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CN-116917104-B - Simple separation method and production system for waste material produced in the manufacture of extruded sheets

CN116917104BCN 116917104 BCN116917104 BCN 116917104BCN-116917104-B

Abstract

The invention relates to a method for separating produced scrap (52) in the production of extruded sheets (36), wherein the extrudate of an extruder (16) is fed to a calender (18) comprising a plurality of temperature-controlled calender rolls (40), the actual temperature of at least one calender roll (40) is measured, the actual temperature is compared with a nominal temperature provided by the calender roll (40), and, in the event of a difference between the actual temperature and the nominal temperature exceeding a predetermined tolerance amount, a portion leaving the calender (18), in particular a portion of an annular semifinished product (20), is discharged as scrap (52). Since sheets which do not meet the desired quality requirements can be identified particularly easily without essentially additional measuring work by treating the part of the semifinished product (20) exposed to the wrong temperature as scrap (52), the scrap (52) generated in the extruded sheet manufacturing process can be discharged easily.

Inventors

  • F. Hulun Kramer
  • P. Wendelin

Assignees

  • 阿卡曾塔板材型材有限公司

Dates

Publication Date
20260508
Application Date
20211112
Priority Date
20210317

Claims (15)

  1. 1. A method of separating waste material (52) produced during the manufacture of an extruded sheet (36), wherein: The extrudate of the extruder (16) is fed to a calender (18) comprising a plurality of temperature controlled calender rolls (40); Measuring the actual temperature of at least one calender roll (40), comparing said actual temperature with a nominal temperature provided by said calender roll (40), and Discharging a portion of the annular semifinished product (20) leaving the calender (18) as scrap (52) in the event that the difference between the actual temperature and the nominal temperature exceeds a predetermined tolerance, wherein The tolerance delta T is less than or equal to 1.0K and less than or equal to 5.0K; -the semifinished product (20) is fed, after cooling and solidification into an annular basic profile (30), to a separating device (32) for separating sheets (36) from the annular basic profile (30), wherein a sheet formed by a portion of the annular basic profile (30) is discharged as scrap (52), said portion of the annular basic profile (30) having been previously exposed to the actual temperature of one of the calender rolls (40) deviating from the nominal temperature by a predetermined tolerance amount; -identifying in the separating device (32) the portion of the endless base profile (30) that has been previously exposed to the actual temperature of one of the calender rolls (40) that deviates from the nominal temperature by a predetermined tolerance amount, based on the conveying speed of the endless base profile (30) in the conveying direction and the distance between the separating device (32) and the calender (18) in the conveying direction, and The conveying device (22) provides a conveying speed v 1 , wherein v 1 is less than or equal to 4.5 meters/min and less than or equal to 21.0 meters/min.
  2. 2. The method according to claim 1, wherein the semifinished product (20) leaving the calender (18) is fed to a smoothing unit for smoothing the upper and/or lower side of the semifinished product (20), wherein smoothing of the smoothing unit is omitted if a part of the semifinished product (20) fed to the smoothing unit has been previously exposed to the actual temperature of one of the calender rolls (40) deviating from the nominal temperature by a predetermined tolerance amount.
  3. 3. The method according to claim 1 or 2, wherein the identification of the scrap (52) in the calender (18) is based solely on the measured actual temperature of the at least one calender roll (40).
  4. 4. Method according to claim 1 or 2, wherein after cooling and solidifying into an annular profile, the semifinished product (20) is fed to an edge cutting device (24) for cutting off an edge region (28) of the semifinished product (20) transversely to the conveying direction, so that downstream of the edge cutting device (24) in the conveying direction the semifinished product (20) is identified as a plate-shaped profile (30) having a predetermined base sheet width extending transversely to the conveying direction, wherein the edge region (42) cut off in the edge cutting device (24) is discharged as scrap (52).
  5. 5. The method according to claim 1 or 2, wherein the separated waste material (52) is conveyed into a recovery vessel (14), wherein the recovery vessel (14) is connectable to the extruder (16) for at least partial and/or temporary loading of the extruder (16) for producing a semi-finished product (20) using educts from the recovery vessel (14).
  6. 6. The method according to claim 1 or 2, wherein the separated waste material (52) is crushed in at least one crushing device (38).
  7. 7. The method according to claim 1 or 2, wherein the actual temperature of the calender roll (40) is determined outside the calender roll (40).
  8. 8. Method according to claim 1 or 2, wherein the actual temperature of the calender roll (40) is determined at a plurality of measurement points of the same calender roll (40), wherein in case the difference between the actual temperature of the calender roll (40) and the nominal temperature at least one measurement point exceeds a predetermined tolerance amount, the portion of the semi-finished product (20) leaving the calender (18) is discharged as scrap (52).
  9. 9. Method according to claim 1 or 2, wherein the actual temperatures of a plurality of calender rolls (40) of the calender (18) are measured and compared with an associated nominal temperature, wherein in case the difference between the actual temperature and the nominal temperature of at least one calender roll (40) exceeds a predetermined tolerance amount, the portion of the semi-finished product (20) leaving the calender (18) is discharged as scrap (52).
  10. 10. A method according to claim 1 or 2, wherein the semifinished product (20) is cooled and solidified to form an annular basic profile (30) by natural convection only.
  11. 11. The method according to claim 1, wherein the semifinished product (20) leaving the calender (18) is fed to a smoothing unit for smoothing the upper and/or lower side of the semifinished product (20) to have a defined surface quality, wherein smoothing of the smoothing unit is omitted if a part of the semifinished product (20) fed to the smoothing unit has been previously exposed to the actual temperature of one of the calender rolls (40) deviating from the nominal temperature by a predetermined tolerance amount.
  12. 12. Method according to claim 1 or 2, wherein the semifinished product (20) after cooling and solidifying into an annular basic profile (30) is fed to a separating device (32) for separating sheets (36) from the annular basic profile (30) along a cutting line extending transversely to the conveying direction, wherein sheets formed by a portion of the annular basic profile (30) that has been previously exposed to the actual temperature of one of the calender rolls (40) deviating from the nominal temperature by a predetermined tolerance amount are discharged as scrap (52).
  13. 13. The method according to claim 1 or 2, wherein the separated waste material (52) is completely conveyed into a recovery vessel (14), wherein the recovery vessel (14) is connectable to the extruder (16) for at least partial and/or temporary loading of the extruder (16) for producing a semi-finished product (20) using educts from the recovery vessel (14).
  14. 14. The method according to claim 1 or 2, wherein the separated waste material (52) is crushed in at least one crushing device (38) to form pourable particles.
  15. 15. Method according to claim 1 or 2, wherein the actual temperature of all calender rolls (40) of the calender (18) is measured and compared with an associated nominal temperature, wherein in case the difference between the actual temperature and the nominal temperature of at least one calender roll (40) exceeds a predetermined tolerance amount, the portion of the semi-finished product (20) leaving the calender (18) is discharged as scrap (52).

