Structural bonding of carbon: the Movingfluid plant

In this article:

• • • • The two-component glue: a potential problem
      • A robotic gluing and curing island that avoids wasting material and money 
      • 2020 to date: a system that is still up-to-date and constantly being perfected 
      • “The glue guys”: once you find us, you can never let go

Structural bonding of carbon automotive components: you never forget your first time 

This is a story of firsts. It is the autumn of 2020 and the first time that one of the most prestigious car manufacturers in the world decides to introduce carbon for its chassis components. 

To connect the various parts of the body together, it necessarily needs two elements: a special and very expensive two-component glue and an automatic system that delivers it with extreme precision, otherwise it will be rejected by the internal quality department and the consequent loss of money. 

Movingfluid specialises in fluid movement (our very name says so!), but has never treated carbon parts, nor that particular type of glue. Yet the company immediately contacted us to produce the first prototype for the structural bonding system of the new components. 

And now we will tell you how it went, because this is not just a story of firsts, it is also a success story. 

The two-component glue: a potential problem

Apart from screws, nuts, bolts, rivets and other mechanical elements, the only way to structurally assemble the parts that make up the carbon cab is with two-component glue.  

Too bad, however, that it is a special glue, with a very high price: about 15/20 thousand euro per 200 litres). In addition, it must be applied according to a catalysis ratio of 50% (with a maximum tolerance of 5%): this parameter is essential to ensure durability and adequate technical performance, avoiding costly wastage. In fact, once dispensed, the glue can no longer be recovered, nor the incorrectly glued part, which immediately becomes waste. All wasted time and money, and with the plant at a standstill: a catastrophic scenario.  

But instead of wringing their hands, our Problemsolvers put their hands to work to prevent all possible mishaps and design the first automatic bonding and curing system for carbon structures: comprehensive, reliable and flexible.

A robotic gluing and curing island that avoids wasting material and money

The request was to deal specifically with all the steps involved in fluid movement: withdrawal from supply drums; pumping; dosage; supplying the dispensing guns. We were also responsible for the curing system; for robotics on the other hand, Movingfluid partnered with another supplier for the duration of the project.

The solution created by Movingfluid consists of an automatic island with three complete gluing and curing stations that enables continuous cyclic production. Each station is in fact equipped with: 

– 24 IR lamps;

– for a total of 67.4 kW of electrical power (a standard residential flat requires 3 kW of power!); 

– 7 temperature sensors for control during curing; 

– 22 temperature sensors to monitor and change the glue temperature.  

The 3 gluing and curing stations are placed side by side in line and a rail-mounted robot moves the individual components between stations. The result? Extremely accurate and controlled management at every step.     

Always perfect dosage thanks to precision sensor technology

Getting the catalysis ratio of glue and hardener wrong means degrading the quality characteristics of the body, leading to unacceptable rejects and losses: it is therefore necessary that the dosage of the two components always be perfect. 

For this we have installed a series of sensors that constantly monitor the quantities fed into the plant (from the withdrawal batch to mixing in the gun tip) and verify that the delivery is always on target. If the recorded value falls outside the tolerance limits, an alarm is triggered which immediately blocks the system, minimising waste.  

Heated system to maintain optimal conditions

Temperature is another essential element: for the drying properties to be unaffected, it must always remain between 25-26°C: a condition we were able to achieve by heating the entire system including the drums and all the pipes up to the dispensing gun. 

From a control panel, the various components of the system can be switched on or off to regulate the temperature and keep it constant. These operations are especially essential when there are seasonal temperature variations, such as the arrival of winter frost or scorching heat in summer, which could alter the stability of the fluid, deteriorating its quality.

Ovens with IR lamps for fast and punctual curing

For glue curing, on the other hand, we chose infrared technology which makes it possible to reduce the drying time enormously (from 24 hours of the classic systems to only 90 minutes!) and to heat only the necessary parts, without unnecessary dispersion. 

Precise and fast, IR ovens are one of the best performing solutions introduced by Movingfluid in the automotive sector with numerous applications, from curing glue to industrial paints. 

The curing program is automatic and maintains a constant temperature of 80-90°C. While lamps are indispensable for the outside, the inside of the carbon frame required a different, specially designed system, which uses heating membranes (heating elements) placed on an aluminium subframe to heat the part. 

2020 to date: a system that is still up-to-date and constantly being perfected

Design, building and testing directly at the company’s factory took about 12 months of work: since 2021 the automatic island has been in operation and in recent years we have carried out further honing.

In 2022, we added more IR lamps than the initial supply to optimise carbon curing, arriving at the number we still have today.

A couple of years later, however, we added a recirculation system inside the plant that allows glue to be moved even when production is stopped (e.g. weekends). In fact, glue degrades when it stands still for a long time, but thanks to this solution, constant quality and temperature are ensured: this also reduces the need for flushing out.

Speaking of quality and temperature, a trend function was also added to the management software at the same time, which generates a CSV file with all the data on the bonding values of each individual processed batch. This data is essential for traceability and to be able to easily trace the production history of each individual car.

More recently, however, we have been faced with the need to recalibrate the system following a product upgrade. The glue supplier changed the hardener formula and this required the support of our technicians to calibrate the entire system to the physical characteristics of the new substance. This operation was carried out in one weekend: our team was also present during the start-up of the cycle on the first Monday morning shift to check that everything was running to the expected quality standards.  

Impeccable service at all times

In addition to the enhancements and improvements described above, we also offer comprehensive support for all routine checks and troubleshooting that may occur during production.

Preventive maintenance in fact allows us to avoid end of life of the components, while the remote service guarantees efficiency and speed of action in every situation.

“The glue guys”: once you find us, you can never let go

After years of collaboration with the company and its partners, we have become ‘the glue guys’: a label we carry with some pride because it confirms our unique expertise. 

So, what is the moral of the story? That it doesn’t matter whether it is the first or the hundredth time you are facing a challenge: if things are done well from the beginning, they work and last over time, adapting to the needs of the reality they were developed for. 

This generates a number of advantages: first of all, significant savings that can make a difference in the long run. Now that six years have passed since commissioning (a very long time for an industrial plant) the island is working at full capacity, with zero rejects, and is able to adapt smoothly to market and company changes. 

This is how we like to work: turning challenges into opportunities for growth.   

You want to do it too? Let’s talk: it could be our first success story together (and, almost certainly, not the last!)

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