Lower unit costs, higher productivity, better accuracy!
JKZ BUČOVICE Inc. based in Bucovice, Czech Republic, started operating in 2000, taking over part of the business from its parent company RS Z (founded in 1995) and specialising in machining, purchasing and selling of tool steel. Within a decade the company almost doubled in size and took over all business activities of its parent company and began expanding into production activities, mainly separation and production of various kind of industrial, specialised and structural steel e.g. Toolox 33 and Toolox 44 and HP1.
As, Ing. Jindřich Žižlavský, the owner and CFO of JKZ states:
"Our company provides tool and construction steel in first-class global quality and is one of the 5 largest companies in Europe, in this segment. We are expanding our portfolio in small and medium sized competitive parts’ production. Our customers insist on short delivery time and high quality.”
Currently, JKZ Bučovice caters to a diverse base of customers engaged in manufacturing instruments, tools and moulds from a wide range of industries including automotive, aerospace and die and mould. JKZ specialises in services like 3 and 5-axis machining and drilling as a job shopper as well as in producing semi-finished goods such as mould frames, different mould segments etc. involving other post-processes at the customer’s site such as die-casting, forging, plastic injection moulding, pressure die-casting of aluminium etc. The weight of the semi-finished goods can range from a few grams to 36 tons.
Higher productivity and better accuracy
In 2015, JKZ bought their first Makino machining centres – an a61nx and an a81nx. The main purpose of this investment was to find a compact machining centre, mainly for production of small to medium sized mould frames and other mould segments.
The outlining criterion was to acquire the right compact high-speed machining (HSM) centre with a pallet changer, without requiring a floor foundation. The goal was to increase production capacity and efficiency. Being in a highly competitive market, the mould and die makers increasingly find the need to reduce lead times and production costs to meet the requirements of their customers.
A substantial amount of value is added in the machining process, as large volumes of metal are generally removed and the finished product must meet strict tolerance requirements regarding surface roughness, geometric and dimensional accuracy. This must be achieved within the constraints of short lead times and competitive pricing. As such, the use of HSM for the production of moulds and dies is becoming more widespread. Significant advantages of HSM are high material removal rates, good surface finish since high cutting speed avoids built-up edges, low cutting forces and minimal workpiece distortion.
As the Head of application department, Mr. David Dluhoš recalls: We performed several test-cuts on different machines and after a stringent process we chose the Makino machines – they have the best spindle in the market. We even tested with a 160 mm end mill, the Makino machine could not produce 2 mm chips, but even this result was good as the other competing machines didn’t even budge – they already had vibration issues with a 100 mm end mill.”
With the installation of the Makino a61nx and a81nx the process was improved manifold, in terms of efficiency and capacity. The biggest improvement was in the lead time, the production of easier mould frames were more than 60% faster and it was possible to achieve accuracy between 0.01 to 0.02 mm. With the structural rigidity of the machines and the spindles it was possible to complete the entire process from roughing to finishing on the machine. This eliminated the need for any off-line operations, drastically reducing the overall machining time. Additionally, the second pallet for external setup further reduced the non-cutting time. The end product had the desired surface quality and optimum accuracy.
As Mr. Dluhoš went on to explain further:
"The Makino machines are structurally and mechanically very rigid. The 10,000 rpm spindle has the power and rigidity required for highly hardened and tempered steel. Drills up to 80 mm and cutter heads up to 125 mm in diameter can be set up easily and offer the excellent interplay of spindle, roller linear guides and high mechanical rigidity at high feed rates. The a81nx has a good working area, which utilises the entire Y-axis travel. On top, the coolant management and chip evacuation system is also very good. We have not faced any problem due to chip accumulation, and I am talking about 3-shift operations. Initially we had a little difficulty with the Makino controller as we were used to Heidenhain but after a couple of training sessions it became quite easy to operate.”