the biggest benefits is repeatability. Once a mould tool is built and validated, it can produce thousands, or even millions, of identical parts with very tight tolerances. This level of consistency is difficult and expensive to achieve with manual or lower volume processes. 

It’s also highly efficient at scale, While the upfront tooling investment can seem significant, the unit cost drops as volumes increase. For medium to high volume production, injection moulding often becomes the most cost effective option. 

The process allows for complex geometries that would be difficult or time consuming to machine. Features such as ribs, clips, hinges, and textured finishes can be built directly into the tool. This reduces secondary operations and assembly time. 

Material choice is another advantage. A wide range of engineering polymers are available, allowing you to balance strength, flexibility, chemical resistance, heat resistance, and cost. That flexibility makes it suitable for industries ranging from consumer goods to medical and industrial applications. 

Finally, injection moulding supports long term scalability. If demand grows, the tool can often be adapted with additional cavities to increase output, rather than redesigning the part from scratch. 
If you’d like to read more about these advantages, you can read our guide on the seven ways plastic injection moulding can benefit your company.

Should I manufacture in the UK or overseas?

This is one of the most common questions we hear. On paper, overseas manufacturing can appear cheaper. Lower labour rates and lower tooling quotes often attract attention at the early quoting stage. But headline pricing rarely tells the full story. 

When you manufacture overseas, you need to factor in shipping costs, import duties, longer lead times, currency fluctuations, and the cost of holding more stock to protect against delays. Communication can also become slower and more complex, particularly if the design changes or quality issues arise. 

There is also the issue of supply chain volatility. Global material shortages, political instability, economic disruption and changes in trade agreements can all have a direct impact on overseas production. Even if your supplier is reliable, external factors beyond their control can delay shipments or increase costs with little warning. Manufacturing in the UK reduces your exposure to many of these variables and gives you a more stable, predictable supply chain.

Manufacturing in the UK gives you greater control. You can visit the site, review tooling in person, and resolve issues quickly. Lead times are shorter and more predictable because you are not relying on international freight or customer clearance. This reduces risk and can improve cash flow, as you don’t need to commit to large batch quantities as far in advance.

 For many businesses, the stability, visibility and responsiveness of UK manufacturing outweigh a small difference in unit cost. 

If you’d like more details about the advantages of UK production, you can read our full guide about using a UK based supplier.

How do I know if a plastic injection moulding company is reliable?

Choosing a moulding partner is a long term decision, so reliability needs to go beyond a competitive quote. You are trusting a company with your tooling investment, your product quality, and often your reputation in the market. 

A dependable manufacturer should be transparent with pricing, clear about what is included in a quote, and willing to explain technical decisions in plain terms. They should be proactive and knowledgeable, reviewing your design before tooling begins and flag potential issues early to save on cost and turnaround times.

Look at their technical capability and experience. Do they have in-house toolmaking knowledge? Can they support design for manufacture, adjusting a part so it moulds efficiently and consistently? Do they carry out proper sampling and validation before full production begins? 

Communication is another key indicator. A reliable partner will be proactive, responsive, and honest about lead times, costs and challenges. They should also have clear quality control processes in place and be open to audits or site visits. 

Ultimately, reliability shows in how a company handles the details. Not just when things go smoothly, but when adjustments or improvements are needed. If you’d like a more detailed breakdown of what to look for, read our guide on what you should look for in your plastic injection moulding company.

Still have questions?

Every project is different. Tooling budgets, production volumes, material choices, and timelines all shape the right approach. The key is having clear information and a manufacturing partner who will talk you through the options honestly. 

At Bowles and Walker, we work with businesses at every stage. Some are developing a product for the first time and need guidance from concept through to production. Others already have tools and are reviewing costs, quality or supply chain risk. 

Whether you need advice on tooling, part pricing, UK manufacturing, or modifying an existing mould, we are happy to have a chat about what makes sense for your project. 
If you’d like to discuss an idea or review your current production setup, get in touch with our team by calling 01953885294 or sending an enquiry through our online form. We’ll help you break down the jargon, help you understand your options, and find the most practical and cost effective solution.

The post Everything you need to know about plastic injection moulding appeared first on Bowles & Walker.

Stainless Finishing Solutions (SFS) is a Norwich-based supplier of stainless steel weld cleaning equipment, best known for its flagship product, the Weldbrush. This partnership marked the beginning of a close and practical working relationship.

The problem 

In late 2024, SFS approached Bowles and Walker to move the production of the Weldbrush casing from Australia to the UK. Their goals were to reduce costs, gain flexibility in production, and build a relationship with a local manufacturing partner. 

They initially asked for a quote to create brand new tooling to manufacture the casings in the UK. From their point of view, a new tool felt like the simplest option and one that could support the expansion of their product offering with new colours and sizes. However, this approach came with a significant cost, which prompted Bowles and Walker to look more closely at what was really needed before moving forward. They set out to help SFS achieve three aims: 

• Bring production of the Weldbrush to the UK, keeping delays to set up production to a minimum. 
• Choose the most cost effective and efficient solution for setting up manufacturing in the UK. 
• Create a setup that offers flexible order sizes and colour options.

