CN-121540758-B - Quick detection method for quality of anti-yellowing agent product based on melting point instrument

Abstract

The invention relates to the technical field of melting point detection, in particular to a rapid detection method for the quality of a yellowing-resistant agent product based on a melting point instrument. The method comprises the steps of rapidly heating a yellowing-preventive sample by using a melting point instrument, collecting a furnace temperature sequence and a transmitted light intensity sequence in the heating process, calculating an instantaneous phase change factor at each moment according to a light intensity change rate and a reference light intensity, constructing a dynamic thermal hysteresis compensation model based on the instantaneous phase change factor, carrying out nonlinear correction on the furnace temperature to reversely reduce the real sample temperature sequence, determining an initial melting point and a full melting point of the yellowing-preventive sample by means of characteristic point identification, and calculating a product purity score by combining a theoretical melting point. According to the method, a phase change endothermic feedback mechanism based on the light intensity change rate is introduced, so that dynamic thermal hysteresis errors at a high temperature rising rate are effectively eliminated, and the timeliness and accuracy of quality detection of the anti-yellowing agent product are improved.

Inventors

• WANG WEIGUO
• XU JUN
• ZHOU YANG
• WANG KAI
• LI WEI
• HE YIFAN
• ZHENG YUAN
• WANG TAO
• YAN JUNJIANG
• REN YANG
• LIU ENZHOU
• HE YU
• GUO YANG
• YANG DONGYUAN
• HU JUN
• FENG AILING
• GAO TING
• YAO NING
• Guo you
• CHEN SHUAI
• JI HUI
• LI JUNPING
• YAO ZHONGDONG
• WANG YING

Assignees

• 陕西大美化工科技有限公司

Dates

Publication Date

20260512

Application Date

20260116

Claims (7)

1. 1. A method for rapidly detecting the quality of a yellowing-preventive product based on a melting point instrument is characterized by comprising the following steps: The method comprises the steps of rapidly heating a yellowing-preventive sample by using a melting point instrument, collecting furnace temperature and transmitted light intensity at each moment in the heating process, obtaining a furnace temperature sequence and a transmitted light intensity sequence, determining all-solid-state reference light intensity and all-liquid-state reference light intensity according to the transmitted light intensity sequence, and calculating the light intensity change rate at each moment; calculating an instantaneous phase change factor according to the light intensity change rate, the all-solid-state reference light intensity and the all-liquid-state reference light intensity to represent the heat absorption degree of the anti-yellowing agent sample; constructing a dynamic thermal hysteresis compensation model based on the instantaneous phase change factor, and carrying out nonlinear correction on the furnace temperature at the moment by using the dynamic thermal hysteresis compensation model so as to invert and restore the real sample temperature of the anti-yellowing agent sample at each moment to obtain a real sample temperature sequence; The characteristic points of the real sample temperature sequence and the transmitted light intensity sequence are identified, so that the initial melting point and the full melting point of the anti-yellowing agent sample are determined; obtaining a theoretical melting point of the anti-yellowing agent sample, and calculating a product purity score based on the initial melting point, the full melting point and the theoretical melting point, so as to realize rapid detection of the quality of the anti-yellowing agent product; the method for determining the all-solid-state reference light intensity and the all-liquid-state reference light intensity according to the transmitted light intensity sequence comprises the following steps: Dividing the heating process into an initial stage and a stable stage according to the transmitted light intensity sequence, taking the average value of the transmitted light intensity at all times in the initial stage as an all-solid-state reference light intensity, and taking the average value of the transmitted light intensity at all times in the stable stage as an all-liquid-state reference light intensity; The instantaneous phase change factor is based on the following relationship: In the formula (I), in the formula (II), Is that The instantaneous phase change factor of the moment in time, Is that The transmitted light intensity at the moment in time, For an all-solid-state reference light intensity, Is the reference light intensity of the full liquid state, Is a preset numerical stability constant for preventing the denominator from being 0, Is a preset weight coefficient for amplifying the influence weight of the light intensity change rate, Is that The rate of change of the intensity of light at the moment in time, Is an absolute value symbol; the true sample temperature of the anti-yellowing agent sample at each instant was based on the following relationship: In the formula (I), in the formula (II), In the sample of anti-yellowing agent The actual sample temperature at the moment in time, Is that The furnace temperature at the moment of time is equal to the furnace temperature, To provide a rapid heating rate for the anti-yellowing agent sample, As an inherent fundamental lag time constant of the melting point apparatus, For a predetermined basic thermal resistance constant, Is a preset phase-change endothermic gain coefficient, Is that Instantaneous phase change factor at time.
2. 2. The rapid inspection method of the quality of anti-yellowing agent product according to claim 1, further comprising the following pretreatment operation after collecting the furnace temperature and the transmitted light intensity at each moment in the heating process: and presetting a filter window, and executing moving average filter processing on the furnace temperature and the transmitted light intensity at each moment according to the filter window so as to realize smooth pretreatment on the furnace temperature and the transmitted light intensity at the moment.
3. 3. The rapid detection method of quality of anti-yellowing agent according to claim 1, wherein the light intensity change rate is determined based on the following manner: The transmitted light intensity at each moment is subtracted from the transmitted light intensity at the previous moment and divided by the time interval between the moment and the previous moment to obtain the light intensity change rate at the moment.
4. 4. The method for rapidly detecting the quality of a yellow inhibitor product according to claim 1, wherein the determination of the primary melting point and the full melting point of the yellow inhibitor sample by performing characteristic point recognition on a real sample temperature sequence and a transmitted light intensity sequence comprises the following steps: in the sequence of transmitted light intensities, the transmitted light intensity is reached When the temperature of the real sample corresponding to the characteristic moment is taken as the first characteristic moment, the temperature of the real sample corresponding to the characteristic moment is recorded as the initial melting point, and the transmitted light intensity reaches In this case, as a second characteristic point in time, the actual sample temperature corresponding to this characteristic point in time is designated as the full melting point, wherein, For an all-solid-state reference light intensity, Is the full liquid reference light intensity.
5. 5. The rapid inspection method of product quality of anti-yellowing agent according to claim 1, wherein calculating product purity scores based on the primary melting point and the full melting point and the theoretical melting point is performed based on the following relation: ; In the formula, The purity of the product is scored, For the penalty coefficient to be preset, Is the temperature value of the full melting point, Is the temperature value of the primary melting point, To the temperature value of the theoretical standard melting point of the anti-yellowing agent sample, As a logarithmic function.
6. 6. The rapid detection method of quality of anti-yellowing agent product according to claim 5, further comprising, after calculating the product purity score: and acquiring a preset quality grading threshold value table, comparing the product purity score with a threshold value in the quality grading threshold value table, determining the quality grade of the anti-yellowing agent sample, and outputting the quality grade.
7. 7. The rapid detection method for quality of anti-yellowing agent product according to claim 1, wherein the rapid heating of the anti-yellowing agent sample is performed by using a melting point instrument, and the furnace temperature and the transmitted light intensity at each moment in the heating process are collected, and the rapid detection method comprises the steps of grinding the anti-yellowing agent sample, loading the anti-yellowing agent sample into a capillary tube, compacting the anti-yellowing agent sample, setting the heating rate of the melting point instrument to be 5.0 ℃ per minute, and synchronously collecting the furnace temperature and the transmitted light intensity at each moment by using a photoelectric sensor after the heating is started.

