Advantage and disadvantage of HDPE, PP

17/11/2019
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HDPE Plastic Raw Granules Manufacturer from Mumbai

What material is HDPE?
HDPE is an opaque white wax-like material. The specific gravity is lighter than water, and the specific gravity is 0.941~0.960. It is soft and tough, but it is slightly harder than LDPE and can be slightly elongated, non-toxic, and tasteless. It is a product of polymerization under low pressure under the catalyst of the Ziegler catalyst, so high-density polyethylene is also called low-pressure polyethylene.
The unique characteristics of various grades of HDPE are an appropriate combination of four basic variables: density, molecular weight, molecular weight distribution, and additives. Different catalysts are used to produce customized special performance polymers. The combination of these variables produces different grades of HDPE; the best balance is achieved in performance.

The advantages of HDPE:
1. HDPE has excellent resistance to most household and industrial chemicals. It can resist the corrosion and dissolution of strong oxidants, acids, alkalis, and organic solvents.
2. HDPE is non-hygroscopic and has good water vapor resistance. It can be used for moisture and moisture-proof or packaging.
3. HDPE has very good electrical properties, especially high dielectric strength, making it very suitable for wire and cable. Medium to high molecular weight grades has excellent impact resistance, even at room temperature or even at low temperatures of -40F.
4. HDPE has good processability and heat sealability.
5. HDPE has a high degree of paper-like, stiffness, and opening, and the hardness is 4~5 times that of LDPE film. Its surface hardness, tensile strength, rigidity, and other mechanical strengths are close to PP and tougher than PP.
6. HDPE is non-toxic and odorless, and can also be used in food, clothing, knitwear and other packaging materials, economical and affordable, and low price.
Disadvantages of HDPE:
1. Its aging resistance and environmental stress cracking are not as good as LDPE, especially thermal oxidation will reduce its performance, so high-density polyethylene is added with antioxidants and ultraviolet absorbers to improve its deficiencies when it is made into plastic coils. Office.
2. HDPE has low transparency and a poor barrier to oxygen and other gases.
3. It is difficult to print. When printing, surface discharge treatment is required. It cannot be electroplated and the surface is matte.

polypropylene granule

What material is PP?
Non-toxic, odorless, low density, strength, stiffness, hardness, and heat resistance are better than low-pressure polyethylene, can be used at about 100 ℃. It has good dielectric properties and high-frequency insulation and is not affected by humidity, but it becomes brittle at low temperatures, is not wear-resistant, and is easy to age. Suitable for making general mechanical parts, corrosion-resistant parts, and insulating parts. Common organic solvents such as acids and alkalis have little effect on it and can be used in tableware.

The advantages of PP:
1. The relative density is small, only 0.89-0.91, which is one of the lightest varieties in plastic;
2. Good mechanical properties, in addition to impact resistance, other mechanical properties are better than polyethylene, molding performance is good;
3. Has high heat resistance, continuous use temperature can reach 110-120 ℃;
4. Good chemical properties, hardly absorb water and do not react with most chemicals;
5. Pure texture, non-toxic;
6. Good electrical insulation;
7. The transparency of polypropylene products is better than that of high-density polyethylene products.


Disadvantages of PP:
1. The product has poor cold resistance and low-temperature impact strength;
2. The product is susceptible to aging due to light, heat, and oxygen during use;
3. Poor coloring;
4. Easy to burn;
5. Poor toughness, high static electricity, poor dyeability, printability, and adhesion.