阅读说明：本技术 一种汽车零部件材料阈值法气味评价方法 (Odor evaluation method for automobile part material by threshold method ) 是由 刘亚林 王焰孟 陈鲁铁 郭金玉 李传杰 王科 姚谦 李骊璇 王崇 于 2020-06-08 设计创作，主要内容包括：一种汽车零部件材料阈值法气味评价方法,一、统计零部件材料的采样评价方法,解决的零部件材料气味评价方式的差异,方便了不同层级产品的气味差异比较,有利于得出不同层级产品间气味强度的传递。二、取样、环境处理参考原有条件,可与原有方法进行比较。同时取样、环境处理条件可以随时按需要调整不影响方法的使用。三、气味评价人员可使用本方法的方式进行训练,增加了气味评价人员能力的筛选,保证了气味评价人员的能力一致性与稳定性。四、本方法将原有多个语言描述难以与感官界定困难的评级描述转化为气味是否可识别的判断,降低评价难度的同时,提高了数据的可靠性。五、试验使用了空白的盲样,增加了实验数据的可信度。(A method for evaluating odor of automobile parts by a threshold method is a sampling evaluation method for counting the parts, solves the problem of difference of odor evaluation modes of the parts, facilitates comparison of odor differences of products of different levels, and is beneficial to obtaining transfer of odor intensity among the products of different levels. Second, the sampling and environmental processing are compared with the original method by referring to the original conditions. Meanwhile, sampling and environmental processing conditions can be adjusted at any time according to needs without influencing the use of the method. Thirdly, odor evaluators can be trained by using the method, so that the screening of the abilities of the odor evaluators is increased, and the consistency and the stability of the abilities of the odor evaluators are ensured. And fourthly, the method converts the original grading description with a plurality of language descriptions and sensory definition difficulty into judgment whether the smell can be identified, so that the evaluation difficulty is reduced, and the reliability of the data is improved. And fifthly, blank blind samples are used in the test, so that the reliability of the test data is improved.)

1. A smell evaluation method of a material threshold method for automobile parts is characterized by comprising the following steps: 1) storing the part materials in an environment according to requirements; 2) uniformly using a vacuum gas collecting barrel for different samples of part materials to collect gas to be detected into a special air bag; 3) determining a limit dilution multiple r, and diluting the gas in the gas bag according to different limit dilution multiples r aiming at different samples; 4) placing the diluted sample and two blank sample air bags into an odor evaluation instrument by an odor evaluation organizer, and recording the positions of the sample and the blanks; 5) each evaluator sequentially identifies the odor of the 3 unknown samples and judges whether the odor exists or not; 6) odor evaluation organizer checks the validity of the data according to the results of the sample and blank and summarizes the final conclusion.

2. The automobile part material threshold value method odor evaluation method according to claim 1, characterized in that in step 3), a limit dilution multiple r is determined and divided into two types of liquid reagent simulation samples and automobile part material samples, in step 3.1), aiming at the liquid reagent simulation samples, a certain amount of pure liquid odor substances are taken by using a micro-sampling needle and injected into a non-odor sampling bag filled with a certain amount of high-purity nitrogen, the sample is heated in a high-temperature box for 0.5-1h to accelerate the volatilization and uniform mixing of the samples, the heating temperature is 40-60 ℃, then the sample is taken out and kept stand for 5-10min to be cooled to room temperature, and the initial concentration C of the compounds in the bag is reduced to room temperature₀C is calculated according to the following formula ①₀= V × ρ × a/V, where V is the injection amount of the pure product, a is the purity of the pure product, ρ is the density of the pure liquid, and V is the aerated volume in formula ①.

3. The automobile part material threshold odor evaluation method according to claim 2, wherein the method comprisesCharacterized in that, in the step 3.2), aiming at the automobile part material sample, a certain amount of the automobile part material sample is put into an odorless sampling bag, a certain amount of high-purity nitrogen is filled after air is exhausted in a sealing way, the sample is kept for a specified time at a certain temperature, then the sample is taken out and kept stand for 5-10min to be cooled to room temperature, and the initial concentration of a compound in the sample bag is set as C₀。

