Recent developments in the manufacture of thick blankets of intertangled mineral fibers include systems comprising a plurality, e.g. 4 to 6 or more, fiber forming and web forming modules, each producing a relatively thin, permeable, lightweight, web of intertangled mineral fibers. The webs from each of these modules are sequentially delivered to a transfer conveyor running under the modules to form a thick layer of superposed webs, which layer can later be processed into relatively thick mineral fiber blankets having a high degree of uniformity through the thickness of the blanket. These modular processes represented a significant improvement in the prior art technique of forming relatively thick mineral fiber blankets, particularly in the uniformity of the resultant product. Typical systems of the type described above are described in more detail in U.S. Pat. application Ser. No. 236,372 filed Mar. 20, 1972 and in U.S. Pat. No. 3,824,086, the disclosures of which are herein incorporated by reference.
Although the above described systems represent a significant improvement in the manufacture of thick fiber glass blankets, there are features in these systems that need further improvement to permit the systems to be used more effectively. The initial capital expenditure required to build a system of the type described above, containing five or six modules, amounts to several millions of dollars. Once built, each module, in a pot and marble operation, requires an operator to insure that the fiberizing portion of the module is always operating properly. Although many products desired to be manufactured on these systems require that all of the modules operate simultaneously, many of the products are of a thickness that require the operation of less than all of the modules. When such products are being manufactured by the system described above, one or more modules remain idle, and the operators of these modules either remain idle or must be transferred temporarily to other duties, which is not always possible. Because of the large capital investment requirement of these systems, and operating costs that continue regardless of whether each module is operating or idle, the economics would be improved considerably if all of the modules could be operated continuously regardless of the requirements of the primary product being manufactured by the system.
One solution to this problem is discussed in Ser. No. 236,372 and amounts to dividing the transfer conveyer into two sections with the direction of travel of each sectional transfer conveyer being reversible. Then, if only a portion of the modules are required in the manufacture of the primary product, this portion of the modules can be selected from the modules at one end of the process, leaving the remaining modules on the opposite end of the system to manufacture a secondary product. The transfer conveyer under the modules not required for the primary product is reversed, these modules deliver their individual mats to the reversed transfer conveyer which delivers a secondary product of one, or two or more superposed layers, to the end of the system opposite the end to which the primary product is being delivered. While this modification can be used to solve the above described problem it adds to the building space requirements of the over-all system because it requires that additional processing equipment be located adjacent, and extending from, each end of the system. Also, additional personnel are required to operate the equipment at each end of the system simultaneously and this additional personnel becomes surplus when the primary product requires operation of all of the modules. Thus, this solution to the problem, while operable, is not entirely satisfactory from an economical standpoint.
It is an object of the present invention to modify the systems described above in such a manner that all or some of the modules can be operated independently of the overall system to manufacture separate and useful products when simultaneous operation of all of the modules are not required in the manufacture of the primary product.
It is a further object of the present invention to modify the systems described above to accomplish the above described objective using a minimum amount of additional equipment located in available space, i.e. without requiring additional building space requirements.
It is a further objective of the present invention to accomplish the described objectives and further to manufacture additional useful products without requiring additional operating personnel.
It is a further objective of the present invention to accomplish the above described objectives and also to provide the above described systems with increased production capacity and versatility.