When cutting and welding operations are performed in automotive metal fabrication workshops, a large volume of hot molten metal droplets splashes. The core objective of the whole manufacturing process for anti-spatter fire suits is to endow fabrics with the capability to repel molten metal particles while retaining flame retardancy and tear resistance. From incoming fabric inspection, surface functional finishing, pre-stabilization treatment, pattern cutting, sewing assembly, semi-finished setting to finished-product testing, every process parameter directly affects the suit’s ability to resist molten slag splashes. Unlike ordinary flame-retardant protective garments, suits for automotive metal fabrication focus on low-adhesion surface modification and sealed seam protection to prevent hot molten droplets from adhering and burning fabric, while preserving freedom of limb movement.

　　Incoming fabric inspection and pre-stabilization treatment mark the start of the workflow. After fabric rolls arrive, inspectors test areal density, breaking strength, limiting oxygen index and surface wettability, checking for weaving defects, thin yarn lines and uneven coating. Qualified fabric undergoes relaxation and standing to release internal stress generated during winding and storage. This prevents shrinkage and deformation of finished garments under high temperature or after laundering, which would tighten fabric, alter its micro-structure and weaken adhesion stability of the anti-spatter coating. After relaxation, low-temperature hydrothermal pre-shrinking and setting are applied to eliminate latent shrinkage risks. High-temperature baking is forbidden in pretreatment; excessive heat will damage the modified coating on fiber surfaces and reduce droplet sliding performance. After pre-stabilization, samples are tested for anti-spatter performance to confirm molten metal droplets slide off quickly without adhesion before moving on to functional finishing.

　　Fabric anti-spatter functional finishing is the core procedure. A padding and coating process deposits low-surface-energy high-temperature modified chemicals evenly onto fiber surfaces. The formula adopts silicon-based halogen-free systems, which do not release large volumes of toxic smoke when heated. The liquid pickup rate in padding is strictly controlled. Excessive chemical loading stiffens fabric and reduces air permeability; insufficient loading fails to form a continuous protective film and allows molten droplets to adhere easily. After padding, staged low-temperature curing locks modified components firmly to fibers and improves laundering durability. Temperature gradients during curing must be stable; local overheating causes uneven crosslinking of chemicals and triggers partial anti-spatter failure. After finishing, a dense low-energy protective film forms on fabric surfaces. When hot metal droplets contact the fabric, they cannot wet the surface and slide down rapidly under gravity to cut heat transfer. After functional finishing, samples are subjected to vertical flame and molten droplet impact tests to verify both anti-spatter and flame-retardant indicators.

　　Pattern layout and cutting adopt zoned design based on splash risks. A CAD layout system uses ergonomic patterns and distinguishes warp and weft directions to guarantee uniform stress on cut panels. Chest, shoulders, upper arms and front thighs are high-splash zones and use fully anti-spatter treated fabric. Armpits, waist sides and joint bending areas adopt lightweight fabric of the same system to preserve mobility. CNC laser cutting equipment is preferred; melted and sealed cut edges prevent yarn fraying and block splash ingress through panel gaps. Manual inspection follows cutting. Panels with microholes, scratches or damaged coatings are discarded and never sent for sewing. Panels are marked and managed separately; fabric for high-risk and low-risk zones cannot be mixed to avoid protection weaknesses.

　　Sewing assembly focuses heavily on seam protection, because seams are the weakest points against metal splashes. All sewing accessories are flame-retardant of matching grade. Aramid flame-resistant thread is used for stitching, while zippers and hook-and-loop base fabrics are all flame-retardant textiles. Double-lock stitching is adopted, and bartack reinforcement is added on high-stress positions including shoulders, elbows and knees to boost seam strength. Stitch spacing is precisely controlled during sewing. Overly large stitches create big pinholes for hot molten droplets to penetrate; stitches that are too tight squeeze yarns and scratch the fabric’s anti-spatter coating. For seams in high-risk areas, a thin flame-retardant sealant is coated to plug pinhole gaps. Sealant thickness is tightly regulated; thick layers stiffen fabric and restrict limb movement. In-line inspection stations are arranged during sewing to detect skipped stitches, incomplete seams and coating scratches. Unqualified semi-finished products are repaired promptly.

　　Semi-finished post-finishing and pre-aging simulate long-term workshop usage. Semi-finished garments after sewing are dedusted to remove loose threads and fiber debris, which can scratch the surface protective film and weaken anti-spatter performance. Low-temperature setting follows, with gentle ironing to smooth wrinkles. High-temperature heavy pressing is prohibited to avoid damage to surface coatings. After setting, washing pre-aging tests simulate repeated cleaning cycles in workshops. Changes in anti-spatter performance and flame retardancy after washing are measured to screen fabric batches with fast performance degradation in advance. Low-temperature processes are used throughout washing and drying to protect the surface modified layer from high heat damage.

　　Comprehensive finished-product inspection is the final quality control before delivery. Test items include vertical flame test, molten metal splash test, seam strength and wash stability. The molten metal splash test serves as the core inspection item to verify fabric resistance against hot molten droplet impact and observe whether droplets slide off quickly without adhesion and burning. Random sampling is adopted, focusing on seams and accessory splicing areas. If any indicator fails, the whole batch is put on hold. All previous processes are reviewed to identify process deviations and adjust padding, curing or sewing parameters.

　　In summary, the process design of anti-spatter fire suits centers on fabric surface modification and sealed seam protection, specifically targeting hot molten droplet splash hazards in automotive metal fabrication workshops. From fabric pre-stabilization, anti-spatter padding finishing, zoned cutting and sealed sewing to aging testing, tiny deviations in process parameters will reduce the garment’s molten droplet protection capability. While maintaining flame-retardant safety benchmarks, the full manufacturing workflow lowers risks of adhesion and burning from metal splashes, and preserves flexibility and comfort for wearers, delivering reliable high-temperature protection for operators at automotive metal fabrication stations.