Various plastics provide ample opportunities for the creation of certain structures and components.It is no coincidence these elements are used in various fields ranging from engineering and radio engineering to medicine and agriculture.Pipes, accessories for cars, insulation materials, housings for appliances and household items - a considerable list of what can be created from plastic.
main varieties
plastics and their use based on what underlying polymer - natural or synthetic.They are subjected to heat, pressure, and then operate molding products of varying complexity.The main thing is that when these manipulations to keep the form of the finished product.All plastics are thermoplastic, that is reversible, and thermosetting (irreversible).
Reversible become plastic under the influence of heating and further pressure, with the fundamental changes in the composition do not occur.Compression and has already become a firm can always soften the product and give it a definite shape.Known types of such plastic (thermoplastic) such as polyethylene and polystyrene.The first is resistant to corrosion and dielectric properties.On its basis the pipes, films, sheets, it is widely used as an insulating material.
from styrene to polystyrene
The polymerization prepared styrene polystyrene.Thereof further create different parts or by injection molding.Such plastics are widely used for the production of large components and products such as components for refrigerators and bathrooms.Among thermosetting plastics are often used pressporoshki, laminates, fiber reinforced plastic, which can be further processed to produce various components.
Plastics - very convenient to use and from which you can create a variety of products.Depending on the thermal properties are the following types of plastics processing:
- pressing.It is the most popular way of getting products from thermosetting materials.The molding is carried out in special molds under high temperatures and pressures.
- Die Casting.This method makes it possible to create products of various shapes.For this special tanks filled with molten plastic.The process itself is characterized by high productivity and efficiency.
- extrusion.Through such processing receive many kinds of plastic products, such as pipes, yarns, cords, tapes of different purposes.
- blowing.This method - the possibility of creating an ideal form of bulk products, which will have a seam on the spot closing the mold.
- Stamping.In this way, products are plastic sheets and plates with special forms.
Features polymerization
plastics can be obtained by polymerization and polycondensation.In the first case the monomer molecules are linked to form a polymer chain without release of water and alcohol, in the second - by-products are formed, not bound to the polymer.Various kinds of polymerization methods and allow to obtain plastics compositions which differ initial properties.An important role in this process is played by the correct temperature and the heat of reaction to the molding composition polymerize properly.In the polymerization, it is important to pay attention to the residual monomer - less than it, more reliable and longer in service is plastic.
porosity
If you have violated the polymerization, it can lead to defects in finished products.They appear bubbles, streaks and high internal stress.There are different types of porous plastic:
- Gas.It occurs due to the fact that violates the polymerization, benzoyl peroxide, and boils.If the gas pores are formed in the thickness of the prosthesis, it is required to alter.Granular
- porosity occurs due to excess polymer powder, evaporation of monomer from the surface of the material quality or insufficient mixing of the plastic composition.
- porosity ratio.It arises from the reduction of the volume of the polymerizing mass under the influence of insufficient pressure or a lack of the molding material.
What to consider?
should be aware of what types of porosity are plastic, and avoid defects in the final product.It is necessary to pay attention to the small porosity on the surface of the prosthesis.This happens because of the large amount of the monomer, and the porosity is not subjected to grinding.If while working with the plastic forms an internal residual stress, the product will crack.This situation occurs due to an abnormality in the polymerization, when the object is too long in the boiling water.
In any case, the deterioration of the mechanical properties of polymeric materials as a result leads to aging, and therefore the production technology must comply completely.
Basic plastic - what's that?
the material in question is widely used in the manufacture of bases removable plate dentures.The most popular types of basic plastics are synthetic base.Mass for the bases, usually a combination of powder and liquid.When mixed create a molding mass that hardens when heated or spontaneously.Depending on the material that turns hot curing or self-hardening.For basic plastics Hot polymerization include:
- etakril (AKP-15);
- akrel;
- ftoraks;
- Akron.
materials to create dentures are flexible plastics, which are needed as soft padding for the bases.They must be safe for the body, fixedly connected with the base of the prosthesis maintain elasticity and a constant volume.Among these plastics noteworthy eladent, which is lined for bases of removable dentures and ortoksil which is obtained based on siloxane resin.