What we did

The strategy began with several planning meetings across November and December 2024. This helped both teams understand what was feasible and what the tool may require. 

After careful consideration, Bowles and Walker suggested shipping the existing tool from Australia. This would not only reduce SFS’ investment, but also reduce the time it would take to set up manufacturing in the UK. By using the existing tool, there would also be less risk of producing parts that had discrepancies compared to the original.They made it clear that reworking the tool might involve extra time and work on arrival, but that the long-term savings would be worth it. 

Once the tool landed in the UK in mid February, Bowles and Walker assessed its condition and prepared a full feasibility report. This included three repair options ranging from basic fixes to a full redesign using steel components. Together with SFS, they chose a mid-level option that offered a good balance between cost and durability. The team then adapted their production setup to work with the tool’s unique design.

Results:

Bowles and Walker delivered strong results in a short timeframe. They helped SFS successfully move production to the UK, restore a worn tool, and cut production costs significantly. 

SFS had been paying around £11 per unit in Australia, with a minimum order of 5000 sets and extra charges for overseas delivery. Bowles and Walker offered more than 50% savings per set on orders of 1000 or more, and included free UK shipping. They also provided flexibility for smaller batch sizes from just 250 sets upwards.This gave SFS more control over cash flow, inventory, and lead times. 

The repair and upgrade work done to the mould has made it suitable for UK production for another 10-15 years. While the tool still requires careful handling, the improvements have made it stable and reliable for current production needs. 

SFS now benefits from faster turnaround, improved communication, and greater flexibility. They can order different colours, run smaller batches, and make decisions with more confidence. The environmental impact of production has also improved, with local manufacturing cutting shipping and emissions. 

The partnership has already led to new opportunities, with SFS now exploring further production with Bowles and Walker. This project shows how smart, honest, and practical thinking can turn challenges into progress.

“We would like to extend our sincere thanks to Bowles and Walker for their outstanding support in the development of our new Weldbrush machine shells. Their team has gone above and beyond in helping us source the right material, ensuring not only durability but also compatibility with our specific application requirements.

The colour matching process was handled with impressive attention to detail, and we greatly appreciated the numerous samples provided throughout development. This collaborative approach gave us confidence at every stage and ultimately helped us achieve the high-quality shells we were aiming for.

It’s been a pleasure working with such a responsive and professional partner. We look forward to continuing this relationship in future projects.” – Drewe Briston, Managing Director of Stainless Finishing Solutions

The post Bringing production back to the UK appeared first on Bowles & Walker.

Here is a look back at some of the key moments that shaped the year.

Partnering with Peerless Plastics and Coatings

One exciting development this year has been our ongoing partnership with Peerless Plastics. 

By working closely together, we can now offer clients a more complete, varied manufacturing solution. This includes providing our clients access to specialist coatings that improve durability and resistance to wear and chemicals. Options such as anti-microbial and anti-static finishes help extend product life and performance, particularly in demanding environments. 

Just as importantly, partnering with a local company reduces transport time, cost and emissions, supporting a more efficient and lower impact supply chain.

Investing in new equipment to increase capacity

In February, we made a significant investment in our moulding facilities with the installation of a new five tonne gantry and electric hoist.

This replaced our previous two tonne gantry and manual hoist, significantly increasing the size and weight of mould tools we can safely handle. In practical terms, it allows us to work with larger and more technically demanding tools. With this new equipment, we’ve been able to make great strides in terms of efficiency and safety. 

This investment was made possible with support from the Rural England Prosperity Fund and Breckland Council. Their backing has helped us expand our capabilities in a way that benefits both our customers and our long term growth.

Supporting future engineers through work experience and practical learning

We love taking the opportunity to support work experience and learning for young people, and this year we were lucky enough to do so at several different learning stages.

In July, we welcomed pupils from Wayland Academy in Watton for work experience placements, giving them time to view our tool room and observe how injection mould tools are made. They were introduced to key processes such as milling and EDM machining, and also spent time in production to get a feel of day-to-day manufacturing.

Later on in the year, we hosted students and staff from the UEA School of Engineering, Maths and Physics for a more in depth look at what an SME injection moulder does. The visit covered everything from mould tooling and processing, through to recycling and product logistics. It led to thoughtful discussions around design for manufacture, sustainability, and the practical challenges of plastic recycling. 

Whether through early work experience or university level visits, we value the chance to share practical knowledge and help give a clearer picture of what engineering careers can look like beyond the classroom.

Recognised support and progress towards Net Zero

During September, we were extremely proud to welcome representatives from Breckland Council to view the equipment investments that they supported with grants earlier on in the year. 

These grants have enabled us to increase both moulding and tooling capacity, including the ability to handle mould tools up to five tonnes. Alongside this, we have continued to enhance our solar array, supporting our longer term goal of reducing energy use and moving towards Net Zero.

The result is a business that can grow sustainably, support new employment, and continue to invest in modern, efficient manufacturing.

One full year of the four day working week

In November, we celebrated a full year since introducing the four day working week at Bowles and Walker. 

