Semi-auto bottom lock structure

Before the designer draw an semi-automatic bottom lock structure carton box, he should be very clear about the size relations of the details of the main parts on the bottom of the box. The bottom size has a very close relation with the main dimensions of the box template. The size of length and width and the relations impact the bottom structure of the box template. Let's check the following photo for example.

In the photo above, L stands for length, W stands for width, CAL stands for caliper.(The structure descripted here only when L/4>=W/3, if L/4<W/3, usually we do not suggest this bottom lock structure, for one thing the paper utilization is relatively lower, for another thing the carrying capacity of the bottom is not enough)

The first part, the relations between the size of the parts in the bottom and the length, width of the box template:

Y1=W/2 Y2=Y1-CAL/2(As long as the value of Y2 similiar to Y1 or less than Y1this relations works, it mainly depends on the caliper value)

X1=(W-CAL)/2

X2=(L-X1*2)

X3=X2+CAL

Y3=W/4(Y3 can be similiar to W/4 or less than W/4, it can not be greater than W/4, ) then it will be the roundings of each corner, we will talk later.

The second part is the variety deformations of the bottom sturcture.

①

The left side is enhanced bottom structure, the offset angle T1=30°

②

There's a T2=5° angle in the left buttom structure, the two bottom structure are very similiar, the left one is easier for forming.

③

There's an angle on the left bottom structure, T3=30°, if match the left bottom structure with the enhanced bottom structure ①, the bottom structure will be more stronger, of course, the structure will be a little more complex.

④ Position

As for single box template structure, the change of the position is meaningless, sometimes in order to improve the paper utilization, we will change the position for step and repeat process.

In the photo above, if we changed the postion, the paper utilization improved obviously.

When the value of L is large and the goods loading is heavy within the carton box(fruit box for example), we can change the bottom lock structure into multiple corners for heavy loading. We will discuss this kind of complex bottom lock structure in next article.