4. The automobile part material threshold odor evaluation method according to claim 2 or 3, wherein the step 3.3) is applied to both liquid reagent simulation samples and automobile part material samples, the prepared odor bag is connected to a dynamic odor smell identification instrument, a dilution program is set on software, at least 4 odor evaluators perform odor identification on gas samples of the samples under different dilution times and perform grading according to an odor grade evaluation table, the odor intensity grade takes two decimal points after an integer, and the average value of each odor evaluator is taken as the final odor intensity grade to be recorded as the final odor intensity grade

5. The automobile part material threshold value method odor evaluation method as claimed in claim 4, wherein in step 3.3), the dilution program of the olfactory discrimination instrument sets the dilution factor from large to small according to the original concentration of the sample gas, and inserts blank sequences to ensure that the diluted sample gas is not more than 2.5 grades at the maximum dilution factor.

6. The automobile part material threshold odor evaluation method according to claim 2, wherein in the step 3.1), the injected pure product amount and the injected nitrogen volume depend on the odor intensity of the compound, so as to ensure that the subsequent experiment can be effectively evaluated in the dilution range of the dilution instrument.

7. The automobile part material threshold value method odor evaluation method as claimed in claim 3, wherein in step 3.2), the sample sampling amount, the holding temperature and the time are adjusted according to the automobile material type and the odor evaluation requirement.

Technical Field

The invention belongs to the field of automobile parts, and particularly relates to a smell evaluation method of an automobile part material by a threshold value method.

Background

The odor evaluation of the automobile part materials is currently carried out in a subjective rating mode of personnel, and at present, no unified national standard exists, and only a group standard and an automobile enterprise standard exist. After the component materials are stored in a closed container environment under a certain temperature condition, a trained odor evaluator evaluates the smell of sample gas in the closed container, and the sample gas is graded according to the odor intensity shown in an odor grade evaluation table, wherein the odor grade evaluation table in table 1 is introduced from T/CMIF 12-2016 (odor evaluation Specification for automobile components and materials).

Odor intensity rating scale	Description of the invention
		Level
1	Has no odor and is not easy to be perceived
		Stage 2	Smell, perception, slight intensity
Grade
	3	Has obvious odor and can be obviously feltOf moderate intensity
4 stage			Has obvious smell and high strength
	Grade 5	Has obvious odor and high strength
Grade 6			Intolerable odor

There are two problems with the current evaluation:

first, the odor intensity grades in different standards are classified into 6 grades and 10 grades. The rating descriptions differ even for different standards with the same rating of 6. For people who are evaluated by various standard smells, the state of the device cannot be switched to different states, and the device can adapt to different standards, so that the evaluation is interfered.

And secondly, each odor standard requires an evaluator to score 0.5 or more according to the description of an odor grade evaluation table, and the definition of the odor grade does not clearly cause large errors of subjective evaluation of the evaluator.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for evaluating the odor of an automobile part material by a threshold method. The limit dilution multiple r required by diluting the odor intensity of the odor compliance grade generally accepted by people to the odor threshold intensity is calculated through a relation curve of the odor intensity and the concentration, whether the sample meets the original 3-grade requirement is judged by judging whether the diluted gas can be identified, and the calculation method of the limit dilution multiple r is an important improvement for converting the odor grade expression well known in the automobile industry into threshold judgment.

The invention is realized by the following technical scheme.

A smell evaluation method of a material threshold method of an automobile part comprises the following steps: 1) storing the part materials in an environment according to requirements; 2) uniformly using a vacuum gas collecting barrel for different samples of part materials to collect gas to be detected into a special air bag; 3) determining a limit dilution multiple r, and diluting the gas in the gas bag according to different limit dilution multiples r aiming at various different types of samples; 4) placing the diluted sample and two blank sample air bags into an odor evaluation device by an odor evaluation organizer, and recording the positions of the sample and the blanks; 5) each evaluator sequentially identifies the odor of the 3 unknown samples and judges whether the odor exists or not; 6) odor evaluation organizer checks the validity of the data according to the results of the sample and blank and summarizes the final conclusion.