After a suggestion from staff, we trialled a condensed working week, extending hours from Monday to Thursday and closing on Fridays. Following a short adjustment period and a review with the team, it became clear that the change was working. 

Fast forward one year and we have seen happier, more productive staff, improved work life balance, and reduced energy use, with no negative impact on our performance or customer feedback. 

While this model might not suit every business, it has worked well for us and supports both wellbeing and sustainability.

Industry recognition at the Plastics Industry Awards

In September, we were proud to be named a finalist in the 2025 Plastics Industry Awards in the Toolmaker Supplier Partnership category.

The nomination was made in partnership with Stainless Finishing Solutions, following our collaborative work to bring their Weldbrush product into UK production. Being recognised in this way highlighted the value of close, transparent working relationships and shared problem solving.

The team attended the awards ceremony in London in November. While we did not take home the award on the night, being shortlisted was a first for Bowles and Walker and an important milestone for the business. It was also a great opportunity to meet and speak with other professionals from across the plastics industry, share experiences and see the breadth of innovation happening across the sector.

Looking ahead

As we come to the end of 2025, we feel proud of the progress made over the past year. From new partnerships, industry recognition and steady growth, it has been encouraging to see the business move forward in positive ways.

Along the way, we have worked closely with customers, supported local schools and universities, and shared ideas with peers across the industry. These experiences have helped build strong relationships within both the local community and the wider manufacturing sector, and have reinforced the value of working openly, practically and with people at the centre of what we do.

Looking ahead to 2026, we hope for another year shaped by meaningful connections, shared learning and continued progress across the industry.

The post A 2025 Recap for Bowles & Walker appeared first on Bowles & Walker.

A well designed tool helps control the quality and consistency of each part, and supports an efficient production run. Even small choices in design can affect cycle time, surface finish, and the long term performance of the product. As a rule, the design of your tool has a direct impact on its lifespan too. 

This means that the way the steel is selected, how the cooling channels are placed, and how the parts open and close will all influence how long the tool can run before it needs maintenance or repair. A thoughtful design helps prevent early wear, reduces stress on moving parts and keeps production stable over many cycles.

Designing the tool

When we design a tool, we plan far more than the external shape. We think about how your plastic will flow, cool and release. Generally, a tool is made from steel or aluminium, and includes two main halves known as the core and cavity. Together, they form the profile of your product. 

A good injection moulding tool design considers: 

• the gating and runner system that guides the molten plastic
  
• the venting that lets trapped air escape
  
• the cooling layout that controls how quickly the part sets
  

Each detail supports a stable moulding process.

How injection mould tooling works

During moulding, molten plastic travels through a channel inside the tool from the machine barrel into the cavity. Venting inside the tool lets trapped air escape so you can avoid voids or bubbles on the finished part.

The tool then cools the plastic. This is done by circulating water or oil through internal channels, similar to a car cooling system. Cooling is important because the plastic must set at the right speed to avoid stress marks or distortion. 

Once the part has set, ejector pins gently push it out of the rool, and the cycle starts again.

Key parts of a mould tool explained

Below is a guide to the main components you’ll find in most mould tools. This helps demonstrate how each section supports the moulding process.

1. Location ring – Aligns the tool with the moulding machine so everything sits in the correct position. 

2. Fixed half clamp plate – Holds the fixed side of the tool in place and provides the structure for the cavity. 

3. Pillars & bushes – Precision ground alignment pillars that ensure the fixed and moving halves of a tool lines up with one another.

4. Sprue bush – The entry point for molten plastic. This can be a hot or cold tip. A hot tip can reduce material waste and offer more control. 

5. Fixed half cavity plate – Holds the cavity or female part of the tool and gives on half of the product its shape.

6. Slides – Used when the part needs undercuts or details that cannot be formed with a simple open and shut tool. Not all tools need slides. 

7. Moving half core plate
This holds the other half of the product shape, known as the core or male half. During moulding, molten plastic flows into both the core and cavity and then sets into the final form. The plastic reaches these areas through two key features. 

• Runner – This channel carries the molten plastic through the tool. Runners can be hot or cold. Hot runner systems cost more but offer greater flexibility during moulding and reduce material waste. Cold runners are more straightforward and usually less costly to produce.
• Gate – This sits between the runner and the core and cavity. The gate is slightly thinner so it creates a natural weak point. This helps the runner separate cleanly from the finished part once the moulding has set. 

8. Ejector set – The ejector set includes the plate that holds the ejector pins in the right position, along with the pins themselves. Once the moulding has set and the tool opens, these pins push the part out of the mould so it can be collected and the next cycle can begin.

9. Risers – Provide space for the ejector plate to move.

10. Moving half clamp plate – Holds the moving half of the tool in position on the moulding machine.

Choosing the right tooling approach for your part

Every project calls for a slightly different approach. A new injection mould tool can be the best choice if you’re planning for long term production. A fresh tool delivers better results for a product with complex features, tight tolerances and material flow. It also guarantees a longer lifespan for your tool. 

In some situations, we can adapt or repair an existing tool instead. This can be helpful if you already have a mould tool that only needs small changes, such as an updated feature or a minor size adjustment. Reworking a tool can reduce both lead time and cost, as long as the original steel allows for it. 

