Abstract
In this Magazine No.4, 1952, I found that the fiber strength of gypsum wall board has not only dependence of the breaking stress of wrapping paper but the adhesive strength between the gypsum body and the paper wrapped thereon. After that, I proposed a testing method for it, and I have applied the test to any gypsum board produced in Japan after that year.
According to these results, I found, the more recent products of same factory have certainly the better adhesive strengthes.
Also, I tried to analyse the adhesive stress in board with relation of the fiber strength, and finally proposed the limitative standards.
This is purposed to revise and enlarge our Industrial Standard for gypsum wall board published in 1951, because it is required nothing of strength beside flexual one.
On the otherhand, such manufacturing factories in Japan have been suddenly increased for those years. And so, I think, this manufacturing technic related to adhesive strength will be surely important to apply for new factories.
