A molten metal spatter protection garment and process for making the same

Abstract

The application discloses a molten metal splash protective clothing and a preparation process thereof and belongs to the field of individual protection equipment. The process comprises the following steps: weaving after blending meta-aramid 65-75%, para-aramid 15-20% and flame-retardant viscose fiber 10-15%; adopting a two-dip-two-pad method to dip and pad finishing liquid containing 5-8% nano-alumina sol, 3-5% polytetrafluoroethylene emulsion and 2-3% phosphorus flame retardant; performing super-feeding heat setting at 190-210 DEG C; compounding aluminum-coated film polyimide non-woven fabric through point-shaped hot melt adhesive; and finally sewing into clothes. The process has the advantages of process intensification, low energy consumption, more than 60% reduction of adhesive amount, air permeability greater than or equal to 50 mm / s, less than 1% of defective product rate and the like. The prepared protective clothing has the aluminum liquid impact greater than or equal to 350 g, the iron liquid impact greater than or equal to 200 g, the radiant heat transfer index RHTI24 greater than or equal to 20 s, the breaking strength greater than or equal to 800 N and the thermal stability dimensional change rate less than or equal to 2.5%, and the unity of high-grade protection and process economy is realized.

Description

Technical Field

[0001] This invention belongs to the field of personal protective equipment technology, specifically relating to a protective suit for molten metal splashes and its manufacturing process. Background Technology

[0002] In high-temperature working environments such as steel smelting, non-ferrous metal casting, and welding, workers face various occupational hazards including molten metal splashes, radiant heat, and flames. Molten metal splash protective clothing is a critical piece of personal protective equipment for protecting workers' lives. my country's mandatory national standard GB 8965.3-2022, "Protective Clothing - Molten Metal Splash Protective Clothing," sets forth clear requirements for related products regarding aluminum molten metal impact, iron molten metal impact, radiant heat conduction, flame retardancy, and mechanical properties.

[0003] However, existing commercially available protective suits for molten metal splashes have the following technical defects:

[0004] 1. Limited Protection Level: Most products can only meet the D2 level (≥200g) for aluminum molten metal impact or the E2 level (≥100g) for iron molten metal impact, and it is difficult to achieve both D3 and E3 levels simultaneously. For composite smelting scenarios where molten aluminum and iron metal splashes simultaneously, the protection capability of existing products is insufficient.

[0005] 2. Difficulty in achieving both radiant heat protection and molten metal impact protection: While increasing the thickness of the radiant heat reflective layer can enhance thermal protection, it can lead to fabric stiffness and coating peeling during molten metal impact, thus reducing impact protection performance. Conventional aluminum foil composite fabrics often exhibit melt adhesion in molten iron impact tests.

[0006] 3. Conflict between mechanical properties and wearing comfort: In order to meet the national standard minimum requirements of tensile strength ≥300N and tear strength ≥25N, many products use high-density and heavy fabrics (weight >400g / m²), resulting in poor breathability, inconvenience of movement, and low willingness of workers to wear them.

[0007] 4. Poor dimensional stability: Existing products shrink significantly after repeated washing or heat exposure (the rate of change in thermal stability often exceeds 8%), resulting in garment deformation and displacement of the protective area.

[0008] 5. Discontinuous production process: Most companies simply sew purchased fabrics without a systematic process design that includes fiber blending, functional finishing, heat setting and reflective layer lamination, resulting in large batch-to-batch fluctuations in product quality.

[0009] Therefore, developing a protective suit capable of achieving D3 / E3 / C2 protection levels, possessing excellent mechanical properties and dimensional stability, and suitable for mass production, along with its manufacturing process, is of significant practical importance. Summary of the Invention

[0010] The first objective of this invention is to provide a manufacturing process for a protective suit subjected to molten metal splashes. The protective suit prepared has an aluminum molten metal impact weight ≥350g (reaching D3 level), an iron molten metal impact weight ≥200g (reaching E3 level), a radiative thermal conductivity index RHTI24 ≥20s (reaching C2 level), a breaking strength ≥800N, a tearing strength ≥50N, a thermal stability dimensional change rate ≤2.5%, a water washing dimensional change rate ≤±2.5%, and good breathability, making it suitable for industrial production.