Our team always reviews the part design, the production volume, and your goals before giving advice. We look for the most practical and efficient path, whether that means creating a new tool or making the most of what you already have.

Support from design to production

At Bowles & Walker, we provide support from tooling design right through to production. We work closely with our customers and give pragmatic advice at each stage so your tooling is cost effective and suited to the way you want to mould your parts.

If you would like to talk through a project or need guidance on your next tool, you can call us on 01953 885294 or email info@bowles-walker.com. We are always happy to help you create reliable products, manage costs and support UK manufacturing.

The post What an injection mould tool does and why it matters appeared first on Bowles & Walker.

A partnership built on trust and collaboration

The Toolmaker category shines a light on partnerships that go beyond just delivering a service. It recognises those that can build trust, solve problems together, and work side by side to achieve success in the plastics industry. 

That’s exactly the kind of relationship we aim to build with every one of our clients. Whether we’re producing parts for a long-standing customer or guiding someone through injection moulding for the first time, our approach is always the same – be honest, be practical, and deliver work we’re proud of. 

At Bowles and Walker, we’re always looking for ways to do things better, whether that’s through smarter production, more sustainable processes or working with clients to refine their designs. This project reflects just that.

What the nomination means to us

Being shortlisted in this category is a proud moment for the whole team. It reflects how we’re able to work with openness, technical expertise, and a genuine focus on doing what’s best for our clients.

Sometimes this means building new tooling. Other times, like in this case, it means offering a more cost-effective solution by adapting what’s already there.  

This recognition also highlights the care we take with our in-house tooling, the value of honest advice, and the long-term relationships we continue to build with businesses of all sizes.

Reflecting on the achievement, Bowles and Walker’s Operations Manager, Michael Barwood, said:

“Becoming a finalist in a national award program like the Plastic Industry Awards was certainly a surprise, but very welcomed. We always try our best for our customers, and it’s amazing that we have been recognised for that effort. This is something myself and the whole team are very proud of.”

Looking ahead to the awards

The winners will be announced at the Plastic Industry Awards ceremony on 21st November in London. It’s a brilliant opportunity to celebrate the people, projects and partnerships driving the plastics industry forward, and we’re proud to be part of it.

A huge thanks to everyone involved, especially our team and the team at Stainless Finishing Solutions, for making this such a rewarding and successful collaboration.

The post Bowles and Walker named finalist in the 2025 Plastic Industry Awards appeared first on Bowles & Walker.

The mould you choose will also affect production time, cost per part and overall efficiency.

In this blog, we’ll explain the three main types of injection moulds: single cavity, multi-cavity and family moulds. We’ll break down the benefits of each, and help you understand which might work best for your project.

What is a mould cavity?

A cavity is the hollow space inside of a mould that shapes the plastic injected into it. The number of these cavities affect how many parts are made each time the mould runs. 

Let’s talk about the three common types and their typical uses. 

Single cavity moulds

A single cavity mould makes one part per cycle. It’s often used for low volume production runs, or for parts where precision is very important. 

This approach is common in industries where there’s no room for error. For example, medical components often need to meet strict quality and safety standards. Using just one cavity allows for tight control over each part. It also makes it easier to spot and fix issues during early production.

Single cavity moulds can also be useful if you’re still testing a new design, working through a prototype, or have multiple part variations to try before scaling up. 

Because it only produces one part at a time, this method can take longer and increase the cost per unit. However, if you’re a business that values accuracy, control, or flexibility early on, a single cavity mould might be the most practical place to start.

Multi-cavity moulds

Multi-cavity moulds have several cavities that produce several identical parts at once. This makes them ideal for high-volume production. By creating more parts in each cycle, you can reduce lead times and bring down the average cost per part. 

Although the upfront cost to design and build a multi-cavity tool is higher, it often becomes more cost effective over time, especially when demand is steady or increasing. 

This type of mould is ideal for products where consistency and speed are important. Industries such as automotive and electronics rely heavily on multi-cavity tools to meet high demand without compromising on quality. It might also be a good fit for consumer goods, packaging, and any product where you need to produce thousands of identical parts. 

If you’re looking to scale up production or want to reduce long term costs, a multi-cavity mould might be the right choice.

Family moulds

Family moulds contain different cavities for different parts of the same product. Instead of running separate moulds for each component, you can produce several related parts in the same cycle. This can help to streamline your production process and reduce overall tooling and production costs. 

They work well for assemblies where the parts are used together – like a toy set or a multi-part container. Getting your components produced all in one go speeds up post-moulding assembly and keeps batch sizes consistent. 

Family moulds are especially helpful in low to medium volume production where saving time and avoiding the cost of multiple tools make a big difference. 

One thing to keep in mind is flexibility. If one part becomes redundant or changes in design, that section of the mould may no longer be usable. For that reason, family moulds are best used for well established product designs that are final and unlikely to change. 

What type of mould do I need?

Choosing the right mould will depend on what you’re manufacturing, how many parts you need and how quickly you need them.

