METHOD OF MAKING MULTILAYER FILM WEB Russian patent published in 2020 - IPC B29C55/06 A61F13/15 

FIELD: hygiene.

SUBSTANCE: invention relates to the field of multilayer polymer materials used to produce hygienic absorbent products, and concerns a method of producing a multilayer film web. Web consists of at least two initial film webs comprising a thermoplastic polymer material, wherein each initial film web contains at least one low-melting polymer component and at least one high-melting polymer component. Method includes steps of: making at least two initial film webs by extrusion with blowing, cast extrusion or a combination of extrusion with blowing and flat-slit extrusion; passing at least two initial film webs before their transition into partially melted state, in which in each initial film web at least one low-melting polymer component is in liquid molten state, and at least one high-melting polymer component is not in liquid molten state, together through at least one heating roller; and passing multilayer, partially melted film web through the cooled roll space.

EFFECT: invention enables to prevent formation of microholes due to superabsorbent polymers and breaks of finished film products in packaging devices and provides a requirement for hygienic films, which consists in minimum ultimate tensile strength, which is required for processing of film webs in high-speed machines (converters).

15 cl, 1 dwg, 1 tbl