US 2005/0003175 A1 · Preparation of polyethylene films

Abstract

A process for preparing polyethylene thin films is disclosed. The process comprises extruding a blend that comprises a linear low density polyethylene (LLDPE) and a high molecular weight, high density polyethylene (HMW-HDPE) or high molecular weight, medium density polyethylene (HMW-MDPE). The blend has an LLDPE/HMW-HDPE or HMW-MDPE weight ratio at least 50/50. The blend is extruded through an annular die to form a molten material tube. The molten material tube is then pulled around a fixed internal orientation device (FIOD) to form the film. The FIOD makes it possible to prepare polyethylene thin films from LLDPE-rich LLDPE/HMW-HDPE or HMW-MDPE blends on a high stalk film line. The films have increased machine-direction (MD) tears.

Claims22

Dependent claims

A process for preparing a thin film on a high stalk extrusion line, said process comprising:

(a) extruding a blend through an annular die to form a molten material tube, said blend comprising:
(i) a linear low density polyethylene (LLDPE);
and
(ii) a high molecular weight polyethylene selected from a high density polyethylene (HMW-HDPE) or a high molecular weight, medium density polyethylene (HMW-MDPE);
in a weight ratio of (i)/(ii) greater than or equal to 50/50;
and
(b) pulling the molten material tube around a fixed internal orientation device (FIOD) to form the film.

4 more elements

Dependencies are inferred from the claim text.

Preparation of polyethylene films

Life of this patent

Preparation of polyethylene films

Life of this patent

Abstract

Claims22