The Maxion Wheels aluminium wheel manufacturing plant in South Africa was recently recognised as being one of the most technically advanced in the international group when senior executives, including Marcos Oliveira, President and CEO of Iochpe Maxion, Pieter Klinkers, CEO Maxion Wheels and Juan Lorenzo, President, Europe, Africa, Asia, visited the plant in Alrode, Gauteng to see the recent developments at the plant and to hold executive meetings.
Maxion Wheels is a division of Iochpe-Maxion S.A., a leading Brazilian company in the production of wheels and structural components for light and commercial vehicles. Maxion Wheels comprises 20 manufacturing plants in 12 countries on five continents.
Maxion Wheels and its subsidiaries have been supplying OEMs with wheels and innovative technologies for over 100 years. With an international network of strategically located engineering, technology and production facilities, Maxion is one of the few wheel manufacturers who can deliver on a global platform in the true sense. This allows the company to reduce logistical costs and eliminate duplicate processes.
Maxion Wheels South Africa’s business is all about manufacturing and supplying OEMs with aluminium wheels – some more complicated than others
Initial melting of ingot and scrap metal before degassing is done on two Striko tower furnaces before the metal is transferred to the individual low-pressure die-casting machines
A world leader in the light-weight wheel market, the company currently supplies aluminium passenger car wheels to every major automotive OEM in the world. Maxion Wheels produces cast aluminium wheels at multiple plants throughout the world with a high degree of styling flexibility and an endless selection of coatings, finishes or claddings.
The company produced more than 58 million wheels in 2018, had US $2.1 billion in sales in 2018, employs more than 10 000 employees around the world, and one out of every eight OEM wheels in the world is a Maxion wheel.
“This is the first time that the senior executives of Maxion Wheels have visited the plant in South Africa,” explained Milos Despotovic, Plant Manager for South Africa.
“We have been investing substantially in our plant, equipment, processes and people over the last four years. In 2016 we spent R60 million on a quality expansion programme, in 2017 and 2018 we spent R90 million on capacity expansion for the manufacture of 19” and 20” wheels and so far in 2019 we have spent R30 million on automation and equipment upgrades,” continued Despotovic.
“This included installing x-ray inspection upgrades, a new paint plant, upgrading equipment in both the foundry and machine shop, installing numerous robots to automate material handling and installing a conveyor system to eliminate as much as possible the human handling element.”
“As a result our flow lines within the plant, from melting of metal to casting in the foundry and then on to heat treatment, machining, painting and finally dispatch, have improved dramatically.”
There is also a third melting furnace, which melts shavings and chips from the machine shop once they have been degreased, dried and preheated. This shaving recovery or chip melting furnace is in the process of being replaced by a new Striko tilting furnace
Processed shavings and chips from the machine shop being melted
“Over and above this was the beginning of our programme with implementing Industry 4.0 and AI and our accelerated move towards becoming a smart factory.”
“The capacity expansion programme was two-fold. On the one side we extended our capacity to respond to the volume demand from the local OEMs while at the same time we took into account increased export requirements.”
Moving from 15/18” wheels to 15/20” wheels
“However, you can’t just judge it on production figures alone because there are many variables at play. Our expansion programme included moving from just manufacturing 15” to 18” wheel sizes to adding 19” and 20” wheel sizes. We now manufacture the biggest size wheels in the group and one of the most complicated, a factor that makes us stand out.”
“All through this expansion and upgrade programme we have not neglected our staff. Money has been spent on a brand-new canteen and they can now enjoy subsidised meals in a very pleasant environment, which they did not have before.”
Aluminium being transferred to a low-pressure die-casting machine holding furnace. Each low-pressure die-casting machine has its own holding furnace
A mould being pre-heated
“But it is not just about keeping the tummies full. Training and mentoring are a high priority in the company. This includes both local training and travelling abroad to our other group plants. Additionally, we are working on our own training academy that will be Merseta recognised.”
“We believe that we have to provide the tools and the environment that will attract the best, whether it is an operator on the floor or an engineer in the design department. A combination of this culture and our expansion programme has seen us having a stable and secure working environment.”
“This is despite all our automation investment, which includes the deployment of 80 robots across the manufacturing process.”
“The senior executives wanted to come and see for themselves what made our plant start to be recognised within the group. The Turkish plant has been winning most of the internal awards in recent years and now suddenly South Africa is up with them. We are very proud of this.”
NF Die Casting was founded in 1965 by the Anglo American group as a general-purpose non-ferrous foundry. The foundry focus was on aluminium production in high pressure, low-pressure, gravity and sand castings before the introduction of low-pressure die-casting for wheels in 1979 for the South African automotive OEM market. The first export of alloy wheels was for the E30 generation BMW 3 Series to BMW AG in November 1985.
