Functional indicators and equipment types of the h

With the continuous development of China's economy, the number of large-scale production enterprises is increasing. How to meet the needs of various industries for the localization of 25-50kg large bag packaging equipment has become a new topic in the packaging machinery industry. It is true that the large packaging of goods has existed since ancient times. In the past, baskets, gunny bags, wooden cases, plastic woven bags, cement paper bags and so on all belong to the containers of large packaging, but modern large-scale production puts forward higher and newer requirements for packaging

functional indicators of large bag packaging

large bag packaging basically has the following six functional indicators:

1 High speed and efficiency: it can meet the requirements of packaging more than 20 tons of materials per hour and continuous production

2. Fastness: the tensile and impact strength of the packaging bag can withstand gravity, pressure in stacking and impact in transportation

3. Sealing: due to different packaging materials, there are different sealing requirements, especially for powder or toxic substances, and substances that are afraid of being polluted

4. Moisture proof and mildew proof performance: materials that are prone to moisture or mildew have special requirements for the air tightness of packaging materials

5. Environmental protection requirements: it is the consensus of the world to protect the environment on which human beings live, and the level of environmental protection is a symbol to measure the degree of civilization of a country; Therefore, packaging bags must be degradable and recyclable materials to alleviate environmental pollution

6. Easy to disassemble: modern large-scale industrial production inevitably requires high efficiency. Most of the large bag packaging is raw materials or primary processed products, so the packaging bag also needs to meet the requirements of easy to disassemble and easy to dump

since the reform and opening up, China has successively introduced a number of complete sets of equipment, including high-speed and efficient automatic packaging machines, which meet the above functional requirements according to different needs, and most of them use degradable and environmental friendly packaging materials. Most of these equipment come from Japan, Germany, the United States and other countries, accounting for the vast majority of China's market. Over the past ten years, developed countries have successively developed a variety of more reasonable packaging methods and equipment, which provides valuable experience and inspiration for China's packaging machinery industry

in recent years, domestic industries have generally improved their understanding of the importance of packaging, which is a gratifying phenomenon; However, the packaging industry lacks guidance on the selection of large bag packaging methods and equipment, and each control mode can be switched automatically and smoothly without impact, falling behind the market demand. Buyers often buy according to the picture and choose similar imported equipment. However, the price of imported equipment is expensive. In the past, most enterprises invested by the state or with abundant funds purchased imported equipment, and some technological transformation projects or small and medium-sized enterprises had to sigh with admiration; Another situation is that enterprises exporting products, the foreign party puts forward packaging requirements or provides samples of packaging bags. Due to the lack of information, these enterprises look everywhere to meet the requirements of the foreign party. Most of the users entrust complete sets of equipment suppliers to provide supporting facilities. However, complete sets of equipment supply companies also lack professional shopping guides, which also takes a lot of trouble. This paper briefly introduces and explores the large bag packaging mode, equipment selection and development trend

types of large bag packaging at home and abroad

1 Heavy plastic bag automatic heat sealing packaging. The so-called heavy plastic bag refers to the PE, PP plastic film bag or aluminum-plastic, paper-plastic composite bag with a single-layer bag thickness of 0.2-0.5mm packed with 25-50kg materials

this kind of packaging bag has good sealing performance, especially the composite bag, and the sealing process is relatively simple. Because the film is thick and has a certain fastness, the aluminum-plastic composite bag also has the function of sealing and shading, and the new packaging equipment also has an exhaust device. The vented packaging bag is pressure-resistant and impact resistant during stacking and transportation, and it is also suitable for the sealing of flat bags and m-fold bags. However, avoid contact with sharp tools during stacking and handling, and pay attention to the recycling of packaging bags to avoid white pollution

2. Folding seam automatic packaging and tape suture automatic packaging. This kind of packaging adopts plastic woven bags, which are first folded and then stitched; Or wrap a saddle shaped wrinkled paper belt on the mouth of the kraft paper bag, and then sew it. These two ways of packaging have certain fastness, convenient unpacking and low cost; It is suitable for packing materials with coarse particles and low sealing requirements. Both woven bags and kraft paper woven fabric composite bags are non degradable materials, which are no longer used in countries with strict environmental protection management

3. Paper bag sealing and sewing automatic packaging. Such packaging is made of kraft paper bags or multi-layer kraft paper bags. The mouth of the bag is sewn first, and then wrapped with a saddle shaped hot-melt tape to seal the pinhole, which not only enhances the fastness of sealing, but also meets the sealing requirements. If it is a strictly leak proof material, it must also be lined with a plastic bag; Or heat seal the lined plastic bag first, and then wrap it with folded saddle shaped corrugated paper tape to sew up, so as to achieve the sealing effect. The number of layers of kraft paper bags is selected according to the stacking degree, transportation, storage and other conditions of materials, and there is a corresponding model of packaging machine. This packing method has high impact strength and excellent sealing performance after being sealed by exhaust

the equipment designed for this packaging method is quite mature. Only the packaging process includes dust removal, sewing, thread cutting, braiding, pressing, cooling, counting and other processes, which are automatically controlled by PLC

