Renlaw – Africa’s leading manufacturer of industrial cutting tools

The industry of consumer packaging, generally speaking, may be full of consumable items, but the process of raw material sourcing, designing, engineering and finishing of components for OEM manufacturing processing lines, are often closely guarded secrets.

For most manufacturers, an industrial blade is a consumable. For Renlaw, it is an engineered component that can influence machine uptime, product quality and the cost of production. Established in 1985, the Retreat, Cape Town-based company has built its business around the manufacture, supply and resharpening of industrial cutting tools.

Renlaw make use of a number of surface grinders for providing finishes to components

Renlaw’s tooling solutions serve an array of applications ranging from metalworking and automotive production to food processing, packaging, paper converting, plastics and recycling. From its Cape Town factory, with sales operations serving Gauteng and KwaZulu-Natal and Southern African customers supplied from the Cape Town head office, Renlaw’s approach is based on engineering the cutting tool around the application rather than simply supplying a replacement blade, explains Mikko Brunner, a Mechanical Engineer by trade and very hands-on Managing Director.

“My father Walter Brunner started the business over 40 years ago and we used to manufacture milling tools and special profile cutters as well as service the sharpening side of that industry. We decided to change course and found ourselves a new niche in the manufacturing of food production and packaging blades,” continued Brunner.

The company’s range of equipment includes in-house built drills and presses

“We’ve designed and built several of our own CNC machines over the years as well as redesigned and retrofitted our 5-axis Saacke CNC tool and cutter grinder. Essentially these are our tooth and profile grinding machines, for which we have also developed our own in-house software for. This has enabled us to freely programme these machines for manufacturing very specialised blades.”

“But this business wouldn’t be what it is without my fantastic team,” says Brunner.

Jerome Williams, Renlaw’s Production Manager, has been involved in the metalworking and print industries since he left school 20 years ago. After working as a machine operator for a number of years, he joined Renlaw in 2013. Initially working as an operator, Williams progressed his way through the business to become the Production Manager. Having completed several courses, and the companies “FastTrack” training programme, Jerome brings a tangible passion and in-depth knowledge to the blade manufacturing and sharpening business.

Renlaw have recently invested in their second Mitsubishi wirecut electrical discharge machine (EDM), the MV2400S. As standard, it is a high-precision, 4-axis CNC system designed for tight-tolerance component manufacturing and die and mould production. Operated in a temperature-controlled environment, this machine uses tubular, contact free motor technology to cut components to extremely high accuracies. The Renlaw team have incorporated EDM wirecut machines into production processes, and are highly skilled at fine tuning them to get the high accuracies demanded by their customers. Renlaw’s other EDM is a Mitsubishi MV1200S, designed for tool-and-die component manufacturing, as well as punch manufacturing. Both of Renlaw’s EDM machines were supplied by WD Hearn Machine Tools

“Our specialised, advanced setup has helped redirect operational efficiencies away from declining industries such as the manufacturing and resharpening of milling tools and blades for the local shock absorber and catalytic converter industries,” explained Williams. “We were able to diversify our range, and my role now not only encompasses managing the operators, but I also know exactly how every machine we have on the shop floor works – how to programme them and how to run them. I am by no means the most experienced operator at Renlaw – some of the experience we have here when it comes to highly specialised grinding goes back decades, and that knowledge is something that really sets us apart.”

“Mikko’s decision to change the direction of the business and diversify our product offering has been a real highlight of my time working here. It’s enabled me to gain a lot of experience by manufacturing highly specialised tooling, some of it with tolerances in the +/-0.0025mm range. I work with a management team that have become really close-knit as a result of being designated essential workers during Covid. There were just a few of us working the shop floor during that time and we all came together to get production done and push out components,” said Williams.

In-house capabilities include an EDM drill which can rapidly drill small holes through hard steel and tungsten carbide, even in the range of 1mm in diameter x 300mm deep

Clint Arendse, Renlaw’s Technical Operations Manager, joined Renlaw in 2019. “Mikko brought me into the business to help with some of the more technical aspects of streamlining operations and bringing about leaner manufacturing processes. At the time, we had just adopted a new material requirement planning software package. This was right before the pandemic began and so when we entered that Covid phase it gave me the time and capacity to start rolling out the software, which is very modular, and I was able to implement very specific stock management and process controls as well as quoting systems,” says Arendse.

“I have also begun to spearhead new operations within the company as we started to bring some of our previously outsourced operations in-house such as our laser-welding, wire cutting and fiber laser cutting. Essentially my role has progressed from assisting Mikko with technical operations to one where I am helping to consolidate the overall operation of the business. We have grown very quickly in a short period of time, and this has also allowed me the opportunity to be exposed to a number of different technologies in manufacturing,” continued Arendse.

Precision surface grinding forms a fundamental part of Renlaw’s manufacturing operations

“Without saying too much, we currently have a couple of machines on the water that will further add to our production processes and help to improve efficiencies for our ready-made meal packaging components that we manufacture.”

