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CN-122016617-A - Prescreening and quality control system for improving light resistance of lettering film resin and production method thereof

CN122016617ACN 122016617 ACN122016617 ACN 122016617ACN-122016617-A

Abstract

The invention discloses a pre-screening and quality control system for improving the light resistance of a lettering film resin and a production method thereof, wherein the pre-screening and quality control system at least comprises a raw material pre-testing module, a raw material screening module, a production control module and a finished product verification module; the four modules are sequentially arranged, the information flow and the material flow are transmitted in a unidirectional way and finally form a closed loop, so that a complete light resistance quality closed loop control circuit is formed. According to the invention, the pre-test and pre-screening links are arranged after raw material purchase, so that the light resistance quality of the resin raw material can be controlled from the source, the production risk caused by the fluctuation of the raw material quality is effectively avoided, and the resin raw material entering the production flow is ensured to have stable and reliable light resistance. Compared with the traditional 'post test' mode, the quality control intervention in advance is realized, and the production cost and quality risk are obviously reduced.

Inventors

  • CHEN CAIWANG
  • QIN DEMING

Assignees

  • 东莞市幸达新材科技有限公司

Dates

Publication Date
20260512
Application Date
20251225

Claims (10)

  1. 1. A pre-screening and quality control system for improving light resistance of lettering film resin is characterized in that, The system comprises at least: the raw material pre-testing module is configured to sequentially perform a first light resistance test for simulating ultraviolet aging and a second light resistance test for simulating sunlight aging on the purchased resin raw material for the lettering film; The raw material screening module is configured to set a qualified threshold according to the results of the first light resistance test and the second light resistance test, and the resin raw materials with the test results meeting the qualified threshold enter a production flow; The production control module is configured to receive the qualified resin raw materials from the raw material screening module and process the qualified resin raw materials into a lettering film semi-finished product or a finished product according to preset production process parameters; The finished product verification module is configured to retest the finished product of the lettering film output by the production control module by adopting the test conditions and the qualification threshold value which are the same as those of the raw material pre-test module; The raw material pre-testing module, the raw material screening module, the production control module and the finished product verification module form a light resistance quality closed-loop control circuit from raw materials to finished products.
  2. 2. The pre-screening and quality control system for improving the lightfastness of a lettering film resin according to claim 1, wherein said raw material pre-testing module comprises: the first test unit adopts an ultraviolet aging test box to test, the test light source is an ultraviolet lamp tube with the wavelength range of 280nm to 400nm, and the irradiation time is 6 to 12 hours; The second test unit is used for testing by adopting a sunlight aging test box, the test light source is a xenon lamp or a solar lamp which can emit ultraviolet rays with the wavelength range of 280nm to 400nm and contains visible light spectrum, the irradiation intensity is 15-30W/m < 2 >, and the irradiation time is 12-24 hours.
  3. 3. The system for pre-screening and controlling the quality of the engraved film resin according to claim 2, wherein the first test unit is characterized in that two 15W UVA-340 ultraviolet lamp tubes are adopted, the wavelength is 280-400 nm, the resin sample is irradiated for 6 hours in the room temperature environment, the second test unit is characterized in that a xenon lamp with the power of 300W is adopted, the ultraviolet intensity is 25+/-0.4W/m < 2 >, and the sample rack drives the sample to rotate at the rotating speed of 1-5 r/min so as to ensure uniform irradiation.
  4. 4. The system according to claim 1, wherein the raw material pre-testing module further comprises a sample preparation unit configured to apply the raw material of the resin to be tested on the substrate to form a uniform coating with a thickness of 150-250 μm before the light fastness test, and cut into test samples with a specified size after curing.
  5. 5. The production method for improving the light fastness test stability of the lettering film resin according to claim 1, wherein the qualification threshold set by the raw material screening module is judged based on a color difference change value (delta E) and/or a mechanical property retention rate, and the qualification threshold is preferably that the yellowing index delta E after aging is more than or equal to 4.0 and the tensile strength retention rate is more than or equal to 80%.
  6. 6. A method for improving the light resistance of a lettering film, comprising the steps of: S1, purchasing a resin raw material, namely purchasing the resin raw material for the lettering film; s2, pre-testing and pre-screening the light resistance of the resin raw material, namely performing a first test of ultraviolet aging resistance and a second test of sunlight aging resistance on the purchased resin raw material; S3, screening raw materials, namely screening out resin raw materials which pass through the first test and the second test simultaneously as qualified raw materials according to the test result of the step S2; S4, producing the lettering film, namely preparing the lettering film according to a preset production process by using the qualified resin raw material screened in the step S3; And S5, verifying the light resistance of the finished product, namely, performing light resistance test on the finished product of the lettering film prepared in the step S4 by adopting the test conditions which are completely the same as those of the step S2, and verifying the qualification of the finished product.
  7. 7. The method for improving the light resistance of a lettering film according to claim 6, wherein in the step S2, the first test is to make a test specimen with the thickness of 200+/-10 μm from the resin, put the test specimen into an ultraviolet aging test box, and age for 6-12 hours under the irradiation of ultraviolet rays with the wavelength of 280-400 nm; In the step S2, the specific parameters of the first test are that a UVA-340 lamp tube is used, irradiance is 0.68W/m < 2 >, temperature is 60+/-3 ℃ and the drying environment is adopted, irradiation is carried out for 6 hours, and the specific parameters of the second test are that a xenon lamp light source is adopted, irradiation intensity is 25+/-0.4W/m < 2 >, blackboard temperature is 65+/-3 ℃ and relative humidity is 50+/-5% and irradiation is carried out for 24 hours.
  8. 8. The method for improving the light resistance of a lettering film according to claim 6, wherein after said first test and said second test, the color difference Δe value of the test piece is not less than 4.0, and the retention of tensile strength is not less than 80%.
  9. 9. The method for improving the light resistance of a lettering film according to claim 6, wherein in the step S4, the predetermined production process comprises uniformly mixing a qualified resin raw material, color paste, an auxiliary agent and a solvent according to a formula, coating the mixture on a substrate, controlling the thickness of a wet film to be 80-120 μm, curing the wet film at the temperature of 80-120 ℃ for 2-6 minutes, and finally bonding glue and slitting; The formula comprises, by weight, 40% -50% of polyurethane resin, 15% -20% of color paste, 0.3% -0.8% of antioxidant, 1% -3% of light stabilizer titanium pigment and the balance of organic solvent.
  10. 10. The method for improving the light fastness of a lettering film according to claim 6, wherein in step S2, the light fastness pre-screening method of the resin raw material comprises: a. Preparing a standard test sample of the resin to be tested; b. performing a first aging test on the standard test sample, wherein the first aging test simulates an ultraviolet environment; c. performing a second aging test on the standard test sample, wherein the second aging test simulates a sunlight full spectrum environment; d. respectively measuring the color difference change value and/or the mechanical property change value of the sample wafer after aging in the step b and the step c; e. And comparing the measurement result with a preset qualification threshold value, and judging that the batch of resin raw materials can be used for subsequent lettering film production only when the results of the two tests meet the qualification threshold value.

