Case Study: Component Design for Streamlining the Manufacturing Process Using 3D Printing

Abstract

The innovative pressure device, developed to address contamination issues on Essity Slovakia’s carton production line, was successfully implemented using 3D printing technology. This approach resulted in a precise prototype that significantly reduces contamination, simplifies packaging procedures, and lessens the need for manual labor. The project entailed a comprehensive review of the current system, 3D scanning, creation of a model using SolidWorks software, and fabrication with a Trilab DeltiQ 2 printer. The outcomes demonstrate a staggering 96% decrease in contamination, elimination of downtime, and a boost in overall line efficiency. This research underscores the transformative capabilities of additive manufacturing in industrial modernization and accentuates the significance of technological advancements in enhancing efficiency, sustainability, and quality within the manufacturing industry.

1. Introduction

Three-dimensional printing marks a significant milestone in contemporary manufacturing and design, enabling digital models to be translated into tangible objects via the layer-by-layer addition of materials. The process initiates with the generation of a 3D model using computer-aided design (CAD) software. This model exists in a virtual environment and is subsequently segmented into numerous horizontal layers, serving as the blueprint for printing the final product. Prior to printing, the 3D model undergoes conversion into the STL (Standard Tessellation Language) format, ensuring compatibility with the majority of 3D printers. Subsequently, the file is transmitted to the printing apparatus, where the actual fabrication occurs. Throughout the printing phase, material is systematically deposited layer upon layer, with each subsequent layer adhering firmly to its predecessor [1,2]. This technique facilitates the production of intricate and highly precise structures.

Despite its flexibility, efficiency, and cost-effectiveness, 3D printing necessitates more than merely a printer and filament. The selection of material hinges on various considerations, such as the printer’s type, desired strength, aesthetic appeal, and intended use of the printed item. Each material presents unique benefits and drawbacks, making it essential to choose the most suitable option based on the particular requirements of a project [3,4].

The diverse array of materials utilized in 3D printing encompasses plastics, powders, resins, metals, and carbon fibers. This variety enables the production of an extensive range of components, from precision-engineered aerospace elements to tailored consumer items. The adaptability of these materials opens up exciting potential for numerous sectors.

Our research used PLA, a biodegradable plastic originating from renewable resources like corn, sugarcane, or potatoes. By combining PLA with other substances, we were able to produce specialized filaments such as WOOD (wood particles), PLASTER (plaster), BRONZEFILL (bronze), and STEELFILL (steel). Hard PLA boasts impressive strength, rendering it ideal for a multitude of applications. The printing temperature impacts PLA’s final appearance; lower temperatures (below 225 °C) yield a glossy finish, while higher temperatures (225–230 °C) result in a matte texture. PLA’s benefits include effortless printing, an absence of unpleasant odor, minimal shrinkage, superior surface coverage, and uniform color consistency across various batches (

Table 1. Strength properties of PLA material.

	PLA
Tensile strength	78 MPa
Elongation at break	14%
Bending strength	90 MPa
Bending modulus	1984 MPa
Notch toughness	5.6

) [5].

PLA exhibits a tensile strength ranging from 50 to 70 MPa, surpassing the mechanical properties of typical polymers such as polypropylene (PP) and polyethylene (PE). Consequently, PLA is well-suited for applications demanding mechanical properties, albeit not critical ones. Its elastic modulus, approximately 3.5 GPa, classifies PLA as a rigid and hard substance. This trait is advantageous for producing robust structural components but may pose challenges in scenarios necessitating flexibility or impact resistance. Notably, PLA’s primary constraint lies in its low ductility and propensity for brittleness [6].

