Plastic blown film lines form a variety of products

Plastic Blown Film Lines Plastic blown film is created when molten extruded plastic is pulled through an air ring and air is blown inside forming a tube or bubble of thin plastic. The tube is pulled until nipped which collapses the bubble. The plastic is then wound onto a winder. When creating blown film, several pieces of equipment are required. One component is an extruder. When purchasing a used extruder, consider the make, the L/D ratio, type (AC or DC) and horsepower of the motor, barrel venting, types of controls, type of feeder, condition of the barrel, and overall appearance. Blown film extruders include a 24-inch center line height, an L/D ratio of 24:1 or 30:1, and a screen changer. Another component is the die package. A die package includes a die, air ring, blower, and sometimes a polycool. When purchasing a used die, consider the diameter of the die, the die gap (to control the thickness of the film), whether the die rotates, and brand. An air ring is either single lip or dual lip. Dual lip air rings have increased cooling capacity. To ensure correct sizing and thickness, consider the horsepower of the blower. If a polycool is included, note the CFM rating. Common brands include Gloucester, Alpha Marathon, Western, and Sano. Another component to blown film lines is the primary nips. Key elements are face width, roll diameter, and height. Sizing of a blown film line depends on the width of the product and thickness of the plastic. A collapsing frame guides the bubble into the primary nips. Mounted between the air ring and collapsing frame is a bubble cage that maintains the diameter of the bubble. Common brands include Gloucester, Egan, Davis Standard, and Western. The final component to a blown film line is the winder. Key elements of a winder are the brand, model, face width, diameter of the rolls, and whether it is single turret or dual turret. Common brands include Egan, Welex, Cantilever, Gloucester, APV, Cincinnati, Parkinson, and Sano. Used blown film equipment can be purchased by component or as a complete line. If buying by component, ensure the width and thickness of the film matches the rate of the existing system. Used Blown Film Line Accessories Some blown film lines have an optional 'treater' that allows plastic to be printed on it. Ensure the roll width and speed is consistent with the rest of the line. Printing can be single or double sided. Consider the brand and how many colors it can print. Brands include Wolverine and Gloucester. Another accessory is a bag machine. A bag machine seals and perforates blown film to allow one end of a bag to be sealed while the other can be opened. If purchasing a used bag machine, consider the brand, model, width of the unit, and sealing location. A bag separator is used in conjunction with a bag machine and creates an opening at the top of a bag. Consider the brand, model, and width of the unit. Used Blown Film Lines When purchasing used plastic blown film lines, consider the condition of the equipment and its configurations. Ensure all components of the die package are included along with the primary nips. Choose a winder that suits your application. Other accessories are also available. The advantages of buying used plastic blown film lines include immediate delivery and competitive price. Choose a reputable brand with maintenance records. ------ Perry Videx has been at the center of the used equipment and machinery world for almost 80 years and currently maintains a large inventory of used plastic blown film lines. For more visit http://www.perryvidex.com