Method for automatic monitoring of purity during switching of extruder compounds

Abstract

The application provides a method for automatically monitoring purity of rubber material switching of an extruder, which comprises the following steps: after a host computer receives a rubber material switching instruction, the host computer downloads a material formula and performs electronic inspection; after a feeding port of the extruder receives a rubber material switching signal, an MES system identifies that the current rubber material is different from the previous rubber material, and sends a rubber material switching starting signal, starts first interval countdown, and monitors current of a head of the extruder; when the extruded rubber material reaches a set first interval countdown end or the current of the head of the extruder changes, the rubber material code spraying is stopped, a die plate suitable for the next rubber material is replaced, a production line continues to run, and second interval countdown is started; when the extruded rubber material reaches a set second interval countdown end and the current of the head of the extruder changes stably, the next rubber material code spraying is started, the production line continues to run, and third interval countdown is started; when the extruded rubber material reaches a set third interval countdown end, the production is stopped, and the automatic monitoring of the rubber material switching is realized.

Description

Technical Field

[0001] This invention relates to the field of tire manufacturing technology, and more specifically to a method for automatically monitoring the purity of rubber material during extruder switching. Background Technology

[0002] Tires are mainly composed of tread, sidewall, tread rubber, belt layer, cord fabric, steel wire rings, inner liner, and crown belt layer. The tread, in contact with the ground, primarily functions as a driver, braker, anti-skid, shock absorber, and tire protector. Its rubber compound properties are also closely related to tire wear and rolling resistance. Therefore, different rubber compounds are used to press out the tread to meet the relevant performance requirements of the tire. During tread pressing, rubber compound switching is necessary to ensure that the rubber compound and product performance meet the expected requirements. However, during rubber compound switching, different rubber compounds will inevitably mix. The performance of the mixed rubber cannot fully meet the design requirements, easily leading to market problems such as poor tire crown wear and premature damage. To avoid rubber mixing, there are currently three measures:

[0003] One approach is to stop the machine, empty the machine head, and then refeed the glue for production. However, this method has drawbacks such as low efficiency and high losses.

[0004] Second, based on experience, a certain amount of mixed rubber tread is recycled, and the rubber material is manually checked and recorded by meter before being discarded. This measure is affected by the sense of responsibility and experience of the main operator, which makes it impossible to guarantee the initial quality of the rubber material.

[0005] Third, without stopping the machine, the screw speed can be used to control the distinction between pure rubber and mixed rubber. However, this method is greatly affected by the type of rubber and the process parameters of the production equipment, and cannot accurately distinguish and control the purity of the rubber.

[0006] In summary, under the backdrop of lean manufacturing and influenced by cost and cycle conditions, it is imperative to adjust and change existing measures to make them more suitable for product design and modern industrial production trends. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for automatically monitoring the purity of extruder rubber compound during switching, the method comprising:

[0008] Scan the code at the extruder feed port to apply the adhesive.

[0009] After receiving the rubber material switching command, the host computer downloads the material formula and performs electronic checks.

[0010] After receiving the rubber compound switching signal at the extruder feed port, the MES system identifies that the current rubber compound is different from the previous one and issues a rubber compound switching start signal, and starts the first interval countdown and monitors the extruder head current.

[0011] When the extruded rubber reaches the end of the first interval countdown or the extruder head current changes, stop the rubber material code printing, replace the die plate suitable for the next type of rubber, the production line continues to run, and the second interval countdown begins.

[0012] When the extruded rubber reaches the second interval countdown and the extruder head current stabilizes, the next rubber material code inkjet printing begins, the production line continues to run, and the third interval countdown begins.

[0013] Production stops when the countdown for the extruded rubber reaches the set third interval.

[0014] Furthermore, the segment corresponding to the countdown in the first interval is the final segment of switching to the previous type of adhesive.

[0015] The second countdown interval corresponds to the mixing segment where the current and previous rubber compounds are switched.

[0016] The third interval countdown corresponds to the production segment for switching to the next type of rubber compound.

[0017] Furthermore, if the set time for each interval is denoted as T, then the following formula is satisfied:

[0018] T = w / (s*ρ*v)

[0019] Where w is the weight of the rubber compound in the extruder, s is the cross-sectional area of ​​the extrudate, ρ is the density of the rubber compound, and v is the extrusion linear velocity.

