As the processes of industrial manufacturing of goods are optimized, approaches to their technical organization also change. The use of compact machines allows the use of small premises, which also affects the saving of production costs. The tendency toward rationalization in ensuring the production process is especially noticeable in areas serving domestic needs. So, the production of polypropylene bags focuses on a wide audience of consumers, among which, however, are not only ordinary customers, but also large enterprises. This causes interest in the segment from small entrepreneurs who decide to open their own production lines.
What is a polypropylene bag?
This is a type of packaging bags, the purpose of which can be considered as universal. Nevertheless, the main scope of such products is reduced to domestic use - as a rule, they contain bulk materials, dry mixes, feed fillers, etc. Use a polypropylene bag and to store non-food items. Even the construction industry widely uses such packaging for the storage and transportation of cement, coal, various mixtures and garbage.
Depending on the manufacturing technology used by the enterprise, the product is endowed with certain characteristics. For example, the production of polypropylene bags in Russia has recently been actively mastering the technology of conductive fabrics. Thanks to the innovation, the assortment is replenished with electrically conductive and antistatic bags. As for the primary characteristics in the form of ability to cope with loads, the standard polypropylene is oriented to a mass of 5-10 kg. Specialized big bags can withstand 50 kg or more, but such products are usually manufactured on individual orders.
Technological stages of production
The process begins with the preparation of raw materials, from which later the basis for the formation of bags is made. First of all, a plastic filler from granules is mixed and dried. In order to save, it is also possible to produce polypropylene bags from recycled materials, which can be mixed with a clean base, after which the mixture is dyed and diluted with modifying additives.
The next step is to feed the prepared mass into the extruder, where it is heated to 260 ° C. The result of this stage is the process of forming flat threads. Cutting and cooling methods allow technologists to form flat-sized fibers that are optimal in size to weave future bags.
The creation of the fabric base is carried out on circular looms, which release the sleeve by winding woven fibers onto special bobbins. The final stage is the cutting of the finished fabric base to the specified sizes and stitching the material into the finished product. This is what the classic production of polypropylene bags looks like. Technology and equipment may also include some process features that are specific to customer requirements. For example, flexography may be introduced as an additional step.
Flat Thread Extrusion Line
The direct manufacture of the material from which the polypropylene bag will be made begins with the extrusion process. To begin with, an appropriate mixture must be prepared, which is also developed taking into account the required operational qualities of the final product. The basis of the line is an extruder that produces a plastic film. Most models work with a wide range of polymer bases, but in any case, the main operations include heating, extrusion and drawing. If the production of polypropylene bags of large sizes is envisaged, the extruder is initially configured to supply wide dense fibers. However, the subsequent steps allow you to adjust the film to the desired format.
Circular looms
Kruglotkatsky aggregates are used to form the fabric base. With their help, the creation of continuous sleeves of polypropylene. There are several modifications of such equipment, which differ in the number of shuttles. So, among the basic versions can be noted 4-shuttle machine. The advantages of this unit include the minimum number of parts subject to wear, due to which it outperforms analogues in durability. It also increases the overall reliability of the line on which the production of polypropylene bags is carried out.
The equipment is equipped with a transmission system with roller wheels that do not need constant lubrication. These nuances, in turn, determine the ease of maintenance.
Bag cutting and stitching machines
Cutting can be performed mechanically and manually. On an industrial scale, manufacturing often uses the first option. In this case, units are used that automatically cut the bags from prepared hoses at an average speed of 40-50 pcs. At the same time, the maximum width of the rolls available for processing reaches 800 mm in standard formats. In some cases, the manual production of polypropylene bags also pays off.
This type of cutting technology involves the use of special tables on which operators service, including sleeves of non-standard sizes. After that, equipment for stitching the chopped bag bases comes into play. Typically, such aggregates form an undercut seam along the upper and lower layers of plastic fabric.
Flexography machines
Printing is performed by special machines provided with photosensitive matrices. The most common flexible machine provides the ability to print on a plastic fabric made of polyethylene and polypropylene. Offset units are also used on some lines, which differ in their ability to apply two- and three-color printing. These are modern high-precision devices, which are controlled through electronic panels. In particular, the production of polypropylene bags (photo below) involves the use of flexographic equipment of this type.
Requirements for production conditions
Regardless of the composition of the working line, the owner of the production must ensure the proper operating conditions for the equipment. First of all, like all workshops, the operation of which is associated with the processing of polymers, such lines should be removed from residential buildings. In the premises themselves, an efficient ventilation system should be provided, communications should be made in the form of sewer and water circuits, and care should be taken to install cleaning filters.
As for the size of the room, the production of polypropylene bags is usually carried out on production lines with an area of at least 50 m2. Accordingly, for optimal maintenance of such a complex, the size of the working area should be at least 80 m2.
Conclusion
The process of manufacturing polypropylene bags requires considerable investment in the organization. Rental of premises and purchase of equipment are only basic expense items, but in the future it may be necessary to create additional technological stages of the enterprise.
For example, competitive production of polypropylene bags in modern conditions is possible only with careful control of product quality. Consequently, an arrangement will also be required for an item to conduct examinations of manufactured products. The organization of storage conditions for the goods will also be needed. Although polypropylene bags do not take up much space and do not require special storage conditions, their appearance can be damaged by mechanical influences during transportation - this should also not be forgotten.