EDI Extrusion Coating Technology

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1 Extrusion Dies Industries, LLC EDI Extrusion Coating Technology Designers and manufacturers of high performance die systems Headquarters and Main Office: Extrusion Dies Industries, LLC 911 Kurth Road Chippewa Falls, WI U.S.A. Tel: Fax: Website: Rework website: Autoflex VI-R EPC Die Wholly owned subsidiaries: EDI GmbH Kastanienweg Reichshof Wehnrath Germany Tel: Fax: info@edi-gmbh.de EDI Precision Dies (Shanghai) Co., Ltd. Building No. 4, Dakun Industrial Park 860 Zhongde Road Songjiang, Shanghai P.R. China Tel Fax edishanghai@extrusiondies.com Your international partner in extrusion die technology, EDI provides a broad line of custom-engineered extrusion dies and related system components for the extrusion coating & laminating market. Highly qualified engineers, with in-depth experience in both die manuacturing and processing, are available to discuss and help define your requirements and to work with you after your equipment is delivered. Visit EDI at

2 EDI is a leading international supplier of extrusion coating & laminating die systems. The keys to our success have been a program of continuous investment in skilled human resources, advanced manufacturing hardware and sophisticated software tools, along with a relentless pursuit of technological innovation and uncompromising quality. Our success in the industry is a direct result of the excellence of our products and services. This is especially true of recent developments in extrusion coating and laminating technology that provide real solutions to problems that have plagued the industry for many years. Extrusion Die Developments Successful die designs for the extrusion coating and laminating industry need to address a specific set of today s performance needs: Trouble-free coating width variation for versatility and efficiency. Ability to reduce edge bead size to minimize expensive waste. Precise control of coat-weight uniformity so that desired physical properties are achieved with the least amount of coating material. This precise control is required for a wide variety of coating materials with differing rheological properties. Accurate coextrusion of materials with dissimilar melt temperatures or rheological characteristics, so that the composite structure provides the desired physical properties at a lower cost. Ease of maintenance for splitting and cleaning the system along with removing lip build-up in-between cleanings. Coating Width Variation Devices that adjust extrudate width, commonly called deckles, have been used by the industry for decades. The most sophisticated version available today is shown below. The bronze components are the internal deckle plugs which completely seal-off the ends of the internal channels. This full plug approach eliminates stagnation or dead areas in the channel. The silver-gray colored component at the bottom of the figure is an external back-up deckling system. Autoflex VI-R H100 EPC Die with Internal/External Deckle and Air Cooling Feature

3 External deckles are well known for their ability to provide highly effective sealing characteristics. By combining these two deckle systems, which were previously thought to be mutually exclusive, EDI has developed a significantly better approach to deckling. Just like the coextrusion of two coating materials leads to a higher performance product by combining the superior adhesive properties of one material with the superior strength properties of another, so does this new deckle concept lead to a dramatic performance improvement. Processors find that die systems equipped with only internal deckles require a great deal of experience and skill to adjust without leakage problems. They also find that external-only deckle systems do not allow for edge profile control and are not as streamlined. EDI s dual deckle system allows for simple, convenient width adjustment procedures, without any leakage issue. Both systems are driven together either by a hand-wheel or by a motor drive. Linear bearings ensure alignment and smooth movement. Edge Profile Control One of the chief goals in extrusion coating is to maintain a uniform coating thickness across the entire application width. This is not always easy. The common problem of edge bead an increased thickness along both edges of the coating makes it necessary to trim the edges to meet product specifications. Edge bead is particularly costly in extrusion coating because the scrap includes both coating and substrate. The bead is formed by the imbalance of forces that is created when tension is applied to the coating web. As the web becomes oriented in the machine direction, it necks-in (becomes narrower) resulting in a build-up of material on the edges. EDI s adjustable internal deckle components allow the operator to minimize the width and size of the edge bead. The result is a minimal overcoat requirement, so waste is significantly reduced. Image of Material with a Tuned Edge Profile Image of Material with a Heavy Untuned Edge

4 Control of Coat Weight Uniformity There are three key features that EDI has developed to maximize the amount of control the processor has over coat weight uniformity. Lip land lengths that provide a significant response to an operator or gage control system adjustment. A flow channel design is available that combines a varying geometry in the center of the die with a constant geometry on each end. The constant geometry on each end allows for fully adjustable internal deckling and the varying geometry in the center helps to promote flow to the ends of the die. A thermally isolated automatic lip adjusting system provides extremely accurate product tolerance. Body Bolt Layout Parallel To Die Lip Opening Multiflow IV Manifold Design 57 (1450mm) Autoflex VI-R Die Lip Land Design Approach EDI s approach is to provide an appropriate lip land length, with a good balance between the pressure drop across the lip land compared to the pressure drop across the whole die. Depending on the materials and rates to be processed, lip lands can be provided in a range from 6 to 13mm. This approach can allow a broader window of materials to be accurately distributed by one die, for example LLDPE and LDPE. Many other die manufacturers design for internally deckled dies utilizing a very short final lip land at the exit area of the die (only 3 to 5 mm long). This is done to minimize the pressure generated in the lips, so the die becomes less of a challenge to seal. This represents a compromise, however, since shorter lip lands will promote more die swell and afford less lip tuning control.