[0011] To achieve the above-mentioned objectives, this invention provides a process for preparing a protective suit for molten metal splashing, comprising the following steps:

[0012] S1. Fiber blending: Meta-aramid, para-aramid and flame-retardant viscose fiber are blended in a certain mass ratio to obtain blended yarn;

[0013] S2, Weaving: Weaving blended yarns into high-density greige fabric;

[0014] S3, Multifunctional finishing liquid padding: The fabric is padded with a finishing liquid containing nano alumina sol, polytetrafluoroethylene emulsion and phosphorus flame retardant, and then dried and baked;

[0015] S4. Heat setting: The impregnated fabric is subjected to overfeed heat setting treatment;

[0016] S5. Radiative heat reflective layer composite: Aluminum-coated polyimide nonwoven fabric is laminated onto the inner side of the heat-set fabric using dotted hot melt adhesive.

[0017] S6. Garment sewing: Cut and sew according to the garment pattern, and double-stitch and seal key seams.

[0018] Specifically, in step S1, the mass percentages of meta-aramid, para-aramid, and flame-retardant viscose fiber are as follows: meta-aramid 65%–75%, para-aramid 15%–20%, and flame-retardant viscose fiber 10%–15%. A ternary blend system of meta-aramid, para-aramid, and flame-retardant viscose fiber is used. Meta-aramid provides inherent flame retardancy and thermal stability; para-aramid, as a reinforcing fiber, significantly improves breaking strength and tearing strength; and flame-retardant viscose fiber improves hand feel and moisture absorption, and reduces static electricity buildup.

[0019] Specifically, in step S2, the weaving employs a 2 / 2 twill or 5 / 3 satin weave, with a warp density of 180–220 threads / 10cm and a weft density of 160–200 threads / 10cm. This weave design ensures uniform distribution of yarn interlacing points, a smooth surface that facilitates the rolling off of molten metal, and a low internal porosity (≤15%), effectively preventing the penetration of molten metal.

[0020] Specifically, in step S3, the finishing solution comprises, by mass percentage: 5%–8% nano-alumina sol, 3%–5% polytetrafluoroethylene emulsion, 2%–3% phosphorus-based flame retardant, 0.5%–1% crosslinking agent, 0.2%–0.5% penetrant, and the balance being deionized water; the padding process is two dips and two treads, with a roll-off rate of 70%–80%. Nano-alumina forms a micro-nano rough structure on the fiber surface, which, on the one hand, melts at high temperatures to form a continuous ceramic layer to block liquid metal, and on the other hand, synergistically imparts liquid repellency with PTFE; the phosphorus-based flame retardant further improves the limiting oxygen index.

[0021] Specifically, in step S4, the heat setting temperature is 190℃~210℃, the setting time is 60~90 seconds, and the warp overfeed rate is +1.5%~+2.5%. After this treatment, the warp dimensional change rate of the fabric after washing can be controlled within 0~-1.0%, and the weft dimensional change rate after washing can be controlled within -1.5%~-2.5%; the thermal stability (dimensional change rate in a 260℃ oven for 5 minutes) is ≤2.5%.

[0022] Specifically, in step S5, the aluminum-coated polyimide nonwoven fabric has a thickness of 0.20–0.30 mm and an areal density of 60–80 g / m²; the dotted hot melt adhesive has a dot diameter of 0.5–1.0 mm, a dot spacing of 3–5 mm, and an adhesive amount of 8–12 g / m²; the lamination pressure is 0.3–0.5 MPa, and the lamination temperature is 150–160 °C. The dotted hot melt adhesive lamination process combines the radiant heat reflective layer with the base fabric. This dotted lamination method ensures both the strong bond between the reflective layer and the base fabric and preserves the overall flexibility and breathability of the fabric. This reflective layer can increase the radiant heat reflectivity to over 85%.

[0023] Specifically, in step S6, the sewing thread is aramid 1414 flame-retardant sewing thread with a linear density of 40 / 3 or 30 / 3; the pressure sealing uses a flame-retardant silicone rubber strip with a width of 12mm.

[0024] The second objective of this invention is to provide a protective suit for molten metal splashing, which is prepared using the above-mentioned manufacturing process. The protective suit has an aluminum molten metal impact amount ≥350g, meeting the D3 level requirements of GB 8965.3-2022 standard; an iron molten metal impact amount ≥200g, meeting the E3 level requirements; and a radiative thermal conductivity index RHTI24 ≥20s, meeting the C2 level requirements.

[0025] Furthermore, the protective suit has a tensile strength of ≥800N in the warp direction and ≥800N in the weft direction; a tear strength of ≥75N in the warp direction and ≥45N in the weft direction; a thermal stability dimensional change rate of ≤2.5%; and a water washing dimensional change rate of -1.0% to 0 in the warp direction and -2.5% to -1.5% in the weft direction.

[0026] Furthermore, the fabric weight of the protective suit is 320-360 g / m², and the air permeability is ≥50 mm / s.

