The new bottles will be phased in during 2019 and will also include a minimum of 30% recycled material.
Unilever predicts this could lead to a further 2,500 tonnes of plastic bottles to be recycled every year.
The solution will be shared with other manufacturers across the industry.
Many black plastic bottles are not detected by optical sorting machines due to infra-red light which is absorbed by the carbon black pigment.
Unilever has carried out extensive trials, in partnership with RECOUP and waste management partners Veolia, SUEZ, Viridor and TOMRA, which have proven that this new pigment can be technically detected within their material recycling facilities in the UK.
Richard Kirkman, chief technology and innovation officer, Veolia UK & Ireland, said: “We have deployed an innovative solution within the software and invested in our sorting technology at our flagship recycling facility in Southwark and this, together with Unilever modifying the pigment in the black dye for their HDPE packaging, enables it to be successfully detected.”
“Adjusting the detection mechanism in this way - with both technology and packaging modified was the key.”
WRAP has now called for wide-scale adoption of detectable black pigment by brands and retailers.
Unilever is a signatory of the UK Plastics Pact and has set up a Get Plastic Wise campaign- a strategy which tackles plastic waste in the UK and move towards a closed loop system.