LDPE film and HDPE film
DATE：2019/11/22 9:04:38 / READ： / SOURCE：This station
LDPE film and HDPE film
Low density polyethylene (LDPE) film
LDPE packaging film is widely used, accounting for more than 60% of all packaging film. It can be produced by extrusion casting method and extrusion inflation method. The melt flow rate (MFR) is preferably 0.2-7 g/10 min. LDPE with low MFR can be used for the production of repackaged film bags. The characteristics of the LDPE film are as follows:
1. Good transparency, light transmission and UV transmission;
2. The film is soft and has strong impact resistance, but the tensile strength and pinhole resistance are low;
3. LDPE film can be used for a long time at 60 ~ 60 ° C, thickness of 10 ~ 50μm LDPE film, suitable for 2-8 ° C refrigerator refrigerated packaging and -18 ~ -24 ° C frozen food packaging
4. LDPE film with a thickness of 0.02-0.1 mm and a liner bag with a diameter of 300-1000 mm which can be used for daily necessities and fertilizer packaging;
5. Using LDPE film with MFR<1g/I Omin and thickness of 0.2-0.3mm, it can hold 20~30kg of material for heavy packaging.
6. LDPE film is odorless, non-toxic, odorless, good in opening, heat-sealing and transparency. LDPE film with thickness of 0.015-0.03mm can be used for packaging of general foods, especially for dry foods, because LDPE film Excellent moisture resistance, but high gas permeability.
High density polyethylene (HDPE) film
The HDPE film has a high molecular weight HDPE with a relative molecular mass of 150,000 to 300,000, a medium molecular weight HDPE with a relative molecular mass of 80,000 to 150,000, and a low molecular weight HDPE with a relative molecular mass of <80,000. The relative molecular mass HDPE film accounts for 80% of the HDPE film (Japan), and its strength is 4 to 5 times that of the medium molecular weight HDPE. HMWHDPE with a density of 0.947~0.954g/cm' and an MFR of 0.05-0.1g/10min can produce high-strength ultra-thin film with thickness of 5~8μm by extrusion inflation method, accounting for more than 90% of the whole HDPE film. Garbage bags and shopping bags have the following characteristics:
1. Low transparency and ability to prevent UV light transmission
2. It has a high degree of opening, a certain stiffness, and a hardness of 4 to 5 times that of the LDPE film, and has a high degree of paper-like property;
3. It has high tensile strength and toughness. At the same thickness, its strength is more than twice that of LDPE film, but the tear strength is lower than that of LDPE film;
4. Excellent moisture resistance, water vapor transmission rate is 1/2 of LDPE film, N2, CO2, O2 gas permeability is 1/7, 1/10 and 1/5 of LDPE film respectively;
5. Water resistance, oil resistance and chemical resistance are better than LDPE film;
6. Heat resistance is better than LDPE, can be used below 120 °C, but the heat sealing temperature range is narrower than LDPE.
Low density polyethylene (LDPE) film
LDPE packaging film is widely used, accounting for more than 60% of all packaging film. It can be produced by extrusion casting method and extrusion inflation method. The melt flow rate (MFR) is preferably 0.2-7 g/10 min. LDPE with low MFR can be used for the production of repackaged film bags. The characteristics of the LDPE film are as follows:
1. Good transparency, light transmission and UV transmission;
2. The film is soft and has strong impact resistance, but the tensile strength and pinhole resistance are low;
3. LDPE film can be used for a long time at 60 ~ 60 ° C, thickness of 10 ~ 50μm LDPE film, suitable for 2-8 ° C refrigerator refrigerated packaging and -18 ~ -24 ° C frozen food packaging
4. LDPE film with a thickness of 0.02-0.1 mm and a liner bag with a diameter of 300-1000 mm which can be used for daily necessities and fertilizer packaging;
5. Using LDPE film with MFR<1g/I Omin and thickness of 0.2-0.3mm, it can hold 20~30kg of material for heavy packaging.
6. LDPE film is odorless, non-toxic, odorless, good in opening, heat-sealing and transparency. LDPE film with thickness of 0.015-0.03mm can be used for packaging of general foods, especially for dry foods, because LDPE film Excellent moisture resistance, but high gas permeability.
High density polyethylene (HDPE) film
The HDPE film has a high molecular weight HDPE with a relative molecular mass of 150,000 to 300,000, a medium molecular weight HDPE with a relative molecular mass of 80,000 to 150,000, and a low molecular weight HDPE with a relative molecular mass of <80,000. The relative molecular mass HDPE film accounts for 80% of the HDPE film (Japan), and its strength is 4 to 5 times that of the medium molecular weight HDPE. HMWHDPE with a density of 0.947~0.954g/cm' and an MFR of 0.05-0.1g/10min can produce high-strength ultra-thin film with thickness of 5~8μm by extrusion inflation method, accounting for more than 90% of the whole HDPE film. Garbage bags and shopping bags have the following characteristics:
1. Low transparency and ability to prevent UV light transmission
2. It has a high degree of opening, a certain stiffness, and a hardness of 4 to 5 times that of the LDPE film, and has a high degree of paper-like property;
3. It has high tensile strength and toughness. At the same thickness, its strength is more than twice that of LDPE film, but the tear strength is lower than that of LDPE film;
4. Excellent moisture resistance, water vapor transmission rate is 1/2 of LDPE film, N2, CO2, O2 gas permeability is 1/7, 1/10 and 1/5 of LDPE film respectively;
5. Water resistance, oil resistance and chemical resistance are better than LDPE film;
6. Heat resistance is better than LDPE, can be used below 120 °C, but the heat sealing temperature range is narrower than LDPE.
Author：admin