[0027] The protective suit for molten metal splashing and its manufacturing process of the present invention have the following advantages over the prior art:

[0028] (1) Synergistic enhancement of fiber selection and blending process, eliminating the need for additional reinforcing layer process: This invention adopts a ternary blending system of meta-aramid (65%~75%), para-aramid (15%~20%) and flame-retardant viscose fiber (10%~15%). Through precise control of the para-aramid ratio, the yarn strength is ≥25N, the fabric breaking strength is ≥880N in the warp and ≥860N in the weft, and the tear strength is ≥85N in the warp and ≥50N in the weft. The high strength requirements of GB 8965.3-2022 can be met without the need for lamination or coating of reinforcing layers. This blending process only requires conventional ring spinning equipment, avoiding the spinning difficulties and cost spikes caused by excessive para-aramid content. While ensuring high strength, it simplifies the process and keeps raw material costs controllable.

[0029] (2) Multifunctional finishing solution one-bath padding process, energy-saving and environmentally friendly with streamlined process: This invention combines nano alumina sol, PTFE emulsion, phosphorus flame retardant and crosslinking agent into a single finishing solution, and treats it with a "two dips and two pads" one-bath process, simultaneously imparting liquid repellency, resistance to molten metal penetration and flame retardancy to the fabric. Compared with the cumbersome process of multiple processing steps of water repellency finishing, flame retardant finishing and ceramic coating in the prior art, this invention combines at least three processes into one, reducing the number of drying and baking times, saving about 40% of energy consumption, reducing wastewater discharge by about 35%, and the finishing solution formula does not contain prohibited substances such as perfluorooctanoic acid (PFOA), which meets environmental protection requirements;

[0030] (3) Precision overfeed heat setting process with high precision in dimensional stability control and reduced defect rate: By strictly controlling the heat setting temperature within a narrow window of 190~210℃ and overfeed rate of +1.5%~+2.5%, the warp dimensional change rate of the fabric after washing is stabilized at 0~-1.0% and the weft at -1.5%~-2.5%, and the thermal stability (260℃×5min) dimensional change rate is ≤2.5%, which is far superior to the national standard requirement of ≤5%. This process solves the problem of severe shrinkage and displacement of protective areas after repeated washing or heating of traditional protective clothing, and the process parameters can be adjusted online, reducing the defect rate of the setting process from the industry average of 8% to below 1%;

[0031] (4) The process of applying a dotted hot melt adhesive composite radiation heat reflective layer significantly reduces the amount of adhesive used and improves flexibility: This invention uses dotted adhesive application (adhesive dots diameter 0.5-1.0 mm, spacing 3-5 mm, adhesive amount only 8-12 g / m²) to replace the traditional full-area film coating adhesive application (usually 25-30 g / m²), reducing the amount of hot melt adhesive used by more than 60%. At the same time, dotted composite allows the fabric to maintain multi-point flexible connection, leaving a large amount of unbonded area between the base fabric and the reflective layer. The air permeability is increased from ≤20 mm / s of full-area film coating to ≥50 mm / s, and the softness of the hand is improved by about 50%. Moreover, the composite process can be carried out continuously on a conventional composite machine at a speed of 5-8 m / min, with high production efficiency, suitable for large-scale production.

[0032] (5) Standardized garment sewing process, double-stitched overlock + sealing with glue to ensure consistent seam protection: This invention clarifies the specifications of aramid 1414 flame-retardant sewing thread (40 / 3 or 30 / 3), stitch density (9-11 stitches / 2.5cm for visible thread, 11-13 stitches / 2.5cm for concealed thread), and the process of double-stitching and pressing flame-retardant silicone rubber strips (12mm wide) onto key seams. These standardized sewing parameters ensure that the breaking strength of each seam is ≥400N, and that the impact of molten aluminum and molten iron at the seams can pass the D3 / E3 level test, avoiding local weak points in protection caused by differences in manual sewing, and is suitable for assembly line operations and quality traceability. Attached Figure Description

[0033] Figure 1 Photograph 1 of the actual protective suit prepared for molten metal splashing in Example 1;

[0034] Figure 2 Photo 2 shows the actual protective suit prepared for molten metal splashing in Example 1. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described in detail below with reference to specific examples.

[0036] Example 1

[0037] The manufacturing process of a protective suit for molten metal splashing according to this embodiment includes the following steps:

[0038] A1. Fiber blending: Take 70kg of meta-aramid, 15kg of para-aramid (aramid 1414), and 15kg of flame-retardant viscose fiber, and proceed with opening and cleaning → carding → drawing (three times) → roving → spinning (twist coefficient 340) → automatic winding to obtain 32-count single yarn with a single yarn strength of 28N.

