Preface
The Folder Gluer Machine plays a vital role in post-press processing, primarily responsible for folding and gluing die-cut paperboards into box-shaped products that meet packaging requirements. This technology is extensively used in the production of packaging items such as cartons and paper bags.However, during actual operations, occasional folding and gluing failures may occur, potentially affecting production efficiency and final product quality.
Lei Jun, founder of the prominent Chinese tech company Xiaomi, once said: “All the setbacks and failures you’ve experienced, even those seemingly pointless and time-wasting moments, will become your most valuable assets.” By analyzing the causes of folder gluing failures and proposing solutions, we hope to help you improve both your competitiveness and the quality of your products. This article explores four common failure scenarios in folder gluing and their potential causes, aiming to help you learn and grow from these challenges.
1. Glue Flap Separation or Weak Adhesion
The issue of glue flap separation is much like cracks forming in a romantic relationship—beneath the surface, the causes are often intricate and multifactorial. The visible “separation” is merely the result, while the actual reasons may lie much deeper:
- Choosing the wrong glue is like choosing the wrong partner—what appears compatible at first may turn out to be fundamentally mismatched.
- Unsuitable environmental conditions are similar to vast differences in upbringing—these external factors can silently erode the bond over time.
- Surface treatment issues are akin to poor communication styles—how things appear and interact on the surface plays a major role in how well they connect underneath.
Some people naively believe that simply increasing the amount of glue—much like forcing a couple to spend more time together—will solve the issue. “However, a true and lasting solution requires comprehensive evaluation and systematic thinking that address the root of the problem, not just its appearance.
1-1. Problem Description
- The glue flap area of the finished box cannot adhere firmly, resulting in glue separation or structural looseness, which compromises both the packaging function and its appearance.
- Even after applying pressure, the glue flap still detaches or shows incomplete adhesion in some areas.
1-2. Possible Causes
- Inappropriate selection of glue or glue application system:
If the type, viscosity, or chemical composition of the glue is incompatible with the material properties, it will lead to poor adhesion. For instance, using water-based glue on PE-coated cartons may fail because the waterproof surface prevents proper penetration and curing. On the other hand, using glue with excessive viscosity on thin paper may deform the substrate. Additionally, the performance of the glue application system affects the consistency and precision of the glue spray, thereby impacting the overall bonding result. - Insufficient or excessive glue application:
Applying too little glue compromises bonding strength, while too much may cause overflow and affect the product’s appearance. - Inadequate pressing force or duration:
If the pressing time is too short or the pressure is insufficient, the glue may not fully penetrate or cure, leading to suboptimal adhesion. - Paper surface treatment issues:
Excessive coating, high gloss, or the presence of waterproof agents on the paper surface reduces glue adhesion. - Inappropriate ambient temperature and humidity:
Low temperatures or high humidity in the production environment can affect the glue’s drying time and bonding performance.
1-3. Solutions
- Select appropriate glue and glue system:
Choose glue types based on material characteristics, such as water-based glue, hot-melt glue, or PUR glue, to ensure optimal bonding. SBL’s Folder Gluer Machines are equipped with automated glue systems in collaboration with Germany’s Baumer hhs and the United States’ NORDSON. These systems provide stable glue application quality and support both cold and hot glue modules, allowing flexible configurations for customers. - Precisely control glue quantity:
Adjust the amount of glue according to the paper’s absorbency to ensure even and adequate application. - Optimize compression parameters:
Adjust the pressure and duration settings on the Folder Gluer Machine to allow the glue sufficient time to cure and ensure a strong bond. - Improve paper surface treatment:
For papers with glossy surfaces or special coatings, sanding the surface or using specially formulated adhesives can significantly improve bonding strength. This is a common and effective technique for solving adhesion problems with smooth materials.
2. Carton Deformation or Dimensional Deviation
In the packaging production process, carton deformation and size deviation are much like common challenges in romantic relationships. When a box is crooked or misaligned, it’s as if a couple’s relationship has lost its balance—their pace and direction no longer match.
- Inaccurate paper feeding and positioning is like uneven emotional investment—one person is overly passionate while the other is indifferent.
- Environmental effects on paper are like external stressors—such as work or family—that strain the quality of the relationship, warping what was once a compatible match. Just as paper exposed to moisture can never fully return to its original shape, a relationship impacted by pressure may also shift in ways that are hard to reverse.
2-1. Problem Description
- The finished carton appears skewed or off-size, affecting both its appearance and assembly accuracy.
- After gluing, the boxes cannot be aligned properly, leading to poor packaging quality or difficulty with stacking.
2-2. Possible Causes
- Inaccurate paper feeding or mispositioning:
Mechanical deviation or paper misalignment within the feeder system causes folding to occur at incorrect positions. - Improper compression adjustment:
Uneven pressure during the folding process may result in board deformation or misaligned crease lines. - Fluctuation in paper moisture content:
Changes in ambient temperature and humidity affect the dimensional stability of paper, leading to size deviations during production.
