Bridgestone is commemorating the 50 year anniversary of its Bulldog retread factory in Bourne, Lincolnshire, with a multi-million pound investment to mark the beginning of an exciting new chapter in the site’s history. The Manufacturer Editor Joe Bush, paid a visit.
Beginning life as Bulldog Remoulds in 1974, the company began working closely with Bridgestone in the 1990s as the latter began developing its business in the UK and recognised the need to offer a complete package of new tyres, retreads and service. This culminated in 2005 when Bridgestone bought the entirety of the Bulldog company.
What followed, four years later, was the subsequent acquisition of Bandag, an American company and world leaders in retread tyres. Bridgestone had become more interested in this side of the commercial tyre business, and had developed an understanding of the importance of retreads from a sustainability perspective.
Bandag Retreads extend the wear life and performance of premium tyres, delivering near-new tyre performance while lowering the total tyre cost per kilometre for fleet owners and managers. Retread tyres use less than one-third of the amount of raw materials used in new tyres and enable the reuse of other tyre components, such as the casing. The retreading solution significantly contributes to the reduction of discarded tyres as well as the reduction of waste in communities.
In more recent times the company has launched Project Mercury, which involved a closer look at the business, both internally and within the market, and at customer demand. “We reviewed the overall business and we felt that retreading would only increase in importance in the future as people become more invested in the ideas of sustainability and recycling,” said Dan Edwards, Plant Manager at the Bourne factory.
Therefore, the company looked at how it could become as efficient and effective as possible. And, while the Bulldog factory had traditionally been involved in both retreading processes – hot cure and precure (more on that later), in the UK, the market share leaned more towards the hot cure market.
As such, the company began to look at developing its offerings to meet customer demand, and so there has been significant investment in putting the correct equipment in place to develop the company’s hot offering. “In addition, in order to get the best value to customers, we’ve been making sure that our hot products match as closely as possible with the latest generation of Bridgestone new tyre products,” Dan added.
Over the last three to four years, the company has been busy turning that vision into reality; investing heavily in the Bulldog factory to allow Bridgestone to ramp up production of hot cure retreads, which will grow market share accordingly. And, with the extension of its hot retreading portfolio, Bridgestone is offering its fleet customers an extended range of premium retreading solutions.
Investment
To achieve the goal of evolving its retread product offering, the company first had to turn its attention to infrastructure and factory layout. With an ethos of reuse and recycle, an extension to the factory has been created to house existing autoclaves and associated equipment, plus a disused mezzanine has been repurposed as a storage area.
“As well as preaching the sustainability message, we’ve tried to practice it as well, Dan added. “Even though we’ve invested in development, we’re also looking to reuse where we can.”
In terms of equipment, the company has invested in two new Bandag developed buffing machines which are more energy efficient than their predecessors, using a slightly smaller motor to achieve the same finish. Bridgestone estimates a 25% energy reduction versus its previous generation buffing machine. A ten per cent improvement in cycle time has also helped increase productivity.
The key advantage of these machines is that they are integrated into the company’s digital systems. All the tyres that go through production carry a barcode and when scanned, the operator can establish the type of tyre and the level of specifications that need to be applied. “In the past an operator had to work that out and feed in specifications manually – now it’s all automated,” continued Dan.
Eight new hot cure presses have also been deployed in the factory, which are more thermally efficient than the previous generation of presses, generating a 15% energy saving. Dan added: “One side benefit is that, because the new presses are more thermally efficient, it’s more pleasant for the operators to be working near these machines.”
However, the jewel in the crown of Bridgestone’s new equipment deployment is its latest generation TRM Black Dragon hot cure building machine, which performs the action of putting the rubber onto the tyres that are being remanufactured. Again, there is a 20% cycle time improvement, a ten per cent energy reduction and employee handling is kept to a minimum as operations that were previously performed by hand have now been automated.
Finally, the Basys digital system, developed by the Bandag part of the organisation, fully tracks every single tyre from the point at which it has arrived with the service provider all the way through the relevant remanufacturing processes, to the point at which it goes back out for retread delivery. “It’s a cornerstone of how we’re automating and digitalising our operations,” added Dan.
Under the new ‘Bandag Hotread’ name, Bridgestone’s retread solutions will become some of the most advanced in the UK, featuring 17 new products being manufactured from the Bulldog plant.
The investment offers significant environmental and sustainability benefits, with retread tyres offering economical value for commercial fleets along with a massive reduction in the use of raw materials. Typically, a retread tyre uses 70% less oil in its production compared to a new product, along with 80% less CO2 emissions in the manufacturing process.
In 2022 alone, Bridgestone’s Bulldog factory recycled 520 tonnes of rubber dust and 4,400 tonnes of scrap tyres. This equated to savings of four million litres of oil, 2,000 tonnes of rubber, 900 tonnes of steel and close to 4,000 tonnes of saved CO2 emissions versus equivalent production of new tyres.
