Date of Award

9-1962

Degree Name

Bachelor of Science

Department

Pulp and Paper Technology

Abstract

This problem was approached by making multiply handsheets in the laboratory with various equicaliper ply arrangements of bleached sulfite pulp and overissue news, testing these sheets under standard conditions, and analyzing the data.

The handsheets were made by passing two Noble and Wood formed fiber mats placed face to face through an unlocked wet press. After removal of a forming wire a third ply could be added, followed by a second wet pressing. Upon constructing the sheet in this manner final wet pressing was accomplished by passing the multiply sheet through the loaded wet press. Sheets so formed were dried on the steam drum, conditioned, and tested.

Sets of three-ply and five-ply sheets having various ply configurations were evaluated. A second set of five-ply sheets showed the effect of replacing a portion of stock with bleached kraft pulp in any one ply of a basic arrangement.

From the foregoing, the following conclusions were made:

1) The method employed for making multiply sheets gave accurate and reproducible results.

2) The modulus of elasticity and the moment of inertia of the liner plies are of primary importance in overall sheet stiffness.

3) The filler stock has the basic function of separating the liners causing the liner plies to have high moment of inertia values.

4) Upgrading to increase stiffness at constant caliper will have maximum results when done to the liner furnishes.

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