June 2016 Roundtable on Extrusion Equipment
VP of Extrusion & Solution Coating
35 years with the company
Mamata Extrusion Systems Pvt. Ltd.
18 years with the company
VP of Sales
Hosokawa Alpine American, Inc.
20 years with the company
Pearl Technologies Inc.
4 years with the company
Technical Sales Manager, Extrusion Equipment
Windmoeller & Hoelscher
5 years with the company
Q: What’s new with your company? Did you release anything new or notable at Drupa?
Keller: We have introduced an expansion to our successful dsX flex-pack product. It is being expanded to include shaft-less unwinds and rewinds, and line speeds to 450 MPM. A full range of widths is now available for 1,200-, 1,350- and 1,550-mm widths.
Shankar: We have recently introduced 1200-mm (48-inch) width 3-layer blown film lines with output range of 300-400 lbs/hr. These lines will replace monolayer lines while providing great savings on polymers and energy, giving very good ROI. We have also introduced similar width barrier film lines with 5 and 7 layers. Output range is 350-550 lbs/hr.
Campbell: There is always something new at Hosokawa Alpine, as we continually make advances on all facets of the blown film process, including improved efficiencies in cooling, die enhancements, optimized web handling and intuitive controls. We do not participate in Drupa, as it is traditionally a printing show, but we will be introducing new technology at this year’s “K” show in Düsseldorf, Germany. That information will remain under wraps for a few more months.
Huennefeld: Drupa and K in the same year creates quite a challenge for W&H, being a major player on both shows. We’ll keep our highlights on the extrusion side of the business close to the vest until the K-show. New press developments will be mind-blowing though…
Q: It seems that changeovers and purging times are still some of the big things that contribute to waste when it comes to extrusion equipment. What’s being done to help minimize waste?
Huennefeld: That is absolutely correct. The by far biggest impact in this field was presented during our in-house expo in June 2015, when we introduced TURBOCLEAN, our fully-automated resin purging system that reduces changeover time drastically. In some cases, from 30 minutes down to 2 minutes.
Shankar: As per our understanding, blown film has four main wastages: startup waste, changeover waste, trim waste and purging/shutdown waste. In most cases, trim wastage is the highest contributor as it is a continuous wastage. It is followed by startup and purging wastages. Changeover wastage is subject of the type of changeover which can be of the following types: color change from master batch to natural, overall recipe change (specialized resin to standard resin) and film width and thickness change.
Changeover from master batch to natural is subject of die design. In our case, we have die design with metal-to-metal contact taper-lock spiral mandrels with streamlined entry ports. This ensures very quick changeover or flushing within 10 minutes.
In order to reduce and control trim wastage, recycle units should be adopted in the plant ancillaries which feed trim wastages back to the extruder hopper for further processing. Of course, this has worked well in manner when natural film or single color film/similar group of raw material is in processing.
In terms of overall waste, our customers are able to maintain it below 1 percent due to our unique system of trim-less manufacturing of film. This is achieved with a combination of auto width control and special slitting systems.
Campbell: Alpine has led the industry in reducing changeover times for several years, beginning with the introduction of the X-Die. Quick purging is one of the key features of the patented X-Die. The design provides the lowest die profile in the industry, resulting in the shortest residence times, and consequently the quickest purge times. We have customers that have published articles that confirm that with the X-Die and grooved feed extruders, they are achieving difficult color changes in less than 10 minutes. Alpine’s quick changeover capability is not just the X-Die, we have also incorporated the quick change concept into our U.S.-designed and manufactured ExVis control system. ExVis also features the recipe driven “one touch” job change feature, significantly reducing time and scrap when transitioning from one job to the next.
Cros: Pearl Technologies’ products are always designed to increase ease of use and quick changeovers. On the extrusion side of our business, Pearl continues to innovate in process enhancements that offer extruders flexibility in bubble management while minimizing waste. For example, innovations allowing quick transitions from a gusseted application to a non-gusseted product, without having to stop production for an extended period of time, creates flexibility and versatility that allow film producers to increase the range of use and the output of their lines.
Pearl is the uncontested leader of gusset boards and collapsing frames. Our gusset boards, with removable or even automated retractable tips, coupled with our new actuators, make changeovers in a matter of minutes, not hours, while also enhancing safety. Other upgrades include our low coefficient of friction engineered materials in bubble cages, or in web management after the nips. Teflon rollers and idler rollers eventually wear or stop turning and without constant maintenance lead to marking, pinching and tearing of the film. Pearl’s fixed idlers create uniform tension between primary and secondary nips for better quality rolls.