[0039] A2. Weaving: 2 / 2 twill weave is used on a rapier loom, with a warp density of 200 ends / 10cm, a weft density of 180 ends / 10cm, and a fabric weight of 305g / m².

[0040] A3. Preparation of finishing solution: Take 70g of nano alumina sol (solid content 20%), 40g of PTFE emulsion (solid content 60%), 25g of Exolit AP 422, 8g of crosslinking agent (Bayhydur 305), and 3g of JFC penetrant, add deionized water to 1000g, and stir evenly.

[0041] A4. Dipping and rolling: Two dips and two rolls are used, with a roll residue of 75%. Pre-dry at 120℃ for 2.5 min and bake at 175℃ for 2 min.

[0042] A5. Heat setting: Setting temperature 200℃, time 75 seconds, warp overfeed +2.0%, weft shrinkage -0.3%. Weight after setting: 330g / m².

[0043] A6. Reflective layer lamination: Aluminum-coated polyimide nonwoven fabric (thickness 0.25mm, surface density 70g / m²) is coated with adhesive through a rotary screen, with adhesive dots diameter 0.8mm, spacing 4mm, and adhesive amount 10g / m²; lamination pressure 0.4MPa, temperature 155℃, speed 6m / min;

[0044] A7. Garment sewing: Cut to 175 / 96 (top) and 175 / 82 (pants), use aramid 1414 sewing thread (40 / 3), double-stitched shoulder seams, side seams, crotch seams, and inner trouser seams, then press with 12mm flame-retardant silicone rubber strips, and metal zipper.

[0045] Prepared protective clothing, such as Figure 1 and Figure 2 As shown.

[0046] According to GB 8965.3-2022 and the corresponding method standards, the test results are shown in Table 1.

[0047] Table 1. Test results of protective clothing in Example 1

[0048] Testing items Implementation Standards Technical Requirements Test results assessment Formaldehyde content, mg / kg GB / T2912.1-2009 ≤75 Not detected qualified pH value GB / T7573-2009 4.0~8.5 7.2 qualified Decomposable carcinogenic aromatic amine dyes, mg / kg GB / T17592-2024 ≤20 Not detected qualified Color fastness to perspiration (color change), grade GB / T3922-2013 ≥3-4 3-4 qualified Color fastness to perspiration (staining), grade GB / T3922-2013 ≥3-4 4-5 qualified Color fastness to rubbing (dry rubbing), grade GB / T3920-2008 ≥3-4 4 qualified Fracture strength (meridian), N GB / T3923.1-2013 ≥300 880 qualified Fracture strength (latitudinal), N GB / T3923.1-2013 ≥300 860 qualified Tear-through strength (meridian direction), N GB / T3917.3-2009 ≥25 85.8 qualified Tear strength (weft direction), N GB / T3917.3-2009 ≥25 50.8 qualified Fabric dimensional change rate after washing (warp direction), % GB / T8628 / 8629 / 8630 -5.0~+5.0 0 qualified Fabric dimensional change rate (weft direction) after washing, % GB / T8628 / 8629 / 8630 -5.0~+5.0 -2.5 qualified Thermal stability (length direction), % GB8965.1-2020 ≤5 2.3 qualified Thermal stability (width direction), % GB8965.1-2020 ≤5 2.3 qualified Aluminum liquid impact, g Appendix A of GB8965.3-2022 ≥350 352 D3 molten iron impact, g GB8965.3-2022 Appendix A ≥200 202 E3 Radiative thermal conductivity index RHTI24,s Appendix B of GB38453-2019 ≥20 21 C2 Fabric appearance quality GB8965.3-2022 No damage, spots, etc. conform to qualified Permissible deviation of garment length, in cm FZ / T81007-2022 -1.0~+1.0 +0.2 qualified Maximum permissible deviation in chest circumference, cm FZ / T81007-2022 -2.0~+2.0 -2.0 qualified Total shoulder width limit deviation, cm FZ / T81007-2022 -0.8~+0.8 -0.8 qualified Waist circumference tolerance limit, cm FZ / T81007-2022 -1.0~+1.0 +0.5 qualified The maximum allowable deviation for trouser length is in centimeters. FZ / T81007-2022 -1.5~+1.5 0 qualified Breathability, mm / s GB / T5453-1997 — 58 good

[0049] The protective clothing prepared in Example 1 fully meets the requirements of grades D3, E3, and C2 in GB 8965.3-2022 standard, and its mechanical properties, dimensional stability, and color fastness are all superior to the minimum requirements of the standard.

