How to correctly distinguish the quality of heat shrinkable film?

Heat shrinkable film quality identification method:

1, ignition identification method:

Heat shrinkable film with good quality is easy to ignite, and the flame is obvious when it burns, while those with unqualified substances are not easy to burn.

2, feel recognition method:

Heat shrinkable film, a food with qualified quality, feels smooth and flexible to the touch, while those with stiff and sticky feel are unqualified packages.

3, immersion identification method:

Heat shrinkable film with qualified packaging will float if it is placed in a container filled with water, and those with poor quality or unqualified packaging will often sink to the bottom of the water. Of course, the performance of this method is not improved at present, and many inferior products can achieve this effect through special production processes now.

PVC heat shrinkable film assembles scattered goods into a whole, which is also suitable for packaging single goods. Secondly, the heat shrinkable film film is close to the surface of the package, which makes people feel sticky and makes the goods more beautiful, crisp and shiny. It is a wise choice to improve the competitiveness of goods. The important point is that PVC has low input and high output, which is why many businesses choose it. The surface protection of high-shielding products forms a light and shielding surface around the products, thus achieving the goals of dust prevention, water resistance and theft prevention. It is particularly important to compress the film packaging to make the packaged goods evenly stressed and prevent the uneven stress from harming the goods, which cannot be done by the traditional packaging methods (bundling, packaging, tape packaging, etc.).

PVC heat shrinkable film has the characteristics of good transparency, good toughness, impact resistance, corrosion resistance and low water vapor permeability. When the film is subjected to the corresponding temperature, it automatically shrinks and tightly wraps the goods, thus achieving the functions of protecting the goods, rust prevention, pollution prevention, breakage prevention and theft prevention. The stability of commodity storage and transportation is good, and the packaging technology and equipment are simple, which is convenient for automatic heat-shrinkable packaging.

The materials used in thermal heat shrinkable film are mainly various thermoplastic films. At first, PVC was mainly made in heat shrinkable film. With the continuous development of market demand, the heat shrinkable film of PVC gradually decreased, while various multi-layer co-extruded heat shrinkable films such as PE, PP, PET, PVDC and POF developed and became the mainstream of the market. At present, there are nearly 20 shrink film manufacturers in China, only the Plastic Packaging Committee of China Packaging Federation, with an output of nearly 80,000 tons. It is predicted that in the next five years, the domestic heat shrinkable film market will grow at a rate of more than 20%.

Heat shrinkable film film is easy to break when printing. It is not that the quality of PVC heat shrinkable film is not good, but that there is a solvent in the printing ink for PVC that will dissolve the PVC film, and the volatility of this solvent is small. Therefore, if there is too much solvent in the solvent for dissolving PVC in PVC ink, the PVC heat shrinkable film will be dissolved and broken during printing. However, if the printing ink for PVC is not used, the printing fastness is not good. Heat shrinkable film film machine can assemble scattered goods into a whole, and it is also suitable for packaging single goods. Secondly, the heat shrinkable film film is close to the surface of the package, which makes people feel sticky and makes the goods more beautiful, crisp and shiny. It is a wise choice to improve the competitiveness of goods. The important point is that PVC has low input and high output, which is why many businesses choose it. The surface protection of high-shielding products forms a light and shielding surface around the products, thus achieving the goals of dust prevention, water resistance and theft prevention. It is particularly important to compress the film packaging to make the packaged goods evenly stressed and prevent the uneven stress from harming the goods, which cannot be done by the traditional packaging methods (bundling, packaging, tape packaging, etc.).

In actual production, all manufacturers control the heat sealing strength as an important quality index of ZI, whether for bag-making products or coil products used in automatic packaging production lines. Analysis of heat shrinkable film Film Manufacturers The following is a brief analysis of the factors that affect the heat sealing strength of hot heat shrinkable film film based on the experience in actual production:

1. Heat sealing pressure:

In order to determine the heat sealing strength of plastic composite soft packaging, the corresponding heat sealing pressure is indispensable. Therefore, the heat sealing pressure is required to be moderate and uniform in the heat sealing process. If the heat sealing pressure is insufficient or uneven, bubbles will be generated in the heat sealing part, which will lead to poor heat sealing.

2. Heat sealing temperature:

The heat sealing temperature directly affects the heat sealing strength of plastic composite packaging products.

3, heat sealing time:

The heat sealing time of automatic packaging machine or old bag-making machine is determined by the machine speed. Under the condition that the heat sealing temperature and pressure are unchanged, the longer the heat sealing time, the better the combination between heat sealing layers. However, if the heat sealing time is too long, the heat sealing part of the composite film will be wrinkled and uneven, which will seriously affect the appearance quality of the product.