As manufacturing intensifies, the demand for high-volume metal precision stamping products is steadily going over the top. It’s resulted in the mass production of metal parts for machinery and electronics and subsequent high volume runs. That has left a dent in metal stamping manufacturing, increasing the chance of metal stamping defects. These faults often accrue losses to manufacturers and need quick dealing with.
Inadequate maintenance, tooling wear, and the inability to inspect each part are viable precursors. But, more challenges leading to this issue exist pretty openly. That causes a headache to most manufacturers, making it easy to maintain clients and all metal stamping products’ recipients. This article will dig deeper for solutions to eliminate high-volume metal stamping defects and minimize the overall costs and losses you might incur.
Types of Metal Stamping Defects
Metal stamping is quite a rigorous process involving cutting and shaping forces and therefore has a fair share of defects. That can be incredibly crippling if this inconvenience occurs in significantly immense proportions, rendering production inefficient. Here are the common flaws in high-volume metal stamping.
Wrinkles
Wrinkles mainly occur when the binder force is incorrect or the production process is wrong. However, the blank material and thickness largely dictate whether or not wrinkling will occur. Thicker blanks resist compressive forces and wrinkle more thanes. Besides, some materials resist seamless flow during stretching, leading to wrinkling.
Splits
Splits result in overstretching blank materials beyond their safe limits. It begins as localized necking and further advances to a complete break. It’s a minor issue but can be worrying if it occurs in significantly enormous proportions. Corrective methods may include forming limit diagrams (FLD) as simulated software predicts.
Springback
Springback defects usually appear after the stamping process is complete and manifest as disproportional shapes, far much varied from initial projections. Usually, materials’ stress-strain curves of the elastic region determine whether or not springback defects will occur.
Excessive Sheet Thickening and Thinning of Sheet
During formation, blanks may excessively stretch, resulting in thinning. Besides, compression can also lead to thickening, yielding unexpected dimensions. Thinning and thickening also result from poorly measured and inaccurate dies. This defect can be concerning if it occurs on a high volume capacity and needs quick solutions to mitigate.
What Problems Lead to High-Volume Metal Stamping Defects?
Metal stamping defects don’t come out of the blue, but a few underlying causes significantly result in this inconvenience. Most precision stamping manufacturers run into these glitches due to their persistence in minimizing production costs or having less time inspecting and identifying the existing and imminent tooling defects. Here are the reasons for having high-volume metal stamping defects.
Inadequate Inspections
Usually, press operators don’t have the mandate for progressive inspections as they stamp metals. But quite frankly, it’s where everything goes wrong, and it comes a little too late when it’s already caused significant damage. Some stamping manufacturers fail to do these inspections, assuming that perfect dies result in equally impeccable products. Sometimes, miniature unintended maladjustments create a butterfly effect, with tiny issues significantly becoming concerning in the long haul.
Tooling Wear and Inadequate Tooling Repair
Dies are subject to wear and tear during precision metal stamping. It’s a challenge that all manufacturers face every day, and often they come up with workable solutions. But despite being overly keen on minimizing rub and tear, maintaining such standards consistently is quite a challenge. Friction usually tears and wears stamping dies despite being sturdy and resilient to the action and reaction of the shape-forming processes.
Incompetent Customer Custom Designs and Specifications
Sometimes, fault hardly comes from the manufacturer, and defects ensue without warning despite being avid with the stamping process. Sometimes, clients demand stamping products with somewhat over-the-edge specifications that seem pretty achievable. However, it smacks manufacturers of the reality of how infeasible and incompetent these designs are later in the manufacturing process.
Incompetent Sampling Production Processes
Usually, manufacturers dry-test blank material for compatibility with the sheer forces before embarking on full-house stamping. However, if none of these testing and sampling processes are incompetent, it yields more defective stamping products. Some materials have low tolerances and don’t seamlessly flow during stamping, leading to distorted edges and bent corners, creating low-quality and faulty parts. Besides, improperly measured stamping forces are a precursor for high-volume metal stamping defects.
Solutions to Eliminate High-Volume Metal Stamping Defects
Metal stamping defects are usually expected as part of the stamping process. However, it becomes a problem if they’re high volume, raising costs, or compromising production. However, every issue has its solution, and it so happens that high-volume defect issues in metal stamping have their antidotes. Sometimes these solutions cost a lot and raise the production costs. And perhaps that’s one of the unjustifiable reasons some stamping manufacturers wouldn’t compromise profits for quality. However, a vast majority of proficient metal stamping manufacturers understand the importance of quality metal stamping products. Here are the solutions to eliminate high-volume metal stamping defects.
Solution 1: Using Camera Vision Systems, Sensors, and Custom-Made Gauges
High-volume metal stamping is inarguably fitting for the high metal stamping product demands since it fills a void that low-scale stamping would have left. However, it usually results in significant proportions of stamping defects, sometimes unprecedented. Most press operators don’t get the urge to inspect ongoing stamping processes to single out potential defects.
Press operators should inspect parts during the stamping process, unlike the conventional way of doing it as a post-production procedure. Ongoing inspections help identify the possible defects early in the production process and correct them at the drop of a hat. Most metal stamping manufacturers use camera vision systems and sensors to monitor ongoing operations, which is the real deal to minimize potential defects. But what are camera vision systems, sensors, and custom-made gages?
Camera Vision Systems and Sensors – machine vision systems combine hardware and software to capture and process images and foster seamless processing. These systems must be robust and reliable enough to image potential defects and disproportions in stamp products to guarantee unrivaled quality. Machine vision systems largely depend on digital sensors with exceptional optics for capturing images. These images head to computer hardware and software for analysis and processing to ensure high precision.
