Automation Roadmap for Ndulj, UK

Assess production methods and provide an automation roadmap to underpin future business growth
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Ndulj Ltd, UK

Ndulj Ltd produce the ‘Fudged Up’ range of chocolate coated fudge from a small manufacturing facility in Grantham in the UK. All products are currently handmade in small batches with ethically sourced ingredients, and supplied in fully recyclable, plastic-free, and home compostable packaging. The Ndulj ethos is a duty to the environment, supporting charities and organisations such as Forest Stewardship Council, Rainforest Alliance, and One Tree Planted.
Currently 3 flavours are produced (Raspberry Cheesecake, Outrageous Orange, and Majestic Mint) with more flavours planned to be released later. There are 2 formats, bars (70g), or small pieces in gift tube (250g). Current outlets for the products are through independent farm shops, coffee shops, food halls, and delicatessens, with some direct online sales.
All sales channels are growing, and the business needs to increase production from the current ‘kitchen scale’ to small scale industrial production. Ndulj currently has 1 fulltime operative covering all aspects of the business: purchasing, production, marketing, sales, and distribution.

The regional Partner for Lincolnshire Drizzle Company, UK:

Motivation/Starting Point

As sales volumes increase, Ndulj have engaged with the COTEMACO SME support programme to improve production capacity, efficiency, and productivity. The currently weekly production is <300 bars/week, with a projected need for 1,000 bars/week within 1 year, and 7,500 bars/week within 3 years.
Current production is an entirely manual batch process. Belgian chocolate, evaporated milk, sugar and flavourings are heated and blended, then poured into parchment lined trays. These trays are placed on rack trolleys and moved to the cool room to set the fudge. Once cooled, the parchment is removed and then the fudge slab cut into bars or pieces as required. Coating is currently performed by melting c.1kg batches of chocolate in a domestic microwave and manually dipping the cut fudge into the chocolate and shaking off excess. After dipping bars/pieces are placed onto parchment on trays and cooled again to set the chocolate. Ingredient stores and cooling are adjacent to the production space (Figure 1). The bars are then bagged and labelled, the pieces are bagged into 250g lots and placed into prelabelled tubes.

SME Support Activities

It was clear from the outset that a step change immediately to a cobotic / robotic automation manufacturing solution would not be suitable for this 1-man SME at this point in time. There were restricted technical automation skills within the business, capital investment funding was limited, and beneficial gains could be achieved with simpler, lower cost interventions as initial phases of a staged automation roadmap.
An initial assessment of the production operations was carried out to identify bottlenecks, effort intensive operations, and process flow issues where automation would provide business benefit. Initial process bottle necks were identified as the coating/enrobing process, and tube labelling.
Ideally tubes would be pre-printed with designs, however minimum production runs of these were excessive for Ndulj in terms of cash flow, storage space, and business uncertainty as to which flavour(s) would prove most popular. A simpler operation of buying-in plain tubes and manually applying an appropriate label produced a similar package, but at a substantially lower cost. Manual application of the labels had a high reject/waste rate of 40-50%, and gave an overall labelling rate of 120s/tube. A range of suitable equipment to assist with labelling was identified and assessed in terms of cost vs. labelling rate (Figure 2). Broadly speaking an increase in cost gives an increase in production rate, but the largest ratio is at the lowest capital cost for a simple set of guide rollers and rails to more reliably align the labels to the tubes in the manual label application process.
Fudge coating/enrobing was the second bottleneck identified as an inhibitor to production growth. Currently small (1-2kg) batches of chocolate are melted in a microwave, and a hand tool is then used to dip fudge pieces or bars. After dipping, the bars/pieces are shaken to remove excess chocolate, and placed onto parchment lined trays. The process is limited by the small batch size able to fit the microwave, and the need for the work to be done rapidly before the melted chocolate starts to solidify. Further challenges are in the need to attain precise temperatures in the chocolate to achieve the correct i). flow for enrobing, and ii). final crystal structure in the cooled product. The manual dipping of each fudge piece is also time- consuming, repetitive, and tedious. Currently c.700 pieces can be coated in 4 hours, giving a mean overall production rate of c.21s/piece when the chocolate preparation time is taken into account.
A 3-stage approach was initially recommended to allow for limited capital availability and cash flow:

