Packaging box and production process thereof

A packaging box, comprising a cover body and a box body, wherein the cover body is detachably buckled with the box body;

• the cover body comprises a cover sheet material and a first buckle part;
• the first buckle part is arranged at an edge of a surface of the cover sheet material;
• the first buckle part is formed by injection molding at the edge of the surface of the cover sheet material;
• the box body comprises a box sheet material, a second buckle part, and angle frames;
• the box sheet material comprises a bottom surface and four side surfaces connected to the bottom surface;
• the box sheet material is formed into a box by folding four side surfaces;
• four corners of the box are fixed and sealed through the angle frames;
• an edge of an opening part of the box is connected to the second buckle part;
• the second buckle part is connected to the angle frames;
• the second buckle part and the angle frames are integrally formed by injection molding;
• the second buckle part is formed at the opening part of the box by injection molding;
• the angle frames are formed at the four corners of the box by injection molding;
• each angle frame comprises a side frame and a bottom frame;
• the side frame is fused with edges of two corresponding adjacent side surfaces;
• and the bottom frame is fused with bottom edges of two corresponding adjacent side surfaces and a corresponding corner edge of the bottom surface;
• wherein the bottom surface is square;
• four corners of the bottom surface have fillets;
• two ends of a side surface extend outwards to any adjacent two side surfaces;
• after folding, the two ends are fused together with the side frame along corresponding fillets to seal junctions of the four side surfaces;
• the bottom frame is in an arc shape;
• and the bottom frame is fused together with bottom edges of end portions of two corresponding adjacent side surfaces and edges of the corresponding fillets of the bottom surface to seal junctions of the four corners;
• and
• wherein first flush stiffening ribs are arranged on the side frames;
• second flush stiffening ribs are arranged on the bottom frames;
• the first flush stiffening ribs are intersected with the second flush stiffening ribs;
• after folding, the edges of two adjacent side surfaces resist against two sides of the corresponding first flush stiffening ribs;
• bottom edges of the end portions of the two adjacent side surfaces resist against upper sides of the corresponding second flush stiffening ribs;
• and edges of the fillets of the bottom surface resist against lower sides of the corresponding second flush stiffening ribs.