5 Advanced Automatic Lip Adjusting Systems EDI s automatic lip adjusting system, named Autoflex VI-R, provides three key advantages over previous systems. Since the translator blocks are mounted outside of the die body, there is significantly less heat transfer between the body and the blocks than with previous systems that were mounted within the die body. This eliminates much of the thermal cross-talk, so accurate gage control can be achieved more quickly. The translator material is a beryllium-copper alloy, whose high thermal conductivity provides a rapid response to a control action. Also, due to a large coefficient of thermal expansion, the translators provide a great deal of stroke (+/- 0.38mm of automatic adjustment range). 63 (1600mm) Autoflex VI-R H40 Die with Internal/External Deckle Ease of Use and Maintenance The new-generation EPC die includes innovations that reduce downtime in four ways: Rapid and accurate changes in width. A more robust support structure and drive mechanism for the deckle ensures a more stable and repeatable width-adjustment system. Changes in width are carried out by means of a single movement of the entire assembly of deckle components. Once those components have been adjusted to obtain the desired edge-bead profile for a polymer, that setting is preserved without variation through repeated changes in width. Easily inserted scraper to remove build-up. Operators can now quickly retract the external and die-gap deckle components and insert a simple brass scraper that cleans away carbonized polymer that causes die lines. In the past it was impossible to remove such buildup upstream of the lips without complete disassembly, but the new scraper reaches beyond the lip opening and into the secondary manifold of the die. Ready access for replacing seals and adjusting die gap. In the past, much of the deckle had to be disassembled to make it possible to replace end seals. The redesign of the EPC die makes it possible to carry out these tasks quickly and easily, without dealing with numerous fasteners and handling heavy deckle components.

6 Fast removal of deckle system for split and clean. It is now possible to open the die without completely disassembling the deckles at either end. Instead, each deckle assembly can be removed intact by unfastening four bolts. Another innovation is optional: External cooling by forced air makes it possible to cool end seals and deckle components. Lip Scraper Feature to Remove Build-Up Rapidly Multimanifold Coextrusion Fast Removal of System for Split & Clean The most accurate way to co-extrude is to use a multi-manifold die. Since each layer is spread to the full width prior to combination, there is greatly improved uniformity over the coextrusion feedblock approach. Also, the multi-manifold die can be designed to help maintain a large temperature differential between layers and our dual flex lip design provides a great deal of distribution control for each individual layer. Since each flex hinge is located in a position where lip adjustment influences both the lip gap and the individual combining gaps, one can accurately fine-tune the distribution of each layer (2000mm) Autoflex VI-R H40 Die with Dual Flex Lip Technology

7 Coextrusion Feedblock Developments EDI has worked towards the goal of significantly advancing coextrusion feedblock technology for the past couple of decades, with great results. The Ultraflow is the most widely used feedblock that is supplied by EDI. The Ultraflow feedblock utilizes custom-engineered flow inserts that function as mini-manifolds within the feedblock, yielding a high degree of control over product dimensions. Using computer modeling techniques, EDI designs each insert to fine-tune the layer distribution of a given material. Product variation is possible with the same feedblock because the inserts are exchangeable. The Ultraflow feedblock makes product changeovers possible by providing convenient access to the flow inserts, which are located immediately inside a removable cover plate and can be exchanged for other inserts without taking the feedblock off of the line. 3 Layer Ultraflow I Feedblock Ultraflow I Feedblock Inserts New Adjustable Ultraflow Feedblock Increases Productivity Our Ultraflow V feedblock is the next generation of feedblocks that EDI supplies. It has adjustable combining planes located where the melt streams join the central flow channel. The combining planes can operate in two modes, each with a different advantage in terms of ease and adjustability: Eliminating feedblock adjustment by the operator. By leaving the adjustable plane in free-floating mode, operators can let the position be determined directly by the equilibrium pressure developed by flow from the extruders. The combining plane responds to the pressures of the different mass flows from the extruder by achieving a state of equilibrium reflecting these differences. In this way, a change in flow from one of the extruders causes a readjustment of the combining plane at the point where materials merge. Optimizing layer-to-layer interfaces. For polymers whose interaction at the point of confluence poses the possibility of disrupting or compromising the multilayer structure, the adjustable plane can be moved manually to fine-tune polymer flow. Shafts extending from outside the feedblock into the centers of the adjustable planes provide ease of operation. Simple settings will change the adjustable planes from free-floating mode to varying levels of responsiveness to melt flow pressure. Once adjusted, an adjustable plane remains in a fixed position. Due to the inherent streamlining, this design is compatible with sensitive materials, like EVA, Nylon, and EVOH.

8 Our standard Ultraflow feedblock is an industry workhorse that enables processors to fine-tune layer thicknesses by interchanging specially machined flow inserts, without having to disassemble the feedblock. The new Ultraflow V feedblock eliminates even this step by using built-in combining planes. It is, in addition, a compact device, easy to disassemble and clean, and streamlined for optimal flow. Ultraflow V feedblocks can be designed for any number of extruders or layers. Ultraflow V Feedblock Extrusion Dies Industries, LLC October 2010 Rev. 4