A method for detecting and analyzing the contribution degree of volatile organic compounds in non-metallic components inside a vehicle

Abstract

The present invention provides a method for detecting and analyzing the contribution degree of volatile organic compounds of non-metallic components in a vehicle, including the following steps: determining a list of interior components contributing to VOC; confirming the assembly status of the components in the test list, and covering the non-emitting surfaces of the components with non-emitting materials; installing all interior components in an in-vehicle environmental simulation chamber; arranging sampling tubes in the chamber; sealing the chamber and setting operating parameters; collecting the gas in the chamber and analyzing the VOC concentration; after the gas collection is completed, removing any one interior component from the chamber and repeating the previous three steps; stopping the test after all components are removed from the chamber; and analyzing the VOC contribution degree of each component in the actual assembly state according to the change ΔX of the VOC concentration before and after the component is removed from the chamber. n‑y , and analyzing its VOC contribution degree in the actual assembly state. In each test cycle of the present invention, one interior component is removed, and the change of VOC in the chamber before and after the removal of this component is analyzed, so as to analyze the contribution degree of this component to the vehicle's VOC, and the problems existing in the vehicle's VOC can be improved.

Description

Technical Field

[0001] One or more embodiments of this specification relate to the technical field of detecting volatile organic compounds in automobiles, and in particular to a method for detecting and analyzing the contribution degree of volatile organic compounds in non-metallic components in a vehicle. Background Art

[0002] VOC in a vehicle generally refers to the collective name of eight substances: benzene, toluene, ethylbenzene, xylene, styrene, formaldehyde, acetaldehyde, and acrolein. Currently, mainstream domestic and foreign automobile manufacturers all have internal enterprise standards for the VOC test methods and limits of interior components, and control the VOC of interior components to achieve the control goal of the vehicle's VOC. However, with the continuous improvement of consumers' requirements for the health of the vehicle interior environment, automobile manufacturers are required to continuously improve and enhance the vehicle's VOC.

[0003] The bag method is generally used to test the VOC of interior components. After placing the interior component in a bag and sealing it, an inert gas such as nitrogen is filled, and the gas in the bag is collected and its VOC concentration is analyzed after heating at 60°C for two hours. For example, Chinese Patent Application No. 202010324792.3 discloses a method for testing harmful volatile substances in a passenger car interior assembly. The test method puts a specific type of car interior assembly into a sampling bag, and is equipped with a blank sampling bag of the same specification. By heating, harmful volatile substances are separated from the object to be detected, and benzene substances are collected through a TENAX sampling tube, and the benzene substances in the TENAX sampling tube are extracted through a thermal desorption system and introduced into a gas chromatograph-mass spectrometer. The quantitative values of each benzene substance are obtained through the benzene substance analysis curve. Aldehyde and ketone substances are collected through a DNPH sampling tube, and the DNPH sampling tube is eluted with acetonitrile to prepare a reagent for aldehyde and ketone substances, which is introduced into a high-performance liquid chromatograph-diode array detector. The quantitative values of each aldehyde and ketone substance are obtained through the aldehyde and ketone substance analysis curve, and finally the concentration of each harmful volatile substance is calculated. Through detecting the concentration of harmful substances volatilized from each car interior assembly, unqualified car interior assemblies are locked, and targeted improvements are achieved.

