Efficient Overnight: Four Ways to Fast-track Material Savings
Most efficiency gains in raw materials are achieved through quality improvement techniques. That’s a methodology that should be ingrained into your operation; however, it often requires time to bear fruit.
There is a faster way. You can use less materials by adding more equipment and capabilities. Here are four specific areas in the converting process you can achieve immediate efficiency gains, and the equipment that can help you do it.
1. Improve spacing
Most material waste on a web process can be blamed on poor spacing. The closer you can place parts together on the web, the less material you waste and ultimately use.
That’s no easy task on a complex job, where your base web is traveling at high rates of speed.
Solution: Island placement and island transfer
One way to improve spacing is to run two different webs, and transfer parts from one to another. This can be difficult, as two webs running at different speeds could result in a tug of war on the part during the transfer.
Using servo motors and specialized modules, you can program the web to speed up or slow down to place parts with minimal waste.
2. Reduce coating fluid losses
During the coating process, there is often fluid waste due to imprecise application of the coating. Coated fluid that is left on rollers, for example, is waste.
There is also the issue of uniformity. With most coating methods, the Transverse coating weight Profile Td uniformity is 5-8%, so you must set the average coating weight higher so that the lowest point in the profile meets product performance requirements.
Finally, the aging and contamination of coating fluids can result in waste.
Solution: Slot die coating
By using slot die coating, you can immediately eliminate the fluid losses due to contamination, as the materials are contained in closed reservoirs.
With slot die coating, the fluid solution is administered in precise measurements immediately — there is no set-up time required, and you avoid start-up losses as you set the correct flow rate.
In addition, the transverse coating weight Profile Td uniformity is only 1-2%, which is far better than the typical 5-8% with other coating methods, which means the average coating weight control point can be reduced.
3. Eliminate multiple passes
Many converters rely on a step and repeat process for complex projects.
In the case where you’re performing multiple functions, such as die cutting, laminating, dispensing, or placing a product on a web, you may have to use a multi-pass process simply because of equipment constraints.
However, this can result in inefficient use of labor, materials, and time to market. In addition, you risk accumulating tolerance deficiencies with each pass through the machine.
For example, a transdermal manufacturer previously produced their product in four separate passes of the machine. While the upfront equipment cost of their machinery was lower, the manufacturing cost per part was extremely high due to the added cost of storing material and tooling between passes; additional personnel; validation of each pass; and decreased product accuracy.
Ultimately the increased cost of a fully integrated, single pass, manufacturing line led to reduced product cost.
Solution: Do more in one pass
Most converters avoid adding in the type of converting equipment that could consolidate all these processes into a single in-line process out of cost concerns. However, they tend to underestimate the impact of efficiency gains on the bottom line.
With the right converting solution, you can manufacture a product from web to package. Vision and reject systems ensure product quality, equipment validation is streamlined, material storage is minimal, and you can also add different modules for enhanced capabilities.
Tapemark™ added a lamination module that was part of a move to an inline process, resulting in an 11x increase in throughput with savings in materials and a lower cost per part.
4. Improve scrap removal
Hand removal of scraps, such as slugs, is a costly manual process. That is, if you can even find the workforce who wants to take on this kind of work.
If you’re relying on labor to remove scrap on individual pieces, you are fighting a losing war against a task that demands automation.
A less expensive alternative is to use spring plungers or foam inserts to plug cavities in a rotary die, but those methods may prove to be largely ineffective.
Solution: Use vacuum or forced air eject systems
An alternative approach is to use a standard eject system, blown through the journal of the die. The forced air blows through the die cavities as the tool rotates. A web vacuum can be used to assist in clean up.
A vacuum transfer can also be used when the job will not allow materials to be ejected near the point of the cut.
The cost of slug removal systems shouldn’t just be defined in terms of capital expenditures — the savings that result from reduced tooling and press damage, scrapped parts, and reduced labor costs are a big part of the equation.
Instant efficiency measures: Reducing quality assessment times
As we mentioned earlier, you should always be reassessing your processes, and taking the steps to make quality improvements. But we all know this is a time-consuming, lengthy process.
The low-hanging fruit, such as the efficiency measures we’ve highlighted here, are there for the taking. And any capital expenditures will likely be covered by the increases in productivity and the potential for new gains.
So how do you get there? Converting equipment manufacturers see a variety of products from a variety of industries. There are tricks of the trade that can be applied in numerous different industries.
Be willing to engage in consultative dialogues with your equipment provider to discover how you can gain production efficiencies AND increase capabilities. That’s a win-win any converter loves to see.