First of all, we first come to understand that the definition of flowers: the cymbid is also called flowers, water, is produced in the injection molding surface similar to the blister-like lines, mostly scissors, head pointing to the plastic mouth.

Figure 1 typical pattern of silver defects

Figure 2 typical pattern of silver defects

The reason for a flower
1. Equipment aspects
Nozzle hole is too small, the material in the nozzle salivation or drawing, barrel or nozzle with obstacles, high-speed material flow through the friction generated when the material decomposition;
Barrel, screw wear or plastic head, the existence of plastic tape dead ends, long-term heat and decomposition;
Heating system out of control, resulting in high temperature decomposition, should check the thermocouple, heating rings and other heating elements are problematic. Improper screw design, resulting in decomposition or easy to bring into the air.
2. Mold side
Due to the design of the defects, such as: gate position is poor, the gate is too small, multi-gate parts gate arrangement asymmetry, flow channel small, mold cooling system unreasonable so that the mold temperature difference caused by too much In the cavity flow is not continuous, blocking the air channel.
The corner is too sharp, the material flow through the cut too much to cause the appearance of the text;
The mold parting surface lacks the necessary exhaust hole or the exhaust hole is insufficient, the jammed position is not good, there is no insert, the thimble and so on the processing gap exhaust, causes the air in the cavity to be able to leave at the same time when the plastic enters The
Mold surface roughness is poor, frictional resistance, resulting in local hot spots, so that through the plastic decomposition.
Mold oil leakage, leakage, leakage into the mold cavity is easy to cause parts that crazing.
3. Process aspects
The material temperature is too high, causing decomposition. Barrel temperature is too high or heating disorders, should be reduced by the barrel temperature. Feeding section of the temperature is too high, so that part of the plastic premature melting filled with a groove, the air can not be discharged from the feed port.
Injection speed is too fast, so that the molten plastic by the role of large shear decomposition, resulting in decomposition of gas; injection speed is too slow, can not be filled in time cavity caused by insufficient surface surface products produce crazing.
Lack of material, feeding cushion is too large, the material temperature is too low or mold temperature is too low will affect the melt flow and molding pressure, resulting in bubbles.
Screw pre-plastic when the back pressure is too low, the speed is too high, so that the screw back too fast, the air is easy with the material together to the front of the barrel.
4. Raw materials
Raw materials mixed with mixed materials or aggregates mixed with a lot of dust, melting easily entrainment of air, sometimes there will be crazing. When the raw material is contaminated or the dust is too large, the raw material is susceptible to heat decomposition.
Water supply material (raw material) to add too much, too much water or the number of renewable material or the proportion of new materials is too high (generally should be less than 20%).
The auxiliaries in the material decompose to form a crayon.
Too much moisture in the material can not be fully dry, resulting in pieces of silver.
Material moisture content is too high or the material has a honeycomb, resulting in pieces of silver.

Two field investigation steps
1. whether the material is damp
Investigation materials are not obvious over the water damp phenomenon, you can visually observe the packaging with no water damp phenomenon, open the bag with the hand touch the material with or without moisture phenomenon, there is water damp material is difficult to dry;
2. Feeding links
Check the feeding link to ensure that the barrel and the feeding process clean to avoid mixed with the material to see whether the material particles with obvious honeycomb;
3. Drying equipment investigation
Check the drying equipment to see whether the heating temperature of the drying equipment is normal (the bottom of the barrel has a thermometer), the blast is easy to enter and exit, you can touch the outlet with a clear feeling of the wind;

Figure 3 for the drying cylinder inlet temperature and the actual temperature to match the set temperature

Figure 4 for the outlet to the wind smooth

4. Does the shot block have a foaming phenomenon?
Exit the shot to see the presence of plastic foam phenomenon, the normal production materials should not have foaming phenomenon, there is a bubble is to have the gas to continue to dry or reduce the barrel temperature;

Figure 5 block bubble obvious, the material overheating decomposition or not drying

Figure 6 Block smooth and round well dry

5. Check the nozzle heating coil and barrel
Check the nozzle heating coil and barrel heating is normal, the mouth of the mouth can be used in the above test, the material is melting, the material does not respond to the temperature is not normal; barrel temperature can view the temperature screen, Value deviation of more than 20 degrees;
6. Injection molding process
Check the key conditions of the impact of the injection molding process, loose position as much as possible to reduce the back pressure may be appropriate to increase the speed of injection and reduce the two-way verification;
7. Mold problem check
Check the mold with or without oil, leakage, leakage effects;