To make the best decision for your project and your business, it’s worth looking at the bigger picture. Ask yourself the following questions to help narrow things down.

How many parts do you need? If you’re producing thousands of parts, speed and efficiency will matter more. If you’re only making a few hundred or still in development, flexibility might be the priority.

Are your parts identical or different? If you’re producing one part repeatedly in high volumes, a multi-cavity mould may meet your needs. If you’re producing several different parts in batches, a family mould is likely better suited. 

Will the part design change? If you plan to enhance your parts in the future or bring out model variants, it may be more cost effective to use a single cavity tool. You can test and refine the design without committing to a full production setup. 

How precise do the parts need to be? Some industries, like medical or XX, have strict quality control standards. In those cases, a single cavity mould is often the most reliable choice. 

What are your long term plans?

If you’re testing the waters now but expect to scale up later, we can help you plan for that by starting with a flexible solution and adapting it when the time is right.

Once we have a stronger understanding of your goals, we can help you choose the best mould to suit them. Here’s a simplified guide to get you thinking.

Choosing the right mould with Bowles & Walker

The right mould makes a significant difference to cost, quality and turnaround time. At Bowles & Walker, we’ve helped businesses of all sizes, from early stage prototypes to large scale production. 

We’ll always give honest advice. If modifying an existing tool is the most cost effective option, we’ll say so. If a multi-cavity mould will save you money in the long term, we’ll help you build it. 

Give us a call on 01953 885294 or email info@bowles-walker.com to chat through your project today.

The post Single Cavity vs Multi-Cavity Injection Moulding appeared first on Bowles & Walker.

In this post, we’ll explain the process of injection moulding, common materials used and which industries rely on this manufacturing method.

How does it work?

The injection moulding process consists of 5 key steps. Here’s a more detailed breakdown of how it works.

• 1. Loading and melting: Plastic granules are placed into a hopper, then a heating chamber, where they are melted into a liquid using heat and friction. 
• 2. Injection: Once the plastic has fully transformed into a liquid, it is fed through a nozzle into a closed mould cavity, where pressure is applied. 
• 3. Cooling: The mould is cooled, and as the plastic inside hardens, it takes on the shape of the mould.
• 4. Ejection: Once fully cooled, the finished part is ejected. 
• 5. Cycle repetition: The process is repeated to produce as many parts as necessary.

Plastic injection moulding allows for large scale production without compromising on precision and efficiency. It’s a versatile method that can be used to produce a range of different shapes and sizes for plastic components, making it useful for a variety of industries.

What is it used for?

Plastic injection moulding is used across many industries to produce large quantities of identical parts from a single mould. It is a versatile and efficient manufacturing method for mass production.

Here are a few examples of the key industries that commonly use plastic injection moulding.

Automotive: Injection moulding is used to produce lightweight and durable parts such as headlight surrounds, door handles, and dashboard panels. It is ideal for the automotive industry because it is highly precise and can produce the complex shapes needed for specific parts. 

Medical: Precision and durability are essential in the medical industry. Injection moulding is ideal for creating products such as syringes, medical vials, and microplates. The process ensures that each product is consistent so that they are reliable in medical applications. 

Consumer goods: Toys, containers, and household items are all a common end product of injection moulding. This is because it has the ability to produce large quantities with detailed designs. This is well suited for the consumer goods industry as it is affordable to mass produce with an efficient turnaround time (dependent on the manufacturer).

Fire and safety: Injection moulding is a common method to produce nozzle guards and handles in the fire safety industry. It can produce strong, durable components that withstand high-impact and harsh conditions. 

Construction: The construction industry needs sturdy components for electronics, fasteners and connectors. Plastic moulding is ideal for producing large quantities of precise parts that can withstand environmental conditions.

Aquatics: Filters for fish tanks and water treatment systems can also be produced using injection moulding. The process ensures precision and sophistication for the complex component designs used in water filtration systems. 

What are the advantages of injection moulding?

Injection moulding offers many benefits that make it the preferred manufacturing choice for many businesses. 

• Cost-effective: After a mould tool has been made, the process of injection moulding becomes a highly economical method for large scale production. As production volume increases, the cost per unit will decrease, making it ideal for mass production of identical components. This makes it a suitable choice for businesses that are aiming to scale up their production while controlling costs,
• Design complexity: Plastic moulding can produce highly detailed and complex parts that would be difficult to achieve with other manufacturing processes. Features such as undercuts, threads and thin walls can be integrated into a single part, avoiding the need for multiple assembly steps or additional machining.
• Consistency: Automated systems and high-precision equipment ensures tight control and high quality standards, ensuring each part is produced identically. This is essential for industries where uniformity is crucial, such as medical and automotive parts manufacturing.
• Efficiency: Once tooling is complete and the process is fine-tuned, injection moulding can run consistently with minimal human intervention. It can produce thousands of parts per hour with very low waste and energy. The end result is fast turnaround times and a lower environmental impact compared to other manufacturing techniques. 

What are the disadvantages of injection moulding?

While injection moulding is a popular and efficient manufacturing method, there are a few important considerations to bear in mind when deciding if it’s the right fit for your project.

