In recent times, we are witnessing a rapid increase in demand for extrusion coating and lamination materials over a wide range of products. Extrusion coating and laminating production lines are usually custom-built and can be configured for a variety of growing applications including aseptic packaging, flexible packaging, toothpaste tubes, medical packaging, contraceptives packaging industrial wraps and other uses. These growing applications attract many OEM’s to jump into manufacturing of extrusion coating and lamination machines.
What is Extrusion Coating and Lamination?
Extrusion coating and lamination is a process where molten plastic is applied to a variety of paper, plastic film and aluminum foil combinations. Once coated or laminated, the product is chilled to form an extremely thin, smooth layer of uniform thickness. The molten plastic can be used as an adhesive to laminate a plastic film or a metal foil. Extrusion coating and lamination are used to achieve:
- Moisture protection
- Barrier to oxygen, aroma, etc.
- Grease resistance
- Heat sealability
- Sales appeal, for example shiny surfaces
Processing knowledge is critical to run a successful packaging business with extrusion coating. Knowledge must focus on the equipment selection, raw materials and processing parameters such as uniform gauge control, corona treatment level, anchor coating, proper extrudate melt at the correct temperature, air gap from the die, nip pressure and chill roll temperature, to name a few.
Every extrusion laminate manufacturer faces many process challenges such as adhesion, gauge bands, over/under specification, pin holes and voids, and other situations. To answer these, extrusion lamination products must exhibit minimal quality variation with flat roll structure and meet stringent quality demands. So, no matter how good the coating or lamination process is, there will always be some thickness or basis weight variation. These variations can be created by a number of process or equipment disturbances, such as extruder speed, temperature variations or material surging in the extruder.
How Automatic Gauge Control Can Help
An automatic gauge control system not only helps in measurement and control of both automatic cross direction/profile and machine direction variations – but it also helps in the troubleshooting of many process challenges the extrusion laminator faces daily. Below is a list of benefits that can be expected when using an automatic gauge control system:
- Providing a tool for selling your product and company
- Eliminating customer complaints
- Reducing operator/laboratory burden
- Increasing operator efficiency
- Enabling management/executive decisions
- Start-up savings
- Product optimization
- Scrap reduction in both upstream and downstream operations
- Raw material savings
As mentioned above, automatic gauge control plays a critical role in troubleshooting both the extrusion and lamination process challenges during the various stages of manufacturing. These measurements and controls help ensure proper adhesion, barrier properties and downstream operations through the printing, slitting and cutting conversion processes. In this highly competitive world where quality compliance, raw material use and process information play such an important role to ensure customer loyalty and help expand market share, automatic gauge control is a powerful business capability.
What ROI Can the Manufacturer Expect?
The Return on Investment (ROI) is an important factor when evaluating an automatic gauge control system. The real-time approach using an automatic gauge control system produces significant economic benefits for the extrusion coating and lamination manufacturer. Based on multiple case studies, start-up and product changes have been reduced from 30 to 45 minutes down to 10 minutes using advanced measurements and controls. This corresponds to a reduction of 50% to 70% in start-up/change-over time. Coat weight material savings can be expected are around 3 to 5% due to coat weight optimization. Profile-related scrap is typically reduced by 50% and line speed increases are in the range of 8% to 10% due to increased process visibility and process stabilization that is afforded by an automatic gauge control system.
In sum, a good automatic gauge control system provides a comprehensive window into extrusion coating and lamination process challenges in order to maximize quality and minimize costs. In addition, the improved process visibility of a good system assists the operator in taking control of the process.