Description

Simple separation method and production system for waste material produced in the manufacture of extruded sheets The present invention relates to a method and a production apparatus by which waste material generated in the manufacturing process of an extruded sheet can be easily separated. In particular, the extruded sheet can be used to produce panels that cover the surface of a room. From WO2007/079845A1 a production plant for panels made of wood is known, in which a desired panel length can be separated from a longer semifinished product by means of a cutting tool. A production plant for panels made of plastic is known from EP3578384A1, in which a plate-shaped annular (Endlosprofil) profile is first produced. In the manufacture of extruded sheets, there is a constant need to be able to simply separate the waste material produced. It is an object of the present invention to provide means capable of easily separating waste materials generated in the process of manufacturing an extruded sheet. One aspect of the invention relates to a method of producing waste material in the manufacture of extruded sheet material, in particular panels for covering room surfaces, wherein the extrudate of an extruder is fed to a calender comprising a plurality of temperature-controlled calender rolls, the actual temperature of at least one calender roll is measured, the actual temperature is compared with a nominal temperature provided for the calender roll, and a part, in particular a part of an annular semifinished product, leaving the calender is discharged as waste material in case the difference between the actual temperature and the nominal temperature exceeds a predetermined tolerance. The extrudate from the extruder (especially a wide gap extruder) is still generally relatively warm and soft. With the aid of the temperature-controlled calender rolls of the calender, the extrudate can be solidified by cooling and rolled into the desired shape of the semifinished product. For example, the calender may have at least 4, at least 6, at least 8, or even more calender rolls to properly shape and/or cool the extrudate. The semifinished product leaving the calender is specially designed as a plate-shaped annular profile. Furthermore, the semifinished product leaving the calender may already have sufficient strength so that the conveying device is able to convey the semifinished product out of the extruder and the calender. In the continuous operating state of the production plant for manufacturing extruded sheets, the semifinished product can leave the calender with a substantially flat arm of sheet, which can still be subsequently smoothed and separated. However, in discontinuous operation of the production plant (in particular in start-up operations or in the event of operational faults), it may happen that the shape of the semifinished product leaving the calender is not flat but wavy. In principle, in case the waviness of the semifinished product is sufficiently low, the semifinished product can be changed from a wavy shape to a flat shape in a subsequent smoothing process. However, it has been recognized that this can lead to localized compression and strain of the material of the semifinished product, which leads to inhomogeneous material properties of the separator sheet, thereby affecting the quality of the separator sheet. In particular, non-uniform material properties may impair the visual appearance in the finishing step, for example, the formation of embossed structures to different extents and/or the possible adhesion to different extents of color pigments. In order to achieve an optimal quality of the separator sheet, the wavy portion of the semi-finished product will be discharged as waste material and not be used as a marketable or workable product. However, after smoothing, it is difficult to identify the previous wavy portion of the semi-finished product by a non-destructive method. Before smoothing, contact-based measurement methods of detection waviness may damage the shape of the semi-finished product, since the semi-finished product is still relatively soft, so that essentially only non-contact optical methods can be used for detection waviness, but these methods are complex, difficult to implement and expensive. However, it has been recognized that it is not actually necessary to directly detect the waviness of the semifinished product leaving the calender at all. In particular, even if low waviness is considered unacceptable, quantification of waviness is unnecessary, and therefore indirect qualitative detection of waviness is entirely sufficient. Here, the knowledge is utilized that the waviness of the semifinished product can be traced back to the actual temperature of the calender rolls deviating from a specific nominal temperature. For example, if the temperature profile provided by the different nominal temperatures of the calender rolls is not sufficiently precisely achieved within the calender, i