CARTON WITH IMPROVED FOLDING

Abstract

The present invention provides a carton (100) made of paperboard having flaps (101, 105), the carton (100) comprising, at least one score (102) along a crease line (103) of at least one flap (101, 105), wherein the score (102) is 25% to 85% of thickness of the paperboard and 5% to 70% of length of the crease line (103). The invention also provides a method of securing flaps (101, 105) of the carton (100).

Claims

1. A carton (100) made of paperboard, having flaps (101, 105), the carton (100) comprising, at least one score (102) along a crease line (103) of at least one flap (101, 105), wherein the score (102) is 25% to 85% of thickness (104) of the paperboard and 5% to 70% of length of the crease line (103).

2. A carton as claimed in claim 1, wherein the score (102) is 30% to 70% of the thickness (104) of the paperboard.

3. A carton as claimed in claim 1, wherein the score (102) is 50% to 60% of the thickness (104) of the paperboard.

4. A carton as claimed in claim 1, wherein the score (102) is 20% to 65% of the length of the crease line (103).

5. A carton as claimed in claim 1, wherein the score (102) is 40% to 60% of the length of the crease line (103).

6. A carton as claimed claim 1, wherein the score (102) is at the crease line (103) of each flap (101, 105).

7. A blank for making the carton (100) as claimed in claim 1.

8. A method of securing flaps (101, 105) of a carton (100) made of paperboard, the method comprising, making at least one score (102) along a crease line (103) of at least one flap (101, 105), wherein the score (102) is 25% to 85% of thickness (104) of the paperboard, and is 5% to 70% of length of the crease line (103).

9. A method as claimed in claim 8, wherein the score is 30% to 70% of the thickness of the paperboard.

10. A method as claimed in claim 8, wherein the score is 50% to 60% of the thickness (104) of the paperboard.

11. A method as claimed in claim 8, wherein the score is 20% to 65% of length of the crease line (103).

12. A method as claimed in claim 8, wherein the score is 40% to 60% of length of the crease line (103).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0049] FIG. 1 is a schematic representation of the paperboard carton of present invention with open flaps.

[0050] FIG. 2 is a schematic representation of the paperboard carton of present invention with closed flaps.

DETAILED DESCRIPTION OF DRAWINGS

[0051] FIG. 1 shows the carton (100) of the present invention having flaps (101top and bottom; the bottom flap is not shown; 105side flaps) both along the length and breadth of the opening of the carton. The figure shows scores (102) on the crease lines (103) of the flaps. A partially cut-away enlarged view of the crease line (103) of the flap (101; 105) shows that the scores (102) along the crease line (103) are less than the thickness (104) of the paperboard carton.

[0052] FIG. 2 shows a closed paperboard carton of the present invention with scores (102) depicted on the crease lines (103).

EXAMPLES

[0053] Technical benefits of the disclosed invention will now be explained further with the help of a non-limiting example.

[0054] Methodology

Example 1

[0055] Two types of paperboard cartons were taken for conducting experiments for testing the crease recovery force of the cartons of the present invention. [0056] 1) Carton I350 GSM grey back board with 10 m metalized polyethylene terephthalate (MET-PET) lamination on the paperboard on the outer side of carton. [0057] 2) Carton II350 GSM white back board with 10 m metalized polyester (MET-PET) lamination on the paperboard on the outer side of carton and 10 m clear polyethylene terephthalate (PET) lamination on the inner side of the carton.

[0058] Both boards were top printed using transparent inks and UV texture and spot varnish on the top. After the printing and varnish application board sheets are left for curing for 12-36 hours.

[0059] Post curing board was punched using special dies fabricated to make score profile on the creasing line in step operation. The score was around 50% deep. Plurality of scores along top and bottom flaps covered around 70% of the crease line and a single score on each of the side flaps covered around 33% of the crease line. Carton punching, creasing & scoring was done as a single step process. Single die having different finish blades were used for producing punched cartons, creasing and scoring profile on desired position. A pneumatic pressure of about 120 tons was used for the die on a board size of 1020720 mm.

[0060] For the controls, a different die was used without a provision for scoring. Therefore for each type of carton the controls had no score across the crease line, whereas the experimental cartons had scores on two flaps on the left opening of the rectangular carton box (L1 and L2) and two flaps on the right opening of the rectangular carton box (R1 and R2).

[0061] Process of Performing Test:

[0062] Carton strips of required sample size are taken and mounted on the crease recovery tester (IDM instruments: Crease and Stiffness Tester, model C0039). While sample preparation it is important to keep in mind samples should contain the creasing area equidistant from both the edges.

[0063] Post mounting samples, an external force is applied for 15 sec and then removed. Due to the inherent property of regaining the original position post removal of external force, the crease gives a crease recovery force and measured in terms of gf (gram force) named at crease recovery force.

TABLE-US-00001 TABLE 1 Testing Crease recovery force of Cartons Without With score Carton Score/Control (gram Type Flap (gram force) force) Carton I L1 140.3 101 Carton I L1 135.5 89 Carton I L1 122.5 82.4 Carton I L2 138.1 93.5 Carton I L2 127.7 93.6 Carton I L2 115 93 Carton I R1 125.6 97.1 Carton I R1 121 86.6 Carton I R1 135 87.8 Carton I R2 125.7 96.3 Carton I R2 118.1 63.3 Carton I R2 123 88.1 Carton II L1 157.2 86.7 Carton II L1 161.1 94.2 Carton II L1 153.6 92.2 Carton II L2 161.1 87.0 Carton II L2 179.1 98.6 Carton II L2 165.4 85.1 Carton II R1 179.7 94.5 Carton II R1 196.7 89.3 Carton II R1 154.4 90.4 Carton II R2 165.2 88.9 Carton II R2 152.2 92.3 Carton II R2 150.6 99.5

[0064] The data in Table 1 shows that the trial carton having score profile on the creasing shows lesser crease recovery force values post removal of the external force vs. a carton on which there is scoring.