Blow Mould Regular Maintenance And Repair
Regular maintenance of the blow mold (machinery should be cleaned regularly, especially the extruder screw and nose) and to keep the machinery, raw materials and workshop clean and clean, help to ensure the normal blow molding. So how to carry out maintenance and maintenance?
Parison head cleaning. Keeping the parison head clean is an important prerequisite for extruding blown high performance products. Some polymers are degraded during processing, especially if the melt is to be retained in the storage chamber for a period of time when the processing temperature is high or intermittent blow molding. In addition, blow molding grade polymers contain a variety of additives, the melting process will form by-products. These degradation products or by-products will accumulate in the nose of the machine, so that the surface of the parison appears stripe, affecting the appearance of the product. The flow path of the nose is chunk or chrome can reduce the appearance of parison fringes. So that the inflated parison in the contact blow mold cavity when a higher temperature, may be appropriate to offset the effect of parison stripes on the appearance of the product. The production process with copper, etc. to remove the nose in the mouth of the aggregates, and sometimes can eliminate the stripes on the stripes. If not, we must shut down to conduct a comprehensive clean-up. Here are some ways to clean up the head
1, manual cleaning method
Before removing the head, use an electric heater to heat it above the plastic melting point. Can not use acetylene flame to heat, because it will cause the nose of the local overheating and warping, affecting the die and mandrel size and shape. After the stop heating, remove the heater, open the nose. First with copper or copper beryllium scraper shovel to most of the melt, and then do the final cleaning with brass cotton. But also with high-speed air to remove the melt on the nose, but still use brass cotton to wipe the already oxidized melt, and sometimes also use the grinding wheel or by heating to remove the melt. The melt on the thread can be removed with an anti-sticking agent. Hand to clean the head to avoid scratches the flow channel, especially the die area. This method of heavy workload, will be the nose of the nose of the machine to produce physical damage, and often the destruction of metallurgy. Use the following cleaning method to avoid it.
2, solvent cleaning method
Ie by means of an acid or a basic chemical, an organic or inorganic solvent. The equipment of the acid or alkaline chemical cleaning method is low in cost, but the cost of the chemical is high, and the cleaning efficiency is low, and the metal is also corroded. Organic solvent cleaning efficiency is high. Solvent cleaning method to set up recycling equipment, so as not to pollute the environment.
3, ultrasonic cleaning method
This method is good cleaning, but the cost of equipment and chemicals is high, and there are corrosion problems, it is best used for post-cleaning, remove the inorganic residue. In addition, there are salt bath, oven or fluidized bed cleaning method.
Blow molding transparent containers to a high degree of polishing blow mold cavity, the production process to be polished every time. Use polish and soft cotton paper to polish the mold cavity, so that a small amount of polishing agent to penetrate the cavity surface, and then use a clean cotton paper to polish until the mold cavity appears so far. Polishing should always change the cotton paper, so as not to scratch the mold cavity. Bubble mold clip blank mouth after wear and tear by skilled manufacturers to repair. The shearing block on the neck of the blow mold and the shearing sleeve on the intake rod is the key part and must be kept in good condition and replaced if necessary. For example, when the cutting edge of the cutting block is unevenly worn, the molded container may leak at the time of use. Blow mold cooling pipe due to clogging or corrosion and affect the flow of cooling medium should be immediately cleaned. Blowing mold guide pin and guide sleeve to regular lubrication, each work at least once a year to replace, to ensure that the two mold alignment, improve die life. When the production or blow mold to stop the inventory, to use compressed air blowing mold cooling channel, mold cavity to be coated with protective agent, so as not to be corroded.