How to plan corrugated carton production factory Corrugated cardboard box production
Outline of Manufacturing Process and Materials Utilized
The manufacture of corrugated packaging can be roughly classified into two processes: the containerboard combining process, which glues one or more sheets of fluted corrugating medium to one or more flat facings of liner board; and the box manufacturing process, which is used to assemble the corrugated sheets into boxes. Figure 1 depicts the typical manufacturing process flow and the auxiliary facilities that are used at a corrugated packaging plant.
Figure 1 Overview of Manufacturing Process Flow for Corrugated Packaging
Printing for corrugated packaging has evolved from the use of oil-based inks to quick drying inks and now to flexo inks, which are most common. Theuse of oil-based inks has almost completely ceased and even quick drying inks are now utilized only occasionally. The special characteristics of each type of ink are shown in Table 2.
Table 2-Characteristics of Printing Inks Used for Corrugated Packaging
Printing Process – Printer Slotter
The printer slotter performs printing, scoring and slotting. There are two types of printer slotter: one type that utilizes flexo inks and another type that utilizes quick drying inks.
Printing and Forming Processes-Flexo Folder Gluer
The flexo folder gluer first performs printing onto the surface of box blanksthat have been scored lengthwise. Next, the machine performs slotting andwidthwise scoring, finally gluing the manufacturer’s joints together to formboxes.
Punching Process- Die Cutter
The die cutter utilizes cutting dies to punch out specific shapes from printedbox blanks. Rotary die cutters and platen die cutters are most commonlyutilized, however, die cutters are also used in combination with flexoprinting machines.
Figure 4 depicts the methods used to glue the joint when manufacturing the most common type of general-purpose corrugated box, as shown in Figure 3(type 02 – refer to JIS Z 1507). Currently, of the methods shown below, An extremely efficient gluing method (glue joint method) employing high strength adhesive is most widely utilized.
The machines that are used to form boxes with this glue joint method are called “folder gluers”. Folder gluer machines generally utilize vinyl acetate emulsion adhesives, in particular, those adhesives containing di-n-butyl-phthalate and xylene (or toluene), in order to improve heat resistance, cold resistance and drying speed.
However, new adhesives have recently been introduced to the market, which contain significantly reduced amounts of di-n-butyl-phthalate in order to meet the standards prescribed under the PRTR Law. Therefore, it is expected that, in the near future, the adhesives used shall make the transition to substances that no longer employ Class I Designated Chemical Substances.
Figure 3-Forming of a Corrugated Box
Figure 4 -Method of Forming of a Corrugated Box