An investigation into the wear characteristics of bandsaw blades and their influence on the sawing rates and costs of bandsaw operations

• Main Author: Taylor, Robert W.
• Published: Sheffield Hallam University 1976
• Subjects: 621.8; Machinery & tools
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.348753

The work includes summaries of the mechanics of wear in sliding systems under light loading, and severe wear mechanisms under metal cutting conditions. Applications of different wear mechanisms to cutting tool wear, and the problems associated with defining cutting tool life and failure criteria are discussed. Applications of dimensional analysis to the metal cutting problem are presented and include sections on: tool temperature, tool life/cutting speed relationships, tool life/temperature and temperature/time relationships, Colding's three dimensional tool life equation and.an analysis of the Taylor constant. The development of empirical cutting tool life equations is reviewed and includes Taylor type relationships, equations based on the concept of the chip equivalent and Colding's tool life equation. The effectsof cutting conditions, tool geometry, tool material and workpiecematerial on cutting tool life are considered. The fundamentals of sawing are outlined and the variations of modern power hacksaw and bandsaw machines discussed. This section includes a description of modern saw blades and saw blade nomenclature. A comprehensive review of previous work carried out on both the power hacksaw and bandsaw operations shows the present state ofknowledge in this field. The experimental work based on an adaptation of Colding's three dimensional tool life equation forms the first thorough investigation of bandsaw blade wear and its effects on cutting rates and economics. Relationships between the wear rate of the band and relevant parameters such as band speed, machine load and geometry of the workpiece are shown. Wear rate and cutting rate have been expressed in terms of a cutting constant, which defines the penetration of the teeth and its decay with use. A computer based simulation of the bandsaw operation has been developed and used to investigate the influence of relevant engineering parameters on productivity and cutting economics. The data obtained from the simulation model has been used to determine cutting rates and costs of bandsaw operations using constant feed rate and constant thrust load principles. The data is based on tests carried out on workpiece material classified as difficult to cut and trends obtained are believed to be typical of those that would beobtained when cutting the more common materials. For the firsttime, direct comparisons are made between carbon blades and high speed steel bi-metal blades under various bandsaw conditions, and the bandsaw and power hacksaw operations are directly compared. The investigation results in the following conclusions. The bandsaw operation may be a low cost, high cutting rate operation when high speed steel bi-metal blades are used under optimised operating conditions. High speed steel bi-metal blades should be preferredto carbon. A bandsaw machine operating with constant feed rate is superior to one operating with a constant thrust load system. A reduction in the total cost per cut can usually be obtained by optimising feed rates at the expense of blade life. The bandsaw operation can be as economical as the power hacksaw operation whilst achieving a higher cutting rate.