The 4 dimensions of automatic bagging solutions for optimum performance

Designing an automatic bagging solution goes beyond choosing the right machine. In any project there are a number of variables that must be balanced to achieve maximum reliability, performance and service life of any bagging system. These variables are the 4 dimensions we talk about in this article.

Before getting into the subject, it is useful to introduce some of the concepts mentioned below.

• Flexible packaging: refers to a packaging system made from materials that can be folded, rolled or compressed without losing functionality. It is characterized by its lightness, adaptability and resource efficiency, and is key to sustainability and product protection in sectors such as food, pharmaceuticals and cosmetics. [1]

• Automatic bagging: these are systems that carry out the entire bagging process automatically, from loading to bag sealing, with minimal human intervention, whether for start-up, supervision or consumables replenishment. In other words, all operations are carried out automatically: bag placement, dosing, filling, closing, evacuation and even palletizing. [2]

• Dimension: it is understood as the entity that can be described and characterized with different physical magnitudes. That is to say that it can be characterized, is measurable and identifiable, and from which, together with other dimensions, a technical solution is defined. [3]

The 4 dimensions of automatic bagging.

In the flexible packaging sector, and in particular in the field of automatic bagging of solid bulk products, it is well known to experts that there are three dimensions (3D) on which any technical solution for automatic bagging must be based.

These three dimensions are: product, bagging machine and flexible packaging (bag).

In addition, there is a fourth dimension that is obviously present, but which for various reasons is not usually taken into consideration on most occasions, and that is the operation of the equipment (understanding by operation everything external that influences and interacts with the product, the bag and the bagging machine).

Without a correct alignment of these four dimensions (4d), the technical solution for automatic bagging will not achieve the optimum efficiency and performance to meet the requirements and expectation of the end user.

However, when these 4d balance each other, they allow to achieve the best technical solution for automatic bagging. In addition, the interrelationship between all of them is of utmost importance, as we will see below.

The product.

The product and its intrinsic properties provide a highly relevant level of information. Properties such as vibrated density, slope angle, particle distribution or relative humidity, among others, affect both the type of bag and the bagging machine.

In addition, operating conditions (temperature, ambient humidity, manufacturing process, etc.) may compromise its performance.

The sack.

Their dimensional characteristics of manufacture and composition materials determine aspects such as:

• Thickness

• Weldability

• Permeability

• Hardness

• Consistency

• Stacking stability

These factors determine the compatibility of the bag with the product and with the bagging machine. Even the handling and treatment of the bag by the bagging machine supervisor can condition or influence this compatibility.

Bagging machine.

The systems that make up each machine are designed to operate robustly and optimally with specific products and bags, and within established ranges. Likewise, the bagging machine must be operated and maintained correctly, with operators who operate and maintain it optimally.

Operation.

As mentioned above, it is everything external that can condition or alter the stability of the other 3D. It includes everything that surrounds the equipment: upstream process conditions, environmental surroundings, personnel training, etc.

Illustration 1: Concept of interrelated dimensions, 3d and 4d.

Analysis of real cases.

In order to understand the importance of these dimensions, we share some examples of real experiences we have had to deal with in the past.

Experience 1: product with high temperature and high humidity.

Application:

• Product: powder, food additive.

• Type of bag: open mouth.

• Bagging machine: dosing by auger (ILERPES-BS) and open mouth bagging machine (ILERSAC-H).

Description of the experience:

The customer built a completely new plant for the production of its product, which had a special process for its production.

The automatic bagging solution delivered to the customer had all parts in contact with the product made of stainless steel materials, with mirror polished finish and surface roughness ≤ 0.8 [µm], so as to facilitate cleaning and mitigate product sticking.

The product was delivered to the equipment with high temperature and, sometimes, also with high humidity. These changes modified the behavior of the product, causing clogging in the dosing system and product adhesions in different parts of the equipment, which impacted its performance and operating capacity.

Resolution:

With the current state of the art, it was not feasible to implement effective changes in the equipment that could solve these incidents, so it was recommended to the customer to intervene in the process upstream of the bagging machine.

