The concept of polymeric raw materials (plastics) usually includes two types of materials:
- 1.Primary polymers are high molecular weight compounds with a small number of different additives (stabilizers, plasticizers, inhibitors, pigments, lubricants, etc.). They are subdivided into thermoplastics, which are repeatedly converted into a viscous flow state and can be recycled and thermoset, which after the product manufacturing go into a non-melting and insoluble state.
The first class of the most widely used polymers include: high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polyamide 6 (PA-6), polyvinyl chloride (PVC), polycarbonate (PC), polyethylene terephthalate (PET), polystyrene (PS), acrylonitrile butadiene styrene plastic (ABS). Epoxy and polyester resins are widely used among the reactants.
2.Polymer composite materials that include a polymeric matrix (thermoplastic or thermoset) and fillers (dispersed or fibrous) and / or other polymers, and various additives. Such materials usually are used to create products with high or specific characteristics for specific purpose.
Recyclable and primary polymeric raw materials
Today polymers are used in different spheres of human life and industries, so recycling of polymeric raw materials is relevant. Due to their complex properties, polymers can be reprocessed into new from recyclables or recyclables mixed with primary raw materials in different proportions.
Thermoplastic injection molding and extrusion materials
Most part of thermoplastics can be processed by molding under pressure and also by extrusion. The processing method will be determined by the properties of the polymeric raw material. There are a lot of polymeric materials, the most popular in use are:
Polypropylene is a synthetic thermoplastic polymer, usually transparent, which belongs to a group of polyolefins. PP is one of the lightest polymers with an average density about 900-905 kg / m3, it’s available in the form of granules or powder. PP has excellent transparency, ability to paint and shine. It has good water resistance, chemical resistance, and is also characterized by excellent thermophysical and physical-mechanical properties (tensile strength, hardness, modulus of elasticity, heat resistance). A significant disadvantage of polypropylene is the lack of frost resistance and oxidation sensitivity.
Low-pressure polyethylene is a synthetic thermoplastic polymer with linear structure, it is produced in the form of granules with a low degree of transparency, belongs to the group of polyolefins, with an average density about 960 kg / m3. It is a high-strength frost-resistant material.
High-pressure polyethylene is a synthetic thermoplastic polymer with some degree of branched macromolecular structure, produced in the form of translucent glossy granules, with an average density about 910-930 kg / m3. It has high moisture and frost resistance, low vapor and gas permeability, excellent resistance to mechanical damage and to the influence of alkali of any concentration, solutions of basic and neutral salts, organic and inorganic acids. The main disadvantage of all polyethylenes is the tendency to senesce, especially under the influence of ultraviolet radiation.
Polyvinyl chloride is made in the form of fine powder or opaque granules. Density of polyvinyl chloride is about 1350-1460 kg / m3. Thanks to the addition of special additives - plasticizers, PVC can be rigid or soft with a different set of thermophysical and physical-mechanical properties. PVC is divided into vinyl plastic (content of plasticizer up to 10%) - rigid polymer with high strength; plasticizer (plasticizer content from 10% to 90%) is a soft polymer with the ability to adjust elasticity, strength and toughness; plastisol (content of plasticizer more than 90%), which is a dispersion of PVC particles in the plasticizer.
Polyamide 6 is made in the form of granules from white to light yellow color with density about 1110-1160 kg / m3, structural polymeric material with extremely high mechanical properties, has good antifriction ability. This polymer is chemically resistant to the effects of oils, gasoline, alcohol, weak acids, diluted and concentrated alkalis, non-toxic. The details obtained from polyamide 6 have high quality, form resistance, special strength, resistance to biochemical influences. They have good resistant to low temperatures, shock loads and have considerable operational period.
Additional Chemicals
Various special chemicals are becoming more widespread for eliminating of different disadvantages of specific polymers, improving the properties and reducing the cost of plastic products.
- Plasticizers. Give the material more elasticity, facilitate its processing, increase the resistance of finished products to low temperatures.
- Flame retardants. Reduce the combustibility of polymers, increase their safety. The use of flame retardants is especially important for the manufacture of parts of electrical appliances, electrical insulation, both for household and industrial items.
- Impact modifiers. Are used for the manufacture of plastic products, for which the indicators of resistance to shock loads are important. Protect polymers from negative climatic factors influence.
- Mineral fillers. Improve product performance, improve appearance and reduce the cost of the final product. Often used to give polymeric materials specific characteristics (magnetic, electrical, thermophysical, anti-frictional, antistatic, bactericidal, etc.).
- Pigments. Give plastic products any color. There are substances that increase the transparency of polymers that give a pearly luster, sparkle or matte effects.
- Antioxidants, thermal and light stabilizers. Increase the resistance of polymeric materials to the UV radiation, the oxidizers action, the elevated temperatures, in such way greatly increase the service term of the finished products and facilitates the conditions of their processing.
- Fluidity and recyclability modifiers. They allow to facilitate processing of polymeric raw materials and to improve conditions of production of products.
- Antimicrobial additions, abiotic additions, biocides. Increase resistance to bacteria (fungi and molds). Prevent fogging of material in water (algaecides).
The rational selection of polymeric raw materials is a crucial factor for receiving of quality polymeric products without using difficult production technology. At the same time, much of the problems that arise during the manufacture and operation of polymer product can be solved by modifying or replacing the components of the raw materials from which it is made.
The company can work both with your raw materials and with the possibility of selecting raw materials for the specific requirements of your product