” BLOWN FILM MACHINES AND USEFUL TIPS IN INCREASING THE CACO3 FILLER MASTERBATCH DOSAGE”
The process of blown film is reasonably simple. First step, plastic pellets are put into the extruder and heated to their melting point at 180 to 210 Celcius degree. The plastic is then forced through a cylindrical die and forms a thin walled bubble. This bubble is sustained by air, and is fed up through a scaffold where the tube continues to rise. Over this length, the plastic begins to cool. Once it has cooled enough, it is collapsed down on itself, forming a flattened tube. This tube is passed through various rollers and spun onto a spool. The edges of the tube can be trimmed and it can also be punched, cut or printed on before going on the spool.
Blown film manufacturing is great for producing products that require uniform properties along the length and width of the product. It’s also a great high volume production method, however it requires massive capital cost to purchase a blown film machine. Blown film can produce up to 130 metres of products in a single minute. The sheets and film they can produce can be as fine as 10-20 microns (0.01mm – 0.02mm) to 250 microns (0.25mm) thick. Most Blown film is either High or Low Density Polyethylene (HDPE or LDPE) but there are exceptions. The downside to blown film is that it can only product sheets or tubes.
The blown film process is used to produce a wide variety of products and so there are equally various types of PE film blown film machines.
According to the numbers of film layer of the final product, it ranges from simple monolayer blown film machines used to fabricate bags like shopping bag, garbage bag to very complex multilayer structures for films used in food packaging or household packaging. According to capacity, there are blown film machines with big capacity which produces more than 65 Kilogram per hour (KG/h), average capacity from 35 to 65 KG/h and small ones with that of below 35 KG/h.
One of the challenges to produce price-competitive PE film is to reduce the production cost while still maintaining the features which are considered to be indicators of high quality film such as smooth surface, stable tensile strength and good elongation. When considering to use a larger dosage of this plastic raw material, there are several matters to put into the table, for example:
For monolayer blown film machines, in case you are producing LLDPE or HDPE film with current 30% CaCO3 filler masterbatch dosage and you would like to increase the dosage of filler masterbatch up to 40~60%. Our recommendation is firstly, control the humidity/ moisture of the material composition by using desiccant or anti-foam masterbatch to eliminate the moisture or drying the composition in the mixer within a specific of time.
For multilayer blown film machines such as ABA, ABC blown film machines, to increase the CaCO3 filler masterbatch ratio in the mixture and the final film still has good surface and good strength, besides the suggestion to control the humidity/ moisture of the material composition as previously mentioned, we will give suitable advice with more details so that you can use at 60 % in B – layer in multilayer blown film machines, depends on your current formula. In addition, it is recommended that the adjustment is made step by step within a small scale to evaluate the effects.
About US Masterbatch Joint Stock Company
US MASTERBATCH JSC, An ISO 9001: 2015 Certified Company, one of the fastest-growing name Masterbatch Manufacturers and Exporters from Vietnam. We specialize in researching and producing calcium carbonate filler masterbatch, color masterbatch, white and black masterbatch. Currently with 8 production lines with latest technology double screw extruders, our yearly capacity has reached to 80,000 tons to supply products to customers in more than 50 countries around the world.