The E8 commitment
The recent investment in the Bulldog facility in Bourne is intrinsically connected with Bridgestone’s wider E8 Commitment. This corporate vision, launched a few years ago, is the company’s North Star and heavily weighted on the principles of sustainability, society, ecology and economy.
Andrea Manenti, Bridgestone’s North Region Vice President, continued: “We want the whole company to aspire to this in anything we do in terms of initiatives and investment we embark on. In many ways, Bulldog is a perfect embodiment of the E8.
“Take energy and ecology, for example. We’ve demonstrated a fantastic way to reuse carcasses (casings) from tyres to extend material life instead of throwing them away. Like many companies, we have an objective to achieve 100% carbon neutrality by 2050, and this is something that we’re committed to. The circular economy embodies what is happening at Bulldog.”
The Bridgestone E8 commitment provides a set of eight focus areas that guide strategic priorities, actions and decision making towards the achievement of the company’s vision and ensures that business is always done in a sustainable way.
- Energy and Ecology: Bridgestone has clear environmental targets – to achieve carbon neutrality, work with 100% sustainable materials and operate in better balance with nature by 2050.
- Emotion and Empowerment: Sustainability is about people as well as planet; that starts with the company’s own people and the communities in which it operates.
- Extension and Ease: Bridgestone want to achieve smarter and safer mobility and are continuously innovating to make nonstop mobility and operations possible.
- Efficiency and Economy: The company acknowledge the importance of safeguarding a sustainable business and are committed to improving productivity and customer value.
The benefits of retread
So, what exactly is retreading? Retreading is a re-manufacturing process for tyres that replaces the worn out tread of a used tyre and places it back into the market. All Bridgestone TBR tyres are designed to be suitable for retreading.
With sustainability and Scope 1, 2 and 3 emissions being of increasing importance to commercial fleets, it’s hardly surprising that 80% of all civil airlines and 70% of all supermarket delivery lorries are now fitted with retread tyres. In addition, retreads are now fitted to around 25,000 UK buses.
- Retreads use one-third of the raw materials required to manufacture new tyres. •
- Quality retreads are produced with just 30% of the oil required to manufacture new tyres.
- It takes a fraction of the energy to produce quality retreads in comparison to new tyres – up to 80% less CO2 and other carbon emissions.
- Reusing the worn casing as the main retread component allows a saving of up to 70 litres of oil, 32kg of rubber and 14kg of steel.
“It’s critical that we keep reminding ourselves of the benefits of retread tyres,” said Michael Howling, Service Operations Business Partner for Bridgestone and in charge of retreads for the North Region, UK and Ireland. “And this is the message we drive home to our customers. It’s surprising how many fleet operators across the UK still focus on price sensitive, cheaper budget tyres, rather than looking into retread options.”
However, Michael went on to explain that inevitably the market will migrate towards more sustainable solutions, and therefore the retread market will ultimately replace budget alternatives. Indeed, he added that it is already becoming more critical in the decision making process when awarding top contracts.
“We’re seeing more and more tender contracts coming to us that are firmly looking at the environmental angle,” he added. “Unless you pass certain sustainability criteria, you won’t even get into the tender process, and that wasn’t the case ten years ago.
“A key factor for us is that our tyres are made to be retreaded from the outset. We’ve seen an increase in the number of customers who are genuinely asking about retreads from the point of view of the lifecycle of the product, the impact on society and CO2. This is now measurable and important to customers, as they need to be able to justify their decisions. These are companies that would not normally have looked at retread products from a commercial perspective.”
The retread tyre market has faced stiff competition from the influx of budget tyres from Asia, which are set at a similar price point. This has proven to be a challenge for Bridgestone but is one of the key reasons the Bourne facility has seen such investment.
The EU has taken steps to combat the alleged dumping of cheap tyres from the Far East into the European market and there is more legislation to come. For example, the new Deforestation Regulation will come into force in Europe from 1 December and requires companies trading in a number of raw materials, including rubber, to conduct extensive diligence on the value chain to ensure the goods do not result from recent deforestation.
This would basically enforce the full tracking and tracing at GPS level of anything that contains raw material from forests, something which will have a huge impact on the tyre industry. Eventually, every tyre that enters the European community will have to carry traceability and proof that the rubber has not come from an area which is protected against deforestation.
“It should be said that there has been great progress in the budget market and they certainly have their place,” Andrea added. “However, there’s still plenty of uncontrolled products which are difficult to track and trace in terms of materials used and how they’re produced.
“We need to increase the level of awareness and education of end users and industry operators, as often there is not the right level of understanding around the production, performance or safety of tyres. They carry lives – and a difference of a few metres of breaking distance could be the difference between life and death.”
