Machining Equipment Fast-turnaround machining of packaging moulds
Six Hurco 3-axis vertical machining centres carry out a majority of prismatic machining in the toolroom of plastic packaging manufacturer in Beccles, UK. Instead of subcontracting machining jobs, the company is now able to offer the production of bigger multi-cavity moulds, for instance.
Berry M&H designs, develops, produces and prints to British Retail Consortium standards a large range of plastic bottles, jars, tubs, flexible tubes, closures, caps and dispensing systems. The packaging solutions are sold into the personal care, healthcare, pharmaceutical, nutritional, pet care, automotive and household product markets. The company has an extensive range of almost 5000 standard products and also offers bespoke design, prototyping and moulding services. There are manufacturing sites across the UK, mainland Europe, America and Australia. Mr Knights' department produces blow moulds and injection moulds for many of the group's factories across Europe.
Although the history of packaging manufacturer Berry M&H dates back to 1973, the first Hurco machines, a VM10i and a VMX30i, did not arrive until 2015 when the assets of another toolmaking company were acquired, including its machine base. Prior to that, manual knee-type mills in the toolroom were followed by 3-axis CNC milling machines and then a succession of machining centres with automatic tool change. All of the CNC machines were fitted with the same G-code-based brand of control system to provide commonality for the convenience of the staff.
Berry M&H's Beccles toolroom manager Kurt Knights, who has been with the company for over 20 years advised, “When we started using Winmax conversational software in the Hurco control, it made shop floor programming far easier and quicker for our operators — and it also simplified training for new people and our apprentices alike.
Most programs the company prepares take advantage of the Hurco's NC-Merge feature. Complex parts of a cycle for contour-milling 3D mould surfaces are output from either NCG CAM or Solid Works CAD/CAM systems in the design department and the file is imported directly into the control. Conversationally programmed blocks prepared at the machine using Winmax are then automatically merged in the control with the offline content into a single program for milling the block parts of the moulds.
Offline code generation for a mould takes typically ten hours, while the shop floor element is completed in around two hours, faster and more simply than is possible on a machining centre driven by a G-code control. It quickly became apparent that the Hurco/Winmax combination was ideal for Berry M&H's requirements, which centre mainly on fast-turnaround production of moulds from 170 mm wide Alumec 89 billets. Most moulds comprise neck, body and base blocks manufactured from the high strength aluminium alloy, held together by a steel back plate.
Two new Hurco VM5i 3-axis VMCs were purchased for machining these moulds, as well as for new tool development that was formerly the province of the CNC mills, all but one of which have now been sold. The VM5i was chosen as it has a generous 457 x 356 x 356 mm working volume in a compact 1.6 x 2.9 metre footprint. It suited the toolroom space and layout well and was correctly sized for machining the company's moulds. Four halves at a time are fixtured, each of which takes about three hours to machine. The resulting twelve-hour cycle is more than sufficient for a full light-out shift overnight.
As the size and performance of the two VM5i machines were ideal, the decision was taken in 2019 to buy a third, this time for producing items such as printing chucks, bracketry and other general, non-mould items for different departments across the Beccles site. It brought in-house a lot of previously subcontracted milling, delivering considerable financial savings.
In November 2020, a larger Hurco VM30i with a 1,270 x 508 x 508 mm working volume was purchased that Knights described as “a superb machine and excellent value for money”. The investment was down to Berry M&H's decision to move more strongly into the production of bigger moulds up to 700 mm wide and with up to six cavities. Both Alumec 89 and 1.2316 stainless steel are used, the latter as it has good thermal conductivity and wear resistance and is also magnetic, allowing a mould to be clamped conveniently on the bed of a grinding machine. There had always been a requirement for this size of tool and their production was previously subcontracted out, so this expense is now also saved.