Each low-pressure die-casting machine has its own Fanuc robot for material handling
Inside an aluminium wheel mould
A new wheel plant was constructed in 1990 and since 1992 has been linked to Hayes Lemmerz through a technology agreement. In 1998 Hayes Lemmerz acquired a 35% stake of NF Die Casting and upped this to 76% in February 2000 before acquiring the remaining 24% of the shares in May 2002. The company had previously been acquired by the Industrial Development Corporation of South Africa from Anglo American.
A name change – Hayes-Lemmerz South Africa – took place in 2004 before the Brazilian company Iochpe Maxion acquired Hayes-Lemmerz in 2014, forming Maxion Wheels. In 2016 the South African plant began its upgrading towards manufacturing 19” and 20” wheel production and the first of these wheels were delivered in 2018.
“There has been a worldwide trend towards OEMs using bigger wheels on their vehicles and we have had to respond to this trend.”
Aluminium alloy wheels manufacturing processes have developed a great deal since the 1970s. Due to sophisticated wheel design, casting has become the dominant manufacturing process. Alloy wheel material has evolved too. Car wheel alloys now contain 7 to 12% silicon content, and varying contents of magnesium in addition to aluminium, in order to meet the demand for metal mould casting properties, corrosion and fatigue resistance.
The aluminium alloy wheel usually has better heat conductivity, anti-corrosive properties and is much lighter than the steel wheel, making it the best option for passenger vehicles. Aluminium alloy wheels are manufactured using the casting and forging process. Less weight on the wheel creates less stress on the tyre, and so a balance is created. Aluminium and alloy wheels are largely corrosion-resistant, but prone to galvanic corrosion. They also enhance performance by manipulating handling and suspension and add a brilliant appearance to the vehicle.
Furthermore, high thermal conductivity of aluminium allows heat to dissipate faster and improves braking performance in highly demanding driving conditions that lead to over-heating related brake failures. Hence, wheels constitute nearly 15% of the average aluminium content in passenger cars and light trucks with aluminium wheels on approximately 50% of the vehicles produced today.
A general view of the foundry
Maxion Wheels South Africa have installed an extensive conveyor system to eliminate as much as possible the human handling element
Their main advantages, when compared to steel wheels are a high styling versatility, weight (equal or less than steel without styling), dimensional accuracy (mass distribution), recycling ability and static and dynamic behaviour.
At the heart of the manufacturing process at Maxion Wheels’ South African plant is its foundry, although the wheels that you see on your car today cannot exist without the other downstream operations and processes.
The foundry department is the biggest department within the South African subsidiary, which includes melting, degassing, low-pressure die-casting, x-ray inspection, sprue removal and heat treatment.
There are numerous low-pressure die-casting machines in the foundry, all of them with their own Fanuc robot for material handling and each having its own holding furnace.
New Striko furnace
Initial melting of ingot and scrap metal before degassing is done on two Striko tower furnaces before the metal is transferred to the individual low-pressure die-casting machines. There is also a third melting furnace, which melts shavings and chips from the machine shop once they have been degreased, dried and preheated.
In the machining department cells have been set up with three machines and a Fanuc robot to load and unload wheels
Plant Manager at Maxion Wheels South Africa Milos Despotovic
This shaving recovery or chip melting furnace is in the process of being replaced by a new Striko tilting furnace, which has a large holding capacity to accommodate the 2-ton an hour melting capacity. This new furnace is being supplied by Ceramic & Alloy Specialists.
Two of the power sources for the low-pressure die-casting machines are now fully Industry 4.0 compliant and are supplying data to DataProphet, a Cape Town-based machine learning company, for AI and machine learning analysis.
Processing after casting
After casting, wheels are 100% x-ray inspected and then eventually heat-treated prior to machining. This step is followed by a pressure tightness testing. After a cosmetic inspection wheels are then painted or varnished. This operation includes a pre-treatment (degreasing, phosphating and/or chroming). 3D dimensional controls, dynamic balance checking, bending and rim roll fatigue as well as impact tests are also usually performed.
“The wheel industry continues to evolve and has for many years. The main story had been the substitution of aluminium for steel in many applications. This continues to be the case, but in recent years lighter materials have been gaining, though limited to certain niches on account of cost and other factors. Reports estimate that the global wheel market was at US $81.7 billion in 2017, up from US $64 billion in 2012, and they anticipate a robust growth of 8.7% per year through to 2022, when the market will approach US $124 billion,” noted Despotovic.
For further details contact Maxion Wheels South Africa on TEL: 011 617 4700 or visit www.maxionwheels.com