Owing to its fragile characteristics, PLA is susceptible to fracturing or shattering under impact or extensive bending. Research indicates that incorporating plasticizers, such as polyethylene glycol (PEG), can augment its flexibility. Nevertheless, this enhancement is accompanied by a decline in tensile strength. PLA’s hygroscopic nature, which permits moisture absorption from the surroundings, further compromises its mechanical properties, particularly when exposed to humid storage or processing conditions. Elevated humidity accelerates hydrolytic decomposition, diminishing molecular weight and eroding its strength. The cooling rate during production plays a pivotal role in determining PLA’s crystallinity; slow cooling fosters higher crystallinity, thereby bolstering mechanical properties and heat resistance [6,7]. Conversely, rapid cooling engenders lower crystallinity, rendering the material more amorphous, brittle, and thermally unstable. The incorporation of fillers, such as carbon fibers, glass fibers, or nanoparticles like nanoaluminum or graphene, can fortify PLA’s mechanical properties, enhancing its strength, stiffness, and heat resistance, thus rendering it more appropriate for technical applications.

Heat resistance constitutes one of PLA’s most substantial limitations [8]. With a glass transition temperature (Tg) of approximately 60 °C, PLA is vulnerable to softening or losing strength when subjected to elevated temperatures. The melting temperature (Tm) fluctuates between 180 and 220 °C, contingent on the specific PLA blend and printing parameters. The annealing procedure can enhance PLA’s crystallinity, thereby augmenting its heat resistance and enabling it to endure temperatures up to 120 °C. However, this improvement in heat resistance is accompanied by increased brittleness [8].

PLA is classified as biodegradable due to its capacity to be decomposed by microorganisms under industrial composting conditions [9]. Nevertheless, in standard outdoor settings, PLA degrades at a sluggish pace and does not function as a rapidly biodegradable material. Experimental data reveal that under-regulated composting conditions (temperatures exceeding 58 °C, elevated humidity, and microbial presence), PLA can disintegrate within 1–6 months [10,11]. In natural habitats like soil or water, PLA degradation spans several years, thereby diminishing its efficacy as a swift remedy for plastic waste in the environment [12,13].

Contemporary 3D printing research extends beyond refining the technology itself, encompassing the exploration of novel materials and techniques to broaden its applications. Pivotal studies underscore the myriad benefits of 3D printing, including enhanced prototyping, optimized manufacturing design, and heightened product personalization [14,15]. Furthermore, research demonstrates that 3D printing can expedite production cycles, minimize waste, and generate intricate geometric configurations that would be financially prohibitive or technically unfeasible using conventional manufacturing methods. Nonetheless, obstacles persist. Studies have identified constraints related to specific alloys and apprehensions concerning the longevity and caliber of printed materials [16]. These hurdles accentuate the necessity for ongoing investigation in additive manufacturing. Sustained progression will facilitate the surmounting of these constraints, paving the way for 3D printing’s comprehensive incorporation into diverse industries [17,18].

The foremost benefit of 3D printing is its capacity to facilitate expedited and adaptable production of both prototypes and definitive products. This markedly expedites innovation cycles across various sectors. The scholarly literature frequently underscores its advantages, encompassing the economical production of prototypes, the prospect of product individualization, and the capability to generate intricate geometric forms with high accuracy and negligible waste [19,20]. Pivotal investigations by researchers substantiate the substantial influence of 3D printing. The technology is currently permeating industries such as automotive, aerospace, healthcare, and architecture. In the medical field, for instance, 3D printing is routinely employed to manufacture custom-made implants and surgical instruments. Evidence indicates that these innovations can enhance quality and curtail surgical durations [2,17].

Technologically, 3D printing encompasses various processes, each characterized by distinct advantages and constraints. The most prevalent method is Fused Deposition Modeling (FDM). This approach entails liquefying thermoplastic material and depositing it successively in layers. FDM is predominantly utilized in industrial contexts [21,22].

