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EP-4739482-A1 - METHOD FOR MANUFACTURING A PVC BASED FLOOR COVERING

EP4739482A1EP 4739482 A1EP4739482 A1EP 4739482A1EP-4739482-A1

Abstract

The present invention relates to a method for manufacturing a multilayer polyvinyl chloride floor covering intermediate sheet or a multilayer PVC floor covering, the floor covering intermediate sheet or the floor covering comprising recycled PVC material. The present invention also relates to an apparatus for manufacturing a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering, and to a multilayer PVC floor covering intermediate sheet and a multilayer PVC floor covering obtained thereby.

Inventors

  • DE KEYZER, Daan
  • MAGHERMAN, Chloë
  • MISSEEUW, Lara
  • VIAENE, Herwig

Assignees

  • Beaulieu International Group NV

Dates

Publication Date
20260513
Application Date
20240704

Claims (14)

  1. 1. A method for manufacturing a multilayer polyvinyl chloride floor covering intermediate sheet, the multilayer polyvinyl chloride (PVC) floor covering intermediate sheet comprising recycled polyvinyl chloride material, the method comprising the steps of: a) providing a first batch of recycled PVC material and a second batch of recycled PVC material; b1) mixing the first batch of recycled PVC material with a first blowing agent, the first blowing agent having a predetermined decomposition temperature T di , to form a first blend; b2) optionally, mixing the second batch of recycled PVC material with a second blowing agent, the second blowing agent having a predetermined decomposition temperature Td2, to form a second blend; c1) mixing and melting the first blend, below the decomposition temperature of the first blowing agent Tdi, to form a first mixture; c2) mixing and melting the second batch of recycled polyvinyl chloride material or the second blend, below the decomposition temperature of the second blowing agent Td2 if present, to form a second mixture; d1) processing the first mixture, below the decomposition temperature of the first blowing agent Tdi, to form a first film; d2) processing the second mixture, below the decomposition temperature of the second blowing agent Td2 if present, to form a second film; e) providing an intermediate layer and adhering the first film to one side of the intermediate layer, and the second film to the opposing side of the intermediate layer, thereby forming a multilayer structure; and, f) heating the multilayer structure to a temperature that is higher than decomposition temperature T di thereby causing the first film to expand, optionally also higher than the decomposition temperature T d 2 thereby causing the second film to expand; thereby forming a multilayer PVC floor covering intermediate sheet.
  2. 2. The method according to claim 1 , further comprising the steps of: b2) mixing the second batch of recycled PVC material with a second blowing agent, the second blowing agent having a predetermined decomposition temperature Td2, to form a second blend; c2) mixing and melting the second blend below the decomposition temperature of the second blowing agent Td2, to form a second mixture; d2) processing the second mixture, below the decomposition temperature of the second blowing agent Td2, to form a second film; and, f) heating the multilayer structure to a temperature that is higher than decomposition temperature T di and higher than the decomposition temperature T d2 , thereby causing the first film and the second film to expand.
  3. 3. The method according to claim 1 , wherein the second batch of recycled PVC material is not mixed with a second blowing agent.
  4. 4. The method according to any one of claims 1 to 3, wherein the recycled PVC material comprises at least 20% recycled PVC based on the total weight of the recycled PVC material; preferably at least 30% recycled PVC, preferably at least 40% recycled PVC, for example at least 50% recycled PVC.
  5. 5. The method according to any one of claims 1 to 4, wherein the multilayer PVC floor covering intermediate sheet comprises at least 50% recycled PVC material, based on the total weight of the multilayer PVC floor covering intermediate sheet, preferably at least 70% recycled PVC material, preferably at least 90% recycled PVC material, for example at least 95% recycled PVC material.
  6. 6. The method according to any one of claims 1 to 5, wherein the first and/or second film each comprise at least 50% recycled PVC material, based on the total weight of the first or second film respectively, preferably at least 70% recycled PVC material, preferably at least 90% recycled PVC material, for example at least 98% recycled PVC material.
  7. 7. The method according to any one of claims 1 to 6, wherein: - in step d1) the first mixture is calendered below the decomposition temperature of the first blowing agent Tdi , to form the first film; and/or - in step d2), the second mixture is calendered below the decomposition temperature of the second blowing agent T d 2, to form the second film.
  8. 8. The method according to any one of claims 1 to 7, wherein: - in step c1) the first blend is extruded below the decomposition temperature of the first blowing agent T d i, to form a first extrudate; and in step d1) the first extrudate is processed below the decomposition temperature of the first blowing agent T d i, to form the first film; and/or - in step c2), the second batch of recycled PVC material or the second blend, is extruded below the decomposition temperature of the second blowing agent T d2 if present, to form a second extrudate; and in step d2) the second extrudate is processed below the decomposition temperature of the second blowing agent T d2 if present, to from the second film.
  9. 9. The method according to any one of claims 1 to 8, wherein step e) comprises the step of adhering a decorative layer to the second film, to form a multilayer structure, prior to performing step f).
  10. 10. The method according to any of claims 1 to 9, wherein step e) comprises the step of adhering a print layer or print pattern to the second film or to the decorative layer, and optionally comprises the step of adhering a wear layer to the print layer, to form a multilayer structure, prior to performing step f).
  11. 11. The method according to any one of claims 1 to 10, wherein step e) comprises the step of adhering a backing layer to the first film, to form a multilayer structure, prior to performing step f); and wherein after step f) a multilayer PVC floor covering is formed.
  12. 12. The method according to any one of claims 1 to 11 , wherein the intermediate layer comprises glass fibres or PET.
  13. 13. The method according to any one of claims 1 to 12, wherein the first and/or second blowing agent is selected from the group comprising: azodicarbonamide (AZO), 4,4- oxy-bis(benzenesulfonylhydrazide) (OBSH), P-toluenesulfonyl-hydrazide (TSH), P- tolyenesulfonylsemicarbazide (PTSS), dinitrosopentamethylenetetramine (DNPT), sodium bicarbonate, 5-phenyltetrazole (PT), or any combinations thereof; preferably wherein the first and/or second blowing agent is AZO
  14. 14. Apparatus for manufacturing a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering, wherein the apparatus is configured for performing a method according to any one of claims 1 to 13, and wherein the apparatus comprises - a section configured for mixing and melting the first batch of recycled PVC material with a first blowing agent to form the first mixture; - a section configured for mixing and melting the second batch of recycled PVC material or the second blend to form the second mixture; - a section for processing the first mixture; - a section for processing the second mixture; - one or more calender rolls following the section for processing the first mixture for calendaring the first mixture to form the first film; - one or more calender rolls following the section for processing the second mixture for calendaring the second mixture to form the second film; and, - a lamination station configured to laminate the first film, the second film and the intermediate layer into a multilayer PVC floor covering intermediate sheet.

