Techniques for handling and converting timber. Safety and health guidelines.
Personatges:
Tema: Timber
Competències
Competència en Comunicació Lingüística
Competència Matemàtica, en ciència, tecnologia i enginyeria
Competència personal, social i aprendre a aprendre
Competència emprenedora
Matèries i cursos per Sistema Educatiu
Espanya > Tecnologia i Digitalització > 1r ESO > Procés de resolució de problemes. Eines i màquines de taller
Espanya > Tecnologia i Digitalització > 2n ESO > Procés de resolució de problemes. Eines i màquines de taller
Espanya > Tecnologia i Digitalització > 3r ESO > Procés de resolució de problemes. Eines i màquines de taller
Enunciat
If we had to cut a log into planks using a handsaw, it would take several days and we would end up exhausted. Fortunately, today we have circular saws. The first circular saw was invented by Sarah Tabitha Babbitt, this was used to cut the logs into planks, in a more precise way and, above all, with much less danger and effort for the sawmill staff.
a) Use arrows to connect the name of the different ways of obtaining planks and boards from a log, so that we can make the most of wood, taking its characteristics into account.
| BAULKING | Sawing one big piece of timber by cutting the edges of a log. |   |
| PLAIN SAWN | A long sawn longitudinally with a succession of parallel cuts. Fewer pieces are obtained, but they are good quality. |  |
| PARIS SAWN | Triangular cut for logs in which the core is in poor condition and must be discarded. |  |
| CROSS SAWN | After two cross-cuts, boards are obtained by alternating cuts in a row from each quarter piece. |  |
| TANGENTIAL SAWN | Wood pieces are obtained by sawing tangentially to the annual rings. |  |
| CANTIBAY/TRIANGULAR SAWN | The log is quartered lenghtwise, resulting in wedges that are then cut along the axis. |  |
| RIFT & QUARTER SAWN | Variant of plain-sawing in which bigger core pieces are obtained. |  |
| QUARTER SAWN | A big core piece is extracted, then two smaller ones to create a cross. The rest is obtained by cutting it at a 90º angle. |  |
b) What safety and health guidelines must a sawmill worker follow when using a circular saw?
c) Circular saws only cut when spinning in a certain direction, but they don't when they spin the other way. What direction must this circular saw spin in so that it can cut wood?
d) We want to cut a piece of wood using a circular saw. How should we place the piece of wood so that it does not shatter as much? Give reasons for your answer.
Observacions i context
We can relate the invention of the circular saw, made by Sarah Tabitha Babbitt, to other far-reaching inventions for industry and technological progress made by women: Wifi (Hedy Lamarr), GPS (Gladys Mae West), the electronic book (Ángela Ruiz Robles), anti-reflective glass (Katharine Blodgett), vacuum packaging (Amanda Jones), fiber optic cable (Shirley Jackson), VoiP technology (Marian Croak), portable X-rays (Marie Curie) or Kevlar (Stephanie Kwolek).
Descripció
Type: Exercises to put into practise the different techniques for log handling and conversion, as well as the safety and health guidelines that should be followed, framed in the topic of timber.
OBJECTIVES: Analysing the methodology for obtaining timber, the properties of this material and its byproducts, and how it is used in technological projects; learning about safety and health guidelines.