[0020] Furthermore, after receiving the rubber material switching command, the host computer downloads the material formula and performs electronic checks, which also includes reading the material formula and the rubber material density, extrusion cross-sectional area, extrusion line speed, and extruder head current of the products before and after the switching through host computer programming.

[0021] Furthermore, the method also includes checking whether the inkjet printer on the linkage line prints the material code to identify the defective products in the mixing section, and removing the unprinted defective products before the linkage line is collected.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] During compound switching, this invention automatically identifies and monitors three segments: the end of the previous compound (i.e., the finishing segment), defective mixed compounds (i.e., the mixing segment), and the next compound (i.e., the production segment), by setting countdown times for each segment on the main unit and monitoring changes in the extruder head current. Defective compounds are identified by the inkjet printing device on the production line, and any unmarked defective compounds are removed before the production line is retracted. This achieves automatic monitoring of compound switching, eliminating the need for line stoppage and idling to clean the extruder head, thus improving production efficiency and ensuring the purity of the extruded compound. Attached Figure Description

[0024] Figure 1 This is a block diagram of the host control program execution according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the extruder production process according to an embodiment of the present invention. Detailed Implementation

[0026] To make the technical solutions and effects of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0027] This invention aims to provide a method for automatically monitoring the purity of rubber compound during extruder compound switching, thereby solving the problems of low production efficiency and high losses caused by the need to stop the extruder, empty the die head, and refeed the compound during compound switching. Figure 1 As shown, the method mainly includes the following steps:

[0028] Step 1: Scan the extruder feed port to apply the adhesive material;

[0029] Step 2: After receiving the rubber material switching command, the host computer downloads the material formula and performs electronic checks. Specifically, the host computer reads the material formula and the rubber density, extruded cross-sectional area, extrusion line speed, and extruder head current of the products before and after the switching through programming.

[0030] Step 3: When the extruder feed port receives the rubber material switching signal, the MES system identifies that the current rubber material is different from the previous rubber material and issues a rubber material switching start signal, and starts the first interval countdown and monitors the extruder head current.

[0031] Step 4: When the extruded rubber reaches the set countdown of the first interval or the extruder head current changes, the inkjet printer receives a signal from the host to stop the inkjet printing of the rubber material code, the production line stops running and the die plate for the next product is replaced. After the replacement is completed, the production line continues to run and the countdown of the second interval begins.

[0032] Step 5: When the extruded rubber reaches the second interval countdown and the extruder head current changes stably, the coding device receives the host signal and starts coding the next type of rubber material code. The production line continues to run and starts the third interval countdown.

[0033] Step 6: Stop production when the extruded rubber reaches the set third interval and the countdown ends.

[0034] The countdown for the first interval corresponds to the final segment of switching to the previous rubber compound; the countdown for the second interval corresponds to the mixing segment of switching between the current and previous rubber compounds; and the countdown for the third interval corresponds to the production segment of switching to the next rubber compound.

[0035] Let T be the set time for each interval segment, then the following formula is satisfied:

[0036] T = w / (s*ρ*v)

[0037] Where w is the weight of the rubber compound inside the extruder, s is the cross-sectional area of ​​the extrudate, ρ is the density of the rubber compound, and v is the extrusion linear velocity. Specifically, the cross-sectional area of ​​the extrudate and the density of the rubber compound are the BOM information of the extruded semi-finished product, which can be obtained during product design; the extrusion linear velocity can be read directly from the equipment; the extruder head current varies depending on the rubber compound being produced and can also be read directly from the equipment; the weight of the rubber compound inside the extruder is generally a fixed value, but it varies due to factors such as the extruder model and screw clearance, and can be obtained by measuring the actual rubber compound.

[0038] The marking device on the production line is used to mark the material code of the rubber to identify the defective products in the mixing section, and the unmarked defective products are removed before the production line is collected.

[0039] When switching rubber compounds, this invention can automatically identify each segment of the extruded rubber compound, ensuring production efficiency while achieving automatic monitoring to prevent errors during rubber compound switching and to prevent mixing of rubber compounds.

[0040] Example

[0041] like Figure 2 As shown, when the extruder switches from extruding compound A to compound B, the two compounds are different. The specific process is as follows:

[0042] After receiving the instruction to switch to material B, the host computer downloads the formula for material B and performs an electronic check.

