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PLASTICS - Coggle Diagram

- - - - -Plastics that decompose on contact with certain bacteria and biological agents.
      - -Plastics that dissolve in hot or cold water.
- - - - This technique has four stages:
        
        We put thermoplastics, in granular form, into a previously heated cylinder.
        
        We apply pressure by means of a large, roating screw, wich forces the melted material out, through a nozzle.
        
        We cool the shaped material slowly in a refrigerated water bath until it`s solid.
        
        Finally, we collect the pieces of plastic through a feeder system.
      - Used to form: wrapping, lining for electric cables, tubes and pipes.
    - - Thermoplastics produced by the extrusion method is passed through a series of hot cylinders to produce sheets of varying thickness.
        
        With this technique, we can produce different finishes, for example, glossy, matt or textured. This depends on the outer coating applied by the final cylinder.
        
        Used to form: worktops, to cover surfaces of kitchen cupboards and drawers.
    - - We use plastic sheets with large surface for this technique.
        
        We put thermoplastic into a mould.
        
        We then use a heater to heat the mould and soften the plastic.
        
        We extract the air below the sheet so that the plastic is pulled against the inside walls of the shaped mould, and the desired from is created.
        
        We leave the mould to cool, then remove the object.
      - Used to form: bathtubs, dashboards, shop signs and egg boxes.
    - - There are three principal techniques:
        
        Injection moulding
        
        We inject melted thermoplastic into a mould.
        
        When the material has cooled and solidified, we extract it the form mould.
        
        Used to form: domestic utensils such as buckets and containers, vehicle and aircraft components.
        
        Blow moulding
        
        We put a tubular-shaped piece of plastic into a hollow mould wich has the same shape as the object that we awant to make.
        
        We close the mould and blow perssurised air into it, so that the plastic adherers to the sides of the mould and takes its shape.
        
        When the object is cold, we remove it from the mould.
        
        Used to form: hollow objects, for example bottles and flasks.
        
        Compression
        
        We put thermostable plastic, wich can be in granular form, into the base of a cavity mould.
        
        The outer part of the cavity mould, shaped the same, is closed to compress the material inside. We then heat it and it becomes soft and malleable.
        
        The plastic adapts to the shape of the cavity between the two parts of the mould.
        
        We extract the object when the plastic has cooled solidified.
        
        Used to form; different types of containers, machine bodywork and electrical appliances.
- - - - Cutting
        
        Cutter: To cut sheets of different thickness, depending on their hardness.
        
        Scissors: To cut soft, thin flexible sheets.
        
        Steel bit: To cut sheets less than 1mm in thickness.
        
        Fretsaw: To cut soft, low densisty plastics. Can make straigth, slanting and curved cuts.
        
        Jig saw: To cut every large sheets of plastic, and rigid plastics in general. Can make straight, slanting and curved cuts.
        
        Powe press: To cut flat sheets of low densisty plastic. Makes simple objects by applying pressure.
        
        Hot metal thread trimmer: To cut sheets of soft thermoplastic.
      - Perforating
        
        Drill bit: Tool that makes holes in plastics. Consists of incerting a long, thin, round and threaded piece of metal into the head of the machine that revolves at high speed for cutting holes.
      - Trimming and filing
        
        A file has a rough surface. Used to finish the surfaces and edges of hard materials. A rasp has an even rougher surface, covered with `theeth´. Used to finish the surfaces and edges of soft materials.
- - - - We can join and then separate objects with mechanical fasteners.
        
        Nut and bolt: -Used to fasten two objects together. -Nut used to tighten the bolt.
        
        Standard screw: -Used to fasten two objects. -Holes must be drilled first before the screw is insert.
        
        Double ended screw.: -Each end of the screw can be inserted into one of a pair of objects.
    - - We use this type of joint when we don´t want to separate or dismantle the pieces. We can use adhesives or soldering.
        
        Adhesives
        
        Joining two surfaces permanently. Main types: -Resins with two components: liquid, high water resistance. -Acrylic cement: liquid, used mainly with PVC and polystyrene. -Contact adhesives: liquid, work instantly after applying to both surfaces, used with all types of plastics.
        
        Soldering
        
        Joining thermoplastics using heat and pressure.
- - - - We get natural fibres from raw materials. The fibres are cleaned, untangled, stretched and dyed to make threads. These threads are woven to make cloth. Leather is made from animal skins chemically treated to keep its quiality and beauty.
        
        Vegetable origin
        
        Cotton: From the plant of the samer name. Naturally white; can be dyed. Elastic anf flexible. Light and absorbs moisture. Good thermal insulator. Resistant to acids.
        
        Linen: From the flax plant. Naturally white or beige. Elastic and flexible. Good thermal conductor. Resistant to chlorine and bleach.
        
        Hemp: Extracted from a herbaceous plant. Very strong. Used in shoemaking, crafts and decorations.
        
        Animal origin
        
        Wool: From sheep. Various natural colours, but easily dyed. Very elastic. Excellent thermal insulator. Resistant to acids.
        
        Silk: Made from a material secreted by a worm called a silkworm, wich forms extremely fine threads. Highly resistant and elastic. Good thermal and electrical insulator.
        
        Asbestos: Fibrous mineral. Fireproof. Used for fire-resistant roofs. A health risk to use and inhale.
        
        Metals: Threads of gold, silver and copper. Used to make cloth.
    - - Synthetic fibres such as nylon, polyester, rayon and Lycra are plastics. They are long-lasting, resistant and waterproof. A mixture of natural and synthetic fibres is often used to make textiles.