Preferably, in the step 3), the limit dilution multiple r is determined and divided into a liquid reagent simulation sample and an automobile part material sample, in the step 3.1), aiming at the liquid reagent simulation sample, a certain amount of pure liquid odor substances are injected into an odorless sampling bag filled with a certain amount of high-purity nitrogen gas by using a micro-sampling needle, the sample is heated in a high-temperature box for 0.5 to 1 hour to accelerate the volatilization and uniform mixing of the sample, the heating temperature is 40 to 60 ℃, then the sample is taken out and stands for 5 to 10 minutes to be cooled to the room temperature, and the initial concentration C of the compound in the bag is reduced to the room temperature₀C is calculated according to the following formula ①₀= V × ρ × a/V, where V is the injection amount of the pure product, a is the purity of the pure product, ρ is the density of the pure liquid, and V is the aerated volume in formula ①.

Preferably, step 3.2) is performed on the automobile part material sample, a certain amount of the automobile part material sample is placed into an odorless sampling bag, a certain amount of high-purity nitrogen is filled after air is exhausted in a sealed mode, the sample is kept at a certain temperature for a specified time, then the sample is taken out and placed for 5-10min to be cooled to room temperature, and the initial concentration of the compound in the sample bag is set to be C₀。

Preferably, step 3.3) is applied to both liquid reagent simulation samples and automobile part material samples, the prepared odor bags are connected to a dynamic odor olfactory identification instrument, a dilution program is set on software, gas samples of the samples under different dilution times are olfactory identified by at least 4 odor evaluators and are graded according to an odor grade evaluation table, two decimal places after an integer are taken as the odor intensity grade, and each decimal place is taken as the odor intensity gradeThe average of the odor assessors is recorded as the final odor intensity ratingi, each dilution factor is denoted as R_iCounting the odor intensity under each dilution factor, calculating the concentration under each dilution factor to an odor intensity and concentration statistical table under each dilution factor, wherein the concentration of each grade is calculated according to a formula ② C_i=C₀/R_iC in formula ②_iAt a certain dilution factor, C₀At the original concentration, R_iIs the dilution multiple of a certain dilution; 3.4) by odor intensityIs ordinate, log of concentration lgC_iFitting a linear curve, i.e. a log-concentration-intensity curve, to the abscissa to obtain formula ③i=algc+ b, in equation ③:isetting target odor intensity level for odor intensity, c for corresponding sample concentration, a for curve slope, b for curve intercept, 3.5), odor level i when material qualification evaluation_PSetting a perception threshold odor level i whether the odor is perceptible_f3.6) limiting dilution factor r = c is given by the following formula_p/c_fWherein c is_p、c_fIs a reaction of_P、i_fThe corresponding gas concentration is given by equation ③.

Preferably, in the step 2), the dilution program of the olfactory identification instrument sets the dilution times from large to small according to the original concentration of the sample gas, and the blank sequence is inserted to ensure that the diluted sample gas is not more than 2.5 grades at the maximum dilution time.

Preferably, in the step 3.1), the pure product injection amount and the nitrogen injection volume depend on the odor intensity of the compound, so as to ensure that the subsequent experiment can be effectively evaluated in the dilution range of the dilution instrument.

Preferably, in step 3.2), the sample sampling amount, the holding temperature and the time are adjusted according to the type of the automobile material and the odor evaluation requirement.

Compared with the prior art: the sampling evaluation method for the statistical part materials solves the problem of difference of smell evaluation modes of the part materials, facilitates comparison of smell differences of products of different levels, and is beneficial to obtaining transfer of smell intensity among the products of different levels. Second, the sampling and environmental processing are compared with the original method by referring to the original conditions. Meanwhile, sampling and environmental processing conditions can be adjusted at any time according to needs without influencing the use of the method. Thirdly, odor evaluators can be trained by using the method, so that the screening of the abilities of the odor evaluators is increased, and the consistency and the stability of the abilities of the odor evaluators are ensured. And fourthly, the method converts the original grading description with a plurality of language descriptions and sensory definition difficulty into judgment whether the smell can be identified, so that the evaluation difficulty is reduced, and the reliability of the data is improved. And fifthly, blank blind samples are used in the test, so that the reliability of the test data is improved.

Drawings

FIG. 1 is a graph of nonanone strength versus concentration according to the invention.

FIG. 2 is a graph of the intensity versus the log concentration of nonanone according to the invention.

Fig. 3 is a graph of odor intensity versus relative concentration for a leather fabric of the present invention.