Renlaw have also recently invested in their second Mitsubishi wirecut electrical discharge machine (EDM), the MV2400S. As standard, it is a high-precision, 4-axis CNC system designed for tight-tolerance component manufacturing and die and mould production. Operated in a temperature-controlled environment, this machine uses tubular, contact free motor technology to cut components to extremely high accuracies. The Renlaw team have incorporated EDM wirecut machines into production processes, and are highly skilled at fine tuning them to get the high accuracies demanded by their customers. This new EDM machine will give Renlaw the capabilities to do things that standard CNC milling and turning just cannot do.

Their other EDM is a Mitsubishi MV1200S, also a high-precision wire EDM machine designed for tool-and-die component manufacturing, as well as punch manufacturing. The latest edition offers a larger working area and will allow Renlaw to accommodate medium to large manufacturing applications. Both machines were supplied by WD Hearn Machine Tools. Renlaw also operates an EDM drill which can rapidly drill small holes through hard steel and tungsten carbide, even in the range of 1mm in diameter x 300mm deep.

The Amada DB-610 is a flat sander and industrial deburring machine used to remove burrs, finish surfaces, and process sheet metal or flat workpieces

Shop floor equipment includes two large CNC rotary grinders as well a number of custom-built multiple axis CNC grinders specifically engineered or retrofitted by Renlaw. Amongst this equipment are conventional grinders, blade grinders, tooth grinders, cylindrical grinders and polishing machines that are able to provide particular finishes to some of the blades. The range of equipment additionally includes in-house built drills and presses as well as laser engraving facilities and a fiber laser. Renlaw also has the ability to do forging and hardening in-house for some of the specialised punches that they manufacture and can manufacture and process blades up to 2.5m in length, with material thicknesses varying from 0.3mm up to 30mm.

As an engineer-led manufacturer, Renlaw’s customers provide drawings, samples or a description of their specific problem and Renlaw’s production team can develop tooling to suit the customers machine, material and cutting process.

Hardening and heat treatment can be performed in-house

This is important in applications where the cutting tool is a small investment when compared to the machine on which it operates but has a direct effect on production and down-time. A blade that loses its edge, produces an inconsistent cut or requires frequent replacement can result in machine stoppages and increased costs per part. Renlaw therefore positions precision, material selection, cutting geometry and resharpening as part of the same production equation.

From sample to cutting tool
A significant part of Renlaw’s manufacturing capability lies in its ability to produce tooling to a customer’s specification. The company works with high-grade tool steels, high-speed steels, stainless steels, tungsten carbide, carbides and ceramics, depending on the application. Cutting geometries, edge configurations, coatings, mounting arrangements and other features can be selected around the operating conditions.

High-pressure coolant and super-abrasive grinding wheels are used for profile cutting

“This is really where we have created a niche for ourselves in the market,” says Arendse. “Often these packaging machines are imported and supplied to our customers with generic blades or tooling that may not be particularly well suited to the product the client is packaging. That’s when we sit down and work closely with the customer to re-engineer a better solution for them that they may not even be able to get outside of South Africa, let alone in South Africa. This allows us a lot of room to innovate not just from a design perspective but likewise from the finishing and coating side. We’ve been able to extend tool life by sometimes up to seven times longer than what may be supplied or available from OEM suppliers that manufacture the packaging line equipment, and customers value this kind of service for obvious reasons.”

Renlaw’s specialised tooling division manufactures products for cutting, slicing, chopping, die cutting, guillotine cutting, press cutting and punching, as well as circular knives and slitting blades. These are manufactured from tool steels or food-safe stainless steels, with different cutting-edge configurations selected according to the application. The range includes dished knives, crush-cut blades, circular knives, bowl chopper blades, perforating blades, slicer blades, scoring and slitting knives, toothed punches, tray knives and much more.

“Some of the experience we have here when it comes to highly specialised grinding goes back decades, and that knowledge is something that really sets us apart.”

Toothed blades are manufactured with different pitches, tooth shapes and spacing, while slots, holes and mounting features can be incorporated to suit individual machines. This capability is particularly relevant to packaging and food processing equipment, where the cutting tool must interface with an existing machine and produce a repeatable cut at production speed.

The company’s punch and die operation extends this capability into highly specialised precision tooling. Renlaw manufactures corner-rounding, piercing, hanger-slot, hole-punching, tear-notch and venting tooling from solid tool steels or high-specification powder-metallurgy steels. Tolerances down to 0.005mm can be achieved.

Renlaw also operates a separate department dedicated to the manufacturing of ferrous-metal cutting saw blades. The operation works with pre-hardened HSS-DMo5 and HSS-Co blanks. CNC saw-toothing machines are used to produce tooth numbers and geometries according to the cut section and material. The company manufactures blades for stainless and mild steel applications and supplies tooling compatible with a range of machines.

Renlaw offers a wide range of grinding solutions

The saw-toothing process uses high-pressure coolant and super-abrasive grinding wheels. The specialised process is intended to control thermal effects while producing the surface finish and tooth geometry required for the application.

Tooth geometry is not a generic specification in metal sawing. Material, section size and machine conditions all influence the selection. A blade designed for one application may not provide the same performance on another. Renlaw’s experience and ability to alter tooth numbers and geometry therefore forms part of its application-engineering approach rather than simply its manufacturing capability.

