Better 3D prints, by design

In an exclusive chat with the directors of 3D printing specialist Inventex, Technical Editor Steed Webzell learns about the expansive opportunities that arrive with a bespoke design service

Darren and Jo Howton are the directors and founders of Inventex and its sister company The 3D Printers, both based in Kent. While The 3D Printers offers a UK-wide 3D printing service for products, parts, prototypes and models, the launch of Inventex with its in-house design service delivers a whole new take on the possibilities available with this innovative manufacturing process.

“Today, the most successful part of our business is undoubtedly bespoke design,” says Jo Howton. “For example, we work closely with a major online retailer, helping them solve ‘pain points’ during refits at their warehouse and distribution centres. A recent product we designed – a robust, easy-to-assemble retrofit racking clip with locking mechanism – saved the customer £500,000 across its facilities in 2023 because of the previous breakages that our solution eliminated.”

Designs on success

The success of any 3D printed part clearly hinges on its design. And design for additive processes differs to that for other types of manufacture.

“We sometimes have customers who want to replace an injection moulded part with a 3D-printed equivalent,” says Darren Howton, a man with more than two decades of experience in 3D printing design and manufacture. “When preparing the drawing they tend to copy the same features, including a rake/draft angle for injection moulding, which is not required for 3D printing. Many also design nice radiused edges, which is lovely from an aesthetic perspective but doesn’t add anything to the part’s performance. So why not save some money by having a 45° edge instead of a radius. The aesthetic will be almost the same, but more importantly the print job will be faster, cleaner and cheaper.”

3D printing today embraces a wide range of engineering-grade polymers. By way of example, Inventex can process PLA (polylactic acid), PETG (Polyethylene terephthalate glycol), PC (polycarbonate), ASA (acrylonitrile styrene acrylate), flexibles and more. The company can also produce PLA, PC, PETG and nylon infused with carbon fibres if required for extra strength.

 Get the green light

“3D printing is fast, often uses plant-based materials, offers nearly zero waste, and we manufacture here in the UK to minimise carbon footprint,” says Jo. “We have sustainability at our core: we use recycled materials and actively recycle waste [upgrade items rescued from landfills] as part of an eco-conscious approach.”

A large proportion of the company’s printing is FDM [fused deposition modelling], which builds objects layer by layer by feeding a spool of thermoplastic filament into the machine. The printer’s head extrudes melted material in thin strands, depositing them with precision, layer by layer, over a map of XYZ co-ordinates set out by the design. Once in place, the material cools using integral fans and solidifies. Also available is resin printing in its various forms, including SLS [selective laser sintering) and SLA [stereolithography].

“Before we started this business, SLS and resin printing were around 90% of the industry because of its print quality,” explains Darren. “It offered an almost perfect copy of ABS [acrylonitrile butadiene styrene] and PA12 nylon, for example. FDM could not offer the same. However, filament has improved massively, today negating those issues. FDM machines also are much faster and produce cleaner, crisper parts. As a result, the gap between resin printers and FDM printers has closed significantly, yet the cost of FDM is vastly cheaper, while also being far more eco-friendly. Resin printing remains a mucky, rather dirty process.”

3D printing comes clean

To ensure the ongoing quality of parts produced at Inventex, the company is extremely strict about machine maintenance, to a level where its 3D printers still look new. Even those with thousands of hours on the clock.

“As a process, many think 3D printing is still a little rough around the edges, but you’d think the parts we produce were injection moulded,” reveals Jo. “We try very hard to design parts in such a way to minimise any extra finishing, saving both time and money for the customer.”

She adds: “Although more industries are coming on board with 3D printing, it remains a grey area for some, which is frustrating,” she says. “However, we find that once a customer tries 3D printing for the first time, they wonder why they hadn’t done so before.”

Part of the problem is that a little knowledge can sometimes be a bad thing, particularly with the advent of extremely cheap, hobbyist style 3D printers.

“You can buy a 3D printer from a budget supermarket for less than £90,” says Darren. “That won’t even cover a replacement fan on our machines. Cheap machines in combination with a little knowledge learnt on YouTube typically results in the world’s worst 3D-printed parts. That idea of 3D printing is very far removed from the professional arena in which we operate.”

Educate to accumulate

Jo is also keen to educate industry and enhance the image of additive manufacturing processes: “Some still see 3D printing as a quick fix to something, and continue to place way more trust in traditional subtractive processes. But that’s a misconception. We make fully engineered, high-quality end-use parts. It’s not just about prototyping anymore. We’re happy to demonstrate the quality of 3D-printed parts to anyone.”

Although 3D printing offers unparalleled design freedom and agility, if the process is genuinely not the optimal solution for the part, Inventex will help the customer to make it using other manufacturing techniques that include CNC machining, injection moulding, casting, laser cutting or fabrication.

As a problem-solver, Inventex is not about telling customers what can’t be done, but what can be done and how the company is able to optimise the designs of 3D-printed components to drive efficiencies and save money. Typically, this forms part of a proven four-part process: planning, CAD model creation, prototyping and production – prioritising client-centric preferences throughout.

Concludes Darren: “If you can think it, we can design it and we can make it, whether you need one or thousands.”