Apparatus and method of manufacturing pressure compensator type drip irrigation tubes with desired molecular orientation and tubes obtained thereby

A method for accomplishing pressure compensation comprising:

• i. formation of a section of film thinner than a main body of the film;
• wherein formation of the section of film is accomplished using coextrusion;
• ii. formation of a slit inlet and outlet by running through a roller that contains blades;
• and
• ii. section formed in (a) is ultimately formed to be the pressure responsive area;
• wherein process of co-extrusion comprises:
• a. material for the main body is moved from a main extruder into a distribution ring for the main body;
• b. from the distribution ring the material is moved further to the compression zone;
• c. simultaneously, material for the pressure-responsive membrane is moved to another distribution ring and from there to the compression zone;
• d. the two materials are heat sealed as they approach the compression zone;
• and
• e. at the compression zone air is injected into the composite material, which blows the composite material, and thereby forms bubble.

A production line for manufacturing pressure compensator-type drip irrigation tubes at high speed, the line comprising:

• a. plurality, of extruders for extruding a polymer;
• b. a means for inducing a pressure inside the tube;
• c. a means for drawing the blown tube simultaneously to the blowing of tube;
• d. a means for flattening the blown tube by heat welding the collapsed halves together and forming a tape immediately, subsequent to the process of blowing and drawing the tube;
• e. a means for extruding a bonding polymer on one border of the tape;
• f. a means for printing flow channels into the hot and viscous bonding polymer;
• g. a means for forming a tube by lengthwise folding the tape and heat welding the overlapping borders together using the bonding polymer;
• and
• h. a tool for feeding the material for the main body and material for the pressure-responsive membrane for co-extrusion comprising two hollow slots for containing the said two materials.