• Initial setup costs: There is a high upfront initial investment when producing a mould tool. They are often custom made and require precise engineering. However, consider that this is a one-time investment, and your mould tool can be modified in line with changes to your component.
• Production quantity: Injection moulding is best suited to high volume-production. It’s important to consider the number of parts you require as projects with very low quantities may be better suited to other methods such as 3D printing or CNC machining.

What materials are used in plastic injection moulding?

Many different plastic materials can be used in injection moulding, each with their own set of unique properties and applications. Here are some of the most common ones:

• Polypropylene (PP): A cost-effective, versatile material that has good chemical and heat resistance. It has a range of applications, from heat proof food containers, to car parts and medical equipment. It’s worth considering that polypropylene would not be suitable for a component that is exposed to the sun due to poor UV resistance, and can scratch easily. 

• Acrylonitrile Butadiene Styrene (ABS): A very rigid, impact resistant plastic with a smooth surface finish and strong chemical resistance. It is commonly used to create products like LEGO blocks, keys for a keyboard, and automotive parts. However, it also has poor UV resistance, isn’t biodegradable and can emit fumes when in a molten state. 

• Polycarbonate (PC): A strong, tough and transparent plastic, making it a great material to use for electronic and automotive parts. It generally has a higher price point due to its durability, however might not be the best choice for use with solvents and hot water.

• High Impact Polystyrene (HIPS): Derived from standard polystyrene, is a material that is modified for high impact resistance. It’s typically used for a range of domestic and commercial applications such as packaging or appliance housings, but may become weak, flakey or brittle with prolonged outdoor use.

• Low Density Polyethylene (LDPE) and High Density Polyethylene (HDPE): LDPE is chemically resistant and flexible, a popular material used in trays, containers, plugs and pipes. HDPE has more strength and rigidity, often used in bottles, hard containers and outdoor furniture. Both have a high resistance to moisture, but may weaken under UV light without treatment.

• Nylon or Polyamide (PA): A common engineering plastic with excellent high temperature performance alongside resistance to wear and chemicals. Nylon is best applied to electrical components and automotive parts and shouldn’t be used in low temperatures as it may become brittle in the cold.

• Polymethyl Methacrylate (PMMA):  known for its clarity and resistance to UV, ideal for vehicle lights and safety glass and acrylic products. However it is prone to stress-cracking, meaning it wouldn’t be the best choice for high-impact applications.

Injection moulding at Bowles & Walker

Choosing the right injection moulder is crucial for your project’s success. Here at Bowles & Walker, we’re all about delivering high quality parts efficiently and consistently. We’re also on a mission to become as sustainable as possible and reduce our carbon footprint. We’ve already implemented a range of sustainable practices, including using recycled plastic materials and renewable energy sources, like wind and solar power.

If you’re looking for a reliable, environmentally friendly, UK-based injection moulder, look no further. Whether you have a new project or looking for a new manufacturer, reach out to us today by either filling out our contact form below or calling 01953885294. Let’s mould success together!

The post What is Plastic Injection Moulding? appeared first on Bowles & Walker.

Both injection moulding and 3D printing are used in the plastic manufacturing process but can differ greatly when it comes to application and production time. In this post, we’ll explore the strengths and limitations of each method to help you make an informed decision for your next production project.

What is 3D printing?

Also known as ‘additive manufacturing’, 3D printing generally involves layering thin strands of material to gradually build up a final product. It has gained popularity over the last few years due to its versatility, prototyping capabilities, and uses for low-volume production.

Key advantages of 3D printing

3D printing has a wide range of benefits for smaller-scale production projects, or experimenting with prototype parts.

Quick prototypes

3D printing is well-known for its ability to produce prototypes quickly. This not only helps to speed up the product development process but can make it easier to carry out design tweaks and changes along the way that are not always apparent on a computer screen. By using a 3D printer, you can make design adjustments quickly and without incurring steep costs.

Low-volume production

3D printing can sometimes be a more cost-effective option than injection moulding if you’re looking at small-scale production (less than a thousand parts). Since there is no need for expensive moulds or tooling, businesses can manufacture niche or customised products without a significant upfront investment.

Customisation and flexibility

One of the biggest advantages of 3D printing is the ability to create customised designs. This makes it ideal for prototyping, bespoke manufacturing and industries that require frequent design adjustments.

Limitations of 3D printing

Whilst there are some great advantages to 3D printing, it can sometimes lack the versatility and scope for larger scale manufacturing.

Speed 

3D printing is often slower than other methods for production runs, especially for large or complex parts, but it is certainly faster when there are no pre-existing mould tools available.

Material limitations 

The range of available materials is more limited than injection moulding, and some printed parts may lack the strength and durability of moulded components.

Long-term cost 

The per-unit cost remains relatively high compared to injection moulding, making it expensive for scaling up production.

Surface finish

Printed parts may have visible layer lines and require post-processing for a smoother appearance.

Energy consumption

Some 3D printing processes require significant energy, which can impact sustainability.

What is injection moulding?

