Vertically Corrugated Inner Covers

Typewriters, floppy disks, dial up modems, answering machines, vertically corrugated inner covers…what in the world do these all have in common?  They are all items that were considered groundbreaking, state of the art technologies during their advent, but now are almost completely antiquated products.    

In the steel making and steel processing industries, inner covers are a component of the batch annealing process.   Inner covers are used to contain atmosphere, and maintain atmospheric integrity during the annealing process.   Depending on the atmosphere and operating temperature of the annealing cycle, corrugated inner covers are used in place of smooth wall inner covers.  The purpose of the corrugated inner cover is to provide resistance to early failures due to excessive growth, warping, or distortion. Early failures may cause the shape of the cover to interfere with the product inside of the furnace, or the containment unit, which goes over top of the inner cover.  Since corrugations can reduce distortion of the inner cover, they can also prolong failures due to atmosphere leaks caused by cracks.

There are two types of corrugated inner covers:  vertically corrugated, and horizontally corrugated.  They both are intended to do the same job, but the prevalence and usefulness of vertically corrugated inner covers are going by the wayside for the following reasons.

1. Reparability– Horizontally corrugated inner covers are in most cases easily repairable. Due to routine maintenance internally and planned outsourced repair work, we have seen companies that have had horizontally corrugated inner covers in operation for twenty years without needing to purchase new inner covers.  Due to the nature of the corrugations, vertically corrugated inner covers cannot be repaired and salvaged the same way that a horizontally corrugated inner cover can be.
2. Supply – We have observed a trend in the market that suppliers are moving away from participating in the production of vertically corrugated inner covers. With fewer suppliers participating in the fabrication of vertically corrugated inner covers in house, there will be an increase in suppliers outsourcing multiple processes, if not the entire fabrication, of vertically corrugated inner covers. 
3. Value – The way we look at value entails cost vs. functionality. When comparing the prices of vertically corrugated inner covers and horizontally corrugated inner covers used in the same process, the overall price of the horizontally corrugated inner covers is usually the same or less expensive than that of the vertically corrugated inner cover.  Considering the functionality and flexibility that horizontally corrugated inner covers offer, it seems difficult to justify continuing to use vertically corrugated inner covers.

Say goodbye to vertically corrugated inner covers!  Turn to Alloy Engineering as the suppler you can trust during the process of converting your current vertically corrugated inner covers to horizontally corrugated inner covers.  As a follow up to this blog, our engineering team will outline the steps that we will go through together to successfully convert your vertically corrugated inner covers to the horizontally corrugated design.