The moon cake festival(mid autumn festival) is coming up
Moon cake boxes have been in use since the late 1800’s. Today, there are many variations
of possible styles, some of which are illustrated below. For our purposes, we will
describe the manufacture of the most basic style, the wrapped set-up base and lid.
Non-bending chipboard, the material most often used for rigid boxes, may range from
.040 (40 thousandths of an inch) to .080 or more. Compare this to folding cartons, whose
stock may vary from .010 to .036. Note that there are many types of substrate used by
folding cartons depending upon the end use of the packaging, but most set-up boxes
use chipboard. This is because in set-up box manufacturing, the finishing is done to the
wrap, not the substrate.
The exception is when a material called white vat-lined chip is used. In this case, the
chipboard is lined on either one or both sides with a white coating made from newsprint,
giving the box a more finished appearance. This stock works especially well if the interior
of the box is to remain unfinished, or unlined.
The goal in set-up box manufacturing is to bring the wrap and the formed chipboard lid
or base together, adhering them in perfect alignment before forming the finished tray. Of
the six fundamental steps in the production of a set-up box, two make the box, two
produce the wrap, and two bring them together to produce the tray: for the tray –
scoring and staying; for the wrap – printing/preparation and applying adhesive; and
finally, for the completed tray – spotting and wrapping.
The simple steel rule die for the tray contains knives (the black lines) for cutting out the
overall shape from the chipboard, and cut-scores (the red lines) for allowing the panels
to fold. Cut-scores only partially penetrate the chipboard, allowing bending without
You can use the groove machine to make the scoring lines
Set-up boxes can be made without stay tape,but for added stability, ¾” wide adhesive backed tape is applied to the four corners of the tray on a machine called a quad stayer. Image 6 shows an example of an older manually fed model. Two of the four rolls of tape are clearly visible; the other two are blocked by the ones in front. The chipboard blanks are fed into the machine, a plunger forms the box, tape is applied and heat-sealed to the tray. You can see how the taped box looks after it leaves the stayer by reviewing below picture: box corner taping machine
Not all set-up box wraps require printing, but this option, plus foil stamping, embossing, debossing and other decorative techniques; almost anything that can be glued to chipboard and formed into a box are available. Whatever wrap is used, it must be trimmed before adhesive is applied. The corners are cut away or mitred so that when the box is formed, the wrap makes a perfect transition from two-dimensional blank to three-dimensional box.
Pressure is applied to the top of the unwrapped tray to help the glue adhere, then the box moves into the wrapper. Arms grab the tray and pull it at a right angle into the wrapper. The red plunger pushes the lid or base down where the adhesive laden wrap is rolled up and over the tray, gluing it to the sides and onto the inside lip of the box, giving it what is called a turned edge.
The wrap process can be made by below machine: rigid boxes forming machine
There are two methods of adhering the wrap: tight wrap, the most typical technique; and loose wrap. The tight wrap method applies adhesive to the entire back surface of the wrap, a corner cut wrap has just left the gluer on its way to the spotting station, where the formed lid or base will be positioned and placed onto the wrap. Loose wrap is generally applied only to the lid of a box, and as the name implies, the wrap is only spot-glued at the edges, leaving the top panel without adhesive. The purpose of this type of gluing is primarily aesthetic: a box made with a loose wrap appears to be hand-made, and therefore a more expensive package. Back when much of the production was indeed done by hand, loose wraps were more common. But in today’s automated environment, loose wrap constitutes only a small percentage of total production. This brings us to the last two stages of production, where the wrap and tray meet to become a finished piece
The term spotting is derived from the days when an operator would position, or spot the lid or base onto the wrap, “eyeballing” the correct position. While this operation is still done manually in some operations, with the advent of electronic eyes and more
sophisticated positioning equipment, the process is becoming more and more automated. Figure 1 below shows where an operator would be positioned in a semiautomatic boxmaking line.
The wraps, adhesive-side up, move along a conveyor from the left. The lid or base, having been formed in the quad stayer, moves toward the operator from the top of the diagram. The operator then carefully (and quickly) places the tray on the glued surface
of the wrap. From there, the box moves to the right toward the wrapping station. In an automated line, the spotting station appears as it does in Image 8. If you look closely at the top center of the shot you can see a machine-positioned base descending toward the wrap below. At the bottom left of the picture is a base that has just left the station, now ready for wrapping.