Plastic injection moulding is a traditional manufacturing technique that involves injecting molten plastic into a mould cavity. The plastic hardens into the desired shape once cooled. This process is often used for mass production due to its efficiency, consistent results, and cost-effectiveness for large runs.

Key advantages of injection moulding

Although injection moulding is the less modern technique of the two, it is a reliable, versatile method with plenty of applications.

High-speed, high-volume production

Injection moulding is the preferred method for mass production. It allows businesses to create thousands, millions or more of identical parts with brilliant precision in a short timeframe. Automotive, medical and consumer goods industries rely on this process to meet demanding projects with rapid timeframes.

Cost efficiency in larger batches

While initial investment and setup costs for moulds and tooling can be large, injection moulding becomes greatly economical for production runs. The per-unit cost significantly decreases as production volume increases, making it the most cost-effective option for in-demand products.

Superior surface finish and precision

Unlike 3D printing, which can leave visible layer lines, injection moulding delivers products with a smooth, polished finish. It also ensures a strong level of accuracy, which is crucial for components that require tight tolerances.

Recyclable materials

Many of the plastics used in injection moulding are recyclable, making it a more environmentally friendly option for businesses looking to reduce waste.

Long-term return on investment

Although the upfront investment in moulds can be high, injection moulding is a more cost-effective solution over time for businesses that require large production volumes. The low per-unit cost and production speed make it the superior choice for large-scale manufacturing projects.

Limitations of injection moulding

Plastic injection moulding is a reliable technique and delivers a high quality end product, but can come with it’s own stumbling blocks:

Significant upfront costs

The upfront investment in moulds and tooling can be expensive, making it less suitable for small-batch production.

Not ideal for prototyping

Injection moulding is not the most efficient method for creating early-stage prototypes due to the costs associated with tooling.

Injection moulding or 3D printing?

Both injection moulding and 3D printing have their strengths, and the right choice depends on your project’s requirements. If you require rapid prototyping, small-batch production, or highly customised products, 3D printing is a great option. However, if you need large-scale production, cost efficiency, and great quality, durable parts, injection moulding is the ideal choice.

At Bowles & Walker, we specialise in both injection moulding and 3D printing, providing tailored solutions to meet your unique requirements. Whether you need prototypes, low-volume production, or mass manufacturing, we have the expertise and technology to deliver.

Contact us today at 01953 885294 or email info@bowles-walker.com to discuss your project needs.

The post What is the difference between 3D printing and plastic injection moulding? appeared first on Bowles & Walker.

We consider how intricate your product is, the type of material you’re looking for, the production quantity, and how easy or difficult it is to estimate a price for you. In this post, we’ve outlined what could influence the cost of production for you and what decisions you can make to cut costs in the long run.

Toolmaking

If you’re starting your manufacturing process completely from scratch, one of the first steps in your journey will be to get a mould tool produced. This tool sets the foundation for your manufacturing process, as the quality of your mould will have a direct impact on the quality of your finished product. 

If required, Bowles and Walker can produce mould tools in-house. We’ll collaborate with you and advise on making a durable, reliable tool that can produce quality plastic parts. Prototyping with your new mould is also essential for identifying any flaws in your parts before bringing them into mainstream production. 

It’s a wise decision to invest in designing and producing your own mould tool, as it will provide you with high-quality parts and greater control over your production process. 

With a tool that is built specifically for your product, it will be highly accurate and precise. It may come with an initial upfront cost but will make the price of production significantly lower, helping your manufacturing process remain cost-effective. The tool can also be adjusted or modified to suit reasonable product design changes that you may need in the future, and if you decide to change manufacturer, you have a tool to bring with you so that your transition across suppliers is seamless. 

Factors That Affect the Mould Tool Cost

As we’ve mentioned, it can sometimes be hard to gauge a price for mould tooling until your manufacturer knows the scope of your project.

It needs to be designed and built in a suitable material, such as steel. Depending on the complexity of your product, it may also undergo processes such as milling, grinding, hardening, spark eroding or wire-eroding to achieve the finish you desire. 

The three main factors that influence cost are production quantity, the product’s shape, and the product’s size. Let’s talk about them in more detail.

Product quantity

Whether it’s a small batch of a few hundred or a large-scale production of thousands, the cost for tooling can vary greatly. For small quantity production, a single impression tool is usually optimal. This is the easiest style of tooling to create and production time is normally not too long.

For larger quantities, it is more cost-effective to have tooling with dual or multiple impressions. This allows more production in a shorter space of time. However, this can increase costs as more impressions and cavities require more material and time to create the tool.

Product shape

If the shape of your product is quite intricate, specialised tooling may be required which could add to the overall cost. Things like sliding cores, complicated shut-offs or undercuts may be necessary for complex designs. On the flip side, if your product has a simpler design, you might be able to skip these extra costs altogether!

Product size

Simply put, the bigger the product, the more steel is needed to produce a mould tool and the higher the cost. Larger items might also need more durable metal to ensure longevity and in the long run will also need more plastic material for production.

Part production

Once you’ve had your mould tool produced, or if you already own one, it’s time to think about the costs of part production. 

This is likely to be influenced by the quantity of parts you need and the tool parameters. 

How much does it cost to produce a part?

