Linear low density polyethylene (LLDPE) and linear very low density polyethylene (VLDPE) include a wide range of polyethylenes from clear and elastomeric to opaque and rigid and dry. These grades are used when high stiffness and strength are considered along with low density and high flexibility. The important application of LLDPE is in the production of plastic films such as inflatable film, casting film, extrusion coating and food packaging.
Linear very low density polyethylene (VLDPE) is also obtained by increasing the percentage of comonomer, which properties of this polymer include very low density as well as properties such as transparency, softness and toughness, in addition, it is used in the production of medical tubes and meat packaging. is used
Table 3) Characteristics of different grades of linear low density polyethylene
Linear Low Density Polyethylene (LLDPE) has a density between 0.915-0.925 g/cm3. It is a linear polymer that has short branches and is generally produced by copolymerization with short chain alpha olefins such as 1-butene, 1-hexene, and 1-octene.
One of the types of polyethylene granule widely used in the production of thermoplastic products is linear low density granule, which is also known as LLDPE granule.
This type of granule has extraordinary characteristics and properties, the characteristic features of linear low density polyethylene granule are low density, elastic properties and high flexibility.
This type of granule is mostly used in the production of special films and nylons for food packaging, greenhouse covers, etc. The use of linear granules in the production of plastic products creates their high quality and transparency.
Linear low density polyethylene granule is one of the famous and common grades among the types of granules, which is also known as film grade.
Due to its short side branches and low density, the linear low density granule has good resistance and elastic properties, and therefore it is one of the widely used grades in the nylon and nylon industry.
Although LDPE low density polyethylene granule has a low density, it has a higher density than the linear low density grade LLDPE. Therefore, it shows better resistance against tearing, impact and puncture. The evaluation method of polyethylene granules is based on melt flow index, oxygen permeability, molecular mass, environmental stability and hardness.
Physical properties of LLDPE linear low density polyethylene granules
• Difficulty level 315
• Impact toughness of 1.6 to 1.9 kJ/m2
• Maximum temperature tolerance of 180 degrees Celsius
• Yield strength 60 to 80 Mpa
• Density 0.941 to 0.965 grams per cubic centimeter
• Having an elasticity module of 4700 Mpa
• Has a tensile strength of 81 Mpa
This material has good processability due to its chemical structure. Linear low-density granule is also used in the manufacture of thermoplastic impact products due to its high resistance.
This type of granule has a more reasonable price than other types of polymer granules, so the production of products made from it will be more affordable.
LLDPE granule is also highly resistant to chemicals. Therefore, in terms of solubility, it can be said that linear polyethylene granules are considered as a solution, the solubility of which increases by heating in hydrocarbons.
Applications of linear low density polyethylene granules
Linear granules are widely used in the production industries of thermoplastic products. Among the most important applications of linear low density polyethylene granules, the following can be mentioned:
• Production of all kinds of water supply pipes
• Production of all kinds of household and industrial plastic appliances
• Production of all kinds of plastic toys
• Production of all kinds of stationery
• Production of all kinds of plastic vases
• Production of all kinds of nylon and nylex
• Production of disposable and permanent tablecloths
Advantages of using LLDPE linear low density polyethylene granules
The use of linear low-density polyethylene granules in the production of thermoplastic products creates advantages and features in the manufactured goods. Among the advantages of linear granules, the following can be mentioned:
• Creating high resistance against acids, alcohols and dilute bases
• Creating transparency and clarity in thin polyethylene films
• Creating electrical insulation properties
• Processability and affordability of the product
• Creating strength at low temperature and durability in air
• Creating flexibility and high elasticity in polyethylene films
Types of LLDPE linear light polyethylene grades produced in Iran petrochemicals:
1) Linear low density polyethylene LLD209 of Amirkabir Petrochemical
2) Linear low density polyethylene LLD 209 AA of Amirkabir Petrochemical
3) Linear low density polyethylene LLD 209 AA of Arak Petrochemical
4) Linear low density polyethylene LLD209 KJ Tabriz Petrochemical
5) Linear low density polyethylene LLD 22B02 of Lorestan Petrochemicals
6) Linear low density polyethylene LLD 22B02 of Mahabad Petrochemicals
7) Linear low density polyethylene LLD 235F6 Petrochemical Jam