Long-distance coach interior components must balance flame retardancy and safety, wear and weather resistance, lightweighting, passenger comfort, and suitability for mass production. The industry currently favors thick-sheet vacuum forming-utilizing ABS and TPU thermoplastic materials-over traditional injection molding and fiberglass processes. This approach accommodates a full range of interior components, such as ceiling panels, seat backrests, door trim panels, air ducts, luggage racks, and armrest coverings, serving as a core solution for reducing costs, improving quality, and meeting regulatory upgrades in coach interiors.
Vacuum forming is a mainstream thermoforming process well-suited for producing large, complex-curved coach interior parts. The process involves heating a plastic sheet until soft, shaping it against a mold using negative pressure (vacuum suction), and then cooling and trimming it to create the finished product. Compared to injection molding, vacuum forming offers lower tooling costs and shorter mold development times, allowing for rapid adaptation to the varying interior curvatures of different vehicle models and supporting the diverse, small-batch customization typical of the long-distance coach industry. Furthermore, the process yields seamless, one-piece components that are waterproof, dustproof, and structurally robust; the recyclability of scrap material aligns with the low-carbon production requirements of the passenger transport industry.
ABS is the preferred base material for rigid coach interior components due to its exceptional versatility in vacuum forming. Modified flame-retardant ABS sheets offer balanced hardness, impact resistance, and dimensional stability; they stretch evenly when heated and resist cracking or deformation after forming, while also being easy to sand, paint, or emboss with textures. They are widely used for load-bearing rigid parts-such as large ceiling panels, sidewall trim, driver console housings, and luggage rack bases-offering resistance to temperature fluctuations and passenger-induced impacts or wear. These materials meet national flame-retardancy standards for coach interiors and offer a cost-effective solution for mass-production vehicle assembly.
TPU serves as a flexible complementary material, often used in conjunction with ABS substrates during vacuum forming. Elastic TPU offers excellent flexibility, slip and scratch resistance, noise and vibration dampening, and resistance to oil and UV-induced aging, making it ideal for high-contact areas within long-distance coaches. The industry commonly employs a process combining ABS-substrate vacuum forming with TPU skin lamination to manufacture components such as seat armrest coverings, door-side impact-absorbing pads, seat back cushions, and anti-slip footwell mats. This approach mitigates interior noise caused by rattling, enhances tactile comfort, and prevents issues common to standard plastics-such as hardening due to aging or surface peeling-thereby extending the service life of interior components.
In terms of industry trends, the use of flame-retardant, low-odor ABS/TPU composite sheets-paired with high-precision negative-pressure vacuum forming equipment-enables the integrated composite molding of interior parts. This reduces the need for adhesive bonding processes and lowers in-vehicle VOC levels. Looking ahead, this composite molding technology is poised to further meet the evolving needs for lightweight and eco-friendly interior upgrades in long-distance new energy buses.