“Granco Clark’s heating equipment is always in high demand, but that does not stop us from continually challenging our engineers to make product enhancements” Granco Clark

AL Circle: Why do you think Granco Clark’s aluminium extrusion equipment line is the best in the industry? 

Granco Clark: Granco Clark’s dedication to serving the aluminium extrusion industry may be unparalleled.  We proudly support our solutions throughout their entire lifecycle, which is intended to span decades.  Almost every product and service we deliver is “engineered to order” and manufactured custom for each project.   We start with the customer’s goals in mind, then apply the most modern engineering and manufacturing methods to ensure we meet their goals efficiently.  We prefer to collaborate in real-time with the customer to ensure their wants and needs are understood and met at every step of the process.  We manufacture and test our equipment fully in our Belding, MI, USA facility using only the highest quality components.  As a standard, installations of Granco Clark equipment are overseen by one of our highly qualified installation supervisors.

Plus, we also offer customers the option of “turn-key” installations, a benefit to those with already heavily burdened engineering and maintenance staff.  With the equipment installed, our “in-house” engineers – who fully design our equipment controls networks and programs – commission the equipment onsite and transition the solution into live production.  Granco Clark does not stop there.  We value our partnerships with our customers.  As such, our team of engineers, service technicians, and customer service agents continue to offer support in many forms.  These consist of remote support, onsite support, parts, equipment service, and upgrades.  24/7 support is always an option because we understand the value of press extrusion time.

 

AL Circle: Could you underline the desired temperature for aluminium billets to induce proper extrusion processes?

 

Granco Clark: Jumping ahead in the process slightly, what aluminium extruders desire is consistent extrusion temperatures at the exit of the press.

The key indicator of an extrusion process held in control is a stable press exit temperature.  Enough cannot be said about the importance of billet temperature and the process of heating in the context of aluminium extrusion.

Speaking specifically to the direct-acting press application, the first step in the aluminium extrusion process is rapid heating of the billet to an accurate and precise temperature in preparation for delivery to the press.  Rapid heating is paramount to ensure material properties achieved during billet homogenization (a process between casting and extrusion) are not lost.  Extruders seek heating billet accurately to ensure reliable and trustworthy processes.  Extruders seek precision heating because of the stringent process control required by the growing market share of automotive uses for aluminium extrusions and the development of advanced alloys.  For decades, Granco Clark’s Hot Jet SST Log/Billet Furnace has been the standard in the aluminium extrusion industry for accurate and precise heating.

Recent developments to the product have only enhanced its reliability, efficiency, and ease of service.  By pairing our furnace with a Granco Clark Billet Taper Quench, the extruder has at its disposal a billet with the most accurate billet temperature profile available.  And why would anyone want a temperature profile in a billet?  Thinking back to what the extruder truly desires – consistent extrusion temperatures at consistent ram speeds and pressures – the Billet Taper Quench counter-acts heat picked up from friction between the press container walls and billet skin during direct-acting extrusion.

Each extrusion profile – and the alloy from which it is derived – may dictate a wide range of desirable billet temperatures.  But with the Granco Clark billet heating equipment, the aluminium extruder has the right tools at its disposal to meet nearly any challenge.

AL Circle: What is the importance of heat treatment in aluminium extrusion solutions?

Granco Clark: There may be no other quantification more important than temperature when extruding aluminium.  It has everything to do with producing material to the extrusion's desirable and likely stringent characteristics and final performance properties.

Heat treatment is a broad term, but there are few specific and critical forms of heat treatment in the aluminium extrusion process.  For example, solution heat treatment, also known as press quenching, is the process of removing heat from extrudate after exiting the extrusion press.  For 6xxx series alloys, the faster this heat is removed, the better the physical properties of the extrusion will be.

Granco Clark offers the best quenching systems in the industry to meet any extruder's needs and is capable of all cooling rates required, ranging from gentle air cooling to High Impact Velocity spray quenching with heat transfer rates exceeding 100°C  per second, all while maintaining a distortion controlled process.

AL Circle: How different are Granco Clark’s Die, Infrared Die and Age & Anneal Ovens? What varied purposes do they serve?

Granco Clark: In support of the aluminium extrusion industry, Granco Clark designs and manufactures many different appliances for heating, either aluminium products or tooling.  Die ovens serve to heat the tooling necessary for the extrusion process.  Granco Clark offers several types of die-heating equipment in either chest or drawer styles.  We offer natural gas-fired, indirect electrically heated, and infrared-heated options.  Unique in comparison to others, Granco Clark’s Infrared Die Oven heats warm and cold dies alike, using proprietary PID controls via feedback from thermocouples located in several key areas of the oven, including thermocouple readings of the die itself – something Granco Clark was the first in the industry to offer.

Using this innovation, Granco Clark’s die ovens have no reliance on timers and air temperatures to control the die heating process.  Granco Clark’s Infrared Die Oven basically eliminates any chance of die metallurgy damage resulting from overheating a die.  Granco Clark also provides both Age Ovens and Anneal Ovens for heat treatment of aluminium extrusions.  Age Ovens – typically delineated as those capable of operating at temperatures of 500℉ or less – are used to artificially age extrusions to industry-specific temperatures and properties such as T5 and T6.  Granco Clark’s Age Ovens are readily compliant with CQI-9, among other industry certifications.  Like Age Ovens, Granco Clark’s Anneal Ovens heat extrusions, albeit to higher temperatures.

Like our Age Ovens, Anneal Ovens are engineered and constructed to be robust so they can withstand decades of cycles and use.

AL Circle: Does Granco Clark’s Press Feedline use heat to create aluminium extrusions? Could you please elaborate on the temperature they require to operate? 