Custom-Made Gauges – customers have varied demands and specifications for their metal stamping products and require manufacturers to create metal parts according to pre-designed prototypes. However, these designs may sometimes miss a few essential dimensions and measurements, and actual products would hardly correspond to the manufacturer’s die dimensions. Custom-made gauges, therefore, feature the design and dimensional accuracy from the client’s perspective and are best made under the watch of both parties.
Solution 2: Multi-Part Fixturing to Simultaneously Inspect Multiple Machine Parts
Inspecting high-volume runs isn’t a piece of cake, especially when using traditional monitoring and assessment procedures. These processes are outdated and impractical amidst the rising demand for metal stamp parts. That’s why multi-fixturing is becoming the norm for most stamping manufacturers worldwide. This process is pretty workable and includes using coordinate measuring machines (CMMs) for tactile inspections of individual parts in quite a short time. The method combines with machine vision systems exceptionally well and takes on high-volume runs quite effortlessly.
Types of CMMs for Inspecting Multiple Machine Parts
Inspecting and correcting defects in machine parts is the genesis of having less defective and mainly perfect stamping products. That’s essential due to ongoing changes in forms and shapes as action and reaction forces result in friction. CMMs have probes classified as contact, non-contact, and combined. These protrusions are sensors to measure machine part dimensions and check the precision. Here are the CMMs for inspecting multiple machine parts to minimize high-volume metal stamping defects.
Bridge CMM – This type is the most sought-after for quality assurance operations in metal stamping and guarantees high accuracies and tight tolerance requirements. They have an incredibly stable anchor for measuring small to mid-size machine parts, hence ideal for metal stamping manufacturing.
Cantilever CMM – This type also measures small machine parts, ensuring high dimensional accuracies. They’re supported at one point and measure low-weight machined parts since they’re nimble and take measurements quickly. Like Bridge CMMs, these types ensure high dimensional accuracy in high-volume metal stamping and are equally helpful as bridge coordinate measuring machines.
Gantry CMM – These CMMs are well equipped for measuring machine parts with high geometrical complexities and more significant volumes. They’re ideal for measuring dies and gauges, ensuring that the dimensional accuracy goals are met with a total capacity to minimize potential high-volume metal stamping defects.
Horizontal Arm CMMs – This CMM is more helpful in checking for dimensional accuracies in more significant machine parts. Its probe usually faces down compared to other CMMs and takes measurements horizontally than vertically. However, they aren’t so ideal, especially if precisely high dimensional accuracies are needed since they don’t usually promise exactly that.
Solution 3: Engineering Tools That Prolong Die Life and Invigorate Maintenance
Typically, tooling wear, substandard die designs, and incorrect setups diminish die quality and compromise its ability to create high-quality stamps. And while these causes are diverse, they occur randomly, sometimes one being a result of the other occurring. For instance, incorrect setups can increase the chances of friction, leading to tooling tears and wear. Or perhaps, the same could be true if it were to occur the other way around. Therefore, engineering die tools and adequately maintaining them helps prolong die life.
Proper tooling maintenance enables them to function at sustained high levels, locking out the possibility of getting defective stamp parts in high-volume production. Besides, it helps avert high maintenance costs in the long haul, especially if a tiny problem promises a significant increase in the risk of becoming a crippling issue. The die material must also measure up to the production standards and withstand the incredible punching pressures during blank shaping. That way, it cuts down the downtime for production.
Best Die Maintenance Methods
Perfectly nailing 100 percent high-quality parts is pretty far-reaching. And more often than not, getting a few scrapped parts is typical despite using high-end dies. Dies cave into the shear forces and become defective in the long run, affecting production. That’s why scheduling regular maintenance is essential. A few companies do it as a sole service, and stamping manufacturers can outsource this service. However, in-house die maintenance is handy since it’s pretty convenient and cost-effective. Here are the best die maintenance methods.
Shimming – shimming maintains the timing of die stations by reducing lapses and delays and aligning them properly to avoid overhangs. Thicker shims are unequivocally the best since there’s usually no need to use too many of them and are easy to repair and inspect compared to thinner ones. Shimming keeps the pierce holes clear, ensuring passage for the slug drop slot and screws.
Sharpening – Stamping dies get blunt with time and often require maintenance to keep them consistently functional. Worn-out dies result in errors and subsequently lead to low quality and defective parts. It becomes a problem if the production is high-volume, leading to high customer dissatisfaction and disapproval. Thus, sharpening with a suitable grinding wheel improves the cutting quality and the die’s overall efficiency.
Cleaning and inspection
Inspecting stamping dies should be a routine maintenance practice for most manufacturers to maintain quality and efficiency. An inspection helps point out issues and single them out for repairs and corrections before they become more significant and disruptive. Also, cleaning removes accumulated debris, slugs, and slivers in the system, minimizing the chance of producing defective parts. inspecting dies, and the entire stamping system also identifies potential hazard precursors
Conclusion
Metal stamping is quite a rigorous process requiring high dimensional accuracies. That’s only possible with more competent machine parts, regular die and stamp product inspections, and engineering the best tools that lengthen die lives. High-volume metal stamping defects are a sheer possibility if industrial production processes aren’t competent enough, leading to significant losses in the long haul. Defects are also off putting to clients and diminish customer retaining rates by metal stamping manufacturers. However, the glad tiding is that these problems have viable solutions to put every stamping problem to bed.
