Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
200 words
Apparatus for producing a coated film comprising an annular die having an orifice and for extruding a tubular extrudate of a thermoplastic polymeric material, means for cooling the tubular extrudate, means for withdrawing and axially forwarding the cooled extrudate, means for reheating and inflating the withdrawn extrudate to form an oriented tubular film, and means for coating the extrudate by spreading a coating medium substantially circumferentially around the periphery thereof, said coating means positioned between said forwarding means and said reheating means and comprising dispensing means for supplying a liquid coating medium to the external surface of the cooled extrudate, a rotatable assembly including a support member providing an orifice through which the tubular extrudate may be fed in an axial direction, a plurality of spreading members spaced-apart from each other around the circumference of the support member orifice, mounting means for each of the spreading members, said mounting means being operatively associated with the support member and displaceable relative thereto, means for biasing each of the spreading members inwardly of the support member for engagement with the external surface of the tubular extrudate, and drive means for rotating the assembly in a plane substantially normal to said axial direction.
Claim 2
Dependent Claim
200 words
Apparatus for producing a coated film comprising an annular die having an orifice and for extruding a tubular extrudate of a thermoplastic polymeric material, means for cooling the tubular extrudate, means for withdrawing and axially forwarding the cooled extrudate, means for reheating and inflating the withdrawn extrudate to form an oriented tubular film, and means for coating the extrudate by spreading a coating medium substantially circumferentially around the periphery thereof, said coating means positioned between said forwarding means and said reheating means and comprising dispensing means for supplying a liquid coating medium to the external surface of the cooled extrudate, a rotatable assembly including a support member providing an orifice through which the tubular extrudate may be fed in an axial direction, a plurality of spreading members spaced-apart from each other around the circumference of the support member orifice, mounting means for each of the spreading members, said mounting means being operatively associated with the support member and displaceable relative thereto, means for biasing each of the spreading members inwardly of the support member for engagement with the external surface of the tubular extrudate, and drive means for rotating the assembly in a plane substantially normal to said axial direction.
Claim 3
Dependent Claim
31 words
Apparatus according to claim 1 wherein said coating means includes a stop assembly engageable with said mounting means to control the pressure exerted by each spreading member on the tubular extrudate.
Claim 4
Dependent Claim
25 words
Apparatus according to claim 1 wherein said coating means includes retracting means for simultaneously disengaging the spreading members from the surface of the tubular extrudate.
Claim 5
Dependent Claim
33 words
Apparatus according to claim 1 wherein said dispensing means comprises a spray assembly for discharging a solution or dispersion of a liquid coating medium onto the tubular extrudate upstream of the rotatable assembly.
Claim 6
Dependent Claim
16 words
Apparatus according to claim 1 wherein each spreading member is supported at the leading edge thereof.
Claim 7
Dependent Claim
17 words
Apparatus according to claim 1 including a resilient contact pad on the surface of each spreading member.
Claim 8
Independent Claim
105 words
A method of producing a coated film by depositing a coating medium on the surface of an axially moving cooled thermoplastic polymeric tubular extrudate and reheating and inflating the coated extrudate to form an oriented, coated tubular film comprising the step of substantially circumferentially spreading the deposited coating medium onto the surface of the extrudate, prior to reheating and inflating, by successive contact of the deposited coating medium with each of a plurality of spreading members resiliently biased into engagement with said surface and rotating around the periphery of the extrudate in a common plane substantially normal to the longitudinal axis of said tubular extrudate.
Claim 9
Independent Claim
105 words
A method of producing a coated film by depositing a coating medium on the surface of an axially moving cooled thermoplastic polymeric tubular extrudate and reheating and inflating the coated extrudate to form an oriented, coated tubular film comprising the step of substantially circumferentially spreading the deposited coating medium onto the surface of the extrudate, prior to reheating and inflating, by successive contact of the deposited coating medium with each of a plurality of spreading members resiliently biased into engagement with said surface and rotating around the periphery of the extrudate in a common plane substantially normal to the longitudinal axis of said tubular extrudate.
Claim 10
Dependent Claim
30 words
A method according to claim 7 wherein the ratio of the rotational speed of the spreading members to the axial speed of the tubular extrudate is from 2:1 to 20:1.
Claim 11
Dependent Claim
18 words
A method according to claim 7 wherein the coating medium is an aqueous solution of an antistatic agent.
Claim 12
Dependent Claim
26 words
A method according to claim 7 wherein the tubular extrudate comprises at least one layer of a high molecular weight stereoregular predominantly crystalline polymer of propylene.