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Manufacturing Techniques

5.1.1 Define manufacturing technique

A specific manufacturing term, sometimes relating to one material group only

5.1.2 Outline the techniques of moulding, casting, weaving, fusing, stitching, cutting, machining, abrading, using adhesives and using fasteners.

The principles of each technique are required.

Moulding

Wikipedia: " Moulding is the process of manufacturing by shaping pliable raw material using a rigid frame or model called a mould."

Moulding involves filling a hollow in a mould with a material such as metals, plastics and glass at the point of being molten. It enables the manufactures to produce any shape with many materials easily and efficiently.

Types of moulding are listed, courtesy of www.wikipedia.org:

Advantages/Disadvantages:

  • Advantages are that moulding can allow you to form any shape in form. Little or no waste. Is considered a clean technology. Suitable for batch and volume production. No finish required as the material takes the finish of the mould.
  • Disadvantages are that moulding is done in one form so there cant be characteristics of assembly or disassembly. High initial capital cost.

Casting

Casting is the manufacturing process of pouring molten material (usually metal) into a mould. There are many types of casting which fall under two main categories, expendable mould casting and non-expendable mould casting. Casting can be done with any material that can be made into a liquid state; this includes resin, plaster, plastic, and nearly all metals. Casting is used for regular manufacture, such as piping, metal frames, furniture etc. and also for artistic figures, a figure is made of clay or wax and a mould is made around it out of clay or plaster, after that the mould can be stored indefinitely until the artist can find a buyer. Once the artist finds a buyer, bronze (for example) is poured into the mould and a bronze statue is made.

Advantages/Disadvantages:

  • Advantage: to the user is that being one piece of material with no joints, thereby making cast products quite strong and durable as well as cheaper. Another advantage is that the cast has an overall smooth design, without any visible joints.
  • Disadvantage is that being solid pieces of metal, damage, can usually be permanent. Finishing may be required.

Weaving

Weaving is an ancient textile art and craft that involves placing two sets of threads or yarn called the warp and weft of the loom and turning them into cloth. In general, weaving involves the interlacing of two sets of threads at right angles to each other: the warp and the weft. The warp are held taut and in parallel order, typically by means of a loom, though some forms of weaving may use other methods.

Advantages/Disadvantages:

Fusing

Fusing is a manufacturing technique used to join similar materials together by melting them at high temperatures and usually adding a small amount of a similar material.

The fusing manufacturing technique is mainly used for metals, glass and some types plastics.

Advantages/Disadvantages:

  • Advantages ... For the manufacturer, the fusing manufacturing process is cheaper and easier to craft, thus the final product for the user will be at a cheaper price due to the cutting costs of a cheap manufacturing process.
  • Disadvantage ... for the manufacturer is that fusing is time-consuming. Moreover, the edges that are being joined may need a better finishing touch, so the manufacturer may also need to integrate the abrading manufacturing process for a smoother edge. Altogether though, the fusing manufacturing process can be considered one of the more cheap and effective manufacturing methods.

Stitching

Stitching
A single complete movement of a threaded needle in sewing or surgical suturing.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2006 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

Stitching is sewing when cloth, leather, furs, bark, or other materials, is sewn using needle and thread. It dates back to Palaeolithic times (30,000 BC). Its use is very popular and nearly universal among human populations. Sewing predates the weaving of cloth. Sewing is the foundation for many needle arts and crafts, such as appliqué, canvas work, and patchwork.

Sewing is used primarily to produce clothing and household furnishings such as:

  • Curtains
  • Bedclothes
  • Upholstery
  • Table linens.

It is also used for

  • Sails
  • Bellows
  • Skin boats
  • Items shaped out of flexible materials such as canvas and leather.

Sewing done by machines:

  • Pieces of a garment are often first tacked together.
  • The machine's complex set of gears and arms pierces thread through the layers of the cloth.
  • The thread is semi-securely interlocked

Advantages/Disadvantages:

Cutting

Cutting: The separation of a physical object, or a portion of a physical object, into two portions, through the application of an acutely directed force.

Cutting can be applied as a process in order to divide materials such as wood or glass. An example where cutting is really useful would be if a board of wood is too large, it can be cut with a cutting tool and any extra wood is disposed of. Another example would be the cutting of glass for window panes.

People cut things daily without even noticing it. In kindergarten, when your little brother or sister are making paper planes they cut some paper. In order to MAKE the paper, a tree had to be cut down. Everything is the size and proportion that it is because it was cut down to be that size; to be accessible to humans.