On an industrial level, 3D printing has emerged as an indispensable resource in product development. Within the automotive sector, it facilitates the production of lightweight yet robust components, thereby contributing to reduced vehicle weight and enhanced fuel efficiency. In architecture, 3D printing enables the generation of elaborate geometric forms and prefabricated building elements [23]. The aerospace domain also leverages 3D printing, employing it to fabricate components directly in space, thereby enabling swift repairs and modifications under extreme conditions. This technology is user-friendly, which allows it to be used not only in research and development centers but also in schools, households, and small businesses. One of its main advantages is the ability to quickly produce physical models directly from digital data without the need for expensive tooling or molds, making it ideal for rapid prototyping. In practice, this technology is used for producing functional prototypes, replacement parts, assembly jigs, or design models. In the medical field, it is applied in the creation of anatomical models for surgical planning or in the production of custom orthoses. In education, it helps students better understand the principles of construction, manufacturing technologies, and spatial design. Overall, FDM represents an efficient, flexible, and cost-effective solution for 3D object manufacturing, with growing importance across various industries and everyday applications [24,25].

This study delves into a particular 3D printing application within the multinational firm Essity Slovakia, with the primary objective of scrutinizing and illustrating the advantages of this technology in streamlining production processes. The practical component centers on the design and fabrication of a specific element—a folding finger. This element is engineered to enhance production efficiency, eradicate contamination concerns, and diminish assembly and maintenance duration [18,26]. The design process involved utilizing SolidWorks software, which facilitates thorough analysis and optimization prior to the concluding 3D printing stage. This software is widely used for 3D modeling, technical drawing, simulation, and various engineering tasks, making it an ideal choice for our project. We selected SolidWorks primarily because of its popularity and versatility in the field of 3D modeling and engineering. Post-manufacturing and model evaluation, the company anticipates achieving amplified efficiency. Moreover, production and maintenance expenses are projected to decrease, culminating in overall advancements in production line efficacy [27]. In essence, this research unveils novel perspectives on the benefits and hurdles of 3D printing in the industry while accentuating its immense prospective for the evolution of contemporary industry and innovation. Currently, 3D printing is assuming a pivotal role in molding the trajectory of manufacturing, design, and research [27,28].

2. Materials and Methods

Initially, we scrutinized the production process at Essity Slovakia to pinpoint critical issues pertaining to contamination within the carton packaging line. Following data collection and 8-week contamination surveillance, we devised a solution in the form of a folding finger designed to ensure accurate positioning and curtail contact with the adhesive applied to the carton’s side flaps. For the fabrication of the folding finger, we employed the TRILAB DeltiQ 2 3D printer, which is grounded in delta kinematics. This printer facilitates high-precision printing and is apt for manufacturing technical components [2,28]. Key printing parameters are included in

Table 2. Parameters used during printing.

Layer thickness	0.2 mm
Thickness of the first layer	0.3 mm
Nozzle thickness	0.4 mm
Print speed	80 mm/s
First-layer printing speed	30 mm/s
Plate heating	60 °C
Nozzle heating	180 °C
Print speed vs. accuracy	balanced at 50%
Support structure type	Rough support

:

For the production of the foldable finger, we employed PLA (polylactic acid), a biodegradable thermoplastic material well-suited for 3D printing. Renowned for its facile processing, elevated strength, and ecological sustainability, PLA was chosen as the material of preference. We opted for a 50% infill, striking a balance between requisite strength and optimal material usage alongside reduced printing duration. This choice was informed by the strength evaluations conducted on PLA material [29,30]. Furthermore, supplementary support structures were indispensable for the printing process and were subsequently detached post-printing. The filament utilized featured a 1.75 mm diameter, with the cumulative material consumption for the final model amounting to 119.1 m (286.36 cm³).

After printing, the component underwent mechanical testing and manual adjustments at the Essity Slovakia facility.

In order to design and optimize our model, we utilized SolidWorks, enabling us to create accurate 3D models and simulate mechanical behavior. For preparing print files, we employed KISSlicer, a slicing software that generates G-code for 3D printers. KISSlicer serves as a toolpath generator specifically designed for 3D printing, converting digital 3D models into detailed instructions that guide a 3D printer in manufacturing an object layer by layer. More precisely, KISSlicer transmutes STL files into G-code commands, which control the printer’s movements, filament feeding, and other operational aspects. Although various printers might adopt slightly dissimilar G-code sets due to their unique hardware and firmware, the majority adhere to a standardized set of instructions. Furthermore, users have the option to manually modify G-codes to enhance print quality and adjust parameters [2,21].