The incorporation of a cooling and drying system in the final part of the product processing process, just before the product enters the equipment, completely eliminated the occurrence of clogging, achieving a significant reduction of product sticking to the inner parts of the automatic bagging technical solution.

Learning:

It is extremely important to know the upstream process of an automatic bagging solution, as well as the temperature and humidity conditions of the product to be bagged.

Experience 2: product with changes in density.

Application:

• Product: pulverulent, baking flours of various types.

• Type of bag: open mouth.

• Technical solution adopted: dosing by conveyor belt (ILERPES-NT) and open mouth bagging (ILERSAC-L).

Description of the experience:

This application consisted of replacing a semi-automatic bagging process with a fully automatic one.

The customer was working with a wide range of products and bag formats. In addition, the products had a significant density variation during the process upstream of the bagging machine, mainly due to the disintegration of fine and coarse particles caused by the pneumatic conveying and settling of the product inside the silos.

In the existing semi-automatic bagging process, which was to be replaced by the new automatic bagging equipment, no significant problems were ever seen. In this semi-automatic bagging system, the operators handled the bags in such a way that the seating of the product in the bag and its closing by sewing was done by manipulating the bag in such a way that the product was accommodated to the available volume.

When the new automatic bagging solution was installed, the variability of the product density meant that at times the available volume of the bag overflowed, and when it did not, it did not allow the sealing (stitching) system to operate robustly.

Resolution:

The idea of acting on the processing and transport of the product upstream of the bagging machine to eliminate the disintegration caused by density changes was an excessive investment for the customer, and also jeopardized the viability of the planned investment.

Therefore, the approach was to resize the bags for the entire product range. By analyzing the most unfavorable products, the number of different bag references was optimized and dimensions were established to absorb this variability in density so that it would not have an impact on the palletizing formats.

Learning:

Always identify if there is variability in the densities of a product and know the customer’s previous bagging process. This information allows to detect possible impacts on bag dimensions.

Moving from a semi-automatic to an automatic process may involve changes in consolidated elements, such as the available volume of a bag.

Experience 3: poor equipment operation.

Application:

• Product: pulverulent, baking flours of various types.

• Type of bag: valve.

• Technical solution adopted: dosing and bagging by fluidization (ILERSAC-VBF).

Description of the experience:

The customer made a large investment to integrate a complete automatic bagging line, including palletizing and stretch wrapping.

The number of variants in product and bag formats was not substantially high, but it was necessary to make adjustments to the recipes for each of the products during the operation of the equipment. In addition, occasional recipe changes were also required due to the changing behavior of the product during flow.

The high turnover of personnel operating the equipment was constant. This was the case from the beginning of putting the facility into operation, which generated a high number of shutdowns and malfunctions, directly impacting the performance of the equipment and, therefore, the client’s productivity.

Resolution:

Several production managers had to pass, until the company’s policy shifted towards training and the consolidation of an operating team that would give continuity to the facility’s operations.

Learning:

Delivering an automatic bagging solution to a user whose equipment operating procedures are poorly defined generates dissatisfaction for all parties involved: manufacturer and user. Detecting this in advance helps to propose solutions that are less complex and better adapted to your current operating processes.

The importance of balancing the 4d in automatic bagging.

In short, we can say that the performance of an automatic bagging line does not depend only on the machine itself. In the above examples we have mentioned only a few factors that can affect it, such as:

1. Product inhomogeneity, temperature and humidity changes.

2. The lack of quality of the bag or aspects related to non-standard tolerances of its dimensions.

3. Lack of training for equipment operation.

Therefore, in order for the customer to obtain a high-value, robust, efficient and cost-effective solution, it is necessary to take into account the 4 dimensions to define the best automatic bagging solution.

At TMI, each project is designed with these four dimensions in mind. Our goal is to offer automatic bagging solutions that maximize the value of each application. For more information, please do not hesitate to contact us.

Juanjo González Toledano – Director Of Engineering at TMI

References:

[1] Flexible Packaging Europe. https://www.flexpack-europe.org/

[2] Article: Differences between a manual and automatic bagging machine: how to choose the best option, TMI. https://www.tmipal.com/es/

[3] JGT, TMI
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