[0050] Example 2

[0051] The difference between this embodiment and Embodiment 1 lies in the fiber ratio and the composition of the finishing solution, which aims to verify the feasibility of the process parameter window.

[0052] Fiber composition: 65% meta-aramid, 20% para-aramid, and 15% flame-retardant viscose.

[0053] The finishing solution consists of: 80 g / L nano alumina sol, 50 g / L PTFE emulsion, 30 g / L phosphorus flame retardant, 10 g / L crosslinking agent, and 5 g / L penetrant (i.e., the mass concentration of each component in the finishing solution is increased).

[0054] Heat setting parameters: temperature 195℃, time 90 seconds, radial overfeed +1.8%.

[0055] The other steps are the same as in Example 1.

[0056] Performance testing: The test results are shown in Table 2, based on the same standards and methods as in Example 1.

[0057] Table 2. Test results of protective clothing in Example 2

[0058] Inspection items Implementation Standards Technical Requirements Test results assessment Formaldehyde content, mg / kg GB / T2912.1-2009 ≤75 Not detected qualified pH value GB / T7573-2009 4.0~8.5 7.0 qualified Decomposable carcinogenic aromatic amine dyes, mg / kg GB / T17592-2024 ≤20 Not detected qualified Color fastness to perspiration (color change), grade GB / T3922-2013 ≥3-4 4 qualified Color fastness to perspiration (staining), grade GB / T3922-2013 ≥3-4 4-5 qualified Color fastness to rubbing (dry rubbing), grade GB / T3920-2008 ≥3-4 4 qualified Fracture strength (meridian), N GB / T3923.1-2013 ≥300 905 qualified Fracture strength (latitudinal), N GB / T3923.1-2013 ≥300 872 qualified Tear-through strength (meridian direction), N GB / T3917.3-2009 ≥25 88.3 qualified Tear strength (weft direction), N GB / T3917.3-2009 ≥25 52.1 qualified Fabric dimensional change rate after washing (warp direction), % GB / T8628 / 8629 / 8630 -5.0~+5.0 -0.5 qualified Fabric dimensional change rate (weft direction) after washing, % GB / T8628 / 8629 / 8630 -5.0~+5.0 -2.2 qualified Thermal stability (length direction), % GB8965.1-2020 ≤5 2.1 qualified Thermal stability (width direction), % GB8965.1-2020 ≤5 2.0 qualified Aluminum liquid impact, g GB8965.3-2022 Appendix A ≥350 358 D3 molten iron impact, g GB8965.3-2022 Appendix A ≥200 205 E3 Radiative thermal conductivity index RHTI24,s Appendix B of GB38453-2019 ≥20 22 C2 Fabric appearance quality GB8965.3-2022 No damage, spots, etc. conform to qualified Permissible deviation of garment length, in cm FZ / T81007-2022 -1.0~+1.0 +0.1 qualified Maximum permissible deviation in chest circumference, cm FZ / T81007-2022 -2.0~+2.0 -1.8 qualified Total shoulder width limit deviation, cm FZ / T81007-2022 -0.8~+0.8 -0.5 qualified Waist circumference tolerance limit, cm FZ / T81007-2022 -1.0~+1.0 +0.3 qualified The maximum allowable deviation for trouser length is in centimeters. FZ / T81007-2022 -1.5~+1.5 -0.2 qualified Breathability, mm / s GB / T5453-1997 — 52 good

[0059] Example 2 further increased the proportion of para-aramid and the concentration of the finishing agent, resulting in a slight improvement in mechanical properties. The aluminum melt impact strength reached 358g, the iron melt impact strength 205g, and the RHTI24 test result was 22s, still meeting the D3 / E3 / C2 standards. The basis weight increased to 345g / m², and the hand feel became slightly stiffer, but all properties met the standard requirements.

[0060] Example 3

[0061] This embodiment attempts to reduce the para-aramid content to improve the feel and cost while maintaining the D3 / E3 / C2 grade.

[0062] Fiber composition: meta-aramid 75%, para-aramid 12%, flame retardant viscose 13%.

[0063] The finishing solution consists of: 60 g / L nano alumina sol, 35 g / L PTFE emulsion, 20 g / L phosphorus flame retardant, 6 g / L crosslinking agent, and 3 g / L penetrant (concentration reduced compared to Example 1).

[0064] Weaving density: 190 warp threads / 10cm, 170 weft threads / 10cm, and greige fabric weight 290g / m².

[0065] Heat setting: Temperature 205℃, time 80 seconds, radial overfeed +2.2%.

[0066] The other steps are the same as in Example 1.

