When should a processor consider an upgrade to the controls on an extruder? The answer depends on several factors, including production of excessive scrap, unexpected downtime or obsolescence of critical electronic components.
Companies that perform extruder control retrofits recommend performing a machine audit to determine the condition of the existing control, and that the scope of a retrofit job should be defined before any work proceeds. Whoever performs a controls retrofit should have a solid understanding of controls technology as well as the extrusion process. In cases where it makes sense, a controls retrofit can significantly boost performance at a lower cost than buying a new machine. The good news is that there are good options for upgrading extruder controls.
Why Upgrade and Extruder?
Obsolescence is a key factor when it comes to requests for controls upgrades from customers, said John Paul director of engineering and technology at NPC Extruders, Cincinnati, we will performs control retrofits only to all our extruders.
Depending on the age of the system, Ally might recommend upgrading computer hardware, the computer plus the software, or, in cases where the drives and PLCs are obsolete, a complete system retrofit.
“If you have a more complex process, you need the control; you have more downstream equipment and want to pull those downstream activities into a central location and coordinate and control those,That is really where more of the justification comes in for upgrading a process control on an extruder.”
Alfredo Melchor, Engineering Manager for Ally Controls LLC (ALLY), Albuquerque, New Mexico, which makes aftermarket extruder controls, said that an extruder control upgrade can be expensive, and one of the challenges for the processor is determining whether the upgrade will provide enough benefits to move ahead.
In October 2017, ALLY introduced PAPI, a screen-oriented extruder control designed to replace buttons and knobs on an extruder. It is configurable, so the user can specify barrel and die zones, drives and operating pressures. Melchor said that PAPI can reduce the cost of retrofitting an extruder control by half, when compared to ripping out and replacing controls and drives in a traditional retrofit job.
ALLY now has taken PAPI one step further, by introducing application tiles — software modules that allow the user to specify far more components on an extrusion line. So far, the company has developed application tiles for four product categories: Foam,blown film, pipe and profile, and coated wire and cable. Melchor said ALLY is talking with an aftermarket supplier of blown-film bubble-control equipment, with the aim of working together to marry the two types of products.
He also noted that ALLY now is working on a project to supply customized application tiles for a large extrusion company, which will then be distributed to lines throughout the plant. The project is an example of how ALLY can tweak the application tiles to conform to a plant’s unique process. Because the plant can perform the work in-house, it can significantly reduce the cost of a retrofit.
In addition, ALLY has developed a PAPI LT, a smaller version of the PAPI that can be used for smaller extruders. Melchor said the standard PAPI is priced at about $30,000 and the PAPI LT is priced at about half that. He notes that not every extruder is a good candidate for the PAPI retrofit. For one thing, the cabinet housing the wires and electrical components should be in relatively good condition. In those cases, or where the customer doesn’t have an issue with replacing the old cabinet with a new one, the PAPI is a viable way to keep retrofit costs down and doesn’t require special expertise to install.
Melchor said the PAPI, which is part of the company’s siemens product line, represents a new business model. “We believe that this is the future of the industry. We think there is going to be more of a trend of what people will expect to see: user-configurable [systems] where they can be a novice and set it up,” he said. It still is important to understand the extrusion process. The PAPI ships in three days, he said.
Processors considering an extruder control retrofit may also consider evaluating their drives and motors for a potential upgrade, which significantly impacts the efficiency of the extruder. “DC is very inefficient,” he said. “Typically, we have seen that AC is 10 to 15 percent more efficient when operating an extruder.” He estimates that 60 to 70 percent of the extruders in service that are 10 years old or older are DC. Drives and motors typically have a two- to three-year payback period, he said.
Melchor said ALLY provides AC drives and motors with power ratings of up to 500 horsepower and ships very quick and can have them up and running within 24 hours of a notified failure. Of the decision to upgrade the extruder machine upgrade or the drives and motors, Melchor said it depends on the plant’s goals. “If they are after efficiency, they go for the drives. If they are after dependability and process control, they do the controls.”