Lead: Wrap-wrapped machine is divided into pre-stretch type and resistive stretch type according to the stretching condition of the wrap film. Pre-stretching means that the wrap film is stretched in advance by the pre-stretching mechanism, and the pre-stretching mechanism is not stretched. It can only rely on the goods to rotate and stretch the film. The differences between the two are explained in detail below.
The wrapping and wrapping machine is divided into a pre-stretching type and a tensile-stretching type according to the stretching condition of the wound film, and the pre-stretching means that the wrapping film is stretched in advance by a pre-stretching mechanism, and the stretching is not a pre-stretching mechanism, only We can rely on the goods to rotate and stretch the film. You can choose which stretching method to use according to the characteristics of the goods. The following two methods of stretching are introduced in detail:
First, the pre-stretch wrapping machine
The pre-stretch wrapping machine refers to pre-stretching the wrapping film according to a pre-set stretching ratio by a pre-stretching film frame mechanism. The operator only needs to set the number of winding layers and the height of the top, put the articles into the turntable, start the equipment, and the film frame motor, the turntable, and the pre-pull motor will automatically run, and the whole winding package of the goods can be realized.
The advantage of the pre-stretch wrapping machine is that the film is uniform, the packaging is beautiful, and the adaptability is strong. The ultra-light and ultra-high goods can be used, and the same condition can save 30-50% of the consumables. In this case, the winding required is used. The film quality is better, and some of the stretched film has a narrower width after stretching, or a pattern appears, and even more suddenly breaks, so it is necessary to carefully select the quality of the stretch film.
The pre-stretched film frame mechanism is driven by the motor, so the motor is equivalent to the heart of the mold frame, and the pre-stretching of the wound film is realized by the rotation of the different rotational speeds of the various components, so the reaction speed of the motor is very important. At the same time, it is required to be soft and not easy to break. The film frame motor is divided into DC motor and AC motor. The DC motor reacts quickly, the force is soft and it is not easy to break the film, it is not hot, stable, and saves electricity. However, the cost is high, and the technical difficulty of controlling the DC motor is large, so it generally has greater strength. The manufacturer will use a DC motor.
Second, the resistance stretch wrapping machine
The resistance stretch wrapping machine refers to the friction damping of the resistance stretching mechanism, so that the speed of the winding film is relatively slower than the speed of the rotation of the pallet goods, and the winding film is pulled apart by the weight of the cargo. The resistance stretching method requires the cargo to have a large self-weight. Generally, it is required to be more than 1 ton. The weight is too light, which may cause the cargo to pull the film without being pulled, and the film may be pulled by the wrapping film, resulting in failure to properly package.
The resistance stretch wrapping machine can adjust the damping to zero, which means that no stretching is required. Therefore, this machine has lower requirements for the wrapping film, and the general wrapping film meets the requirements. The disadvantage is that stable packaging is not possible for lighter, taller goods.
The pre-stretch wrapping machine and the stretch-stretch wrapping machine have their own characteristics and are easy to distinguish. Through this article, I hope to help those friends who are still not very clear.
Editor: Packaging Machinery Network Chen Zheng