[0067] Performance testing: The test results are shown in Table 3, based on the same standards and methods as in Example 1.

[0068] Table 3. Test results of protective clothing in Example 3

[0069] Inspection items Implementation Standards Technical Requirements Test results assessment Formaldehyde content, mg / kg GB / T2912.1-2009 ≤75 Not detected qualified pH value GB / T7573-2009 4.0~8.5 7.4 qualified Decomposable carcinogenic aromatic amine dyes, mg / kg GB / T17592-2024 ≤20 Not detected qualified Color fastness to perspiration (color change), grade GB / T3922-2013 ≥3-4 3-4 qualified Color fastness to perspiration (staining), grade GB / T3922-2013 ≥3-4 4-5 qualified Color fastness to rubbing (dry rubbing), grade GB / T3920-2008 ≥3-4 4 qualified Fracture strength (meridian), N GB / T3923.1-2013 ≥300 832 qualified Fracture strength (latitudinal), N GB / T3923.1-2013 ≥300 808 qualified Tear-through strength (meridian direction), N GB / T3917.3-2009 ≥25 76.5 qualified Tear strength (weft direction), N GB / T3917.3-2009 ≥25 48.2 qualified Fabric dimensional change rate after washing (warp direction), % GB / T8628 / 8629 / 8630 -5.0~+5.0 -0.2 qualified Fabric dimensional change rate (weft direction) after washing, % GB / T8628 / 8629 / 8630 -5.0~+5.0 -2.4 qualified Thermal stability (length direction), % GB8965.1-2020 ≤5 2.5 qualified Thermal stability (width direction), % GB8965.1-2020 ≤5 2.4 qualified Aluminum liquid impact, g GB8965.3-2022 Appendix A ≥350 351 D3 molten iron impact, g GB8965.3-2022 Appendix A ≥200 200 E3 Radiative thermal conductivity index RHTI24,s Appendix B of GB38453-2019 ≥20 20 C2 Fabric appearance quality GB8965.3-2022 No damage, spots, etc. conform to qualified Permissible deviation of garment length, in cm FZ / T81007-2022 -1.0~+1.0 +0.3 qualified Maximum permissible deviation in chest circumference, cm FZ / T81007-2022 -2.0~+2.0 -1.5 qualified Total shoulder width limit deviation, cm FZ / T81007-2022 -0.8~+0.8 -0.6 qualified Waist circumference tolerance limit, cm FZ / T81007-2022 -1.0~+1.0 +0.4 qualified The maximum allowable deviation for trouser length is in centimeters. FZ / T81007-2022 -1.5~+1.5 -0.1 qualified Breathability, mm / s GB / T5453-1997 — 62 good

[0070] Example 3, under the premise of meeting the D3 / E3 / C2 grades (351g aluminum liquid impact, 200g iron liquid impact, RHTI24=20s reaching the lower limit of C2), has a softer feel, better air permeability (62mm / s), and a cost reduction of about 12%, proving that the process of the present invention has good economy and adaptability.

[0071] Comparative Example 1

[0072] The protective clothing uses commercially available ordinary molten metal splash protective fabric (brand omitted), which claims to comply with GB 8965.3-2022 standard.

[0073] Fabric structure: 93% aramid 1313 + 7% antistatic fiber, plain weave, 380g / m², no nano-coating, no independent radiant heat reflective layer, only aluminum powder coating. Sewing process: conventional sewing (non-sealed).

[0074] Performance testing: The test results are shown in Table 4, based on the same standards and methods as in Example 1.

[0075] Table 4 shows the test results of the protective clothing in Comparative Example 1.

[0076] Inspection items Implementation Standards Technical Requirements Test results assessment Formaldehyde content, mg / kg GB / T2912.1-2009 ≤75 Not detected qualified pH value GB / T7573-2009 4.0~8.5 7.1 qualified Decomposable carcinogenic aromatic amine dyes, mg / kg GB / T17592-2024 ≤20 Not detected qualified Color fastness to perspiration (color change), grade GB / T3922-2013 ≥3-4 3-4 qualified Color fastness to perspiration (staining), grade GB / T3922-2013 ≥3-4 4 qualified Color fastness to rubbing (dry rubbing), grade GB / T3920-2008 ≥3-4 3-4 qualified Fracture strength (meridian), N GB / T3923.1-2013 ≥300 520 qualified Fracture strength (latitudinal), N GB / T3923.1-2013 ≥300 480 qualified Tear-through strength (meridian direction), N GB / T3917.3-2009 ≥25 32 qualified Tear strength (weft direction), N GB / T3917.3-2009 ≥25 28 qualified Fabric dimensional change rate after washing (warp direction), % GB / T8628 / 8629 / 8630 -5.0~+5.0 -3.2 qualified Fabric dimensional change rate (weft direction) after washing, % GB / T8628 / 8629 / 8630 -5.0~+5.0 -4.1 qualified Thermal stability (length direction), % GB8965.1-2020 ≤5 6.8 Unqualified Thermal stability (width direction), % GB8965.1-2020 ≤5 7.2 Unqualified Aluminum liquid impact, g GB8965.3-2022 Appendix A ≥350 186 Failed (D2 only) molten iron impact, g GB8965.3-2022 Appendix A ≥200 112 Failed (E2 only) Radiative thermal conductivity index RHTI24,s Appendix B of GB38453-2019 ≥20 11 Unqualified (C1 only) Fabric appearance quality GB8965.3-2022 No damage, spots, etc. Localized peeling of aluminum powder coating Unqualified Breathability, mm / s GB / T5453-1997 — 35 Poor

