Method and device for producing a polymer tape
AssigneeDsm IP Assets B.V.
InventorReinard Jozef Maria Steeman
Life of this patent
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Abstract
The invention relates to a method for producing a highly oriented, high molecular weight polymer tape. The method comprises forming and compression-molding a polymer powder bed at a temperature below the melting point of the polymer to form a sheet; at a temperature below the melting point of the polymer, rolling and stretching the sheet in a calendar unit to form a partially oriented polymer web; at a temperature below the melting point of the polymer, drawing the partially oriented polymer web in a drawing unit; and, optionally repeating step c) to form a more fully oriented non-fibrous high molecular weight polymer tape, the method being discontinuous in that the ingoing line speed of one of the method steps b) to d) differs from the outgoing line speed of the preceding method step.
Claims28
A method for producing a highly oriented non-fibrous polymer tape comprising:
- a) forming and compressing a polymer powder bed at a temperature below the melting point of the polymer to form a non-fibrous polymeric sheet;
- b) rolling and stretching the non-fibrous sheet formed according to step a) in a calendar unit at a temperature below the melting point of the polymer to form a partially oriented polymer web;
- c) drawing the partially oriented polymer web in a drawing unit at a temperature below the melting point of the polymer to form an oriented non-fibrous polymer tape;
- and
- d) repeating step c) to form a more oriented non-fibrous polymer tape, wherein
- the method is practiced in a discontinuous manner such that an ingoing line speed of at least two of the method steps b), c) and d) are lower than an outgoing line speed of a preceding step.
A method for producing a highly oriented non-fibrous polymer tape comprising:
- a) forming and compressing a polymer powder bed at a temperature below the melting point of the polymer to form a non-fibrous polymeric sheet;
- b) rolling and stretching said sheet in a calendar unit at a temperature below the melting point of the polymer to form a partially oriented polymer web;
- b′) winding the partially oriented polymer web onto a bobbin at a winding speed which is substantially the same as an outgoing line speed of b);
- breaking the partially oriented polymer web;
- and then unwinding the partially oriented polymer web to step c) at substantially the ingoing line speed thereof;
- c) drawing the partially oriented polymer web in a drawing unit at a temperature below the melting point of the polymer to form an oriented non-fibrous polymer tape;
- c′) winding the oriented non-fibrous polymer tape onto a bobbin at a winding speed which is substantially the same as an outgoing line speed of c);
- breaking the partially oriented non-fibrous polymer tape;
- and then unwinding the oriented non-fibrous polymer tape to step d) at substantially the ingoing line speed thereof;
- d) repeating step c) to form a more oriented non-fibrous polymer tape, wherein
- the ingoing line speed of method step c) is lower than the outgoing line speed of step b);
- and the ingoing line speed of step d) is lower than the outgoing line speed of step c).
Dependencies are inferred from the claim text.