Patent Application
20080314525
This invention pertains to systems for extruding webs, and in more particular applications, to systems for extruding multiple webs for lamination to one another.
Extrusion systems generally extrude one or more molten polymer webs and/or coatings for use in a variety of products, such as automotive components. Oftentimes, extrusion processes are performed at one machine, are wound into a coil and then processed separately at another machine. For example, extruded material having a base body may be extruded at one machine, wound up and then unwound at another machine for combination with additional webs and/or coatings. This type of process is performed to permit a variety of combinations of extruded materials. For example, it may be desired to produce a multi-layer product having one type of optical finish but later may be desired to have an alternative finish. In this manner, the base extruded layer can be wound and then sent to either of the finishing machines for application of the appropriate finish. Therefore, having multiple separate operations permits a variety of different products to be produced from the same extruded materials. However, with this type of manufacturing, multiple machines are required to produce the various products and therefore, the extra machines may take up necessary floor space. Therefore, in some instances, it may be more economical to have continuously extruded materials that can be combined without being wound and then unwound at additional machines. In some instances, a continuous process may save time, manpower, money and floor space.
Furthermore, conventional processes often extrude a base layer or substrate to which additional layers are coated. For example, a base polymer layer may be extruded and subsequent coating layers, such as a color coating and an outer optical finish coating may be extruded and applied thereto. However, the coating layers, as opposed to webs, are not sufficiently rigid to be self-supporting and therefore generally must be directly coated onto a substrate. In this manner, multiple coatings are often applied, each performing a specific function(s), such as adding color or an optical finish, for the final product. Therefore, oftentimes multiple extrusion coatings must be applied, thereby increasing the complexity of the overall system.
In one form, an extrusion system is provided. The system includes a first extrusion assembly and a second extrusion assembly. The first extrusion assembly is configured to continuously form a first extruded web and the second extrusion assembly is configured to continuously form a second extruded web. The first and second extrusion assemblies are configured to cooperate so that the first extruded web is capable of moving in an assembly path wherein the first extruded web can be joined with the second extruded web to thereby continuously form a composite web consisting of the first and second joined webs.
According to one form, the first extrusion assembly comprises a first roll stack having a plurality of rollers and the second extrusion assembly comprises a second roll stack having a plurality of rollers.
According to one form, the system is in combination with the first and second extruded webs wherein the first extruded web passes through the first roll stack and the second extruded web passes through at least two of the plurality of rollers of the second roll stack prior to being joined with the first extruded web.
In one form, the system is in combination with the first and second extruded webs wherein the first extruded web passes through the first roll stack and the second extruded web is joined with the first extruded web prior to passing through the second roll stack.
According to one form, the system further includes an outlet to output a product.
In one form, the system is in combination with the first and second extruded webs wherein the first and second roll stacks are selectively configurable between: (a) a first configuration wherein the first extruded web is joined with the second extruded web; (b) a second configuration wherein the first extruded web passes through at least one of the first and second roll stacks to the outlet without being joined to the second extruded web; and (c) a third configuration wherein the second extruded web passes through the second roll stack and to the outlet without being joined to the first extruded web.
In one form, at least one roller in at least one of the first and second roll stacks is a conditioning roller.
According to one form, the first extrusion assembly comprises a first extruder and the second extrusion assembly comprises a second extruder.
In one form, the first extruder continuously forms the first extruded web that moves in a predetermined assembly path in a first direction and the second extruder continuously forms the second extruded web that moves in a predetermined assembly path in a second direction, the second direction being substantially opposite the first direction.
According to one form, the system is in combination with at least one of the first and second webs wherein at least one of the first and second extruders is capable of forming a web comprising multiple layers of material.
In one form, the first and second extrusion assemblies are movable selectively towards and away from each other.
Other objects, features, and advantages of the invention will become apparent from a review of the entire specification, including the appended claims and drawings.
In
The system 20 can also be configured as shown in
Additionally, the system 20 can be configured as shown in
In the configuration shown in
The nature of the components making up the first and second extruded webs 26,28 is not critical to the present invention. Virtually any components conventionally used to form discrete webs that might be pre-formed and joined are contemplated. The first extruded web 26 may pass through the second extrusion assembly 24 in traveling to the joining location 30 and collection location 34 or follow a different path thereto. Likewise the second extruded web 28 may pass through the first extrusion assembly 22 in traveling to the joining location 30 and collection location 36 or follow a different path thereto.
Specific exemplary configurations and embodiments of the extrusion system 20 will now be discussed in more detail with reference to
In one form, the extruder 40 continuously extrudes the first extruded web 26 that travels in a first direction, as indicated by the arrow TD1 in
The rollers 44,50 can include a variety of rollers such as drive rollers, idler rollers, conditioning rollers, nip rollers and the like, as understood by those skilled in the art. Such rollers and other extrusion components are discussed in U.S. Pat. No. 7,165,962, which is incorporated herein by reference. For example, in one embodiment, at least one of the plurality of rollers 44 is a conditioning roller to thereby cool the first extruded web 26 and at least one of the plurality of rollers 50 is a different conditioning roller to heat the second extruded web 28 in preparation for lamination to the first extruded web 26. It should be understood by those skilled in the art that other forms of conditioning rollers may also be included in the system 20. Furthermore, it should be understood that additional methods of heating and cooling the webs 26,28 may also be utilized.
In the embodiment of
Furthermore, the system 20 may include a conveyor section 56 having idler rollers 57 to help convey the webs 26,28 in a region between the roll stacks 42,48. Additionally, the system 20 may include motors 58 for driving the rollers 44,50, thereby to convey the first and second extruded webs 26,28 through the system 20.
It should be noted that the first extrusion assembly 22 is spaced from the second extrusion assembly 24 by a distance, represented by D2, which is greater than D1. Comparing
Referring to
Referring now to
Yet another configuration is illustrated in
A further configuration is shown in the embodiment in
Similarly, the second extruded web 28 may pass through the system 20 in a predetermined assembly path without being combined with the first extruded web 26. This system configuration is represented diagrammatically in
It should be noted that the first and second extruded webs 26,28 are distinguishable from coatings, as understood by those skilled in the art, which are in a state that is eventually transitioned into a layer/web. For example, the first and second extruded webs 26,28 have sufficient thickness and rigidity such that they need not be coated onto a substrate for processing in the system 20. A variety of materials may be used as the first and second extruded webs 26,28. For example, various forms of polymers may be extruded to form the first and second webs 26,28 as understood by those skilled in the art. Furthermore, either or both of the first and second webs 26,28 may be coextruded webs comprising a plurality of materials and/or layers. For example, the extruder 40 may be suitable for extruding the first extruded web 26 which has a variety of layers, such as a base layer, a color layer and an outer optical finish layer, all in a single coextruded web. As processed in the system 20, the first extruded web 26 can be maintained having an upward orientation throughout the system 20 (in the various configurations described herein) such that the outer optical layer is maintained having an upward orientation and is not prone to becoming damaged in the system 20.
It should be appreciated that for all of the disclosed embodiments there are many possible modifications. Additionally, it should be understood that the embodiments described herein may be utilized with a variety of additional optional components understood by those skilled in the art.
