When designer make the injection mould design must first determine its opening direction and parting line at the beginning of the design to ensure that the loose core structure parting line effect the on the product appearance are eliminated as much as possible.
 
1. After the mould open direction determined, the product strengthen ribs, locks and other structures should designed and consistent with mould open direction.
 
2. Mould open direction determined, then to choose the appropriate parting line, to avoid undercut and improve the product appearance and performance.
 

•  Draft angle

1. Appropriate draft angle can avoid scratch on product. Product with glossy surface, draft angle should be ≥0.5°. Product with thin texture, draft angle should ＞1° and thick texture surface product draft angle should＞1.5°
 
2. Appropriate draft angle can avoid ejector mark, deform and break by eject
 
3. For deep cavity structure product, the outer surface angle should be greater than inner surface to ensure the mould core is not offset, get a uniform wall thickness, and to ensure the product opening strength.
 

• ØWall thickness

1. All kinds of plastic have a certain wall thickness range, generally is 0.5-4mm, when the wall thickness is more than 4mm, will cause too long cooling time, resulting in product furface shrink mark, then should consider changing the product structure.
 
2. Uneven wall thickness will cause the surface to shrink, and joint mark.
 

•  Strengthen rib

1. The rational application of the ribs can increase the rigidity of the product and reduce the deformation.
 
2. The thickness of strengthen rib must be ≤ (0.5 ~ 0.7) t product wall thickness, otherwise the surface shrinks.