How much influence does the wall thickness of plastic parts have on the quality?
The wall thickness of plastic parts has a great influence on the quality. If the wall thickness is too small and the flow resistance is large, it is difficult for large and complex plastic parts to fill the cavity. The minimum dimension of the processing wall thickness of plastic parts should meet the following requirements:
Sufficient strength and stiffness
It can withstand the shock and vibration of demoulding mechanism when demoulding.
Ability to withstand tightening force during assembly
There is a minimum wall thickness stipulated by the injection processing plant, which varies with the variety, brand and size of the plastic parts. Excessive wall thickness in plastic parts processing not only wastes raw materials, but also increases the time of moulding for thermosetting plastic moulding, and easily causes incomplete curing. For thermoplastics, cooling time is increased. In addition, it will also affect the quality of plastic parts processing. The wall thickness of the same injection part should be as uniform as possible, otherwise additional stress will be generated due to uneven cooling and curing speed.
It is very important to determine the wall thickness of plastic parts reasonably. The wall thickness of plastic parts depends first on the requirements of the use of plastic parts, including the strength, quality cost, electrical performance, dimensional stability and assembly of parts. Generally, the wall thickness can be determined by referring to similar values (e.g. the general wall thickness of iron is 2 mm, and the vacuum cleaner is 2.5 mm). The points of attention are as follows:
The wall thickness of plastic parts should be as uniform as possible to avoid being too thin, too thick and sudden change of wall thickness. If the wall thickness of plastic parts must be changed, gradual change or arc transition should be adopted. Otherwise, the plastic parts will be deformed, the strength of plastic parts will be affected, and the fluidity of injection moulding will be affected due to uneven shrinkage.
The wall thickness of plastic parts is generally in the range of 1-5 mm. The most commonly used value is 2-3 mm.
As far as possible, do not design too thick reinforcing ribs and screw columns. Generally, it is recommended to take half of the thickness of the body wall to be safe. Otherwise, it is easy to cause appearance problems such as miniature.
As far as possible, do not design parts into separate flat plates, the size is very small, otherwise the deformation will lead to uneven parts.
