In the process of automatic packaging of cheese-flavored biscuits, high-speed machinery and frequent material transmission make biscuits very easy to break and lose due to collision and extrusion. The toughness of food automatic packaging film roll, as one of its key physical properties, plays an important role in buffering external forces and protecting the integrity of biscuits.
The operating characteristics of automatic packaging equipment determine the special demand for film roll toughness. Taking the common horizontal automatic packaging machine as an example, it can complete dozens or even hundreds of packaging actions per minute. Biscuits need to experience multiple mechanical forces during the process of wrapping, heat sealing and cutting by film rolls. If the film roll is not tough enough, local stress concentration is prone to occur during traction and stretching, resulting in uneven wrapping force and biscuits being squeezed and broken; at the same time, film rolls with poor toughness may suddenly break during high-speed movement, causing equipment shutdown and material loss, further increasing the risk of biscuit breakage.
The toughness of food automatic packaging film roll is measured by core indicators such as tensile strength and elongation at break. Tensile strength refers to the maximum tensile force that a material can withstand before breaking, and elongation at break reflects the degree of deformation of the material when it is stretched to break. For cheese-flavored biscuits, a higher elongation at break (such as 200%-300%) is usually required to ensure that the film roll is evenly stressed during the stretching and wrapping process to avoid compression of the biscuits due to local tension. For example, the film roll made of polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA) can ensure good tensile ductility and provide appropriate buffering force by adjusting the formula ratio to reduce the rigid contact between the biscuits and the packaging film.
The difference in toughness of food automatic packaging film rolls of different materials directly affects the protection effect of biscuits. Polyester (PET) film rolls have high hardness and strong stiffness, but relatively weak toughness. When used alone, it is easy to cause the corners of biscuits to be crushed due to insufficient stretching deformation; while polypropylene (PP) film rolls have better toughness, but they are easy to become brittle in low temperature environments. To solve this problem, a multi-layer composite process is often used to combine a high-toughness inner layer material (such as EVA) with an outer layer material with strong barrier properties (such as PET), which can not only meet the functional requirements of the packaging, but also reduce the biscuit breakage rate through the buffering effect of the inner layer material.
In addition to material properties, the processing technology of the film roll will also affect the toughness. The blow molding process can adjust the molecular orientation and crystallinity of the film roll by controlling parameters such as temperature and air pressure, and improve its toughness and tear resistance; the film roll produced by the cast film process has uniform thickness and is easier to maintain stable toughness performance in high-speed packaging. For example, the polypropylene (BOPP) film roll produced by the biaxial stretching process has balanced longitudinal and transverse tensile strength, which can wrap biscuits more evenly in automated packaging and reduce breakage caused by uneven force.
In actual production, the toughness of the film roll needs to be dynamically optimized in combination with equipment parameters. Parameters such as the traction speed, heat sealing temperature, and cutting force of the packaging machine will interact with the toughness of the film roll. If the packaging machine runs too fast, the film roll needs to have higher instantaneous tensile toughness to adapt to fast wrapping; if the heat sealing temperature is too high, the film roll may become partially brittle and reduce the overall toughness. Therefore, by adjusting the equipment parameters to match the film roll performance, the biscuit breakage loss can be further reduced.
In the automated packaging process of cheese-flavored biscuits, the toughness of the film roll can effectively avoid the biscuit breakage loss by evenly dispersing external forces, buffering mechanical collisions, and adapting to high-speed movement. From material selection, process optimization to equipment parameter matching, the coordination of each link is the key to achieving efficient packaging and biscuit quality protection.
