The gravity center of a shipment should be identical to its geometry center: This is to avoid damage when vehicle start-up, swerve, or brake during transportation.

• 重心中心合一：包装件的重心和其几何中心应该合一或比较接近，这样可以防止货物在运输过程中由于起动、转弯和刹车给货物带来的损失；