Please enable JavaScript.
Coggle requires JavaScript to display documents.
PLASTICS, This depends on the outer coating applied by the final cylinder.…
PLASTICS
Formation techniques
Plastics come in three different forms: powder, granules and resins.
Lamination
Thermoplastic produced by the extrusion method is passed through a series of hot cylinders to preoduce sheets of varying thickness.
With this technique, we can produce different finishes, for example, glossy, matt or textured.
Used to form: worktops, to cover surfaces of kitchens cupboard and drawers.
Extrusion
Stages:
-
1. We put thermoplastic, in granular form, into previously heated cylinder
-
2. We apply pressure by means of a large, rotating screw, which forces the melted material out, through a nozzle.
Used to form: wrapping, lining for electric cables, tubes and pipes.
Vacuum forming
Stages:
-
3. We extract the air below the sheet so that the plastic is pulled against the inside walls of the shaped mould, and the desired form is created.
-
4. We leave the mould to cool, then remove the object.
Used to form: bathtubs, dashboards, shop signs and egg boxes.
-
Moulding
Blow moulding
2. We close the mould and blow pressurised air into it, so that the plastics adheres to its sides and takes its shape.
3. When the object is cold, we remove it from the mould.
1. We put a tubular-shaped piece of plastic into a hollow mould which has the shape of the object desired.
Used to form: hollowed objects, for example bottles and flasks.
Compression
-
-
2. 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.
Used to form: different types of containers, machine bodywork and electrical appliances
1. We put thermostable plastic, which can be in granular form, into the base of a cavity mould.
Injection
-
2. When the material has cooled and solidified, we extract it from te mould.
Used to form: domestic utensils such as buckets and containers, vehicle and aircraft components
Origin and properties
-
Properties of plastics
Strength, elasticity, rigidity and flexibility are characteristics of many plastics, although they vary from one type to another
-
-
Ecological properties
We can recycle plastics.
-
-
Chemical recycling. We apply chemical processes to make new materials from the original components of plastic residues.
The majority of plastics aren't biodegradable yet. Thanks to new technologies we're increasingly able to produce more, like:
-
-
-
-
-
Joining plastics
When plastics have been formed, shaped and finished, we can join pieces to each other.
-
-
-
-