Method for producing an extruded sheet
AssigneeFlooring Industries Limited, Sarl
InventorThomas Grafenauer
Life of this patent
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Abstract
The disclosure relates to a method for producing an extruded sheet, which includes: a) providing calcium carbonate (CaCO3) powder; b) providing polyvinyl chloride (PVC) powder; c) providing additives as stabilisers; e) heating the mixture until the PVC softens to form a kneadable mass and the CaCO3 at least partially bonds to the PVC; f) cooling the mass; g) conveying the mass to an extruder; h) melting and extruding the mass by means of an extruder and moulding into a sheet by means of a slotted nozzle; i) pressing the still-warm sheet to a desired final thickness by means of at least two calendar rolls; and j) at least one layer of a pigmented lacquer is applied to the upper side; and k) an additional lacquer is applied to the pigmented lacquer to increase the scratch resistance.
Claims19
A process for the production of an extruded sheet comprising at least the following steps:
- a) provision of calcium carbonate (CaCO3) powder,
- b) provision of polyvinylchloride (PVC) powder,
- c) provision of additives in the form of stabilizers, comprising at least Ca/Zn stabilizers, impact modifiers and internal and external waxes, where
- c1) the proportion of calcium carbonate (CaCO3) powder is between 70 and 80% by weight, the proportion of polyvinylchloride (PVC) powder is between 20 and 30% by weight and the proportion of additives is up to 5% by weight,
- d) mixing of a first portion of the calcium carbonate (CaCO3) powder with the polyvinylchloride (PVC) powder, and the additives, and then
- e) heating of the mixture to a temperature of 100 to 140° C. until the polyvinylchloride (PVC) softens to a kneadable composition and the calcium carbonate (CaCO3) binds at least to some extent to the polyvinylchloride (PVC), and then
- f) cooling of the composition to a temperature of 40 to 50° C., after which a second remaining portion of calcium carbonate (CaCO3) is mixed with the composition,
- g) conveying of the obtained composition to an extruder by means of screws, wherein said extruder comprises an outlet and a slot die at said outlet,
- h) melting and extrusion of the composition by said extruder and molding by said slot die to give a sheet, and then
- i) compressing the sheet following the step of melting and extrusion while the sheet generally maintains the temperature when emerging from the slot die by means of at least two calender rolls to a desired final thickness.
Dependencies are inferred from the claim text.