Description

METHOD FOR MANUFACTURING A PVC BASED FLOOR COVERING TECHNICAL FIELD The present invention relates to a method for manufacturing a multilayer polyvinyl chloride (PVC) floor covering intermediate sheet and multilayer PVC floor covering, the multilayer PVC floor covering intermediate sheet and multilayer PVC floor covering comprising recycled polyvinyl chloride material. The present invention also relates to an apparatus for manufacturing a multilayer PVC floor covering intermediate sheet and a multilayer PVC floor covering, and to a multilayer PVC floor covering intermediate sheet and a multilayer PVC floor covering obtained thereby. BACKGROUND Cushion floor coverings are a well-known and popular material today. A wide variety of designs, easy installation, long lifespan, and affordable price make them attractive in the market. Cushion floor coverings are typically made of different layers of PVC based compounds with different material properties per layer. Typically, one or more layers are foamed to a certain extent in order to lower weight per unit area as well as to enhance the properties of the cushion floor covering, such as improvement of acoustics, walking comfort, etc. However, in a circular and sustainable economy, there is a need to include more recycled materials. With known coating technologies, it is not technically feasible to obtain cushion vinyl floor coverings that have a high percentage of recycled content (>40%) and still comply to quality standards. With known calendering technologies, it is not financially feasible to obtain cushion vinyl floor coverings that have a high percentage of recycled content (>40%) and still comply to quality standards. Although the current calendering technologies offer a wider flexibility for processing raw materials due to melting the compound at high temperatures (>150°C), the products today lack sufficient percentage of recycled content. One of the main reasons are the insecure nature and supply of the recycled content available. Further, also foaming of the product during a calender process in order to obtain the typical cushion vinyl nature has its limits, which is more emphasized when using recycled content. Technical issues may arise from residual blowing agent and foamed particles, which in compact calendering needs to be removed prior to the extruder, e.g. by using special Banbury mixers or de-gassing on the extruder, or chemical deactivation It is therefore an objective of the current invention to provide a solution for one or more of the above shortcomings. It is an objective to provide a sustainable method for manufacturing a multiplayer PVC floor covering intermediate sheet or a multilayer PVC floor covering with an increased content of recycled PVC. It is an objective to provide a sustainable method for manufacturing a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering, preferably working towards a circular economy, thereby reducing the environmental impact. It is an objective to provide a sustainable method for manufacturing a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering that reduces virgin fossilbased resource consumption. It is an objective to provide a method for manufacturing a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering that is simplified, and that lowers energy and production costs. It is an objective to provide a method for manufacturing a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering that allows for increased recycled content. It is an objective to provide such methods, that also result in a multilayer PVC floor covering intermediate sheet or a multilayer PVC floor covering with optimal mechanical properties, insulation, and/or acoustic properties. SUMMARY OF THE INVENTION The invention has for its object to remedy or to reduce at least one of the drawbacks of the prior art, or at least provide a useful alternative to prior art. The object is achieved through features, which are specified in the description below and in the claims that follow. The invention is defined by the independent patent claims. The dependent claims define advantageous embodiments of the invention. The inventors have found a production method to produce a floor covering intermediate sheet or a floor covering comprising recycled PVC material. Specifically, the floor covering or intermediate sheet is produced using processing technology, such as calendering, wherein two films, comprising recycled PVC material are produced that are combined to the final floor covering. Typical for the invention is that one or both of the films comprise a blowing agent and that the processing process takes place at a temperature that is below the decomposition temperature of said blowing agent. After the processing, the films are adhered to an intermediate layer, followed by a post-treatment at a higher temperature, in particular at a t