Keller: For coating and laminating, the dsX flex-pack product minimizes waste by using splice tracking software to minimize changeover scrap from one web to another. Additionally, the winders make transfers at full line speed with no waste, and the unwinds splice roll-to-roll with a small amount of web left on the core. Extruder and material controls anticipate the product change and minimize the material used during the process.
Q: There are lots of components that go into an extruder and a lot of utilities that help make it tick (i.e. compressed air). In what ways, if any, does your equipment monitor such to ensure that machinery is working properly and most efficiently?
Campbell: Present day extrusion equipment incorporates many improvements for productivity and efficiency. Modern AC drives and motors have increased performance with less waste. New improved temperature controls keep zones at setpoint without costly overshooting and new software delays heating of fast zones until all zones are ready to further save energy, while preventing material degradation. Overall supervisory controls with full integration allow the system to report failures quickly and allow for quick troubleshooting and repair. This integration also allows for faster job changes with less scrap and less downtime.
Keller: For our flexible packaging lines, the largest consumed energy section is in the water process loops. All flat die systems use large diameter chill and cooling rolls that require high flow rates of cool water to remove the heat from the molten polymer. To this end, we graphically display, monitor and control the process loops showing flow rates and temperatures at every stage in a very detailed fashion such that the operators can instantly check all cooling loops and monitor the chilled water source.
Huennefeld: We offer what we call “energy monitoring” for exactly those two reasons. Offering a tool to find the most energy efficient sweet spot of a production setup is one of them. Additionally, the ability to monitor all energy consumption in real time provides data needed to tweak settings and minimize energy usage.
We add sensors to measure flow rate and temperatures of all water connections, compressed and process air and also the entire electrical consumption is considered. Now imagine you have a broken valve for compressed air. You could waste a lot of money not noticing this for a few days. With energy monitoring you would see a spike on the compressed air diagram right away and maintenance could look for and remedy the problem.
Shankar: There are many inputs (electricity, water and air, etc.) in general to the blown film and specific to the extruders in the form of utilities, which impacts performance of the plant and final quality of product. We offer very customized solutions with closed-loop monitoring system for such utilities.
Just to share, one of the practical approaches where we were to ensure that inner layer of 3-layer lamination film should not be less than 3.6 µ for proper sealing and the outer layer not less than 4.5 µ for better bonding. It was challenging to control individual layer thickness just from most popular automations like gravimetric control and auto gauge control systems, hence we had incorporated temperature control unit (TCU) for supply of water to feed throat zones of extruders to ensure uniform melt temperature at the end of the extruder.
Our equipment is equipped with monitoring gauges/meters to measure and control the blown line operating parameters. The monitoring and control is done through closed loop systems with either alarm and/or auto shut down. We offer all the standard monitoring systems at various system elements of the blown film line as usual.
Q: With films and resins changing so regularly, how does your company best stay up with the latest industry trends?
Cros: Pearl Technologies invested in a technology and application lab. We work closely with our customers to test their films and applications with our innovative products. We have the ability to measure friction and drag on different films, at different temperatures, allowing us to qualify the best cover material for our slats, arms, rollers, etc. This prompted us to develop our new SM-28 wear-surface this year, the most slippery and durable in our history. Our worldwide distribution network is also a great tool, allowing us to identify industry trends through new requests from our customers. Not a day goes by without Pearl being asked for a new application!
Shankar: Resin and film versatility in film extrusion depends on hot packages and cooling systems. We address the issue as under both. For hot packages, pertaining to extruders, we offer smooth bore extruders which are the most versatile extruder in the market handling fractional MFI to 10 MFI. It can also handle bulky/fluffy trims directly. Due to versatility, one can process up to 100 percent LLDPE/m-LLDPE in all the layers, 100 percent LDPE up to 7 MFI in all 3 layers and PP-homo/co-polymer in various blends in any or all the layers. We also offer customized die with layer ratio from 1-1-1 to 1-8-1. The individual layer can be handled for 50 percent of individual layer capacity up to 100 percent.
For cooling systems, the air cooling ring has unique capacity to lock film bubble with following outlets of air. Primary and secondary lip gaps are adjustable. Three set of collars exponentially adjustable with each row from 0 to 100 percent bring in versatility to lock bubble for BUR as low as 1.5 to as high as 4.0. The features are over and above the versatility of changing blower speed and air temperature to control the frost line as usual.
IBC System : It has again 4+1 (i.e. 5) pancakes with each one independently settable to operate at say 40 percent, 25 percent, 50 percent, 75 percent and 100 percent opening respectively from bottom to top. This helps to do quick pre-cooling at entry and progressive cooling of bubble with the rest of the pancakes to get desired output without disturbing gauge.
Keller: Davis-Standard has extensive laboratory facilities serving each of the major product lines in Pawcatuck, Connecticut, Fulton, New York and Suzhou, China. At these laboratories we develop machines to process new materials in conjunction with the polymer producers.
