Six Common Problems in Automatic Packaging Production

[Chinese Packaging Network News] packaging machine has vertical and horizontal points, vertical and continuous (also known as roller) and intermittent (also known as palm-type) of the points, into a bag with three seals, four seals, Back sealing, there are a number of packaging equipment. A wide variety of packaging equipment, the differences between the equipment is also very large. In the actual use of composite membrane coil, you will encounter various problems, this article analyzes the causes of the six common problems for reference.

A cursor problem

In the process of automatic packaging of composite membrane coils, positioning heat sealing and positioning cutting are often required, and an electric eye cursor needs to be set for positioning. The size of the cursor, there are some differences in the different packaging opportunities. General requirements cursor width is greater than 2mm, length greater than 5mm. The cursor is generally chosen to have a dark color with a large contrast to the background color. It is best to use a black color. Generally, red and yellow cannot be used as a cursor, nor can the color of the same color as the photoelectric eye be used as the cursor color, such as the glow of the photoelectric eye being green. Light, you can not use the light green color as the eye color, because the green light eye can not recognize the green color. If the background color is a darker color (such as black, dark blue, deep purple, etc.), the cursor should be designed as a hollow, light-colored cursor.

The electric eye system of a general automatic packaging machine is a simple identification system and cannot have the function of intelligent fixed length as the bag making machine. Therefore, in the vertical range of the electric eye cursor, the film does not allow any disturbing text and pattern, otherwise it will cause Identification error. Of course, some high-sensitivity electro-optic eyes can have their black and white balance finely adjusted. For some light-colored interfering signals, they can be removed by adjusting. However, the color of the electro-optic eye with similar or darker colors cannot be removed.

The distance between the cursors is used to determine the length, so the error between the actual spacing and the design value can not be too large, generally only 0.5mm error is allowed. For many automated packaging equipment, the negative deviation is better than the positive deviation, so it is recommended that the design be negative.

Aluminizing or pure aluminum has a strong specular reflection that affects the recognition of the electric eye. It is recommended that the compound film mark be printed on a white background. For a transparent composite film, it is also recommended that the cursor be printed with a white background due to the influence of the color of the item in contact with it, thereby reducing interference.

Second, the friction coefficient problem

The friction in the packaging process is often both drag force and resistance, so its size should be controlled within an appropriate range. Rolls for automatic packaging generally require a smaller inner layer friction coefficient and a suitable outer layer friction coefficient. The outer layer has a large coefficient of friction, which can cause excessive resistance in the packaging process and cause the material to stretch and deform. If it is too small, Will cause the drag mechanism to slip, causing the eye tracking and cut off positioning is not allowed. However, the friction coefficient of the inner layer can not be too small. Some packing machines have too small friction coefficient in the inner layer, which will cause the stacking material to be unstable during the bag forming process, resulting in the wrong side. For the composite film used in the strip packaging, the inner layer friction coefficient Too small may also cause slipping of the tablets or capsules, which may cause misalignment. The friction coefficient of the inner layer of the composite film mainly depends on the content of the opening agent and the smoothing agent of the inner layer material, and the stiffness and smoothness of the film. The corona treatment in the production process, the curing temperature and the time also affect the product. The coefficient of friction. When studying the friction coefficient, special attention should be paid to the fact that the temperature has a great influence on the friction coefficient. Therefore, not only the friction coefficient of the packaging material at normal temperature should be measured, but also the friction coefficient at the actual use environment temperature.

Third, the heat seal problem

The low temperature heat sealability is mainly determined by the properties of the heat seal layer resin, and also related to the pressure. Generally, the extrusion temperature is high when the compound is extruded, and if the corona treatment is too strong or the film is left for a long time, the low temperature heat of the material is reduced. Seal performance. Hot tack is used to describe the strength of the heat-seal layer's resistance to peeling by external forces when not fully cooled after heat-sealing: This external force often occurs in automatic filling and packaging machines. Therefore, for the automatic packaging composite film, hot-seal material with good hot-tack property should be selected. Contamination-proof heat sealability, also known as inclusion content heat sealability, refers to the ability of a hot cover to still heat seal when it adheres to the contents or other contaminants. Composite films are based on different packaged materials, irrelevant packaging machinery, and different packaging conditions (temperature, speed, etc.) to select different heat-sealing resins. A heat seal layer cannot be used uniformly. For packages with poor heat resistance, low temperature heat seal material should be used. For heavy packaging, heat sealing materials with high heat sealing strength, high mechanical strength, and good impact properties should be used. For high-speed packaging machines, heat-sealing materials with low-temperature heat-sealing and high hot-tack strength should be used. For products with strong pollution such as powders and liquids, anti-pollution heat-sealing materials should be used.