[0043] When compound B arrives at the extruder feed port, the MES system recognizes that compound B is different from the previous compound, sends a compound switching start signal, and begins the first interval countdown.

[0044] When the extruded material reaches the set first interval countdown ends or the extruder head current changes, stop the material coding and change to nozzle type B;

[0045] After the die shape is changed, the production line continues to run and begins the second interval countdown. When the extruded rubber reaches the set second interval countdown and the extruder head current changes stably, the B rubber material code inkjet printing begins until the set third interval is reached.

[0046] The AB mixed rubber section, i.e. the second section, is to be removed. The first section is the remaining A rubber material, the second section is the AB mixed rubber section, and the AB mixed rubber section can be removed before the connected line is collected. The third section is the B rubber section.

[0047] The set time for the first interval = weight of rubber compound A in the extruder / (cross-sectional area of ​​extrudate A * density of rubber compound A * extrusion line speed).

[0048] The set time for the second interval = weight of the AB mixture in the extruder / (cross-sectional area of ​​extrudate B * density of the AB mixture * extrusion line speed).

[0049] In summary, the system reads the rubber compound formula and parameters such as density, cross-sectional area, extrusion speed, and die head current of the output before and after the change through the host computer programming. When switching rubber compounds, the feed port is replaced with the new material while maintaining normal feeding. There is no need to stop the line for idling and cleaning the die head. The extruder pressure remains constant, and the previous rubber compound is extruded normally by the rotating screw, driven by the new material. The host computer program runs normally and monitors parameters such as the die head current. When the extruder die head current changes or reaches a set time, it automatically identifies and controls three sections (i.e., the finishing section) of the previous rubber compound, the mixing section for defective products, and the production section for the next rubber compound. Defective products are marked by inkjet printing on the production line. Unmarked defective products are removed before the production line is retracted, thus achieving automatic monitoring of extruded rubber compound switching, error prevention in mixing, and ensuring production efficiency. It should be noted that other applicable marking methods can also be selected for marking defective products.

[0050] This invention achieves automatic monitoring of rubber material switching by controlling the signal transmission and program control between the host and the equipment, thereby improving production efficiency, ensuring the purity of the extruded rubber material, and solving the problems of low production efficiency and high loss in the current technical solutions where the machine is stopped, the die head is emptied, and rubber is re-fed when switching rubber materials.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for automatically monitoring the purity of an extruder compound changeover, characterized by, The method includes: Scan the code at the extruder feed port to apply the adhesive. After receiving the rubber material switching command, the host computer downloads the material formula and performs electronic checks. After receiving the rubber compound switching signal at the extruder feed port, the MES system identifies that the current rubber compound is different from the previous one and issues a rubber compound switching start signal, and starts the first interval countdown and monitors the extruder die head current; the interval corresponding to the first interval countdown is the final segment of switching to the previous rubber compound; When the extruded rubber reaches the end of the first interval countdown or the extruder head current changes, the rubber material code printing stops, the die plate suitable for the next type of rubber is replaced, the production line continues to run, and the second interval countdown begins; the interval corresponding to the second interval countdown is the mixing section for switching between the current and previous types of rubber. When the extruded rubber reaches the second interval countdown and the extruder head current stabilizes, the next rubber material code inkjet printing begins, the production line continues to run, and the third interval countdown begins; the interval corresponding to the third interval countdown is the production segment for switching to the next rubber material. Production stops when the countdown for the extruded rubber reaches the set third interval.

2. The method for automatically monitoring the purity of extruder rubber material during switching according to claim 1, characterized in that, The set time of each section is denoted as then the formula is satisfied: wherein, is the weight of the compound in the extruder, is the cross-sectional area of the extrudate, is the density of the compound, is the extrusion line speed.

3. The method for automatically monitoring the purity of extruder rubber material during switching according to claim 2, characterized in that, After receiving the rubber material switching command, the host computer downloads the material formula and performs electronic checks. This also includes reading the material formula and the rubber density, extruded cross-sectional area, extrusion line speed, and extruder head current of the products before and after the switch through host computer programming.

4. The method for automatically monitoring the purity of extruder rubber material during switching according to claim 1, characterized in that, The method also includes checking whether the inkjet printer on the linkage line prints the material code to identify the defective products in the mixing section, and removing the unprinted defective products before the linkage line is collected.

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