with continued reference to the drawing , fig1 illustrates process and apparatus for film perforation by skiving off thermoformed projections or pips . thermoplastic polymeric film 10 is supplied to heated s - wrap rolls 12 which raise the temperature of the film to that suitable for thermoforming . the heated film is then placed in contact with a perforated continuous surface means such as stainless steel belt 14 . perforated stainless steel belt 14 is driven by drive roll 16 . belt 14 is heated prior to contact with film 10 in belt - heat oven 18 . film 10 is conveyed by belt 14 through a pressure differential means in the form of vacuum box 20 . the thermoformable film 10 is drawn into the perforations of the belt 14 thus forming &# 34 ; pips &# 34 ;. the film is drawn into but not through the perforations due to the pressure differential . it is within the scope of the invention to provide additional or alternative positive pressure on the other side of film 10 to force portions of the film into the perforations of the belt 14 . it is important that the thickness of the belt 14 be greater than the length of the pips formed to prevent premature destruction of the pips by say the edge of the vacuum box 20 or by other portions of the conveyor mechanism . the thermoformed film 10 is then passed under cooling means 22 which hardens the film . the cooled thermoformed film 10 is then stripped at the end of conveyor roll at location 24 and passed to a skiving means such as between mandrel roll 26 and continuous razor knife 28 thus skiving the pips off parallel to the surface of the film to remove a substantial portion of the pips . vacuum means 30 is juxtapositioned to continuous razor knife 28 to collect skived pips which may be reground and reprocessed into film 10 . it is most important that the skived pips be recovered and not destroyed due to the large percentage of the material the pips represent . the perforated film thus produced is then passed through an orienting tenter and longitudinal stretcher means 31 which stretches the film into the desired reticulated web net . the finished net is then wound on rolls ( not shown ). likewise , the film 10 is provided by supply rolls ( not shown ). fig2 illustrates an alternate embodiment of the instant invention wherein a film 32 is provided by direct extrusion from film supply means such as extruder head 34 . film 32 is preferably extruded vertically downwardly onto the surface of thermoforming drum 36 . vertical extrusion eliminates the type of distortion of film in its plastic condition that occurs in horizontal extrusion . it is also within the scope of the invention to eliminate distortion by extruding film directly into contact with the surface of thermoforming drum 36 . the surface of thermoforming drum 36 consists of a perforated stainless steel belt , for example , 0 . 050 inch holes , 133 per square inch , straight pattern , having a thickness of 20 gauge ( 0 . 037 inch ). as thermoforming drum 36 revolves , it places the film in contact with a pressure differential means in the form of internal vacuum chamber 38 . again it is within the scope of the invention to provide external pressure as well as or in substitution for vacuum to thermoform . film 32 is drawn by the vacuum into the perforations of the belt to produce pips . thermoforming drum 36 continues to rotate and places the film in contact with cooling means in the form of chamber 37 wherein cooling is applied internally to harden the film . external cooling may also or alternatively be provided . film 32 then passes over take - off roll 39 where it leaves the surface of thermoforming drum 36 and is conveyed to mandrel roll 40 and complementary skiving blade 42 which slices off the thermoformed pips . the film thus perforated then passes through orienting means 44 which preferably biaxially orients the film into reticulated web net . the skiving blade 42 is preferably a single bevel blade which will maintain continuity of cutting over long periods of time . the materials that the above reticulated web net can be formed from include any thermoplastic film - forming polymer . among these are polyethylene , polypropylene homopolymer , random copolymers of propylene containing up to 10 percent of another olefin , block copolymers of propylene containing up to 25 percent of another olefin , nylon - 6 , nylon - 66 , polyethylene terephthalate , other high molecular weight thermoplastic polyesters , and vinyl polymers such as polyvinyl chloride , polystyrene and poly ( methyl methacrylate ). conjugate or bicomponent plastic sheets in which two or more different polymers are extruded together to form sheets containing layers of separate polymers are also applicable . it is to be understood that the above description and drawings are illustrative of this invention and not in limitation thereof . as will be evident to those skilled in the art , various modifications can be made in the light of the foregoing disclosure and discussion , without departing from the spirit or scope of the disclosure or from the scope of the claims .