[0004] The whole vehicle VOC test generally adopts the chamber method. The vehicle is placed in a chamber with standard temperature and humidity, the doors and windows are opened for 6 hours of pretreatment, then the doors and windows of the vehicle are closed and sealed for 16 hours, and the gas inside the vehicle is collected and its VOC concentration is analyzed. It can be seen from this that there are two different test methods for components and the whole vehicle. After the components are assembled into the whole vehicle, the emission area will change, and there will also be mutual influence between components. Therefore, it is impossible to determine the key control components according to the existing methods, and thus it is also impossible to carry out targeted control improvement work. For example, Chinese Patent Application No. 202010386677.9 discloses an analysis method for quickly identifying the source of the smell of the whole vehicle, including the following steps: S1: Whole vehicle test, place the whole vehicle in the whole vehicle chamber and seal it for 12h-16h, collect the air inside the vehicle by using a vacuum box, and test the gas on the machine; S2: Assembly test, place the glass cover on the surface of the tested sample, evacuate the air inside the glass cover with a suction gun, irradiate the glass cover vertically with an infrared lamp, and take a 5mL sample with a sampling needle for testing on the machine; S3: Data analysis, calculate the compound concentration value of the whole vehicle and the compound concentration value of the assembly Cmg / m3 respectively, obtain the compound odor threshold αmg / m3, and the contribution degree β = C / α; S4: Odor improvement, or rectify the compound as needed. This patent shortens the assembly test cycle, improves the test efficiency, simplifies the test process, has no sample differences, and there is no situation of missing odor compounds. The test results are true and reliable, the data analysis is simple and reliable, more scientific, more in line with the actual situation, and the test results can be better utilized. However, this patent cannot identify the contribution degree of each component in the volatility of non-metallic components, and cannot guide component manufacturers to formulate and rectify risk components, so as to reduce the emission of evaporation pollutants from non-metallic components. Summary of the Invention

[0005] In view of this, the purpose of this specification is to provide a method for detecting and analyzing the contribution degree of volatile organic compounds in non-metallic components inside the vehicle. The present invention uses an in-vehicle environment simulation chamber, and arranges interior components in the chamber according to the actual assembly state; the test conditions are the same as those of the whole vehicle VOC test. In each test cycle, one interior component is removed, and the change of VOC in the chamber before and after the removal of this component is analyzed, and then the contribution degree of this component to the whole vehicle VOC is analyzed, which can solve the problems existing in the current control and improvement of the whole vehicle VOC.

[0006] For the above purposes, the present specification provides the following technical solutions :

[0007] A method for detecting and analyzing the contribution degree of volatile organic compounds in non-metallic components inside the vehicle, including the following steps:

[0008] 1) According to the VOC enterprise standard of automotive components, determine the list of interior components that contribute VOC;

[0009] 2) Confirm the assembly status of the components in the test list, including the assembly sequence, assembly position, heat dissipation surface and non-heat dissipation surface, and wrap the non-heat dissipation surface of the components with non-heat dissipation materials;

[0010] 3) Install all the interior components on the interior component list in the vehicle interior environment simulation chamber according to the actual assembly positions;

[0011] 4) Arrange a sampling tube at the midpoint of the connection line between the two seat headrests in the vehicle interior environment simulation chamber, and seal and wrap the sampling tube opening with non-heat dissipation materials; the sampling tube is connected to the outside of the chamber;

[0012] 5) Seal the vehicle interior environment simulation chamber and set the operating parameters, and then seal it for 15 - 17 hours;

[0013] 6) After the sealing time is reached, collect the gas in the chamber, analyze the VOC concentration, and record it as X n ; where n is the total number of interior components;

[0014] 7) After the gas collection is completed, remove any one of the interior components from the chamber, and cycle steps 4, 5, and 6, and record it as X n-1 ;

[0015] 8) After all components are removed from the chamber, obtain X n-y , and the test stops; in X n-y , y refers to the number of interior components removed from the chamber;

[0016] 9) According to the change in VOC concentration ΔX n-y before and after each component is removed from the chamber, analyze its VOC contribution degree in the actual assembly state;

[0017] VOC contribution degree of each component = ΔX n-y / total change amount of all components;

[0018] 10) Determine the list of key control components for each VOC based on the contribution degree of each component.

[0019] As an implementation manner, in step 1), the interior components include seats, instrument panels, sub-instrument panels, door panels, ceilings, pillar sills, parts under the carpet, carpets, parcel shelves, sunshades, steering wheels, sun visors, sealing strips and trunk parts.

[0020] As an implementation manner, in step 2), the non-heat dissipation material is aluminum foil.

[0021] As an implementation manner, in step 3), the maximum volume of the vehicle interior environment simulation chamber is 6.5 m 3 ; preferably 4.5 - 5.5 m 3 ; more preferably 5 m 3 .