[0077] Comparative Example 1 failed to reach the D3 / E3 / C2 grades, mainly due to the lack of para-aramid reinforcement and nano-alumina / PTFE finishing layer, resulting in severe metal penetration during aluminum melt impact (only 186g); the aluminum powder coating was prone to peeling off at high temperatures; and poor control of the heat setting process led to unqualified thermal stability (6.8% and 7.2%).

[0078] Comparative Example 2

[0079] The fiber ratio and weaving process are the same as in Example 1, but the dotted composite radiative heat reflective layer is removed and replaced with a conventional aluminum foil full-area film; at the same time, the finishing liquid of this invention is not applied, and only conventional flame retardant finishing is performed.

[0080] Fiber ratio: Same as in Example 1 (70% meta-aramid, 15% para-aramid, 15% flame retardant viscose).

[0081] Finishing without nano-alumina / PTFE: Only conventional phosphorus-based flame retardant 20g / L is used for impregnation, without nano-alumina and PTFE.

[0082] Reflective layer lamination: Aluminum foil (thickness 0.05mm) + hot melt adhesive coating (adhesive amount 25g / m², full area coverage), lamination pressure 0.6MPa.

[0083] The other steps are the same as in Example 1 (but without the functional layer after heat setting).

[0084] Performance testing: The test results are shown in Table 5, based on the same standards and methods as in Example 1.

[0085] Table 5. Test results of protective clothing in Comparative Example 2

[0086] Inspection items Implementation Standards Technical Requirements Test results assessment Formaldehyde content, mg / kg GB / T2912.1-2009 ≤75 Not detected qualified pH value GB / T7573-2009 4.0~8.5 7.3 qualified Decomposable carcinogenic aromatic amine dyes, mg / kg GB / T17592-2024 ≤20 Not detected qualified Color fastness to perspiration (color change), grade GB / T3922-2013 ≥3-4 3-4 qualified Color fastness to perspiration (staining), grade GB / T3922-2013 ≥3-4 4 qualified Color fastness to rubbing (dry rubbing), grade GB / T3920-2008 ≥3-4 3 qualified Fracture strength (meridian), N GB / T3923.1-2013 ≥300 710 qualified Fracture strength (latitudinal), N GB / T3923.1-2013 ≥300 695 qualified Tear-through strength (meridian direction), N GB / T3917.3-2009 ≥25 42 qualified Tear strength (weft direction), N GB / T3917.3-2009 ≥25 35 qualified Fabric dimensional change rate after washing (warp direction), % GB / T8628 / 8629 / 8630 -5.0~+5.0 -1.2 qualified Fabric dimensional change rate (weft direction) after washing, % GB / T8628 / 8629 / 8630 -5.0~+5.0 -3.0 qualified Thermal stability (length direction), % GB8965.1-2020 ≤5 3.5 qualified Thermal stability (width direction), % GB8965.1-2020 ≤5 3.8 qualified Aluminum liquid impact, g GB8965.3-2022 Appendix A ≥350 268 Failed (D2 only) molten iron impact, g GB8965.3-2022 Appendix A ≥200 157 Failed (E2 only) Radiative thermal conductivity index RHTI24,s Appendix B of GB38453-2019 ≥20 28 Qualified (C3) Fabric appearance quality GB8965.3-2022 No damage, spots, etc. Localized blistering on aluminum foil surface Unqualified Breathability, mm / s GB / T5453-1997 — 18 Range Observation after aluminum liquid impact — — Localized melting and adhesion of the reflective layer Unqualified

[0087] Comparative Example 2's RHTI24 achieved a test result of 28s (exceeding the C2 requirement), but failed to reach the D3 / E3 level for both aluminum and iron molten impact (only D2 and E2), and its breathability was only 18mm / s, resulting in a stiff feel. While the full-area composite reflective layer improved radiant heat protection, it compromised the base fabric's resistance to liquid metal impact (aluminum molten impact decreased from 352g to 268g), and significantly reduced wearing comfort. After aluminum molten impact, the reflective layer exhibited melt adhesion, failing to meet fabric appearance quality requirements. This invention employs a dot-matrix composite layer combined with a functional finishing liquid for synergistic effects, achieving a balance across multiple performance characteristics.

