Is there any way to keep the hardness of the polyethylene film stable without being affected by the temperature? It is difficult to be absolutely unaffected, but we can alleviate this problem in two ways. One method is not to make the oil too high or too low and keep it moderate, but the bag making process will be more difficult.
Another method is to add an appropriate amount of cold-resistant agent (also called antifreeze) to the polyethylene film. The cold-resistant agent can increase the toughness of the film and will not be brittle in a low temperature environment below zero. Some PVC bags used in low-temperature areas (such as Russia) usually require that the PVC bags can be kept at minus 15 degrees Celsius without being brittle.
