The structure and production process of plastic masterbatch
Plastics are widely used in our daily lives. Many of the daily necessities, handicrafts and even some machines and equipment are made of plastic. We all know that plastic is synthetic by pouring the synthetic plastic material into the mold and finally forming the finished product. Then, what are the materials that make up the plastic? The plastic masterbatch is one of the special concentrated raw materials synthesized. With the plastic masterbatch, there is no need to add other plastic additives, saving a lot of materials, then, what is the structure of the plastic masterbatch? What about its production process?

The ideal structure of the masterbatch should consist of four parts. Sometimes the masterbatch structure is not so complicated, only a simple two-layer or three-layer structure, but the modification effect is poor.

(1) The innermost layer is the filler core, which mainly plays the role of improving rigidity and reducing cost. The choice of filler core: calcium carbonate, talc, kaolin, wollastonite, fly ash, glass beads, etc. can be used as filler core. Generally, the finer particle size is prefered, preferably 1250 mesh or more, and the added amount is 50%-80%.

(2) The second layer is the coupling layer composed of coupling agent or crosslinking agent for the purpose of improving the bonding force between the filler and the resin. Coupling layer selection: generally coated with the coupling agent such as titanate, silane, phosphate, boric acid ester, aluminate, etc., generally used in an amount of 0.5% to 3% of the filler, sometimes for synergy. Appropriate addition of the cross-linking agent such as bismaleimide to enhance synergy. And for uniform treatment, often add some thinner, such as ethanol, toluene, etc. to make the better effect of coupling agent.

(3) The third layer is the dispersion layer composed of some oligomers and dispersants, the purpose is to uniformly mix, avoid accumulation of fillers, and improve fluidity during granulation. Selection of Dispersion Layer: Stearic acid, stearate, low molecular weight polyethylene, low molecular weight polystyrene and other low molecular weight polymers are generally selected, and the amount thereof is generally within 5%.

(4) The fourth layer, that is, the outermost layer is the thickening layer composed of the copolymer or compatible agent having a certain double bond, in order to better bond with the resin to be filled.

Selection of the mixed layer: Generally, a random polypropylene (APP) is used, which has a low softening point and good coating effect. Other resins such as LDPE, HDPE, LLDPE, PS, CPE, EVA, etc. may be used, and sometimes the blend of above resin may be used as a carrier resin, such as LDPE and LLDPE blending, and the synergistic effect is good. If the masterbatch is used for PVC resin, AMS resin can be selected as the masterbatch carrier, and the filling effect is better. In addition, the filler can be treated with anhydrous maleic anhydride grafted polyethylene, polypropylene, etc., and the effect is also good. The amount of the mixed layer used is 15%-30%.

Production process principle of plastic masterbatch

The production process principle is:

Raw material weighing → proportioning → mixing → extrusion → cooling → pelletizing → inspection → packaging metering → storage

Corresponding equipment:

Scale → Calculation → Mixer Mixing → Single/Twin Screw Extruder → Water/Air Cooling → Pelletizer → Packaging Machine

Masterbatch quality assessment (quality criteria for plastic masterbatch, generally in comparison to standards, such as masterbatches. Sometimes compared in some of the following aspects).


1. Appearance color: Appearance size, cylindrical particles or square particles, whiteness, and whether there are impurities in the color.

2, Water and its volatiles: should be less than a certain value, such as 0.2% -0.3%.

3. Density: such as 1.7-1.9g/ml.

4. Melt flow rate: should be greater than a certain value, such as 0.5g/10min.

5, The specific professional pointer: such as flame retardant masterbatch should indicate the level of flammability, such as UL-94V-0 grade, halogen content.

6, The amount of addition: such as adding 10% - 15%, 30% - 40% and so on.

From the above introduction, we can know that the structure of the plastic masterbatch has three layers. We can't help but marvel that the small volume actually has three layers of structure. It can be said that the sparrow is small and complete, indicating that it has a high concentration type. A good principle of making plastics should be widely used. The production process of plastic masterbatch has strict operation steps, and the corresponding operations of each step require high specialization. Now it is basically completed by the machine, and it is difficult to do so precisely by human. The various ingredients and colors are also relatively standard.