Building materials
main types of plastic used in various fields of construction, depending on the composition.The most popular materials include the following:
- polymer concrete.This composite resin, which is created based on thermosetting polymers.The best in terms of physical and mechanical properties of polymer concrete are considered on the basis of epoxy resins.The fragility of the material is compensated fiberfill - asbestos, glass fibers.Polymer concrete are used to create designs that are resistant to chemicals.
- GRP - modern types of plastic construction, which comprises a sheet material of glass fiber fabric linkable polymer.Fiberglass is created based on or oriented chopped fibers, as well as fabrics or mats.
- flooring materials.They are represented by different kinds of roll covers and zhidkovyazovyh compositions based on polymers.In the construction of widely used PVC linoleum on the basis of having good thermal and acoustic insulation performance.Seamless mastic floor can be created based on the feed mixture with the oligomers.
Plastic and its marking
There are 5 types of plastics, which have their designation:
- Polyethylene terephthalate (PETE is the letter marking or PET).They are efficient and broad scope: is used to store a variety of beverages, oils, cosmetics.
- High Density Polyethylene (HDPE is labeled or PE HD).The material differs efficiency, ease, resistance to temperature changes.Used for the manufacture of disposable tableware, containers for food storage bags, toys.
- Polyvinyl chloride (PVC or labeled as V).From this material are joinery, furniture parts, film for stretch ceiling, pipes, flooring and more.Because the content of bisphenol A, vinyl chloride, polyvinyl phthalates are not used in the production of products (containers, cookware and the like. P.) For storing food.
- polyethylene (LDPE or marking PEBD).This cheap material is used in the manufacture of a package of garbage bags, linoleum and CDs.
- Polypropylene (the letter is marked PP).It features durability, heat resistance, suitable for the production of food containers, food packaging, toys, syringes.
Popular types of plastics - polystyrene and polycarbonate.They are widely used in various industries.
Applications
Different types of plastics are used in a variety of industries.The requirements to them about the same - ease of operation and safety.Let us consider the types of thermoplastics and their scope.
| Plastic | Scope |
| polyethylene (high and low pressure) | Production packaging, unloaded parts of machines and equipment, containers, coatings, foils. |
| Polystyrene | production equipment, insulation films, stiropiana. |
| Polypropylene | widely used in the manufacture of pipes, car parts, components for refrigeration. |
| Polyvinyl chloride (PVC) | Manufacture of chemical equipment, pipes of various parts, packaging, flooring. |
| Polycarbonate | manufacturing precision machine parts, equipment, radio and electrical engineering. |
thermosetting plastics (table)
| Material | Scope |
| Phenoplasts | used to create products haberdashery (buttons, and so on. N.), ashtrays, plugs, sockets, enclosures radio and telephone. |
| aminoplast | used for the manufacture of adhesives for wood, electrical parts, haberdashery, thin coatings for decoration, foam materials. |
| Steklovoloknity | are used in the manufacture of electrical parts in power engineering, large parts simple forms (bodies of cars, boats, buildings devices, and the like). |
| Polyesters | based on polyesters are rescue boats, car parts, furniture, cabinets gliders and helicopters, corrugated sheets for roofs, ceiling lamps, masts for antennas, skis and poles, fishing rods, safety helmets and thelike. |
| Epoxy | used as insulating material in electrical machines, transformers (as a high-voltage insulation) and other devices, in the manufacture of telephone fittings, radio (for the manufacture of printed circuit boards). |
Instead of conclusion
In the present article, we reviewed the types of plastics and their application.When using such materials is taken into account many factors, ranging from the physical and mechanical properties and characteristics of finishing work.For all its efficiency plastic has a sufficient level of security, which significantly expands the scope of its application.
