There are five types of coating film used in PP woven bags mostly. The types of coating film and its properties are the initial requirements of a PP woven bag. These need to know before choosing the best film material.
Depending on the user requirements, five types of coating film or laminated film use in woven polybag production. The most used film types are pearl film, Aluminum film, matte film, imitation paper film, and BOPP film. Which layer should use on woven polybags depend on the requirements of the products would store in them. The other condition also needs to consider from the buyer site, if any. The film used in woven PP bags should protect its inner material and enhance sale appeal at the same time.
Different film types possess diverse qualities and hence suitable for separate end-use. The distinction of these film materials makes the woven polybag suitable for particular product packaging.
PP woven bags use for several purposes, and hence the properties required for each end-use are different. For an instant, a food packaging bag and its coated film need such qualifications so that it can protect the nutritional properties. A granular or powder product packaging materials need such properties so that they can prevent leakage and granular spreading. A liquid reservoir needs complete water-proof finishing obtained from certain coating materials. Due to the required divertible properties of pp woven bags, the film materials used for coating are also different.
1. Pearl Film:
If you require a bag with both requirements of moisture-proof and printable, a pearl film-coated PP woven bag might be the best among all other laminated bags. Here, a polypropylene layer or film attached on both sides of the woven PP fabric, and the result comes outstanding for creating an excellent sale appeal and print facilities. The polypropylene film can easily be attached to the base fabric by a process named heat setting. The coating with this process is also intensively cost-effective. The coat of pearl film is moisture-proof, shading, and anti-corrosive. That is why it can use for several purposes. Food items like rice, flour, or other granular items can easily store in this coated bag. This bag is also quite popular for carrying agricultural goods, chemical fertilizers, and poultry feeds.
2.Aluminum film:
An aluminum film can use on both the face or backside of the PP woven bag. The coating of aluminum foil enhances the functional properties of the pp woven bag. The main advantage comes from the heat-insulating property of the aluminum foil. Due to the low heat shrinkage, the PP woven bags become more substantial and last longer than usual bags. The Aluminum coated PP woven bag is famous for use water-proof material packaging, food products packaging, and other materials packaging that required a sufficient barrier. This coating material makes the convention pp woven bag superior in terms of heat resistivity. It can use for sensitive food packaging where storing temperature controlling is the top requirement like dairy items or tobacco goods.
3. Matte film:
The distinct properties of these coating bags comprise several areas. The matte-coated PP woven bag is moisture-proof and can use for storing food or agricultural products. The stretch resistance property of this film material is high enough which facilitate better stretching properties in both longitudinal and transverse directions. That makes the base fabric stronger and enhances the load-bearing capacity of the PP woven bag. The matte film laminated bag is famous for packaging food items in small amounts. It is due to the excellent handling properties of the packaging film. It is somewhat resistive to heat and possesses a high glossy appearance. It also creates an oxygen barrier which is an essential advantageous property for storing food and agricultural products.
4. Paper film:
A Paper film is laminated to the outer or inner surface of the pp woven bag. That is a complex structure made for the highest puncture resistance, tearing resistance, and improved useability. That film layer enriches the functional properties of the PP woven bag. It can use for storing and transporting powdery or fine granular products. For an instant, cement bag needs superior load-bearing capacity and as well as they transport fine powder. You cannot use plastic, paper, or any other bag for this purpose. Here the paper film laminator bag can use successfully. The PP woven bag possesses enough load-bearing capacity, and the paper film makes it suitable for dealing with cement-like powdery material. This film helps to prevent leakage of the granular material from the porous of the woven fabric. This paper film also makes the bag leak-proof and chemically risk-free. Flour or other food items can easily transport or store for a long time in this particular bag.
5. OPP Film:
The most conventional film used for laminating woven poly bags is the OPP or BOPP bags. OPP instead for Orientated Polypropylene film. This film pack with many suitable properties that make it perfect for packing food items. A food packaging material should protect the nutritional properties until the final consumption. That also includes a sufficient resistance to moisture, sunlight, and gaseous matter. The film also needs to enhance the sale appeal and should cost-effective as well. All the requirements can obtain using BOPP film on a woven poly bag.
It is also worth mentioning that, there is also a PE film between the coating layer and the PP Fabric. The function of the PE film is equivalent to glue. During the application process, the polyethylene melts very near the melting point. It becomes sticky and bonds the film layer and the PP woven fabric together. When the temperature lower, the polyethylene becomes hard. As a result, the bond becomes permanent.
Some other films also use to coat with PP woven bag but, their use is limited. The other film material is the antimicrobial film, anti-virus film, LDPE film, MDPE film, HDPE film, Polystyrene film, Silicone release film and non-woven film are some of them.
