Sep 22, 2019
During production of parts in the plastic industry, it is important to meet certain tolerances, eg. given in the drawing.
For this purpose regular checks of specific characteristics of a sample, mostly at multiple parts, are carried out in practice.
The control chart is a curve, which shows for example the mean of the samples and its standard deviation.
Limit values can be added into the control chart for warnings and necessary interventions. If these limits are exceeded, measures or interventions in the process can or must be taken.
Quality: Example of a Control Chart from the QM- Control Center in “solvtec
CAQ”
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This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Dec 6, 2018
The cooling system in the injection mold is usually inserted into the steel by drilling.
By adding plugs the flow path for the coolant is clearly defined.
The conventional cooling is cheap compared to other cooling technologies and for most molds satisfying.
Feb 1, 2019
In the injection molding process the main source of heat inside the mold is coming from the molten plastic.
The coolant flowing through the cooling channels absorbs the heat, which leads to a rise in temperature inside of the coolant.
One indicator of the cooling efficiency is the coolant temperature in between the inlet and the outlet.
For technical parts the temperature difference should be less than 3 °C in order to ensure good part quality.
The coolant temperature help to evaluate the cooling design. It also help to estimate the number of bridges between cooling channels.
Higher flow rates, larger diameters and/or shorter cooling channels help to reduce the coolant temperature.
Sep 5, 2019
Through the melt, heat is introduced into the mold and it needs to be removed.
Therefore, holes are drilled into the mold. During the process, water or oil will flow through them. The holes themselves are called cooling channels.
For a high effectivity of a cooling channel, its distance to the cavity and to neighboring channels must be chosen wisely.
The length and diameter, as well as the curve angle in which cooling channels meet each other, influence the quality of the cooling.
The same is true for the temperature and the speed of the coolant.
Dec 6, 2018
The injection mold is brought up to a specific temperature by the cooling system, which consists of the cooling device and the cooling channels.
Water or oil is used as a coolant flowing through the channels.
The better the temperature layout, the shorter the cooling time.
The aim is a uniform temperature at the cavity wall.
This way one factor for the warpage can be reduced.
