1. Raw material issues:
(1) In the process of storage, transportation and transportation, raw materials are required to be contaminated with secondary pollution.
(2) In the process of artificial mixing, the external environment is caused by the mixing of color debris.
(3) The use of unreasonable raw materials itself is not good in heat resistance, the temperature of the material tube is too high, and black spots appear in the formation of carbonization.
(4) Some products need to use added toner to meet the production needs. If necessary, the lubricant should be fully stirred even if added. If the addition is insufficient, the toner will be stirred unevenly, and toner accumulation will occur in some parts of the production process. After the tube is heated, a carbon spot is formed to form a black spot.
(5) Adding materials to the customer's request, the raw materials themselves have black spots, the proportion of addition is too large, and the original raw material properties cannot hide the black spots.
2. Reasons for the mold:
(1) When the mold is installed before production, the lubricating oil added during the maintenance process is not cleaned in time, and the overhaul is not complete, and oil stains and impurities fall off.
(2) If the barrel gate is too small or rough, it will generate a lot of friction heat. If the mold is poorly ventilated, it will cause the gas to burn and produce obvious black streaks.
3. Reasons for the equipment:
(1) The mixer is operated for a long time, and it is required to be cleaned regularly;
(2) The filter of the dryer must also be cleaned and replaced regularly. Otherwise, it will enter foreign matter or the material will change color and agglomerate due to poor ventilation.
(3) The mixing machine and the drying machine are not sealed due to negligence of the operator or insufficient working equipment. The protective work cannot be done well, resulting in dust entering the air, and black spots appear in the production process.
(4) When the color change powder of the pulverizer is cleaned, the mask is not in place, and other color materials are mixed.
4. Causes of eccentricity between screw and material pipe;
(1) The screw compression ratio is too large, the shallow part of the feed part is shallow and the friction between the inner wall of the barrel and the raw material causes a large frictional force to cause the carbonization of the raw material to decompose and cause black spots.
(2) The material tube produces different materials for a long time. Due to the change of temperature, the oxidation, degradation, and the adhesion of various materials to the metal surface are different, which leads to the surface of the screw, the wall of the tube, and the shot. At the mouth, etc., the carbonization layer is gradually formed. When the material with higher viscosity is encountered, it is separated and gradually taken out. In addition, if there are scratches or gaps in the screw and the pipe wall, it is easier to let the molten material stay, such as The carbon left on the notch when it is turned on again falls off to form a black spot.
(3) The heater chip is damaged, resulting in incorrect temperature. The actual temperature and temperature gauge error of the heater is too large, and the temperature of a certain section is overheated, which is not easy to intuition, and carbonization causes black spots.
5. Other reasons:
(1) Those who do not understand the material crush the defective product, resulting in material confusion.
(2) The floor material is directly put into the crusher.
(3) When the material is changed, the operation machine is not cleaned thoroughly, or the remaining material in the hopper is not cleaned.
(4) The sanitary finishing in the workshop is not thorough and it is easy to form dust.https://www.fhpails.com/