DS Smith cuts heavy grades to fund £20m lightweighting push at Kemsley

In a decisive move that underscores the ongoing structural shift in the European containerboard market, DS Smith has announced plans this July 2026 to close Paper Machine 4 (PM4) at its Kemsley Mill in the UK. Simultaneously, the packaging giant is proposing a £20 million investment to upgrade Paper Machine 6 (PM6) at the same site. This strategic realignment at the UK's largest recycled paper mill highlights a clear industry trajectory: the relentless pursuit of lightweight, high-performance corrugated case materials (CCM) at the expense of older, heavier capacity.

The technical shift: From volume to efficiency

The proposed closure of PM4 removes approximately 250,000 tonnes of annual capacity from the market. Historically, PM4 has been a workhorse for heavier grades, operating with a grammage range of 125-210 g/m2 and a maximum speed of 770 m/min. In contrast, the £20 million capital injection into PM6 is a targeted play on the lightweighting trend. PM6, which already boasts a production capacity of 290,000 tonnes per year and a much faster operating speed of 1,100 m/min, focuses on a grammage range of 85-130 g/m2. By modernizing PM6, @DSSmith aims to produce new grades of paper at an increased volume, optimizing the machine's output for the modern e-commerce and retail packaging sectors that demand strength without the bulk.

Kemsley's evolving legacy

Built in 1924 by Frank Lloyd originally to produce newsprint, Kemsley Mill has continuously adapted to survive. Today, with a total annual capacity of around 830,000 tonnes, it stands as the second-largest recovered fibre-based paper operation in Europe. The site also houses PM3, which produces 290,000 tonnes annually across a versatile 115-280 g/m2 range. By retiring PM4, Kemsley will streamline its operations around PM3 and the newly upgraded PM6, effectively covering the necessary spectrum of packaging grades while significantly reducing operational inefficiencies and energy consumption per tonne produced.

The International Paper era and market rationalization

This restructuring cannot be viewed in isolation. Following the landmark acquisition of DS Smith by International Paper in 2025, the combined entity has been rigorously evaluating its global footprint to eliminate redundancies and focus on high-margin, sustainable packaging solutions. The year 2026 has already seen the company make tough decisions in the UK, including the confirmed closures of packaging sites in Launceston and Clay Cross. The rationalization at Kemsley aligns perfectly with International Paper's broader strategy to tighten supply in an often oversupplied European containerboard market, ensuring that capital is deployed only where it generates the highest return on investment.

Taking 250,000 tonnes of recycled paper capacity offline is a significant market signal. While it involves difficult workforce changes—currently subject to consultation with employee representatives—it acts as a stabilizing factor for European containerboard pricing. The £20 million investment in PM6, meanwhile, secures Kemsley's position as a future-ready, cost-effective mill capable of meeting the stringent sustainability and circular economy targets demanded by today's fast-moving consumer goods brands.

Streamlining operations at Kemsley is a necessary, albeit tough, step that ultimately secures the mill's future in a market that demands hyper-efficient, low-grammage solutions. Will the removal of 250,000 tonnes of medium-to-heavy grades create a localized supply gap in the UK, or is the European market already too saturated to notice the missing tonnage? Follow The Paper for daily news, market signals and key updates from the global paper, corrugated and packaging industry. — Sigue toda la actualidad del sector en www.thepaper.ai