Delhi High Court Quashes Patent Office Order, Sends Trident's 'Air Rich Yarn' Patent Plea Back For Review

The Delhi High Court has overturned a Patent Office decision that refused Trident Limited a patent for its “air rich” yarn and fabric technology. The court said the Patent Office failed to properly examine the key feature of the invention, which is the “homogeneous distribution of pores across the radial cross-section of yarn”, and had not correctly assessed obviousness under Indian patent law. In a judgment dated November 24, 2025, Justice Tejas Karia held that the Patent Office had not provided a sufficient basis for concluding that Trident's invention lacked an inventive step. The court said the refusal order suffered from several infirmities. Trident, a textile and linen manufacturer, had applied for the patent in 2010. Its invention involved creating “air rich yarns” by mixing base fibres with water-soluble fibres in specific proportions. These soluble fibres dissolve later, creating evenly spaced pores intended to make the yarn softer and more breathable. The Patent Office rejected the application in 2021, saying that earlier documents already disclosed similar fibre combinations and processes. Trident challenged the decision, arguing that none of the cited documents showed yarn with pores spread evenly throughout the cross-section. The company said the Patent Office simply assumed that using similar fibre blends would automatically lead to the same structure, without explaining how a skilled person would arrive at that conclusion. The Patent Office defended its decision and said the process was routine for skilled workers. It also argued that Trident had not proved homogeneous pore distribution and that the examples provided in the application were insufficient. The High Court disagreed and pointed out several gaps in the refusal order. It said the Patent Office had not explained why a skilled person would choose the specific fibre ratios claimed by Trident or how the earlier documents taught the same pore pattern. The Court also noted that the Patent Office had overlooked detailed examples in the patent specification describing how consistent pore distribution could be achieved. The court said, “By providing a yarn having a plurality of pores that are homogenously distributed across a radial cross-section of the yarn, the claimed invention provides a yarn structure that is neither taught nor achieved by any of the prior art references D1 to D4,” The court also referred to the Supreme Court's ruling in Enercon (India) Limited v. Aloys Wobben and repeated that an invention is not considered obvious merely because some of its elements appear in prior art. The Court said there must be a “coherent thread” that would guide a skilled person to the same invention and held that the Patent Office had not demonstrated this. The court set aside the refusal order and sent the patent application back to the Patent Office for a fresh hearing by a different Controller. Case Title: Trident Limited v. Controller Of PatentsCitation: 2025 LiveLaw (Del) 1615 Case Number: C.A. (COMM.IPD-PAT) 162/2022 For Appellant: Advocates Nitin Masilamani, Amritanshu Jha and Amit Singh For the Respondent: Advocates Rupali Bandhopadhya, Abhijeet Kumar and A. GuptaClick Here To Read/Download Order

Delhi High Court Quashes Patent Office Order, Sends Trident's 'Air Rich Yarn' Patent Plea Back For Review

Ayushi Shukla

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