"Vacuum forming" mold? People who know this are great

Hello everyone, today I will talk to you about plastic molds. Plastic mold is the abbreviation of a combined mold for compression molding, extrusion molding, injection molding, blow molding and low foam molding. The coordinated changes of the mold convex, concave mold and auxiliary molding system can process a series of plastic parts of different shapes and sizes.

A good thermoformed product must first be made into a mold after it is designed, and then it can be mass-produced. Many thermoforming machine manufacturers also have fixed mold suppliers, which shows the importance of molds. Today, I will talk about the aspects to be paid attention to in the design of vacuum forming molds.

1. Batch size

For experimental use, the mold output is small, and it can be made of wood or resin. However, if the experimental mold is used to obtain product data on shrinkage, dimensional stability, and cycle time, a single-cavity mold should be used for the experiment, and it can be guaranteed to be used under production conditions. Molds are generally made of plaster, copper, aluminum or aluminum-steel alloys, and aluminum-resin is rarely used.

2. Geometric shape design

When designing, it is often necessary to comprehensively consider dimensional stability and surface quality. For example, product design and dimensional stability require the use of female molds (concave molds), but products that require high gloss on the surface require the use of male molds (punch molds). point so that the product can be produced under optimal conditions. Experience has shown that designs that do not meet actual machining conditions often fail.

3. Dimensional stability

During the molding process, the surface of the plastic part in contact with the mold has better dimensional stability than the part that leaves the mold. If the material thickness needs to be changed in the future due to the material stiffness, it may lead to the conversion of the male mold to the female mold. The dimensional tolerance of plastic parts cannot be less than 10% of the shrinkage.

4. Surface of plastic parts

As far as the range that the molding material can cover, the surface structure of the visible side of the plastic part should be formed at the point of contact with the mold. If possible, the smooth surface of the plastic part should not be in contact with the mold surface. As is the case with the use of female molds for bathtubs and laundry tubs.

5. Shrinkage and deformation

Plastic is easy to shrink (such as PE), and some plastic parts are easy to deform. No matter how to prevent it, plastic parts will deform during the cooling stage. Under this condition, it is necessary to change the shape of the forming mold to adapt to the geometric deviation of the plastic part. For example: Although the plastic part wall remains straight, its datum center has been deviated by 10mm; the mold base can be raised to adjust for this deformed shrink star.