Food processing demands another approach
Food processing customers represent a substantial part of Renlaw’s business and introduce requirements that differ from those of other metalworking constraints.

Meat processing blades, for example, have to deal with a combination of wear, corrosion, sub-zero temperatures, hygiene and cutting performance. Renlaw manufactures meat processing knives, dicers, cubing blades, tenderisers, bowl choppers and slicing blades using food-grade stainless steels. The company says these blades are machined, hardened and precision-ground, with options including anti-microbial surface finishes and Teflon coatings.

One of the company’s own developments is its range of bowl chopper and slicer blades. Renlaw identified a gap in the South African market for locally manufactured blades for rotary food processing equipment and developed the tooling at its Cape Town factory.

The blades are manufactured from food-safe stainless steels, including 440B and Renlaw’s Rencut steel. The company says Rencut provides a combination of toughness and corrosion resistance. Bowl cutters, slicer blades and involute blades are manufactured in different sizes and configurations, with polished, anti-microbial surface finishes and tempered mounting areas intended to reduce the risk of blade breakage.

Renlaw is Africa’s largest industrial blade and cutting tool manufacturer and has more than 1 000 different blades that they are able to manufacture

The same application-based approach extends to bakery processing. Renlaw manufactures and supplies bun slicers, band knives, VFFS blades, toothed packaging knives, scraper blades, flaker blades, guillotine blades, circular blades and scalloped blades. Food contact tooling is manufactured and finished with the hygiene requirements of the application in mind.

Cutting the converting industry
Paper, tissue, packaging, film and foil represent another group of applications where edge condition and wear have a direct effect on production.

Paper converting can be particularly demanding because paper can contain clay, which is abrasive. Renlaw uses tool steels, high-speed steels and tungsten carbide for these applications and manufactures products including slitters, anvils, perforating blades, tissue knives, top and bottom cutters, crush-cut blades, logsaw blades, guillotine blades, sheeter knives and trimmer knives.

The company’s range of industrial toothed blades are manufactured from high quality tool steels or food safe stainless steels

Film and foil present a different challenge. Thin flexible materials require a controlled cutting edge to prevent tearing and maintain the quality of the finished product. Renlaw’s range includes circular and straight knives, punches, pelletiser blades, shredder and granulator blades, bag-production blades, sheeter and trimmer blades, razor blades and punches and dies.

The company also maintains stock of blades while retaining the ability to manufacture application-specific tooling.

Resharpening as part of the process
Manufacturing the blade is only one part of Renlaw’s business. With sustainability in mind, resharpening is another. Industrial cutting tools can often be returned to service rather than discarded once the cutting edge has deteriorated. Renlaw provides grinding and sharpening services intended to extend tooling life and reduce the frequency and cost of replacement. The company’s production philosophy is to consider the complete life of the cutting tool, from manufacture through sharpening and back into production.

Industrial toothed blades are manufactured from high quality tool steels or food safe stainless steels

The company has also expanded its capabilities through the integration of services previously provided by IMK. These include tooling and grinding solutions for the tannery and leather sector, along with deblading, cleaning, repair and reblading of cylinders using shaving and fleshing blades. Renlaw is also the Southern African supplier of Hardy fleshing and shaving blades.

This broadens the company’s activities beyond conventional machine knives and into tooling for heavy industrial processing too.

Supporting local production
Renlaw’s overall manufacturing model represents a wider requirement within South African industry as a whole: Maintaining local engineering capabilities for components that are critical to production but often overlooked. And not outsourcing manufacturing abroad.

A cutting tool may account for a small proportion of the capital cost of a production line, but its condition can influence the output of the entire line. The ability to manufacture a replacement component locally, modify the geometry, resharpen an existing tool or develop a solution for a particular machine can therefore have an impact beyond the price of the blade itself.

Laser engraving of components is another service offered

Renlaw’s objective is to reduce blade-change stoppages and improve cost per cut by supplying tooling matched to the machine and product. Its factory provides the basis for this model, combining manufacturing with application support, supporting a large range of machinery equipment across a broad spectrum of industries.

Today the company serves industries including automotive, bakery, convenience foods, dairy, film and foil, FMCG, fruit and vegetable processing, meat, medical, metalworking, packaging, paper and converting, plastics, poultry, printing and labelling, recycling, tobacco, and fleshing and tanning.

Operating in these sectors means the value of a cutting tool is ultimately measured at the machine. Edge life, dimensional accuracy, cut quality, changeover time and the ability to return tooling to service all contribute to production cost.

Renlaw’s Clint Arendse, Technical Operations Manager, Mikko Brunner, Managing Director and owner, and Jerome Williams, Production Manager

That is where Renlaw has positioned itself in the market – not simply as a supplier of industrial blades, but as a customer-centric manufacturer that’s able to engineer, produce, sharpen and support the cutting tools that influence a product from when material enters and leaves a production process and where a tool is treated as an engineered component that helps to make up the entire production system.

Renlaw currently employs 30 people and operates from roughly 800m2 of under roof shop floor space.

For further details contact Renlaw on TEL: +27 (0)21 701 7917 or visit https://renlaw.co.za