. In addition, the warning system of sewing machine thread breaking, paper tape breaking, chain clamping, overload and other faults is designed to avoid the errors of batch leakage of seams and bags in high-speed production and ensure production safety. In addition, it also has a safety device for the needle to stay at the top dead center when the machine stops, and a clutch device for the sewing machine to reach the rated speed of the motor instantly. This kind of automatic packaging machine adopts advanced technology of optical electromechanical integration and microcomputer control, with perfect mechanism and mature technology. It is an advanced equipment widely used in the world. 4. Paper bag folding, heat sealing and automatic packaging. This kind of packaging has three different ways, but they all fold the mouth of the bag first and then heat seal, and each has its own advantages. At present, it is more popular in European and American countries. Such packaging can be lined with plastic inner bags or not as needed. Now it is introduced as follows:

automatic hot pressing packaging of paper bag folding. This paper bag is made into a bag mouth similar to a Chinese envelope. One side is a single-layer or multi-layer bag mouth tongue, and the surface is adhered with a hot sol coating. The sealing process of the bag mouth includes opening the bag mouth to preheat the inner bag, heat sealing the inner bag through the outer layer, indentation, bag opening tongue, hot pressing, sealing, cooling and other processes. The temperature is adjustable, the speed is stepless and adjustable, and the whole process is automatically controlled

this kind of packaging bag can also be designed with a one-way exhaust valve to exhaust gas during the whole package, so as to prevent the bag from bursting when pressed. This packaging method can meet the requirements of the above packaging functions, but the bag making process is difficult, which restricts the promotion and application

paper bag folding side sealing tape automatic packaging. The difference between this packaging method and the above packaging method is that both sides of the bag mouth are flat. According to the packaging requirements, the paper bag can be one layer or multiple layers, and the bag mouth can be folded once or twice. The process of this kind of packaging is: dust removal, heat sealing inner bags, rolling, pruning inner bags, pressing Jiangnan industrial concentration area has rich element resource traces (one or two), folding (one or two), one side glued paper tape, paper cutting tape, hot pressing, cooling in the development of aluminum based new material industry. Some mechanisms of the packaging equipment are complex, which increases the manufacturing difficulty

paper bag folding tape automatic packaging. The packaging process in this way is: first heat seal the inner bag, then indent and fold the mouth of the bag. Although last year was a year when a large number of Thai plastic machines replaced the imported products, then wrap it with hot melt adhesive tape folded into a saddle shape, and then cut, heat and press it. This packaging method has the above six functional requirements, and it is particularly convenient to fold bags

the equipment designed for this packaging method is also quite mature. It is a new generation of packaging equipment with optical electromechanical integration technology, controllable temperature, variable frequency speed regulation, perfect mechanism and advanced technology

through practice and investigation of users, users generally believe that the two methods of "paper bag sealing and sewing packaging" and "paper bag folding belt packaging" can meet the requirements of six packaging functions, and each has its own uniqueness. Moreover, the packaging equipment is designed reasonably, the process is mature, and the continuous work is stable and reliable, which is in line with China's national conditions and welcomed by the majority of users. The two kinds of equipment can be matched with the automatic production line, and can continuously complete the processes of measurement, filling, bagging, exhaust, sealing, transportation, shaping, stacking and so on, so as to realize efficient and high-quality packaging. In the past 20 years, the design of large bag packaging and the corresponding packaging equipment have been constantly innovated, and the layer is not quite poor compared with Thailand. In addition to the above types that have a great relationship with packaging machinery, I will not repeat them

it is true that a good packaging requires appropriate packaging methods and advanced packaging equipment, and the design and production of packaging bags are also crucial. Low cost and high-quality packaging is the goal pursued by all enterprises. However, due to the fact that the bag making enterprises do not know much about the packaging process and use, the packaging requirements are often not met due to some unnoticed links in the production of packaging bags, and we hope to attract attention. On the premise of meeting the above packaging function requirements, the packaging bag shall select appropriate packaging materials and manufacturing process. The following requirements are put forward for the production of multi-layer paper bags and paper bag lined plastic bags for the reference of bag making enterprises, bag using enterprises and complete equipment suppliers:

1 Multi layer kraft paper bags can be lined with plastic bags, and the layers must be closely nested. The inner layer can be slightly interference compared with the outer layer, and there must be no gap, so as to play the role of multi-layer bearing capacity

2. The inner plastic bag should not be too large to avoid leakage due to wrinkles during heat sealing

3. The thickness of the lined plastic bag shall not be less than 0.06mm, otherwise it is not easy to cut off when trimming the bag mouth, or even damage the cutter

4. If the bag mouth needs dust removal, some layers of the bag mouth must be adhered to each other

5. If the unlined m-fold paper bag needs to be sewn, the m-fold on both sides should be adhered

6. The packaging of lined plastic bags should be lined, and composite bags should not be used, because paper plastic composite bags are not easy to degrade

it may take a long time to fully realize the above requirements, but our packaging industry should take the lead in advocating, so that the development of packaging and packaging equipment in China can keep pace with the world and reach the international advanced level