[0022] As an implementation manner, in step 5), the operating parameters include: a temperature of 25°C, a relative humidity of 50%, and the vehicle interior environment simulation chamber is first ventilated for 6 hours and then sealed.

[0023] As an implementation manner, in step 6), the sampling parameters for collecting the gas in the chamber include: 2 Tenax tubes, 200 mL / min, 30 min; 2 DNPH tubes, 500 mL / min, 30 min.

[0024] As an implementation manner, in step 6), the analysis of the VOC concentration refers to analyzing the concentrations of benzene, toluene, xylene, styrene, and / or ethylbenzene in the Tenax tube using a thermal desorption gas chromatography-mass spectrometry instrument; analyzing the concentrations of formaldehyde, acetaldehyde, and / or acrolein using a high-performance liquid chromatography instrument.

[0025] Any range described in the present invention includes the end values and any numerical value between the end values, as well as any sub-range constituted by any numerical value between the end values or the end values.

[0026] Unless otherwise specified, each raw material in the present invention can be obtained by purchasing in the market, and the equipment used in the present invention can adopt conventional equipment in the field or be referred to the existing technology in the field.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The detection and analysis method of the present invention can determine the key interior list components in the vehicle, simulate the actual assembly state of the interior components, be close to the actual air volatilization situation in the vehicle, and truly reflect the contribution degree of each interior component to the vehicle interior air. Specific Embodiments

[0029] To make the objectives, technical solutions, and advantages of the present disclosure clearer and more understandable, the following further elaborates on the present disclosure in conjunction with specific embodiments.

[0030] It should be noted that unless otherwise defined, the technical terms or scientific terms used in one or more embodiments of this specification should have the ordinary meaning understood by those of ordinary skill in the art to which the present disclosure pertains. The "first", "second", and similar terms used in one or more embodiments of this specification do not denote any order, quantity, or importance, but are only used to distinguish different components. The terms such as "including" or "comprising" mean that the elements or items appearing before this word cover the elements or items listed after this word and their equivalents, without excluding other elements or items.

[0031] In the prior art, the mainstream domestic and foreign automobile enterprises generally adopt the bag method to test the VOC of interior components at present. After putting the interior components into the bag and sealing it, an inert gas such as nitrogen is filled, and the gas in the bag is collected and its VOC concentration is analyzed after heating at a temperature of 60°C for two hours. For the VOC of the whole vehicle, the chamber method is generally adopted. After putting the vehicle into a chamber with standard temperature and humidity, opening the doors and windows for pre-treatment for 6 hours, then closing the vehicle doors and windows and sealing for 16 hours, the gas in the vehicle is collected and its VOC concentration is analyzed. It can be seen from this that for the two different test methods used for components and the whole vehicle, the emission area will change after the components are assembled into the whole vehicle, and there will also be mutual influence among the components. Therefore, according to the existing methods, it is impossible to determine the key control components, and thus it is also impossible to carry out targeted control and improvement work.

[0032] Based on this, as an embodiment of the present invention, a method for detecting and analyzing the contribution degree of volatile organic compounds of non-metallic components in a vehicle includes the following steps:

[0033] 1) According to the enterprise standard of VOC of automobile components, determine the list of interior components that contribute to VOC;

[0034] 2) Confirm the assembly status of the components in the test list, including the assembly sequence, assembly position, emission surface and non-emission surface, and cover the non-emission surface of the components with non-emitting materials;

[0035] 3) Install all the interior components on the interior component list in the vehicle environment simulation chamber according to the actual assembly position;

[0036] 4) Arrange a sampling tube at the midpoint of the connection line of the two seat headrests in the vehicle environment simulation chamber, and seal and cover the sampling tube orifice with non-emitting materials; the sampling tube is connected to the outside of the chamber;

[0037] 5) Seal the vehicle environment simulation chamber and set the operating parameters, and then seal it for 15 - 17 hours;

