Abstract A multiple-roll calender for producing thermoplastics films, in which, viewed in the direction of working, a penultimate roll is spaced from the roll which immediately precedes it so that for a period as it travels from said preceding roll to the penultimate roll the material being calendered is not in contact with any of the rolls, and said penultimate roll and a final roll which together define a final working gap, are provided with drive means whereby they can be driven at varying speeds independently of the other rolls. A guide roller may be provided to guide the material centrally into the final working gap or a pull-off roller or pair of pull-off rollers and a constant pressure roller may be provided to guide the material to the final working gap. Alternatively a pull-off roller and a scraper device, defining with the penultimate roll a gap which narrows in a downstream direction may be provided.
A calender for producing thermoplastics films and comprising a plurality of calender rolls wherein viewed in the direction of working, a penultimate roll of said rolls is spaced from a roll of said rolls which immediately precedes said penultimate roll so that in operation of the calender a portion of the material being calendered, for a period as it travels from said preceding roll to said penultimate roll, is not in contact with any of said rolls, and said penultimate roll and a final one of said rolls which together define a final working gap, are provided with drive means whereby they can be driven at varying speeds independently of the others of said rolls.
Claim 2
Dependent Claim
115 words
A calender for producing thermoplastics films and comprising a plurality of calender rolls wherein viewed in the direction of working, a penultimate roll of said rolls is spaced from a roll of said rolls which immediately precedes said penultimate roll so that in operation of the calender a portion of the material being calendered, for a period as it travels from said preceding roll to said penultimate roll, is not in contact with any of said rolls, and said penultimate roll and a final one of said rolls which together define a final working gap, are provided with drive means whereby they can be driven at varying speeds independently of the others of said rolls.
Claim 3
Dependent Claim
29 words
A multiple-roll calender as claimed in claim 1, further comprising a guide roller to guide the material being calendered from said preceding roll centrally into said final working gap.
Claim 4
Dependent Claim
53 words
A multiple-roll calender as claimed in claim 1, further comprising at least one pull-off roller positioned downstream of said preceding roll and rotated at at least as great a peripheral speed as said preceding penultimate roll, and a constant-pressure roller co-operating with said penultimate roll and disposed upstream of said final working gap.
Claim 5
Dependent Claim
72 words
A multiple-roll calender as claimed in claim 1, further comprising a pull-off roller positioned downstream of said preceding roll and rotated at at least as great a peripheral speed as said preceding roll and a scraper device positioned downstream of said pull-off roller, upstream of said final working gap, spaced from said penultimate roll and so positioned as to form with said penultimate roll a gap which narrows in a downstream direction.