The cost of each plastic part will be impacted by production quantity, part size and material, and the cycle time on the moulding machine. Quality checks and secondary operations after moulding also need to be considered.

Quantity

In plastic injection moulding, the quantity of parts required has a direct impact on the overall cost-effectiveness of your production. Generally, production volumes lead to lower costs per unit.

This is because high-volume production is often more automated, reducing labour costs and increasing cycle time efficiency. Buying raw plastic materials in bulk also leads to cost savings. 

See below a visual of the direct link between the quantity of units produced and the cost per unit.

Summary: The higher the quantity of parts produced, the lower the cost per unit.

Material

It is typically a lot cheaper to use standard materials or additives that the moulder already carries compared to a material that has to be sourced out-of-house. This is the same for the material that colours the plastic, known as ‘master batch’. If the masterbatch is a standard off-the-shelf colour, it will most likely be cheaper than a bespoke shade that needs to be specially ordered.

Summary: Consider ‘off-the-shelf’/standard materials and plastic dyes to keep costs down. 

Product Size

When a product is on the larger side, the tooling will also be quite large, which calls for a larger mould machine to handle it. This can increase the cost compared to a small single impression tool, as it leads to higher operating costs and occasionally longer drying times for each part. 

Summary: Expect higher day-to-day production costs for larger units.

Cycle Time

The longer the cycle time, the longer the production run time. This uses more mould machine capacity and can increase the cost.

Summary: The more complex the parts, the higher the production costs will be.

Some realistic scenarios

Here are a few example scenarios, looking at actual costs in pounds and pence:

Example 1: Large quantity, simple parts

A customer already has a mould and needs 100,000 pieces of ‘Product W’ – a plastic ring similar to a doughnut.

• Size: 8.5cm outer diameter, 3.7cm inner diameter, 1cm height
• Material: Standard polypropylene (a common plastic)
• Mould Type: A 4-cavity mould (which means it makes 4 pieces at a time)
• Weight: Each piece weighs 12 grams
• Machine Used: 50-tonne injection moulding machine
• Production Speed: Each cycle (the time to make 4 pieces) takes 15 seconds

Estimated cost: £6.70 per 100 pieces 

We can see here that making large quantities is cost-effective, as the mould can quickly produce multiple parts at once. 

Example 2: Small quantity, simple parts

A customer needs 5,000 pieces of ‘Product X’, but they don’t have a mould yet.

• Shape: A simple plastic box
• Size: 150mm x 210mm x 100mm (fairly large)
• Material: ABS plastic (a strong, durable plastic)
• Weight: 298 grams per piece
• Mould tooling:
  • Since the product is large, the mould needs a lot of metal, making it more expensive
  • Estimated mould cost: £8,000–£10,000 (one-time investment)
• Production process:
  • Made using a 160-tonne injection moulding machine
  • Each cycle (time to make one box) takes 50 seconds

Estimated cost per box: £1.73 

This example shows that low-quantity production is more expensive per unit because the mould cost is high, and fewer parts are made to spread that cost over.

Example 3: Small quantity, complex moulding

A customer needs 1,000 pieces of ‘Product Y’ and already has a mould.

• Material: Nylon 6 (a strong, durable plastic)
• Weight: 89 grams per piece
• Mould type: Single-cavity mould (makes one piece at a time)
• Production process:
  • Requires insert loading (a manual step before moulding)
  • Uses a 100-tonne injection moulding machine
  • Each cycle (time to make one part) takes 75 seconds
  • Extra step: After moulding, a second operation is needed to remove the insert

Estimated cost per part: £2.04 

This example shows that complex moulding with manual steps increases production time and cost, especially for low quantities.

Example 4: High quantity, complex moulding

A customer needs 75,000 pieces of ‘Product Z’ but doesn’t have a mould yet.

• Shape: A 70mm long, 10mm wide plastic cylinder with detailed external features and an internal shoulder
• Material: ABS plastic (standard purple colour).
• Weight: 5 grams per piece
• Mould tooling:
  • Needs slides and a stripper plate for proper ejection
  • Uses a 4-cavity mould (makes 4 pieces at a time for efficiency)
  • Estimated mould cost: £12,500 (one-time investment)
• Production process:
  • Runs on a 50-tonne injection moulding machine
  • Each cycle (time to make 4 parts) takes 40 seconds

Estimated cost per 100 parts: £11.50

This example shows that complex moulds increase tooling costs, but high quantities make production more cost-effective per part.

How we can help

The general rule of thumb for keeping manufacturing costs low is to keep the product design as simple as possible, order high volumes, and keep things like colouring and additives standard rather than bespoke. 

At Bowles & Walker, we provide support from design through to production, building great working relationships with our customers. When you request a quote from us, we take time to carefully calculate it to ensure it’s as precise as can be. We’re always happy to make recommendations on how you can make your production process more cost-effective. 

For more information about our services, please call us on 01953 885294 or email info@bowles-walker.com. We would be happy to work with you on your journey to create products, reduce costs and support UK manufacturers.

The post What Is the Cost of Plastic Injection Moulding? appeared first on Bowles & Walker.