Description

Prescreening and quality control system for improving light resistance of lettering film resin and production method thereof Technical Field The invention relates to the technical field of lettering films, in particular to a pre-screening and quality control system for improving the light resistance of lettering film resin and a production method thereof. Background Lettering films (also called thermoprinting films) are widely used for thermoprinting pattern marks in the fields of clothing, shoes, caps, bags and the like. It is typically composed of a resin coating (e.g., polyurethane PU, thermoplastic polyurethane TPU, polyvinyl chloride PVC, etc.), a release layer, a substrate, etc. The light resistance, in particular the resistance to Ultraviolet (UV) and solar ageing, of a resin coating is a core quality indicator that determines the durability of the service life and appearance of a lettered film article in an outdoor or illuminated environment. Poor light fastness can lead to yellowing, embrittlement, cracking and falling off of the lettering film, and seriously affects the quality and commercial value of the final product. At present, the general production flow of the lettering film industry is to directly purchase resin raw materials, produce the lettering film according to a formula and test the light resistance of a finished product. The process has the following significant drawbacks: 1. The quality fluctuation of the raw materials is uncontrollable, and the light resistance of the resin raw materials is influenced by a plurality of factors such as the synthesis process, raw material batch, the content and uniformity of additives (such as antioxidant and ultraviolet absorber) and the like. Even from the same supplier, there may be a large fluctuation in the light resistance of different batches or even different packages of resins from the same batch. Quality inspection reports provided by raw material suppliers are generally based on their own testing standards and methods, and are mostly spot-inspected and cannot fully represent the true, stable light resistance of each batch of raw material. 2. The production end is passively applied, the cost is high, and the producer can only produce the resin by 'fortune' because the true light resistance of the resin raw material cannot be obtained at the source. When the light resistance test of the finished product is unqualified, the whole batch of products is at risk of reworking or scrapping. The reworking needs to consume extra energy and labor, possibly introduces new quality risks, and the scrapping directly leads to huge waste of raw materials, auxiliary materials and production cost. The post-inspection mode enables the production end to be in a passive state completely, and stability and consistency of product quality cannot be guaranteed. 3. In the prior art, in order to improve the light resistance of the lettering film, researchers have focused on improving the formulation of the finished product, such as adding more efficient ultraviolet absorbers, light stabilizers, antioxidants, and the like. The light resistance is improved by the combination of the ultraviolet absorber and the hindered amine light stabilizer in a specific proportion. However, such methods have limitations in that, firstly, the cost of the additive is high, excessive addition may affect the physical properties (e.g., tackiness, flexibility) of the resin itself, and, secondly, when the light resistance basis of the resin raw material itself is extremely poor, it is difficult to achieve an ideal stabilizing effect only by the post addition of the auxiliary agent, and the source problem of "raw material fluctuation" is not solved per se. Disclosure of Invention The primary aim of the invention is to overcome the defects of the prior art and provide a pre-screening and quality control system for improving the light resistance of lettering film resin and a production method thereof. The technical scheme for solving the technical problems is as follows: In one aspect, the present invention provides a pre-screening and quality control system for improving the lightfastness of a lettering film resin, the system comprising at least: the raw material pre-testing module is configured to sequentially perform a first light resistance test for simulating ultraviolet aging and a second light resistance test for simulating sunlight aging on the purchased resin raw material for the lettering film; The raw material screening module is configured to set a qualified threshold according to the results of the first light resistance test and the second light resistance test, and the resin raw materials with the test results meeting the qualified threshold enter a production flow; The production control module is configured to receive the qualified resin raw materials from the raw material screening module and process the qualified resin raw materials into a lettering film semi-finished product