|In-line or Off-line Decorating: A 10-Step Analysis|
|by Bob Coningsby, Apex Machine Company|
|Solutions Fall 2011|
Should we run our decorating system in-line with our molding machine? Furthermore, should we run our molding machine and decorating system in-line with our assembly machine and subsequent packaging system?
These are significant questions that are deliberated when proposing the lowest possible unit cost system that will operate in an efficient and economical fashion. This can be determined quite easily provided that the molding machine, decorating system, assembly machine and packaging line are analyzed and assessed in every aspect of their feature and operation. Similarly, long-range goals and economic expenditure are critical factors that also should be considered in advance of the development and final confirmation of the project.
A 10-step analysis is suggested in order to truly verify the feasibility of an in-line operation.
Step 1. Molding
B. Rotational Molding
D. Blow Molding
E. Injection Molding
In summary, running in-line with any of the processes mentioned is certainly feasible and, in many cases, practical. As a rule of thumb, Apex typically recommends running in-line only with blow molding or injection molding equipment, as both of these processes will allow for a better return on investment.
Step 2. Part Type
Flat and round parts are more ideally suited for in-line applications than odd-shaped parts, but the key is in the consistency of the part produced. An inconsistently made part will not allow for the use of specific technologies, which otherwise would be more conducive to an odd-shaped part.
Another factor to keep in mind is the size of the part and the material used to produce it, as some materials have different shrink characteristics than others. Certain materials also require pretreatment for particular decoration processes.
To summarize, smaller parts which are consistently manufactured are appropriate for an in-line decoration process. Before considering the idea of running in-line, the required graphics should be analyzed, as the type of artwork also will impact the feasibility of the decoration process.
Step 3. Volume
Step 4. Artwork or Graphics
Does the round part need to be decorated for a full 360° circumference on the full length, or does it simply need to be spot printed? If a flat part is produced, would this require decoration on both sides, and would the graphics be applied to the full surface of both sides?
In producing an odd-shaped part, where do the graphics need to be placed? Would the part support itself during the decorating process? What type of artwork or graphics is needed? Would a one-color print be required or is multi-color artwork necessary? Is a metallic image needed or does the part require photo-style graphics? Would short runs or long runs be produced; and how often would the artwork or graphics change? All of the above are critical questions, as the style of graphics will dictate the decoration technology; and the decoration technology will determine the feasibility and practicality of running in-line.
Step 5. Decoration Methods or Processes
A. Pad Printing Pad printing is primarily used for odd-shaped parts and small volume applications. This process involves the utilization of a solvent-based ink, recessed printing plate and a silicon pad to achieve very high quality graphics on unusual surfaces or odd-shaped parts. Most pad printing machines operate in a reciprocal fashion and off-line, as the volumes are typically not large enough to justify the automation to interface the molding machine with the pad printing system.
There are continuous-motion pad printing machines on the market, and many of these systems do run in-line. However, the keys to an in-line operation with a rotary pad printer are the part – which in most cases is round – and the volumes. Large volumes will be needed to run with few changeovers to truly justify an in-line interface between an injection molding machine and a high-speed rotary pad printing system.
B. Hot Foil or Heat Transfer
As a rule of thumb, odd-shaped parts cannot be hot foiled or heat transferred; thus, most hot stamped or heat transferred parts are either round or flat. In addition, both technologies utilize a reciprocating part-handling motion, making it ideally suited for small-volume applications only.
In comparison to other technologies, heat transfer or hot stamp has an expensive per unit cost. However, this technology allows for a lower capital investment as heat transfer and hot foil systems are very inexpensive.
As a rule of thumb, silk screen machines have a long changeover time, making a multi-color silk screen machine impractical to run in-line for small volume applications. On the other hand, if running in-line with a blow molding machine, a sufficient buffer can be incorporated between the molding machine and the print to run small orders. Again, the changeover time is extremely critical, as the buffer needs to allow for a sufficient part accumulation while a changeover takes place.
D. Offset and FlexApex Printing Processes
E. In-Mold Label (IML)
F. Laser and Inkjet
Step 6. Assembly Process
Normally, an in-line application is not recommend for high-volume parts that requires multiple assemblies. The assemblies are the key, however. What parts have to be assembled to the decorated parts and do those parts also have to be manufactured in-line?
Step 7. Packaging Requirements
Packaging off-line is recommended because of the complexities normally associated with the packaging process. However, Apex currently is running numerous lines in-line with packaging, and once again, the decision is based on volumes.
Step 8. Automation to Interface
How long does it typically take to perform a changeover? The buffer needs to be larger or longer than the longest possible changeover timeframe, as it will not be affordable to stop the machinery when running in-line. Another key factor is machine efficiency, as an in-line operation will only be successful if each of the machines can operate in an efficient and non-stop process. If any of the machines which are part of this operation cannot operate efficiently, and each of the machines within this operation is not predictable, then Apex does not recommend running in-line.
Step 9. Cost
Step 10. Return on Investment
To summarize, Apex is a huge advocate of an in-line process, specifically in the U.S.; however, running in-line is not easy, and every aspect of the project must be carefully analyzed and assessed to truly define what is possible, practical and – of course – justified.
Bob Coningsby is CEO and chairman of Apex Machine Company. Apex serves every facet of industrial printing systems, custom printing systems and on-product printing, marking and decorating equipment. For more information, call 954.566.1572 or visit www.apexmachine.com.