What is called plastic warping
The official definition: plastic warping is not in accordance with the original design of the shape of the shape, the surface distortion distortion, the fundamental reason for plastic warpage is the thickness of plastic varies. In other words, if the thickness of the entire plastic parts of the same point, then there is no deformation of a said, even if the final size has changed, but also larger or smaller size, rather than deformation.
The problem is, then what is called thin wall, what is called thick wall? When the wall thickness of less than 2mm plastic parts called thin-walled, thin-walled products than thick-walled products more prone to warping problems, then you may ask, why do thin-walled products, of course, is the pursuit of Thin and light, and can save material costs.
With the arrival of thin times, the product more and more biased thin technical requirements, but also accompanied by the emergence of warping problems, only to reduce the plastic warpage, in order to better meet the accuracy requirements of the product.
The reason of the second warping deformation
Warpage is the product in the injection process occurred. May be due to lack of cooling the late plastic, may also be a mold out of the error, but also may be mold design and process parameters do not match a series of reasons. The following analysis of one by one
1. Plastic parts are not fully cooled or uneven
In the injection molding plant, it may be clear on this, the injection molding machine is composed of static and dynamic mold, the dynamic model is the cavity, the cavity is the shape of the shape of the product part of the melt through the pouring system, Cavity, in the cavity cooling molding, in the cooling process, is the need for pressure, until the complete cooling molding, can be ejected, came to the core. Assuming that there is no complete cooling molding, when the mandrel is ejected, the plunger thrust is easy to deform the plastic parts.
2. Pole caused
It is also mentioned above, the mandrel is caused by plastic parts warped, if the mandrel forced out of the plastic parts, and plastic parts of their own rigidity, hardness is not enough, it is likely to cause warping
3. Strain caused by molding
In the molding process, the plastic parts of the direction of the degree of contraction is not the same, when the shrinkage direction of forming a difference, or wall thickness deformation, but also easily lead to warping products
4. Mold temperature distribution is not uniform
Temperature in the injection molding, is a very important factor, it can not only cause the phenomenon of floating fiber, but also cause warping defects. The difference in cooling rates on both sides of the product surface results in an asymmetric contraction in the thickness direction of the product, resulting in a net bending moment that causes the surface of the article to bend toward a lower cooling rate (higher mold temperature).
on the warping summary
Know the reason to know why, is the fundamental way to solve the problem, only to know the reasons for plastic warping, in order to fundamentally do the drastic solution to the problem.