[0038] 6) After the sealing time arrives, collect the gas in the chamber, analyze the VOC concentration, and record it as X n ; where n is the total number of interior components;

[0039] 7) After the gas collection is completed, remove any one interior component from the chamber, and cycle steps 4, 5, and 6, and record it as X n-1 ;

[0040] 8) After all the components are removed from the chamber, obtain X n-y , and the test stops; in X n-y , y refers to the number of interior components removed from the chamber;

[0041] 9) According to the change ΔX n-y in the VOC concentration before and after each component is removed from the chamber, analyze its VOC contribution degree in the actual assembly state;

[0042] VOC contribution of each component = ΔX n-y / Total change of all components;

[0043] 10) Determine the list of key control components for each type of VOC based on the contribution of each component.

[0044] According to some embodiments of the present invention, in step 1), the interior components include seats, instrument panels, sub-instrument panels, door panels, ceilings, pillar sills, parts under the carpet, carpets, parcel shelves, sunshades, steering wheels, sun visors, sealing strips, and trunk parts.

[0045] According to some embodiments of the present invention, in step 2), the non-emitting material is aluminum foil.

[0046] According to some embodiments of the present invention, in step 3), the maximum volume of the in-vehicle environment simulation chamber is 6.5 m 3 , preferably 4.5 - 5.5 m 3 , most preferably 5 m 3 In-vehicle environment simulation chamber; the volume inside the chamber can be adjusted with pads treated with surface inertness. In the present invention, the "in-vehicle environment simulation chamber" used in the embodiments refers to an environmental chamber with temperature control, humidity control, sampling holes, and air cleaning function, with length * width * height = 3.1 m * 1.5 m * 1.4 m and a volume of 5.115 m 3 .

[0047] According to some embodiments of the present invention, in step 5), the operating parameters include: temperature 25 °C, relative humidity 50%, and first ventilate the in-vehicle environment simulation chamber for 6 hours and then seal it.

[0048] According to some embodiments of the present invention, in step 6), the sampling parameters for collecting the gas inside the chamber include: 2 Tenax tubes, 200 mL / min, 30 min; 2 DNPH tubes, 500 mL / min, 30 min.

[0049] According to some embodiments of the present invention, in step 6), the analysis of VOC concentration refers to analyzing the concentrations of benzene, toluene, xylene, styrene, and / or ethylbenzene in the Tenax tubes using a thermal desorption gas chromatography-mass spectrometry instrument; analyzing the concentrations of formaldehyde, acetaldehyde, and / or acrolein in the DNPH tubes using a high-performance liquid chromatography instrument.

[0050] Example 1

[0051] A method for detecting and analyzing the contribution of volatile organic compounds in non-metallic components inside a vehicle, comprising the following steps:

[0052] 1) Determine the list of interior components as: seats, instrument panels, lower instrument panels, door panels, headliners, pillar sills, parts under the carpet, carpets, parcel shelves, sunshades, steering wheels, sun visors, sealing strips, and trunk parts;

[0053] 2) Wrap the non-emitting surfaces of the door panels, pillar sills, and trunk parts with aluminum foil;

[0054] 3) Arrange the components in the list of interior components in the five-cubic-meter vehicle interior environment simulation chamber according to the actual assembly sequence;

[0055] 4) Arrange four sampling tubes at the midpoint of the connection line between the headrests of the two seats, seal the sampling tube openings connected to the outside of the chamber, and ensure that external air does not enter the sampling tubes to cause air pollution;

[0056] 5) Seal the five-cubic-meter vehicle interior environment simulation chamber and set the operating parameters: temperature 25°C, relative humidity 50%; first ventilate for 6 hours, and then seal for 16 hours;

[0057] 6) After sealing for 16 hours, collect the gas in the chamber. Sampling parameters: 2 Tenax tubes, 200 mL / min, 30 min, 2 DNPH tubes, 500 mL / min, 30 min. After the gas collection is completed, remove one interior component from the chamber and repeat steps 4, 5, and 6;