As depicted in Figure 1, the 3D model of the pressure device is showcased within the KISSlicer interface. This intuitive platform offers three distinct levels of parameter control, accommodating users with varying degrees of expertise. Additionally, the software incorporates an error detection mechanism, which underscores erroneous settings with red flags and proposes viable solutions for rectification.

The image shows several color representations:

• Blue zones signify termination points and final surfaces; for the latter, it is advised to set lower printing speeds within the program.
• Light green zones denote final walls, whose thickness can be customized within the program to meet the model’s specifications.
• Gray zones symbolize support material automatically produced by the program, essential for the 3D printing process; without these supports, while printing remains feasible, the resulting 3D print’s quality would be compromised.
• Yellow zones indicate areas prone to deformation and intricate transitions between layers. The remaining zones’ markings are illustrated in Figure 2. Green zones (safe zones) are effortlessly and securely printable, followed by yellow zones, which can be printed by various 3D printers, and red zones, which are unprintable [28].

By leveraging this software, we efficiently fine-tuned printing parameters, including print speed, infill, and support structures. To evaluate the performance enhancement brought by the novel folding finger, we used statistical techniques, contrasting the frequency of production line interruptions before and following the component’s integration. The resulting data unequivocally demonstrated a substantial decrease in contamination incidents and an overall boost in production process efficiency.

3. Data Collection and Analysis

Due to undesired contamination on the folding fingers, the company was compelled to halt the carton—a machine responsible for folding boxes containing products—during operations. This complication adversely affected the production process, as each production line interruption led to a decline in overall efficiency.

The contamination led to subpar gluing of the side flaps on the side valves, causing an abrupt release of accumulated glue that adhered to the cardboard, thereby impairing the final product’s quality. Furthermore, loose glue remnants settled on the production machine’s floor, exacerbating cleanliness issues and negatively impacting efficiency.

A box with applied glue is introduced into the machine from the rear, where it is sealed utilizing pressure devices. Improper machine configuration results in the contamination of these pressure components with glue. The accompanying graph illustrates the contamination levels of the pressure device following eight weeks of operation. The data unequivocally indicate a progressive increase in contamination over time, culminating in regular machine stoppages and a substantial decline in production output.

The average cleaning duration for contaminated folding fingers is 33 s, triggering a carton halt and amassing rejected waste awaiting repackaging during the main line break. Averaging 56 bags being transported to the carton per stoppage, despite their inability to be processed correctly, is observed. Each contamination incident produces 12 low-quality boxes necessitating manual repackaging or resealing, which are subsequently repackaged and dispatched to the finished product warehouse rather than being discarded. Although contamination does not incur direct monetary losses, it diminishes production line efficiency and escalates the volume of manually managed waste. Repackaging transpires during mainline adjustments, temporarily pausing production. Assuming 28 monthly contamination occurrences, this equates to the following (Figure 3):

• Rejected products per month: 1568 pcs bags;
• Number of poor quality boxes per month/repackaged: 336 boxes.

Figure 4 displays the initial pressure device, emphasizing the contamination manifesting as slender glue capillaries. In minor quantities, these capillaries do not obstruct the process or compromise product quality. Conversely, as the capillary count rises, the final product’s quality experiences a marked deterioration. This leads to a higher accumulation of rejected items and necessitates decontamination of the pressure device.

