Still more plastics technical terms
- Weld line
- Synthetic resin additives
In 1835, the powder of "polyvinyl chloride" was invented in France. Four years later in 1839, "Polystyrene" was invented this time in Germany. Although it is still a famous plastic, these plastics at that time had problems such as durability and although it was developed as a plastic, it was lacking in practicality as an industrial product.
"Weld line" refers to a thin line generated at the fused portion where the flow of molten resin joins in the mold during resin formation. For example, when a core or pin is provided to form a hollow part in a molded part, a resin shunting occurs at that part, and a weld line is generated at a joined part. In some cases, it can be seen as a thin line, it may not be visible from the outside, but in the latter case it is called a weld line.
Depending on the type of resin to be injected and the method of designing the mold, there are cases where there is no problem even if a weld line occurs. However, there are cases where the appearance deteriorates, and in the worst case, structural defects may be caused, so the weld line can not be ignored.
Whether weld lines are easy to form depends on the type of resin used. For example, "ABS" is a resin that is prone to weld lines. In addition, if it is only necessary to solve only the problem of appearance, there are a method of increasing the temperature of the mold to delay solidification of the resin, a method of increasing the injection speed and thinning the solidified layer of the surface, and the like.
Synthetic resin additives
"Synthetic resin additives" refers to additives used for the purpose of inhibiting deterioration of synthetic resin and addition of flame resistance. Furthermore, when classifying it, it is called "stabilizer" when used for the purpose of suppressing deterioration of resin, and one which adds added value such as flame resistance is called "modifier".
When looking at plastic products from a practical point of view, the characteristic of general plastics "weak against heat and light" interferes. In compensating for these weak points, it is more economical and more efficient to use a small amount of stabilizer than to improve the plastic itself. The same is true for modifiers that impart functionality, and it is possible to improve the performance of plastics by adding a small amount of modifier.
Knowing the information and properties of these plastics is one of the important points in relation to plastic products. When you need a plastic product, let's grasp what kind of application / characteristics you need and let me prepare the most suitable plastic.