Fourth, heat sealing extrusion PE problem

In the heat-sealing process of composite films, PE is often extruded on the heat-sealing film, and more and more affects the normal production. At the same time, the extruded PE oxidizes smoke on the heat-sealing mold to produce odor. Heat-sealed extruded PE can generally be solved to a certain extent by reducing the heat-sealing temperature and pressure, adjusting the formulation of the heat-sealing layer, and modifying the heat sealing film to reduce the pressure at the edge portion. However, it has been proved that the best solution is to use an extrusion compounding process to produce a composite film, or to increase the speed of the packaging machine so that the PE is too late to be extruded onto the heat seal film.

Fifth, heat sealing pressure, pressure breaking problem

Compression is defined as the formation of a penetrating hole or crack in a packaging material that is squeezed by an external force. The reasons for this are:

1 The heat seal pressure is too high. In the process of heat sealing, if the heat sealing pressure is too large or the heat sealing mold is not parallel, the partial pressure is too large, and some relatively fragile packaging materials are often pressed through.

2 heat sealing mold rough, angular or foreign body. Poorly manufactured heat-sealing molds often crush packaging materials. Some heat-sealing molds produce sharp edges and corners after being scratched, and are also easily pressed through the packaging material.

3 The thickness of the packaging material was not selected correctly. Some packaging machines have requirements for the thickness of the packaging material. If the thickness is too large, some locations of the packaging bag may be pressed through. For pillow-type packaging machines, the thickness of the packaging material should not exceed 60 μm. If the packaging material is too thick, it can be easily broken in the sealing area of ​​the pillow-type packaging.

4 Wrong choice of packaging material structure. Some packaging materials have poor compression resistance and cannot be used to package some harder, angular items.

5 Improperly designed packaging mold. In the design process, if the die hole of the heat-sealing mold does not conform to the shape and size of the packaged material, and the mechanical strength of the packaging material is not high, the packaging material is also easily pressed or fractured during the packaging process.

Sixth, seal sealing problem

Leakage seal is due to some factors, so that should have been through the melting of the melting of the site, not sealed. Leakage seals generally have the following reasons:

1 The heat seal temperature is not enough. The heat sealing temperature required for the same packaging material in different heat sealing positions is different, and the heat sealing temperature required for different packaging speeds is different, and the heat sealing temperature required for different packaging environment temperature is also different. The heat sealing temperature required for longitudinal sealing and transverse sealing of packaging equipment is different, and the temperature of different parts may not be the same in the same heat sealing mold. These are problems that must be considered in packaging. For the heat sealing equipment, there is also a problem of temperature control accuracy. At present, domestic packaging equipment has poor temperature control accuracy, and generally has a deviation of 10~C, that is, if the temperature we control is 140%, In fact, the temperature during the packaging process is between 130-150C. Many companies' airtightness inspections use random sampling in finished products to check. In fact, this is not a good method. The most reliable method is to sample the lowest temperature point within the range of temperature change, and it should be sampled continuously so that the sample can cover the longitudinal and lateral parts of the mold.

2 The sealing area is contaminated. In the filling process of the packaging, the sealing position of the packaging material is often contaminated by the packaging material, and the pollution is generally divided into liquid pollution and dust pollution. To solve the problem of contaminants in the sealing area can be solved by improving the packaging equipment and using anti-pollution and anti-static heat sealing materials.

3 Equipment and operation problems. If the heat seal mold has foreign matter, the heat seal pressure is not enough, and the heat seal mold is not parallel.

4 Problems with packaging materials. If the corona crosses the surface, there are too many heat-sealable lubricants causing poor heat sealing.