Figure 2

Figure 3

Figure 4

Figure 5

Stage 1
Purchase of dedicated automation for melting and maintaining the enrobing chocolate at a precisely controlled temperature (Figure 3). These machines also typically provide a cascade of melted chocolate, under which the fudge can be held with the current hand tool. This will allow much larger batches than the current 1-2kg to be melted and used, reducing the batch preparation time overhead and complex subtleties needed for microwave control and timing. A benchtop unit is recommended as it smaller in footprint (an important consideration the limited current production space), has a lower purchase price (c.£2.5k –
£7k), and 3-phase electricity is not needed. Larger floor standing units have greater capacity but are more expensive (> c.£8k), and most require a 3-phase power supply that is not available in the current production facility. This automation will allow larger batches to be coated improving mean production rate to an estimated c.12s/piece (c.75% increase in production rate from current baseline). Whichever melter/temperer unit is selected, it should have the option for an enrober belt to be added at a later stage.

Stage 2
The addition of an enrober belt (Figure 4) to the melter unit will remove the need to individually hold and turn each fudge bar/piece in the stream of melted chocolate. The operator will need to place fudge on the infeed, and remove coated pieces/bars from the outfeed and place on the parchment tray for subsequent cooling. These 2 simple pick and place operations are expected to require an estimated 4s/piece (c.425% increase in production rate from current baseline). Costs for enrober belts vary dependent on the base melter unit but a guide price is £3k – £6k. The tuneable air blower on an enrober unit is also likely assist with reducing the current giveaway on overcoated pieces/bars.

Stage 3
As business grows there is a key decision to be made on how to increase production time available; this could be achieved by employing staff or investment in cobotics to perform the manual handling of fudge to/from the enrobing unit. Using a cobot would not in itself increase rate of production over stage 2, but would free up the single staff member of Ndulj to perform other duties, avoid the tedious repetitive transfer operations, and postpone the business costs and complexities of employing a first staff member. A layout for this latter option is given in Figure 5.
A trolley rack of cooled, uncoated fudge would be placed on infeed side of the enrober with a location for a tray in front. A similar arrangement of empty trays in a trolley rack would be located on the outfeed side of the enrober. The cobot would take a tray of fudge from the infeed trolley and place it at the infeed tray location, and an empty tray from the outfeed trolley at the outfeed tray location. A gripper (soft finger, or maybe pin gripper) would sequentially pick and place fudge bars/pieces to the enrober infeed, and remove coated bars from the outfeed. The regimented layout of cooled fudge in the infeed tray would likely reduce sensing requirements for enrober feeding, although practical trials would be required to confirm. When the outfeed tray was filled with coated bars/pieces, it would be replaced in the outfeed rack and a fresh empty tray collected.
It is estimated that the cobotic cell option would have a production rate similar to stage 2 (4s/piece) but would operate autonomously allowing the operator time requirements to be substantially reduced. Estimated cobot system costs £25k – 35k.


To date (November 2021) a simple low capital cost set of guide rollers and rails has been purchased to more reliably align the labels to the tubes in the manual label application process. This has approximately doubled the tube labelling rate from c.2minutes/tube to 1 minute/tube and improved the reject rate from 40-50% to <10%.
Further steps will be reviewed and implemented as time progresses and the enterprise grows. Business growth will be both the driver and financial enabler for adoption of further automation including co/robotic cells.
The main opportunity for cobotics at Ndulj occurs later in the automation roadmap to remove the tedious and repetitive fudge handling to and from the enrobing belt that were manually loaded and unloaded in earlier automated process configurations.


Impact of COTEMACO support on the Business

The key benefits of automating for Ndulj are in the reduction of time spent producing the product. In such a small organisation, time is valuable and any less time used in production can be spent on sales and marketing – the key enabler for business growth. Not only is the extra time valuable to the business, a tedious repetitive task is removed giving a more satisfying and stimulating production staff experience.
Phil Bushell, founder and MD of Ndulj commented on the engagement with COTEMACO programme:
“The improvements from the recommendations in this report have so far been very beneficial to the production process. The future benefits in product making and coating will come as we progress to the enrober and possibly a cobot and this is exciting for the business and will support our growth expectations.“

How could COTEMACO support you?

Via the SME support programme, COTEMACO engages with SMEs from the automotive and food sectors through field labs. These regional field labs in the UK, the Netherlands, Belgium and Germany are showcasing key production steps in the automotive and food industries, in order to tackle current low sectorial awareness and knowledge gaps. The field labs will exchange knowledge on different manufacturing tasks, such as handling and (un)loading.
With the COTEMACO programme, manufacturing SMEs are guided through the process of adopting collaborative robotic and shop floor digitalisation technologies, from the exploration of technological opportunities to the detailed definition of a business plan.