Description

Quick detection method for quality of anti-yellowing agent product based on melting point instrument Technical Field The invention relates to the technical field of melting point detection, in particular to a rapid detection method for the quality of a yellowing-resistant agent product based on a melting point instrument. Background The purity of the yellowing inhibitor HN-150 serving as a key chemical auxiliary agent directly determines the yellowing resistance of the downstream polyurethane material, and the melting point and melting range are the most critical physical indexes for detecting the purity of the yellowing inhibitor. The anti-yellowing agent HN-150 generally takes the form of white crystalline powder, which is more sensitive to temperature changes. At present, a laboratory mainly adopts a capillary photoelectric melting point instrument to detect, and in order to ensure detection accuracy, standard operation specifications generally require that temperature rise is carried out at an extremely low rate when the temperature is close to a melting point, and the change of light transmittance of a sample is monitored by a photoelectric sensor to judge the primary melting point and the full melting point, so that the quality of a product is evaluated. However, in the existing detection technology, the time for single detection is too long due to low-speed temperature rise, usually exceeds 15 minutes, so that the detection efficiency is extremely low, the timeliness requirement of factory mass factory detection cannot be met, in order to improve the efficiency, if the temperature rise rate is greatly improved, the temperature of a sample is almost stagnated due to severe heat absorption phase change of the yellowing-resistant agent HN-150 when the temperature is melted, the temperature of a heating furnace sensor is continuously increased, the temperature of the sensor is far higher than the actual temperature of the sample due to the difference of physical characteristics, serious thermal hysteresis is generated, the nonlinear dynamic physical process cannot be captured by the existing linear correction method, and the rapid detection result is seriously high. In addition, as the samples are in powder form, the compaction degree difference of the samples in different batches can change the heat conductivity coefficient, so that the thermal hysteresis characteristics are inconsistent, and the correction by using a unified standard constant is difficult, although the conventional equipment tries to correct errors by subtracting a fixed constant, the linear correction means has poor effect before the yellowing inhibitor is a substance with obvious heat absorption phase change characteristic. Therefore, there is a need for a method for eliminating nonlinear thermal hysteresis errors at high temperature rise rates and reducing the actual melting process to accurately detect the quality of the anti-yellowing agent. Disclosure of Invention In order to solve the problems that in the prior art, in the detection process of the anti-yellowing agent, the detection efficiency is low due to low temperature rising rate, and the detection result is inaccurate due to serious thermal hysteresis generated by phase change heat absorption at high temperature rising rate, the invention provides a rapid detection method for the quality of the anti-yellowing agent based on a melting point instrument, which comprises the following steps: The method comprises the steps of rapidly heating a yellowing-preventive sample by using a melting point instrument, collecting furnace temperature and transmitted light intensity at each moment in the heating process, obtaining a furnace temperature sequence and a transmitted light intensity sequence, determining all-solid-state reference light intensity and all-liquid-state reference light intensity according to the transmitted light intensity sequence, and calculating the light intensity change rate at each moment; calculating an instantaneous phase change factor according to the light intensity change rate, the all-solid-state reference light intensity and the all-liquid-state reference light intensity to represent the heat absorption degree of the anti-yellowing agent sample; Constructing a dynamic thermal hysteresis compensation model based on the instantaneous phase change factor, and carrying out nonlinear correction on the furnace temperature at the moment by using the dynamic thermal hysteresis compensation model so as to invert and restore the real sample temperature of the anti-yellowing agent sample at each moment to obtain a real sample temperature sequence; identifying characteristic points of the real sample temperature sequence and the transmitted light intensity sequence to determine the initial melting point and the full melting point of the anti-yellowing agent sample; And obtaining a theoretical melting point of the anti-yellowing agent sample, and calculating a produc