The pressure part is a crucial mechanism in the company’s packaging process, primarily responsible for accurately and efficiently shaping cartons into the required shape before packaging. Upon application of glue to the carton’s edge, the pressure part descends along the Z-axis, aligning with the carton’s position, and exerts force to mold it into the final box form. This motorized folding mechanism significantly improves the packaging process’s velocity and precision. Key functions of the folding part include the following:

• Carton Folding: The main function of the folding finger is to transform flat cartons into the required shape based on predetermined settings. This process is entirely automated and controlled by a machine system.
• Shape Maintenance: Ensures that cartons preserve their correct shape during the packaging process. This is crucial for maintaining package integrity and stability.
• Carton Transfer: Certain folding fingers assist in moving cartons from the folding station to subsequent phases of production, such as final packaging or handling.
• Accuracy and Repeatability: The mechanism ensures high precision and consistency in carton folding, ensuring consistent product quality across all packaged items.

Contamination during folding finger usage results in multiple negative outcomes. It jeopardizes the hygiene of pharmaceutical and hygiene-related products, endangering both personnel and consumers. Furthermore, contamination reduces product quality and potentially triggers regulatory violations, with severe consequences for the company.

Given the absence of the original design documentation for the pressure part, the company was required to generate new documentation before executing any modifications.

4. Three-Dimensional Model Creation Process

The first and most crucial step in crafting the new design involved meticulously measuring the original component. Initially, a 3D scanner was used for this process, yet it fell short in terms of precision (Figure 5). As a result, we decided to construct an exact 3D model via SolidWorks. Following the modeling phase, we scrutinized the prototype of the folding finger, concentrating on hole precision, effecting essential alterations, and integrating the company’s specific requirements. Once the modifications were complete, we proceeded with the ultimate 3D printing phase of the component. The final step entailed a personal visit to Essity Slovakia, where we evaluated whether our redesigned folding finger effectively resolved the company’s issue while meeting all performance and quality expectations.

After measuring every dimension of the folding finger and before beginning the modeling process, we recreated the component in SolidWorks and created a detailed sketch containing all the necessary dimensions and data obtained from the physical pressure device. These measurements were taken using a caliper to ensure accuracy.

Considering the complexity of the pressure device, the 3D model was constructed from multiple individual parts, which were then assembled into a fully functional unit using the assembly feature in SolidWorks.

Following the creation of the 3D model, the next crucial step was prototyping the pressure device using a 3D printer. This was necessary to physically verify all dimensions directly on the Essity device, as measurement deviations could have occurred, potentially affecting the functionality of the final component. For the rapid prototyping process, we chose the Trilab DeltiQ 2 3D printer (Figure 6). This model employs sophisticated print head movement, integrating electronics and software to print intricate designs at a 60° tilt. This innovation negates the necessity for support structures, thereby reducing costs, saving time, and minimizing material waste.

One of the primary advantages of the DeltiQ 2 is its capability to pause printing at any stage, facilitating real-time inspections and adjustments. Additionally, if the filament sensor detects any anomalies, the printing process automatically halts to prevent defects. The integrated calibration sensor enhances print accuracy by automatically aligning the first layer to the substrate, performing 21 precise measurements before printing, thus eliminating the need for manual alignment. Furthermore, the printer’s powerful cooling fan ensures exceptional surface finishes when using PLA filaments.

The next step in our 3D printing methodology involved creating a G-code file for the 3D printer using the freely available KISSlicer software. We revisited the method, reformulating the problem within a level-set framework [6].

This approach treats the surface Σ of the 3D-printed object Ω as an evolving front. If the object requires scaffolding for printing, its shape is modified such that its surface evolves under a custom vector field v until it reaches a fully printable state—meaning it no longer has overhanging parts exceeding the specified cutoff angle α.

The new object Ω∗ is then printed, and the difference Ω∗\Ω0 is subsequently removed. Note that this difference can be easily identified using standard techniques and printed with a different material (e.g., soluble filament) or at a different printing resolution.

For this purpose, the surface Σ of the object Ω is divided into three subsets based on their printableness (Figure 7. Let G = (0, 0, −1) be the unit gravity vector and again N (x, y, z) be the external unit normal to the surface Σ of the object Ω at the point (x, y, z).

Furthermore, let

θ(N) := arccos (G · N),

(1)

be the angle between G and N.