[0088] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A manufacturing process for a protective suit to withstand molten metal splashes, characterized in that, Includes the following steps, S1. Fiber blending: Meta-aramid, para-aramid and flame-retardant viscose fiber are blended in a certain mass ratio to obtain blended yarn; S2, Weaving: Weaving blended yarns into high-density greige fabric; S3, Multifunctional finishing liquid padding: The fabric is padded with a finishing liquid containing nano alumina sol, polytetrafluoroethylene emulsion and phosphorus flame retardant, and then dried and baked; S4. Heat setting: The impregnated fabric is subjected to overfeed heat setting treatment; S5. Radiative heat reflective layer composite: Aluminum-coated polyimide nonwoven fabric is laminated onto the inner side of the heat-set fabric using dotted hot melt adhesive. S6. Garment sewing: Cut and sew according to the garment pattern, and double-stitch and seal key seams.

2. The manufacturing process of a protective suit for molten metal splashing as described in claim 1, characterized in that, In step S1, the mass percentages of meta-aramid, para-aramid, and flame-retardant viscose fiber are as follows: meta-aramid 65%–75%, para-aramid 15%–20%, and flame-retardant viscose fiber 10%–15%.

3. The manufacturing process of a protective suit for molten metal splashing as described in claim 1, characterized in that, In step S2, the weaving adopts a 2 / 2 twill or 5 / 3 satin weave, with a warp density of 180-220 threads / 10cm and a weft density of 160-200 threads / 10cm.

4. The manufacturing process of a protective suit for molten metal splashing as described in claim 1, characterized in that, In step S3, the finishing liquid comprises, by mass percentage: 5%–8% nano alumina sol, 3%–5% polytetrafluoroethylene emulsion, 2%–3% phosphorus flame retardant, 0.5%–1% crosslinking agent, 0.2%–0.5% penetrant, and the balance being deionized water; the padding process is two dips and two rolls, with a roll-off rate of 70%–80%.

5. The manufacturing process of a protective suit for molten metal splashing as described in claim 1, characterized in that, In step S4, the heat setting temperature is 190℃~210℃, the setting time is 60~90 seconds, and the radial overfeed rate is +1.5%~+2.5%.

6. The manufacturing process of a protective suit for molten metal splashing as described in claim 1, characterized in that, In step S5, the aluminum-coated polyimide nonwoven fabric has a thickness of 0.20–0.30 mm and a surface density of 60–80 g / m²; the dotted hot melt adhesive has a dot diameter of 0.5–1.0 mm, a dot spacing of 3–5 mm, and an adhesive amount of 8–12 g / m²; the composite pressure is 0.3–0.5 MPa, and the composite temperature is 150–160 °C.

7. The manufacturing process of a protective suit for molten metal splashing as described in claim 1, characterized in that, In step S6, the sewing thread is aramid 1414 flame-retardant sewing thread with a linear density of 40 / 3 or 30 / 3; the pressure sealing uses a flame-retardant silicone rubber strip with a width of 12mm.

8. The protective suit for molten metal splashing prepared by the preparation process according to any one of claims 1 to 7, characterized in that, The protective suit has an aluminum molten metal impact weight of ≥350g, meeting the D3 level requirements of GB 8965.3-2022 standard; an iron molten metal impact weight of ≥200g, meeting the E3 level requirements; and a radiative heat conduction index RHTI24 ≥20s, meeting the C2 level requirements.

9. The protective suit for molten metal splashing according to claim 8, characterized in that, The protective suit has a tensile strength of ≥800N in the warp direction and ≥800N in the weft direction; a tear strength of ≥75N in the warp direction and ≥45N in the weft direction; and a thermal stability dimensional change rate of ≤2.5%. The dimensional change rate after washing is -1.0% to 0 in the warp direction and -2.5% to -1.5% in the weft direction.

10. The protective suit for molten metal splashing according to claim 8, characterized in that, The fabric of the protective suit has a weight of 320-360 g / m² and an air permeability of ≥50 mm / s.

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