Compression Molding process

1. Molding method

Carbon fiber is a fiber material, so the carbon fiber material molding process uses fiber material molding
law. The fiber material molding method is a method of putting pre-mixed or pre-impregnated fiber-shaped molding material into a metal mold to form a composite material product under a certain temperature and pressure.

compression septic tank mould

2. The basic principle of molding
The rheological behavior of thermosetting plastics in compression molding is better than that of thermoplastics
The material is much more complicated, and it is always accompanied by a chemical reaction throughout the molding process, heating the initial material
A low-molecular viscous flow state is present, and the fluidity is still good. As the functional groups react with each other, part of it occurs.
Cross-linking, the fluidity of the material gradually decreases, and a certain degree of elasticity is produced, so that the material is gelled
State, and then continue heating to make the molecular crosslinking reaction more perfect, the degree of crosslinking increases, and the material is gelled
The state changes to a glass state, and the resin body has a body structure, and the molding is over.

compression moulding

3. Controlling factors of molding

The controlling factors of molding, commonly known as “three elements”, namely temperature, pressure and time.
1) Temperature: This process parameter determines the heat transfer conditions of the mold to the material in the cavity,
It has a decisive influence on the melting, flow and solidification process of the material.

2) Pressure: close the mold tightly and make the material denser, and promote the flow and melt of the melt
The pressure generated by the volatilization of low-molecular substances in the mold cavity.

3) Time: also known as compression molding insulation and holding time to ensure that the shape of the mold cavity is sufficient
Complete curing.

compression molding

4.Step description:


1. Clean the mold: clean the resin and debris from the last use in the mold and keep the mold
The tool is clean and smooth.

2. Preheating of the mold: heat treatment of the mold.

3. Apply mold release agent: apply a certain amount of mold release agent to the groove of the mold to prevent subsequent
After heating, the molded product and the mold stick together.

4. Material preparation: prepare the raw materials of the carbon fiber to be made into products and calculate the raw materials
Material area, the number of sheets used.

5. Stacking: Stack the raw materials layer by layer, and pre-press the stacked materials at the same time.
Press into a compact body with regular shape and certain quality.

6. Into the mold: put the stacked raw materials into the mold, and put the plastic gas inside
Bag, mold clamping, put the whole into the mold clamping machine, add a certain constant to the internal plastic air bag
Pressure, constant temperature, set a constant time to cure.

7. Cooling and demoulding: Cool the mold after a period of hot pressing for a period of time,
Then, the mold is opened and demolded.

8. Processing and forming: The products after demoulding need to be cleaned, scrape off the remaining plastic with a steel brush or a copper brush, and blown off with compressed air to polish the formed products to make the surface smooth and clean.


Post time: Jul-14-2020