A point (x, y, z) of the surface Σ is known to be unprintable if θ ∈ [0, $\overline{\alpha }$) ∪ (2π − $\overline{\alpha }$, 2π], safe if θ ∈ [π/2, 3π/2], otherwise modifiable.

The modifiable points in the model can be printed since the overlap remains minimal. However, adjusting their positions to make non-printable points printable may be beneficial. This adjustment ensures greater flexibility in shaping the object while avoiding the need for long supports. Definition 1 can be extended so that the set of both modifiable and safe points forms the total printable points.

The KISSlicer software enables 3D print optimization to achieve the desired results. The key settings we used include the following:

• Layer thickness: 0.2 mm.
• Nozzle diameter: 0.4 mm (affects accuracy and speed of printing).
• Infill: 50% (Although Essity Slovakia initially required 100% infill, we determined that 50% infill was sufficient to meet strength requirements while optimizing material usage and reducing printing time).
• Speed vs. accuracy ratio: 50 (To meet the company’s requirement for maximum accuracy, we selected this parameter, which balances printing speed and precision. Increasing speed reduces accuracy, and vice versa).

Support settings in KISSlicer software help prevent deformations, sagging, and other issues during printing. The support levels range from disabled (for simple models) to ultra (100% solid support).

For our solution, we used the Rough setting, which provided adequate support for our model while conserving material and reducing print time. Although higher support levels were available, this setting was sufficient. In 3D printing, support material is considered waste and is typically removed and recycled. Waste PLA from 3D printing can be ground down and reintroduced into the printer’s hopper, allowing it to be reused with nearly identical properties.

The Brim/Skirt setting uses Dia and Ht values to reinforce the model’s base, enhancing adhesion and stability. If a model widens as it builds upward, these settings help prevent shifting or deviations from the intended shape. In our case, the base was strong enough, and the part narrowed as layers increased, so we selected a value of 0. Sometimes, simply adjusting the part’s orientation can optimize stability during 3D printing.

Since KISSlicer does not natively recognize 3D printers, a starting G-code must be created. Figure 7 shows an example of a defined “.gcode” for the TRILAB DeltiQ2 3D printer.

We consulted on the design through personal visits to the company. During these visits, we reviewed all necessary process parts step by step, following the production process. We noted the required changes to the test model of the finger to ensure it fits precisely into the carton. Additionally, the company requested that the finger be adjustable in the required direction.

The final design was a folding finger with adjustable features in multiple directions, providing flexibility in the production line (Figure 8). It was installed directly into the carton machine and adjusted to the required position during production. We monitored the process for two weeks. At this stage, the fixture was still under observation and testing, and it did not yet have the exact final shape to become a fixed element in the process.

For 3D printing, we used 119.1 m of PLA filament, including supports, with a total material volume of 286.36 cm³. The final model of the folding finger was printed on the DeltiQ 2 3D printer, taking 54 h and 19 min of continuous printing. The extended print time confirmed the complexity and high precision required for this model.

We divided the model into two parts to allow adjustments to the lower part of the finger. The folding finger was designed for easy corrections by loosening two screws. We ensured sufficient distance between the finger and the applied glue on the side flaps to reduce the risk of contamination. Additionally, we fine-tuned the shape of the finger to ensure precise fitting with the cardboard. The model was re-drawn in SolidWorks software, and the adjustable part of the finger was designed (Figure 9). Subsequently, we proceeded with the final 3D printing of the finger.

The actual assembly and adjustment of the finger took place at the company’s workplace. Finding the ideal position for the finger required trial and error. The company took several days or even weeks to verify the finger’s effectiveness. However, we can confidently say that we met all of the company’s requirements to their satisfaction, successfully preventing any further unwanted contamination.

In cooperation with the company, we designed several solutions for the adjustable part of the folding pressure device, featuring various mounts and shapes. These solutions were printed and tested in production, with only one achieving the desired results. This successful solution was then mounted to the fixed part of the finger.