Granco Clark: First, the aluminium billet or log must be heated to an appropriate temperature. Temperatures vary some, but the key is to heat the aluminium as quickly and efficiently as possible to an alloy-specific set point, likely above its solvus temperature.

For example, the billet for an aluminium extrusion made from 6061 alloys typically is discharged from the furnace at approximately 900℉ - 975℉ (480°C - 520°C), but the exact value depends on additional factors. Suppose an extruder has a Billet Taper Quench in its arsenal. In that case, they then have additional capability that allows them to soak the billet at higher temperatures and then quench it to much more precise temperatures (and better metallurgy) than those without, all prior to delivery to the press. Also, die factors play a large role in billet temperature.

Friction experienced as the aluminium flows through the die is the last step to getting the material to the perfect temperature for subsequent press quenching and handling. As to the temperatures experienced within the equipment itself, in the impingement zone of the furnace, the flame is burning at approximately 2100 - 2300℉. As those combustion products flow down the furnace tunnel, they cool, transferring their thermal energy into the aluminium, just as intended. In the jet section of the furnace, where the products of production are recirculated for additional energy recuperation, the products of combustion cool to roughly 500 - 1000℉, depending on throughput. But rest assured, Granco Clark furnaces are engineered and manufactured to provide for both energy efficiency and operator safety.

AL Circle: Do Granco Clark’s solutions in the Handling System complement the heating equipment? If yes, then name a few and their functionalities.

Granco Clark: Absolutely.  In fact, Granco Clark’s Handling Systems, Heating Systems, and Extrusion Press are often configured to work in harmony to enhance throughput, recovery, and uptime.  For example, with feedback from both the Press and the Handling System, the Heating System can optimize billet length for better use of live cycle time (press extruding time) and increase recovery.  Billet Taper Quench recipes can be optimized to stabilize extrusion temperatures at press exits and increase extrusion speeds.  Billet discharge times are synchronized to deliver billets as anticipated by the press’s ram speed and position.  This allows the customer to avoid billets with unnecessary dwell time outside the furnace.  In those cases where customers are required to retrieve samples from the extrusions regularly, these sample lengths can be factored into the billet length in advance to prevent any loss of usable cuts at the extrusion saw.  These are only a few examples of how the Granco Clark systems communicate to optimize the entire extrusion process.

AL Circle: What safety measures should be adopted while operating Granco Clark’s heating equipment?

Granco Clark: Granco Clark’s engineers are well-versed in the latest NFPA86, UL, ANSI, CSA, TSSA and other applicable safety standards necessary for providing the aluminium extrusion industry with safe, reliable heating equipment.  We also have several Certified Machine Safety Engineers on our team working to ensure the safety of those operating and servicing our products.

AL Circle: Are Granco Clark’s aluminium extrusion equipment fully integrated?

Granco Clark: Yes, they are.  Each piece of equipment is integrated with adjacent working processes, and the Supervisory Computer System (SCS) can communicate with most modern ERP systems.  There is a default interface for EPICs by Foy Inc.  Granco Clark is also implementing many measures to incorporate Industry 4.0 standards.   This includes remote production monitoring and reporting for the customer.  It is very common for customers to request turnkey solutions.  In this case, the customer can be shielded from any of the project management duties required during the installation and commissioning phase of the project.  Of course, training is included with every solution as well.

AL Circle: Is Granco Clark’s heating equipment line wholly automated? Are you recently planning for any digital upgrade?

Granco Clark: Practically speaking, yes, Granco Clark’s equipment is wholly automated. Plant operators are typically required to feed log or billet into the system, enter the desired setpoints, and then enjoy the benefits of working with best-in-class equipment. Operator involvement can be minimized through Granco Clark’s Supervisory Control System (SCS), a powerful tool for transferring process recipes from a customer’s ERP and sending production data back. We have already begun implementing many digital upgrades to all our products (heating equipment included), keeping our products at the forefront of Industry 4.0 progressions. We are developing and implementing enhancements constantly that make our products more useful to the aluminium extrusion industry. Using IOLink protocol sensors and actuators that can trend device performance, we are able to deploy algorithms that will warn operators and maintenance personnel of thermocouple probes or saw blades approaching the end of life, or any of a litany of other monitoring devices on heating equipment to ensure operations are running at peak efficiency. Another paradigm shift we want to encourage is moving away from a Preventative Maintenance formula, which generally involves replacing components based on an interval. Rather, Granco Clark aims to provide equipment that will inform the user of its health well before any catastrophic failure so that replacement materials may be allocated in a timely manner and downtime can be scheduled in advance to be less impactful on production schedules.

AL Circle: What is the most in-demand heating technology that Granco Clark offers?

Granco Clark: It is tough to say if there is one piece of equipment from our heating system that stands out from the others.  Granco Clark’s heating equipment is always in high demand, but that does not stop us from continually challenging our engineers to make product enhancements.  The Log Furnace has been a stalwart for several decades since industry acceptance of the Hot Log Shear, but especially so since pairing the appliance with hot log sawing technology.  Aluminium extrusion operations stand to gain many benefits from hot log sawing.  It is often advantageous to inventory raw material in log form instead of pre-cut billet by reducing inventory levels and scrap.  Billet lengths are editable up to the point of discharge from the furnace.  Extruders are also seeing tangible benefits from Billet Taper Quenches.  Demand for these machines is high for new installations and existing system additions.  Granco Clark’s Fusion Bonder is a fabulous complement to the Log Furnace and Hot Billet Cutoff Saw for extruders looking to eliminate the complications and unreliability of handling two-piece billets.  With the Fusion Bonder, the remainder of each log is joined almost seamlessly with the succeeding log in the furnace.  The newest equipment addition to Granco Clark’s Heating System is the Log Washer, which is conveniently located between the log loader and the furnace.