The basic knowledge of injection mould
Introduction to injection molding principle of cold runner
Cold runner: refers to the part between the mold entrance and the product gate. Plastic is kept flowing by injection pressure and its own heat in the runner, which is part of the forming material but not the product. The cold runner mold is also the traditional mold, and the ratio of hot runner is no heating device, the material in the runner, after the cooling demould.
Common injection mold introduction
According to the template structure to be divided: two plate mold, three plate mold.Other common mold: two - color mold, flip mold
The advantages of two plate die:
two plate die is the most common, its structure is simple, various forms, easy to maintain。 The gate forms of the two plate mold include direct feeding, side gate (rectangular, fan-shaped), latent gate, horn gate, lap gate, etc
in addition to the latent type and horn type sprue, both of the two plate dies need to be processed to remove the sprue.
Three plate die is in the process of the die is not separated, but the material board, and the mother plate is separated, the material board will be removed from the product, and then the material board is separated, the product out of the mold
Some deformation of two plate die, in three plate die can also be applied, but the mold is relatively complex. A deformation of the three - plate die is applied in combination with the runner of the two - plate die.
Advantages of three - plate mold:
three - plate mold gate only point gate. The three plate mold leaves little gate mark on the product. It can be formed without trace. No additional removal of three - plate die gate. ◎ three board mold
the three plate mold flow channel is longer, need a longer cooling time, that is, need a longer molding cycle. Sound three - plate die consumption of materials. The structure of three plate mold is relatively complicated
Two-color injection mold
Principle: two-color injection molding machine two tubes with two sets of moulds according to the sequence of injection molding two color products.
1. The raw material is made into product A through the material A tube for the first time.
2. Periodically open the mold, and rotate the molding machine template 180 degrees to B to close the mold
3.B material is injected twice through B tube to shape the mold cavity and then ejected
Advantages of two-color mode:
Two - color mold can be formed more than two different plastic, can be multi - color.
Two - color molding products are more beautiful than the assembly, no assembly gap.
Disadvantages of two-color mode:
Two - color forming requires a special molding machine.
Two - color mold needs higher mold processing, positioning accuracy.
Two - color mold needs higher mold installation accuracy, as well as more accurate
The forming process.