Fig. 4 is a graph of odor intensity versus log relative concentration for leather fabrics of the present invention.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

A smell evaluation method of a material threshold method for automobile parts is characterized by comprising the following steps: 1) storing the part materials in an environment according to requirements; 2) uniformly using a vacuum gas collecting barrel for different samples of part materials to collect gas to be detected into a special air bag; 3) determining a limit dilution multiple r, and diluting the gas in the gas bag according to different limit dilution multiples r aiming at different samples; 4) placing the diluted sample and two blank sample air bags into an odor evaluation instrument by an odor evaluation organizer, and recording the positions of the sample and the blanks; 5) each evaluator sequentially identifies the odor of the 3 unknown samples and judges whether the odor exists or not; 6) odor evaluation organizer checks the validity of the data according to the results of the sample and blank and summarizes the final conclusion.

In the step 3), determining a limit dilution multiple r, dividing the limit dilution multiple r into a liquid reagent simulation sample and an automobile part material sample, and in the step 3.1), aiming at the liquid reagent simulation sample, taking a certain amount of pure liquid odor substance by using a micro-sampling needle, injecting the pure liquid odor substance into an odorless sampling bag filled with a certain amount of high-purity nitrogen, heating the odorless sampling bag in a high-temperature box for 0.5 to 1 hour to accelerate the volatilization and uniform mixing of the sample, wherein the heating temperature is 40 to 60 ℃, then taking out the odorless sampling bag and standing the odorless sampling bag for 5 to 10 minutes to reduce the temperature to room temperature, the amount of the injected pure substance and the volume of the filled nitrogen depend on the odor intensity of the compound, so that effective evaluation can be carried out in a subsequent experiment in a dilution range of a₀C is calculated according to the following formula ①₀= V × ρ × a/V, where V is the injection amount of the pure product, a is the purity of the pure product, ρ is the density of the pure liquid, and V is the aerated volume in formula ①.

Step 3.2) aiming at the automobile part material sample, putting a certain amount of the automobile part material sample into an odorless sampling bag, sealing and exhausting air, filling a certain amount of high-purity nitrogen, keeping the high-purity nitrogen at a certain temperature for a specified time, taking out and standing for 5-10min, cooling to room temperature, adjusting the sample amount, the keeping temperature and the time according to the automobile material type and odor evaluation requirements, or referring to related odor test standards, and setting the initial concentration in the sample bag to be C₀。

Step 3.3) is suitable for two types of liquid reagent simulation samples and automobile part material samples, the prepared odor bag is connected to a dynamic odor smell identification instrument, a dilution program is set on software, at least 4 odor evaluators perform odor identification on gas samples of the samples under different dilution times and perform grading according to an odor grade evaluation table, two decimal parts after an integer are taken as odor intensity grades, and the average value of each odor evaluator is taken as a final odor intensity grade to be recorded as a final odor intensity grade

i, setting the dilution times from large to small according to the original concentration of the sample gas by a software dilution program of the olfactory identification instrument, inserting blanks, ensuring that the diluted sample gas is not more than 2.5 grades when the maximum dilution times are ensured, and marking each dilution time as R_iAnd counting the odor intensity under each dilution factor, and calculating the concentration under each dilution factor to obtain an odor intensity and concentration statistical table under each dilution factor.

Serial number	Dilution factor Ri	Strength of smell(grade)	Concentration Ci (mg/m)3）
				1	R1	1	C1
2	R2	2	C2
				3	R3	3	C3
4	R4	4	C4
				5	……	……	……

TABLE 2 odor intensity and concentration statistics table under each dilution factor

Wherein the concentration of each grade is calculated according to formula ②_i=C₀/R_iC in formula ②_iAt a certain dilution factor, C₀At the original concentration, R_iIs the dilution multiple of a certain dilution; 3.4) by odor intensityIs ordinate, log of concentration lgC_iFitting a linear curve, namely a log-log odor intensity-concentration curve, on an abscissa to obtain a formula ③ i = algc + b, wherein in the formula ③, i is the odor intensity, c is the corresponding sample concentration, a is the slope of the curve, b is the intercept of the curve, 3.5) a target odor intensity grade is set, and the odor grade i when the material is qualified is evaluated_PSetting a perception threshold odor level i whether the odor is perceptible_f3.6) limiting dilution factor r = c is given by the following formula_p/c_fWherein c is_p、c_fIs a reaction of_P、i_fThe corresponding gas concentration is given by equation ③.