Delhi High Court Restrains Pronton Plast Pack From Manufacturing Containers Infringing Mold Tek Patents

The Delhi High Court has granted and continued an interim injunction in favour of Mold-Tek Packaging Limited, restraining Pronton Plast Pack Pvt. Ltd. and its agents from manufacturing or selling plastic containers and lids that prima facie infringe two patents held by Mold-Tek.

Justice Tejas Karia, in a judgment pronounced on April 30, 2026, held that Mold-Tek had made out a prima facie case of patent infringement and that permitting Pronton to continue dealing in the impugned products would result in irreparable harm.

Mold-Tek, a Hyderabad-based packaging manufacturer supplying companies such as Unilever, Pepsi, and Dabur, submitted that it holds two patents at the centre of the dispute.

The first patent, titled a “Tamper-Evident Leak Proof Pail Closure System,” relates to a container lid designed with a tear band and a locking mechanism that ensures part of the lid stays attached even after opening, making any tampering clearly visible.

The second patent, titled a “Tamper Proof Lid Having Spout for Containers,” covers a lid fitted with a specialised spout system that uses a shrink-fit structure and tail rings formed through a spinning process to create a secure, leak-proof seal.

Mold-Tek stated that it discovered in November 2023 that Pronton was offering for sale plastic containers on IndiaMart which, according to it, embodied the features claimed in its suit patents.

It was further alleged that Pronton's CEO, Sunil Bajaj, had previously been associated with a distributor of Mold-Tek and had executed a Mutual Confidentiality Agreement with Mold-Tek in 2017. Mold-Tek argued that this prior relationship indicated a mala fide attempt to exploit its proprietary technology.

Pronton contested the suit on the grounds of non-infringement and invoked the Gillette defence, contending that its products were based on prior art and generic industry practices, including a ceased patent.

In relation to Suit Patent I, Pronton argued that its tear band opens on only three sides of the container, unlike the four-sided opening claimed by Mold-Tek, and that its lid does not completely detach, thereby falling outside the scope of the patent claims.

The court, however, found that the differences relied upon by Pronton did not, at this stage, displace Mold-Tek's case of infringement based on the claims of the suit patent.

The court also observed that Pronton had not “cleared the way” prior to launching its products by either challenging the validity of the suit patents or seeking a declaration of non-infringement.

In these circumstances, the court held that the balance of convenience favoured Mold-Tek, noting that the suit patents are valid and subsisting, and restrained Pronton from continuing with the impugned activities pending further proceedings.