[0058] 7) Analyze the toluene concentration in the Tenax tube using a thermal desorption gas chromatography-mass spectrometry instrument to be 0.0059 mg / m 3 ;

[0059] 8) Subtract the toluene concentration before removing one component from the chamber from the toluene concentration after removing this component from the chamber to obtain the change in toluene in the vehicle caused by this component. The specific change details are shown in Table 1;

[0060] 9) Use the sum of the changes of all components as the denominator and the change of each component as the numerator to calculate the contribution degree of each component. The specific contribution details are shown in Table 1;

[0061] 10) According to the contribution degree of each component and the limit requirements, conduct a comprehensive ranking to analyze that the list of key toluene control components is seats, sealing strips, door panels, lower instrument panels, and trunks in sequence.

[0062] Table 1: Toluene concentration change and contribution degree of each component

[0063]

[0064]

[0065] Example 2

[0066] A method for detecting and analyzing the contribution degree of volatile organic compounds in non-metallic components inside a vehicle, comprising the following steps:

[0067] 1) Determine the list of interior components as: seats, instrument panels, lower instrument panels, door panels, roofs, pillar sills, parts under the carpet, carpets, parcel shelves, sunshades, steering wheels, sun visors, sealing strips, trunk parts;

[0068] 2) Wrap the non-emitting surfaces of the door panels, pillar sills, and trunk parts with aluminum foil;

[0069] 3) Arrange the components in the list of interior components in the five-cubic-meter in-vehicle environment simulation chamber according to the actual assembly sequence;

[0070] 4) Arrange four sampling tubes at the midpoint of the connection line between the headrests of the two seats, seal the sampling tube ports connected to the outside of the chamber to ensure that external air does not enter the sampling tubes and cause air pollution;

[0071] 5) Seal the five-cubic-meter in-vehicle environment simulation chamber and set the operating parameters: temperature 25°C, relative humidity 50%, first ventilate for 6 hours, and then seal for 16 hours;

[0072] 6) After sealing for 16 hours, collect the gas in the chamber. Sampling parameters: 2 Tenax tubes, 200 mL / min, 30 min, 2 DNPH tubes, 500 mL / min, 30 min. After the gas collection is completed, remove one interior component from the chamber and repeat steps 4, 5, and 6;

[0073] 7) Use a high-performance liquid chromatograph to analyze the formaldehyde concentration in the DNPH tube as 0.0229 mg / m 3 ;

[0074] 8) Subtract the formaldehyde concentration in the chamber after removing this component from the formaldehyde concentration in the chamber before removing one component to obtain the change amount of this component for the formaldehyde in the vehicle. The specific change amounts are shown in Table 2;

[0075] 9) Use the sum of the change amounts of all components as the denominator and the change amount of each component as the numerator to calculate the contribution degree of each component. The specific contribution degrees are shown in Table 2;

[0076] 10) According to the contribution degree of each component and the limit requirements, conduct a comprehensive ranking, and analyze that the list of key components for formaldehyde control is seats, parcel shelves, steering wheels, sunshades, and sun visors in turn.

[0077] Table 2: Change amounts and contribution degrees of formaldehyde concentration in each component

[0078] Removed component <![CDATA[Concentration change amount mg / m 3 > Contribution percentage Overall 0.0229 100％ Seat 0.0145 63％ Parcel shelf 0.0065 28％ Steering wheel 0.0011 5％ Sunshade curtain 0.0005 2％ Sun visor 0.0002 1％ Trunk parts 0.0001 0％ Instrument panel 0.0000 0％ Sub-instrument panel 0.0000 0％ Door panel 0.0000 0％ Roof 0.0000 0％ Door sill 0.0000 0％ Parts under the carpet 0.0000 0％ Carpet 0.0000 0％ Sealing strip 0.0000 0％

[0079] The beneficial effects of the test method of the present invention are as follows: By simulating the actual assembly state of interior components, it is close to the actual situation of air volatilization in the vehicle, and truly reflects the contribution degree of each interior component to the air in the vehicle.