The production process
To manufacture a retread tyre, the Bulldog facility first requires the used, worn tyre as a starting point, commonly referred to as a casing. Through its fleet customers, Bridgestone generates around 200,000 of these per year within the UK.
A partner company handles the logistics of collecting the casings from the service providers – the organisations that remove the tyres from the wheels. It’s a process that’s fully controlled by the Bulldog facility and there are regular collections and inspections so that quality standards are met.
As mentioned previously, Bridgestone designs and manufactures tyres to be retreaded, so they are engineered to last through more than one lifecycle on the road. Nevertheless, during that life in service, a tyre could suffer certain types of damage that would render it unsuitable for retreading in the future. Therefore, the Bulldog factory conducts a thorough inspection process on a spreading machine which opens the tyre up and allows the operator to see and feel for any bulges or separations that would potentially make a tyre unsuitable for another life in service.
Dan continued: “Because of the very nature of the company, Bridgestone makes up the vast majority of tyres we see come through for retreading. However, we are also able to process other manufacturers’ casings as well. So, when we win a new fleet contract, it may well be running on a competitor, so for that initial period we’ll have competitor casings coming into the factory.”
He explained that the goal is to get the best value from the casings the company get back. So, although the preference would obviously lean towards Bridgestone, using competitor brands in the retread process is better from a resource utilisation point of view. “We have that duty of care, so when we receive a batch of tyres from a customer’s fleet, we make sure we utilise as many of them as we can,” he added.
All the major tyre manufacturers have recognised the benefits of retreading and now have their own programmes. On the budget side of the market, however, tyres tend to be designed as a single life product. There’s currently no infrastructure or systems in place for recycling budget tyres; this remains very much the domain of the premium, well established brands that see the benefits of a full lifecycle package.
Once a tyre has been identified as being suitable for retreading by Bridgestone’s partners, they hold them in stock and are pulled into the Bulldog factory to suit production plans. This ties in with the company’s goals around resource efficiency and ensures that the tyres are only moved around when they are needed. When they come into the Bulldog factory, every tyre is subjected to a shearography quality check.
This performs a similar function to an x-ray machine, using a laser-based camera to detect any kind of abnormalities or distortions in the internal structure of the tyre which could indicate a weakness.
The first real step in the retreading process is called buffing (using the two new machines alluded to earlier), where any preexisting rubber is taken off the tyre. After this main removal of rubber, a skiving process investigates any localised damage within the tyre.
Following incredibly thorough inspection criteria the tyre will then go through secondary inspection and nail hole detection, followed by repairing, cementing and filling.
It was mentioned earlier that there are two different retread processes (hot cure and pre- or cold cure) and up until this point, all tyres are treated the same. The only difference with the hot cure process is that the rubber is taken off the side of the tyre at the buffing stage. Whereas, in the pre-cure process the original side of the tyre is left visible with only the rubber on the actual tread being replaced.
The two key ingredients in curing a tyre is temperature and pressure. Pressure during the hot cure process (which operates at around 155°C) is around 14 bar, and depending on the size of tyre and the amount of rubber used, takes between 60 and 90 minutes.
The pre-cure process operates at around 115°C but takes around four hours. In the past, Bridgestone has favoured the pre-cure method, constituting around 60% of production. However, the company’s new product introductions are focused very much on developing the hot cure offering.
In terms of the manufacturing process, pre-cure is so called because the tyre tread has already been previously cured into its tread pattern. Supplied on ten metre long roll, which will produce around three tyres, the right length for each particular tyre is cut from that roll.
The tyres are then put into both inner and outer envelopes for vacuuming. They will be placed in batches of up to 20 tyres into an autoclave, which is where the curing process takes place.
By comparison, the hot cure process is more akin to the production of a brand new tyre. Uncured rubber is placed on top of the casing that has been prepared; another area of significant investment for the company. This is called the strip wind process; the tyre is rotated and a strip of rubber is applied. It is computer controlled to ensure that exactly the right amount of rubber is used.
Formerly a manual process, new sidewall rubber is also added via computer controlled extrusion, directly onto the tyre. Once the tyre has been built, it is then ready for curing in one of eight new presses. The hot curing method cures one tyre at a time with the tread pattern added by mould segments that close in around the tyre. Regardless of the curing process, every tyre will then go through a final tactile and visual inspection where curing blemishes or any other issues which may have come to light through the production process can be identified. What follows is a rapid inflation pressure test to check the structure of the tyre.
“Because we are dealing with a recycled product, we have to test 100% of the tyres that we retread,” added Dan. “Currently, we produce more hot than cold cure – roughly 60% – but the UK market is closer to 75- 80%. So, our aspirations over the next few years, which is in line with our investment, is to grow our total percentage of hot cure – although our absolute volume of cold will remain the same.”
2024 will see the Bourne factory manufacture around 70,000 units, which will increase to around 100,000 over the next five years.
For more stories like this, visit our Digital Transformation channel.