As one of the mainstream grayboard boxes, the book-type box is named for its book-like opening design. It is widely popular and used due to convenient opening, unique shape and low printing difficulty. With increasing use, warping has become a common quality issue. This article analyzes the causes and provides solutions.

I. Root Cause of Warping: Grayboard-Related Issues

The core cause of book-type box warping lies in the grayboard substrate, specifically divided into shell and inner box problems. In production, shells mostly adopt V-groove technology, and inner boxes use half-through technology; processing accuracy directly affects forming quality.

II. Specific Cause Analysis

1. Inner Box Issue: Dimensional Deviation

Inaccurate inner box size may cause warping, but regular manufacturers will avoid such problems in advance through sample testing before mass production.

2. Shell Issue: Die or V-Groove Deviation

Warping caused by the shell is more common, mainly due to two reasons:

1. Die size error; 2) Improper V-groove processing. Both will lead to warping of the book-type box edge.

III. Solutions

1. Minor warping: For V-groove process deviation, adjust the V-groove position to correct the book-type box edge size;

2. Warping after V-groove completion: Conduct secondary V-groove processing according to actual conditions to correct structural accuracy.

Conclusion

The above are the core causes and solutions to the book-type box warping problem, for reference by industry colleagues. Shengcai Printing is a professional packaging box manufacturer, undertaking custom needs. Welcome to contact us!