Examples of cutting tools:

Wood:

  • Saw (buzz saw, chain saw, hand saw, etc.)
  • Axe or hatchet
  • Chisel and mallet

Glass:

  • Glass cutter

Metals:

Plasma Cutter
  • Diamonds

Diamonds can be used as a cutting tool. They are limited in application because of the size that diamonds come in and the high costs. They are usually used on very hard materials to create a clean soft cut. Used at very high speed

Advantages/Disadvantages:

  • Advantages ... Cutting is a convenient manufacturing technique for the designer. Firstly, it allows for materials such as wood to be shaped without using a mould. A good example of this is found in cookie cutters, which cut dough for cookies or other baked goods into almost any shape.
  • Disadvantage ... is that it requires the use of a sharp edge, which is potentially dangerous and injuries can occur. Another disadvantage is that when it is done by hand, it requires more effort to shape the material. A lot of unused material is discarded if it is not useful, which is not green because it is just a waste. For example, if a clock is made from timber and shaped like a star, there will be leftover scraps of wood, meaning that the timber has not been used very efficiently.

Machining

Machining is a collection of material-working processes in which power-driven machine tools, such as lathes, milling machines, and drill presses are used with a sharp cutting tool to mechanically cut the material to achieve the desired geometry. Machining is a part of the manufacture of almost all metal products. It is not uncommon for other materials to be machined.

The three principal machining processes are classified as turning, drilling and milling. Other operations falling into miscellaneous categories include shaping, planing, broaching and sawing.

Wood lathe Drilling
  • Turning operations are operations that rotate the work piece as the primary method of moving metal against the cutting tool. Lathes are the principal machine tool used in turning.
  • Milling operations are operations in which the cutting tool rotates to bring cutting edges to bear against the work piece. Milling machines are the principal machine tool used in milling.
  • Drilling operations are operations in which holes are produced or refined by bringing a rotating cutter with cutting edges at the lower extremity into contact with the work piece. Drilling operations are done primarily in drill presses but not uncommon on the lathes or mills.
  • Miscellaneous operations are operations that strictly speaking may not be machining operations in that they may not be chip producing operations but these operations are performed at a typical machine tool. Burnishing is an example of a miscellaneous operation. Burnishing produces no chips but can be performed at a lathe, mill, or drill press. (Reference: http://en.wikipedia.org/wiki/Machining)

Advantages/Disadvantages:

Abrading

Description of the process: To wear down or rub away by friction.

Materials suitable: Abrasion can be used in the context of sanding wood, and various other materials using specifically designed abrasion paper or cloth, which is a sheet of paper or wax, with a layer of sand, to be able to successfully wear down anything.

Advantages/Disadvantages:

  • Advantage & Disadvantages for the user: Materials that are worn down and abraded are smoother and less dangerous for the users, and can be more aesthetically pleasing than the same objects that are rough and complete.
  • Advantage & Disadvantages for the manufacturer: When manufacturers abrade or wear down materials, much of the material being worn away goes to waste. This presents a bad point, as abrading costs money but wastes material.

Using adhesives

Adhesive refers to the method of connecting two items using a glue, or other substance merging the two products together. Two or more parts will be prepared for assembly. One part receives a layer of an adhesive substance, and the second part will be placed next to the object with the sides touching. Once the adhesive dries, the products have been formed into one object, with the adhesive between the two holding them together.

Advantages/Disadvantages:

  • Advantage ... to using adhesives, as a manufacturing process is that it is low cost, easily used, and can be applied by user.
  • Disadvantage ... is that the bond may be weak and easily broken, fumes, takes time to set/dry.

An adhesive substance

Using fasteners

The use of fasteners stands for using certain connecting materials/devices (such as screws, buttons, nails, nut bolts...) to bind two or more dissimilar materials together. Fastens can be used to close objects such as a bag or a box or even an envelope.

Nuts & Bolts Screws Keys
Pins Rivets Connector Bolts
Types of Fasteners
bolts, nuts, Screws, keys, studs, pins, rings, rivets and nails.

Advantages/Disadvantages:

  • They simplify the manufacture of machines and their usage
  • They eliminate the usage of one-piece parts of machinery, as it’s easier and simpler to combine smaller components and fasten them together.
  • Simplifies the repair of machines and equipment. ( Makes maintenance easier, repair, replace etc.)
  • Fasteners are provide safety and are less hazardous
  • The encourage design for assembly and disassembly

5.1.3 Describe how the techniques in 5.1.2 relate to different materials.

For example, casting relates to metals, plastics, food, ceramics and some composites, but not to timber or textiles.
Method Materials
Moulding Metals, plastics, food, ceramics and metal matrix composites
Casting Metals, plastics, food, ceramics and some composites
Weaving Metals threads, plastics, ceramics (threads) and textiles.
Fusing Metals,ceramics and plastics.
Stitching Metals threads, plastics and textiles.
Cutting All Materials
Machining All Materials
Abrading Metals, plastics, timber, food, ceramics and some composites
Using adhesives All Materials
Using fasteners All Materials

5.1.4 Discuss advantages and disadvantages of using the techniques to manufacture products.

Refer to the viewpoints of the manufacturer and the user.
  • Included in 5.1.4

References

Bulleted list and italicised paragraphs are excerpted from Design Technology: guide. Cardiff Wales, UK: International Baccalaureate Organization, 2007.

Images are clickable links to its location.


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