What’s a deckle?
Here’s a definition. “Deckle a device in a papermaking machine for limiting the size of the sheet.”
Papermakers wish to maximise the use of the deckle when making gypsum board liner to maximise their productivity. The gypsum board makers want to limit the amount of linerboard they use.
Gypsum board is a sandwich of processed plaster between two layers of linerboard. A creamy face linerboard and a greyer, cheaper back linerboard. For the three common widths of gypsum board produced, there are six linerboard widths.
When producing gypsum board the wider face linerboard edges are wrapped over into an envelope to which the back linerboard is glued.
All linerboard is made on the same paper making machine. Its width, deckle is fixed. At the end of the paper making machine the deckle is trimmed to the widths to suit the gypsum board maker. The trims are wasted and recycled into the paper making process. Increasing amounts of recycle degrades the quality of the paper being made, so only so much can be recycled. The rest is waste.
It was a conundrum.
The gypsum board maker forever attempting to reduce the widths of face and back linerboard reducing the tonnages they purchased. The paper maker wasting more and more of the deckle width.
What if the paper maker could use the full deckle width?
What if the cut pieces were an exact divisor of the deckle widths?
I calculated that for face liner this would be three pieces and back liner four pieces
Further I calculated that with just two liner widths, a single face width and a single back width, all three common widths of gypsum board, 900mm, 1200mm and 1350mm could be produced!
There would be reduction in the sizes stocked at both producer and manufacturer. With the reduction in waste at the paper maker would only have to make liner for the gypsum board maker twelve times a year and not thirteen, a significant saving in trees and setup costs.
I arranged for the paper maker to make a face liner and back liner at the new special widths. We made a short run of gypsum board. The gypsum board produced had superior performance characteristics especially in its edge formation. The glued overlap of the envelope was further into the back of the sheet increasing strength.
The paper makers were at first intrigued and then enthusiastic. In fact, spread across the whole gypsum board making industry there were multi-million dollar savings to be had.
The paper maker proposed the savings to be made would be shared between the papermakers and gypsum board makers. The paper maker rightly pointed out that a change in paper widths was not protectable by a patent so the innovation might be requested by other gypsum board makers. They were agreeable though to recognizing the innovative nature of the idea.
However, the organisation I worked for was unable to see why the benefits should be shared for the whole industry and the country. They refused to progress the matter.
Of the two pallets of gypsum board made just a small sample remains somewhere in my treasured possessions.
Omg! A blog about Deckle Utilisation. Boring? Read on!
What’s a deckle?