HM | RAFFIA
HM-HDPE Full Form:
High Molecular High-Density Polyethylene
What is HM-HDPE?
HM-HDPE (High Molecular High-density polyethylene) grade has higher molecular weight compared to HDPE and hence is extensively used for wear or abrasion resistant components. High molecular high-density poly ethylene (HM, HDPE), a type of plastic carry bag, has a strong degree of rigidity as well as a high initial tear and propagation resistance. They are excellent for applications involving food contact because they impart neither taste nor odor.
How is HM-HDPE made?
The blown film extrusion technique creates the film that can be used to make bags in the form of a tube. An annular die is used to extrude a tube, which is then inflated with air pressure to the desired diameter, cooled, collapsed at the nip rolls (also known as pinch rolls), and lastly twisted into rolls. Granules of HM HDPE are fed into the extruder's hopper where they are heated in the barrels to create a molten resin that flows around a mandrel inside the die and is shaped into a tube. Typically, the die opening ranges from 4 to 6.5 millimeters. A passageway in the die allows pressurized air to be fed into the tube.
In order to inflate the tube to the required bubble size, it is typically extruded vertically upward. Air is then supplied via the centre of the mandrel. The die at one end and the appropriate wind up mechanism at the other end will work together to keep the trapped air in the bubble. The film is oriented in the machine direction as the bubble is dragged away at a speed that is often higher than the polymer flow. The bubble is converged by wood slats, a rack of rollers, or a similar mechanism as it approaches the nip roll above the die to transform it from a tubular bubble to a flat two-layer sheet (lay flat tube).
The major application for HM HDPE film is packaging. It can be utilized in a variety of ways, including continuous rolls, carry bags, shopping bags, pouches, liners, etc. It is currently frequently used to produce carry bags, which are quickly displacing the traditional paper bags used for shopping. The use of carry bags for carrying or transporting numerous products, including groceries, fruits and vegetables, books and stationery, gifts, meal packages, medicines, and a range of other items, has increased significantly. Due to its excellent barrier qualities and inertness, HM HDPE film is utilized as a liner in tea packaging. HM-HDPE is widely used to make bags. Some of the examples are listed below-