2-3. Solutions
- Calibrate the paper feeding system:
Regularly inspect and adjust the feeder mechanism to ensure precise paper alignment, improving gluing accuracy. - Adjust compression parameters:
Modify pressure and timing based on paper thickness and material properties to prevent deformation caused by excessive force. - Control environmental conditions:
Maintain optimal temperature and humidity in the production environment to ensure paper dimensional stability and reduce warping.
3. Poor Folding or Crease Cracking
Let’s use the metaphor of a romantic relationship to explain issues related to poor folding or crease cracking: just as a relationship requires the right balance of force and understanding, so too do the folds and creases in paper packaging.
When the crease is too deep, it’s like one partner being overly dominant in the relationship—eventually causing the other to “break.” When it’s too shallow, it resembles a lack of emotional investment, making it difficult to form a solid connection.
Uneven pressure distribution reflects an imbalance in effort—some areas bear too much while others are neglected. This lack of balance ultimately leads to “distortion” or “fracture” in the relationship, just like improper folding pressure compromises the structural integrity of a carton, making it more prone to damage during later use.
3-1. Problem Description
- After gluing, the folded crease area is prone to cracking or poor folding performance, which affects the overall appearance and diminishes the structural strength and durability of the packaging. This makes the carton more susceptible to deformation or damage during transportation and storage.
- Due to uneven pressure distribution or variations in material characteristics during production, certain areas may fold inconsistently. This kind of inconsistency leads to structural deviations in the carton, affecting the efficiency of downstream automated packaging and possibly causing functional issues during actual use.
3-2. Possible Causes
- Incorrect creasing depth:
If the crease is too deep, the paperboard may tear; if it’s too shallow, the folding will be ineffective. - Paper fiber orientation mismatch:
When the fold line runs against the grain of the paper, it increases the likelihood of cracking or wrinkling. - Uneven pressure application:
If the folding mechanism distributes pressure inconsistently, some areas may not fold properly.
3-3. Solutions
- Incorrect creasing depth:
If the crease is too deep, the paperboard may tear; if it’s too shallow, the folding will be ineffective. - Paper fiber orientation mismatch:
When the fold line runs against the grain of the paper, it increases the likelihood of cracking or wrinkling. - Uneven pressure application:
If the folding mechanism distributes pressure inconsistently, some areas may not fold properly.
4. Production Line Jamming
Production line jamming or paper buildup is like a relationship stuck in a deadlock: when paperboards jam and pile up inside the machine, it’s just like communication between two people breaking down—stuck at a knot they just can’t untangle.
This kind of “stuckness” doesn’t only impact the current moment—it causes problems to accumulate downstream, eventually leading to more serious consequences.
4-1. Problem Description
- During the folder-gluer process, paperboards often get stuck at various points within the machine. These paper jams not only interrupt the production flow, but also require the machine to be stopped for manual clearing, severely affecting overall production efficiency.
- In addition, if the finished boxes cannot smoothly pass through the conveyor system, they gradually pile up along the line. This accumulation effect further reduces production efficiency and may even force the entire line to halt temporarily for cleanup and readjustment.
4-2 Possible Causes
- Uneven paper thickness:
Variations in thickness between batches can affect the stability of feeding and conveying. - Worn-out conveyor components:
Prolonged machine usage may cause belts or rollers to wear out, reducing the smoothness of material transfer. - Improper equipment adjustment:
Mismatched speeds between the conveyor and folding/compression units can cause jamming.
4-3 Solutions
- Strict control of paper quality:
Ensure consistent specifications across batches to minimize the impact of thickness variation. - Regular maintenance of conveyor system:
Inspect belts, rollers, and sensors regularly to maintain smooth machine operation. - Optimize equipment parameters:
Adjust the conveyor speed and folding rhythm according to the paperboard properties and production demands to achieve the best match.
Conclusion
In summary, issues in folder-gluer production are like “minor hiccups” in the overall manufacturing journey. With the right approach, they are entirely solvable.
We’ve explored four common issues: gluing failures, box deformation or dimensional inaccuracies, folding defects, and production line jams. While these problems may seem complex, they often stem from three main factors: material selection, equipment tuning, and environmental conditions.
The most important mindset is to face these challenges with proactive learning and a spirit of continuous improvement. As Lei Jun famously said, “Every setback is a valuable experience.” Only through constant refinement can we take our products to the next level and improve market competitiveness.
We hope this article provides you with practical insights to help you navigate folder-gluer production more smoothly.
If you encounter any technical issues with folder-gluer machines or production processes, feel free to contact us at SBL. We’re here to provide you with expert service and professional advice!