[0080] The specific embodiments of this specification have been described above. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve the desired result. Additionally, the processes depicted in the specification do not necessarily require the specific order or sequential order shown to achieve the desired result. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0081] Those of ordinary skill in the art should understand that: The discussion of any above embodiment is only exemplary and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples; Under the concept of the present disclosure, the technical features between the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of one or more embodiments of this specification as described above, and they are not provided in detail for the sake of brevity.

[0082] In addition, for the sake of simplicity of description and discussion, in the case where specific details are set forth to describe the exemplary embodiments of the present disclosure, it is obvious to those skilled in the art that one or more embodiments of this specification can be implemented without these specific details or with variations of these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0083] Although the present disclosure has been described in connection with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description.

[0084] One or more embodiments of this specification are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification shall be included within the protection scope of the present disclosure.

Claims

1. A method for detecting and analyzing the contribution degree of volatile organic compounds in non-metallic components inside a vehicle, characterized in that, It includes the following steps: 1) According to the automotive parts VOC enterprise standard, determine the list of interior parts contributing to VOC. 2) Confirm the assembly status of the parts in the test list, including the assembly sequence, assembly position, emission surface and non-emission surface, and wrap the non-emission surface of the parts with non-emitting materials. 3) Install all the interior parts on the interior parts list in the vehicle environment simulation chamber according to the actual assembly position. 4) Arrange sampling tubes at the midpoint of the connection line of the two seat headrests in the vehicle environment simulation chamber, and seal and wrap the sampling tube orifice with non-emitting materials; the sampling tube is connected outside the chamber. 5) Seal the vehicle environment simulation chamber and set the operating parameters, and then seal it for 15 - 17 hours. 6) After the airtight time is reached, collect the gas in the cabin, analyze the VOC concentration, and record it as X n ; where n is the total number of interior components; 7) After the gas collection is completed, remove any interior component from the cabin and repeat steps 4, 5, and 6, which is counted as X n-1 ; 8) After all components are removed from the cabin, X is obtained. n-y , the test stops; in X n-y , y refers to the number of interior components removed from the cabin. 9) According to the change in VOC concentration ΔX before and after each component is removed from the cabin n-y , analyze its VOC contribution under the actual assembled state; VOC contribution of each component = ΔX n-y / Sum of changes in all components; 10) According to the contribution degree of each part, determine the list of key control parts for each type of VOC.

2. The detection and analysis method according to claim 1, wherein: In step 1), the interior parts include seats, instrument panels, sub-instrument panels, door panels, ceilings, pillar sills, parts under the carpet, carpets, parcel shelves, sunshades, steering wheels, sun visors, sealing strips and trunk parts.

3. The detection and analysis method according to claim 1, characterized in that: In step 2), the non-emitting material is aluminum foil.

4. The detection and analysis method according to claim 1, wherein: In step 3), the maximum volume of the in-vehicle environment simulation chamber is 6.5 m 3 .

5. The detection and analysis method according to claim 4, characterized in that: In step 3), the volume of the in-vehicle environment simulation chamber is 4.5 - 5.5 m 3 .

6. The detection and analysis method according to claim 5, wherein: In step 3), the volume of the in-vehicle environment simulation chamber is 5 m 3 .

7. The detection and analysis method according to claim 1, characterized in that: In step 5), the operating parameters include: temperature 25°C, relative humidity 50%, and first ventilate the vehicle environment simulation chamber for 6 hours and then seal it.

8. The detection and analysis method according to claim 1, wherein: In step 6), the sampling parameters for collecting the gas in the chamber include: 2 Tenax tubes, 200 mL / min, 30 min; 2 DNPH tubes, 500 mL / min, 30 min.

9. The detection and analysis method according to claim 6, characterized in that: In step 6), the analysis of the VOC concentration refers to analyzing the concentrations of benzene, toluene, xylene, styrene and / or ethylbenzene in the Tenax tube using a thermal desorption gas chromatograph-mass spectrometer; analyzing the concentrations of formaldehyde, acetaldehyde and / or acrolein in the DNPH tube using a high performance liquid chromatograph.

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