The folding prototype allowed for position adjustments in both the X and Y axes, making it easier to find an optimal position for closing the side flaps on the carton. As a result, we were able to prevent unwanted contamination.

5. Results

The aim of our work was to design a 3D-printed component that would significantly enhance and streamline the company’s production process. The main issue with the carton production line at Essity Slovakia was high contamination, which negatively impacted both the operation of the line and led to excessive contamination of the boxes and the working environment.

Workers were called in to remove rejected waste and manually pack the boxes, diverting them from more profitable tasks. Our goal was to provide an innovative and effective solution to reduce contamination and increase production efficiency. We began by conducting a thorough analysis of the production process and identified the area of the carton that could be improved using 3D printing. We then developed a clear plan on how to proceed.

Before addressing the problem, we conducted an 8-week contamination study. This study revealed that the carton production line experienced an average of 28 stops per month. Each stop resulted in 12 contaminated boxes, or 336 boxes per month, that needed to be manually repacked. These findings highlighted that the manual repackaging of boxes and the removal of contamination waste significantly reduced production efficiency.

The carton production line at Essity Slovakia is autonomous, meaning it is not connected to the main line. As a result, the main line does not stop when the carton halts, leading to production delays and affecting overall efficiency. To solve this problem, we designed a folding finger using 3D printing. This solution aimed to address the contamination problem and improve the production process. We created the design for the finger in SolidWorks, optimizing and continuously adjusting it to ensure proper performance. It was crucial to adjust the position of the finger on the carton to avoid damage and ensure efficient box packaging. We focused on testing different folding finger positions using simulations and prototypes. Regular personal visits to the company allowed us to make adjustments and optimize the position, a process that took several weeks.

After weeks of testing, which required daily optimization and monitoring, we compiled 8-week statistics on finger contamination. We then compared these results with those from before incorporating our design into the carton production line. Although contamination was still present every two weeks, it no longer had a significant impact on the production line (Figure 10).

The implementation of our proposal brought significant changes to Essity Slovakia:

• Contamination of the production line was reduced by up to 96% compared to the original finger, nearly eliminating the issue.
• Increased automation: The new component in the carton line reduced the need for workers to intervene in the operation, alleviating the manual packaging of boxes that was necessary with the original finger at regular intervals.
• Enhanced efficiency: The company’s production process became more efficient, ultimately improving its profitability and market position relative to competing companies.

The new statistics confirm that the design of the finger and the subsequent optimization of its position were successful. We have helped the company solve a significant production problem, marking a major step forward in modernizing its production processes. We have achieved the goal we set at the beginning.

6. Discussion

Three-dimensional printing technology offers significant advantages to the manufacturing environment, such as streamlining processes, personalizing parts, and reducing production costs. In this discussion, we will explore the key benefits and challenges of this technology, using the example of Essity Slovakia.

In the Essity Slovakia project, a folding finger was designed and implemented, reducing contamination on the production line by 96%. This innovation streamlined the process and reduced the need for manual intervention by workers. The savings achieved through optimization, such as lower waste and time losses, demonstrate the practical benefits of the technology.

The main advantage of our design is its low weight and environmental sustainability, thanks to the use of PLA material. PLA is a biodegradable polymer produced from renewable resources, making it an attractive alternative to conventional petroleum-based plastics. Additionally, 3D printing allows for rapid prototyping, design flexibility, and waste minimization compared to traditional manufacturing methods such as plastic injection molding or CNC machining. However, the mechanical properties of PLA, particularly its tensile strength and impact resistance, can be inferior to those of conventional materials like ABS or polyamide (PA). Numerical simulations indicate that under load, delamination of the layers and the formation of local stress peaks in critical areas can occur, potentially leading to material failure [25,29,30].