Campbell: Alpine has always maintained a close relationship with resin suppliers – and we continue to do so. In fact, many of the prominent resin suppliers have installed state-of-the-art Alpine co-extrusion lines in their lab facilities. We believe the continuum between resin, equipment and applications are critically important for our customers and in general for the growth of the flexible packaging industry.
Huennefeld: We currently have 6 full size extrusion lines in our lab in Germany. This is where our own R&D department tests a lot of the new materials themselves. We want to be able to make the right recommendations to our customers and, of course, we also need to adjust or invent technology to better process some of these materials.
Q: Being that extrusion equipment is such a large capital investment, we’ve noticed that more manufacturers are getting involved in remanufacturing and updating used equipment so that it’s like new. Is your company involved in this? What are some of the pros and cons of this practice?
Keller: Davis-Standard has an extremely large base of installed machinery going back to the 1950s. We have realized the importance of rebuild and modification to our customer base to use their assets effectively. For this reason, we established a group, Circonix Technologies, that specializes in bringing old equipment up to date through new controls, components, co-extrusion additions and safety upgrades. This way our customers have the option of new state-of-the-art equipment or utilizing remanufactured equipment from the same company with the process knowledge to make it work. The pros of this practice are of course cost to the customer and potential lead time and down time. The potential negative would be the same risks as when you buy a used car, not everything is refurbished and the maintenance costs will of course be higher than on new.
Huennefeld: We established an entire business unit in Germany that specializes in retrofit and upgrade solutions. We started this business unit in 2008 with seven people. Today, the team is comprised of 40 engineers and technicians. So yes, we are absolutely involved in this growing type of business.
In some cases we proactively address foreseeable issues with, for instance, electronic spare parts that will become obsolete. But the bigger part of the business is improving older lines to get higher output and better film quality. This goes from air ring and IBC retrofits up to dies, extruders, haul offs and winders. In many cases, retrofits are a first step into W&H technology. Often, customers that hadn’t previously considered W&H based on price started with an IBC and air ring and are now proud owners of multiple W&H lines.
Campbell: Alpine has led the charge for promoting equipment upgrades and we are very active in the upgrade/retrofit market. Older lines can take advantage of new technology in terms of output and film quality by auditing the condition of the machine and identifying what upgrades make sense. We gave a presentation at the film and bag annual meeting exactly on this subject. New cooling systems, X-Dies, extrusion controls and auto-gauge systems can breathe new life into underperforming assets. These investments pay back in months, not in years.
Shankar: Yes, we do help our customers for upgrading extrusion lines.
Pros: Normally we retain post extrusion equipment like tower, haul-off, winders etc. as available with our customers. We offer hot packages and cooling system including extruders, die and bubble cooling equipment for up gradations. Due to highly efficient and high performing hot packages giving high outputs, energy cost is low and cost of conversion can be reduced by 30-50 percent without compromising on the quality of film. Utilities and auxiliaries in most of the cases are in usable condition and hence, not required to be changed. This reduces overall capital cost further.
Cons: Most old plants were designed for low output and hence have lower height towers. This may reduce the full benefit of upgraded hot packages. The mismatch between new generation control systems (touchscreens, SCADA, etc.) with old systems of mechanically/manually controlled systems can be difficult at times.
Cros: Increasing the value of existing equipment for our customers is what made Pearl Technologies the leader in bubble and web management. Product quality and process speed are key to blown film processors. But, the best extrusion line is only as good as its weakest component. Pearl has been innovating the blown film extrusion process for over 30 years, and has upgraded thousands of installations worldwide. Our products are also utilized by most OEMs. When updating a line, our aim is always to make older lines perform better than when it was new.
Pearl offers 10 key innovative blown film process enhancers that provide immediate results, helping produce better quality film at higher rates of production. Benefits include reduced drag, increased stability, induced cooling and elimination of wrinkles. We have applied our expertise in areas of web guiding and handling such as collapsing frames, side guides and gusset boards, where our very low coefficient of friction product solutions provide critical improvements. We also offer bubble cages and bubble guides with Z-Lift options and SM-24 arms (which can also be retrofitted to any existing cage or arm profile). Our spreader bars are designed to eliminate wrinkle formation and are an inexpensive way to obtain a uniform, smooth finished roll of film. Pearl’s pre-nip chillers, located prior to the nip, reduce sag while cooling film evenly across the layflat. Finally, Pearl’s airless turning bars and fixed non-turning rollers have allowed many of our users to eliminate maintenance and create consistent, uniform tension for better quality film rolls. Pearl’s relatively inexpensive extrusion enhancements, with regard to newer capital equipment, have proven to provide our users with very short returns on investment.