Comparing PLA with materials such as ABS, polyamide (PA), or reinforced polymers (e.g., SCF/PA—glass fiber reinforced polyamide) shows that while PLA is more environmentally friendly, its mechanical properties can be limiting for some applications. Analysis of stress fields at the micro- and mesoscales indicates that reinforced polymers have better stress distribution and a lower probability of delamination. Conversely, PLA tends to be more brittle and has lower shear resistance, as confirmed by experimental bending and shear tests. For applications requiring high strength and resistance to dynamic stress, glass or carbon fiber-reinforced PA may be more suitable. However, for applications with lower mechanical stress, PLA is a viable alternative due to its environmental sustainability and availability [25,29,30].

However, 3D printing also presents technical challenges. When developing a new part at Essity Slovakia, the equipment required multiple tests and optimizations. The accuracy of 3D scanners was insufficient, necessitating the drawing of the part in CAD software. Another challenge was adapting the finger to fit precisely into the production machine while minimizing contamination risk. These adjustments extended production time, indicating that the technology demands thorough preparation.

Despite these challenges, the implementation of 3D printing at Essity Slovakia reduced production line downtime and boosted productivity. The decrease in contamination also improved hygienic conditions, which is crucial for manufacturing pharmaceutical and hygiene products. This case underscores the importance of integrating modern technologies to elevate the quality and competitiveness of manufacturing companies.

Future research should focus on further improvements, such as developing more durable and flexible materials for 3D printing. For Essity Slovakia, testing composite materials could further reduce contamination and extend the lifespan of parts.

The case study at Essity Slovakia demonstrates that implementing 3D printing can significantly enhance production processes. However, it necessitates investment in research and development, along with worker training. For modern industry, it is essential to blend innovative approaches with practical solutions to achieve long-term production improvements.

7. Conclusions

Our work focused on designing a new component, specifically a folding finger, to streamline the production process at Essity Slovakia, which produces personal hygiene and medical products internationally. The folding finger is part of the cartoner production line, where high contamination levels initially affected both the finger and the working environment. By designing a new folding finger, 3D printing it with the TRILAB DELTIQ 2 printer, and optimizing the model, we achieved significant improvements. Contamination was reduced by over 96%, streamlining the entire production process. This also increased automation and reduced the need for worker intervention, resulting in a smoother box-packing process.

The paper was divided into four main chapters. The first chapter provides theoretical knowledge on 3D printing, covering materials, processes, software, and future technological innovations. The second chapter introduces Essity Slovakia and its production problem, which we aimed to solve as effectively as possible. The third chapter, the most important, details the entire process, including designing the folding finger in SolidWorks, 3D printing it at our department using G-codes, and optimizing its position on the carton. The final chapter discusses the results, comparing 8-week contamination statistics before and after incorporating our design.

The cost of 3D printing was estimated at around €150 per line. Alternatively, replacing the components with metal equivalents from the in-house catalogue would cost around €2500 per line. For 20 production lines, the total cost of 3D printing would be €3000, compared to €50,000 for metal replacements. This significant cost difference is crucial in deciding the most suitable solution. Factors such as component lifespan, ease of implementation, and impact on the production process must also be considered. Therefore, it is important to weigh the trade-off between initial investment and long-term savings. Depending on the specific needs of each production line, a combination of both approaches may be appropriate.

Three-dimensional printing, used to construct the folding finger, is a revolutionary technology with vast potential across various industries. It enables the rapid and efficient creation of complex geometric structures, personalized products, and prototypes. As an attractive technology, 3D printing offers companies benefits such as cost reduction, increased efficiency, innovation, competitiveness, and the ability for flexible production or rapid prototyping.

The significance of this research extends beyond its industrial context, contributing to the broader academic discussion on the potential of additive manufacturing. The findings suggest that 3D printing has the power to transform traditional manufacturing processes, leading to significant improvements in productivity and sustainability. These benefits apply not only to large-scale manufacturing but also to customized production. Moreover, 3D printing is driving innovation in fields such as medicine, where personalized implants and prosthetic devices are already being produced. In architecture, 3D printing enables the realization of complex designs that would be difficult or impossible to achieve using traditional techniques.