Originally Published EMDM January 2006
Equipment News
Recent developments in moulding equipment
Balloon-forming machine supports radially opening moulds
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B alloons suitable for angioplasty, stent delivery, and other dilation and occlusion applications can be produced using a computerized machine. The “Clam Shell” balloon forming machine, Model CS2210H from Interface Associates (Laguna Niguel, CA, USA), uses two-piece radially opening moulds to produce balloons ranging in size from 1.0 to 20.0 mm in diameter and 1.0 to 250.0 mm in length. The machine can process a variety of materials, including PE, PVC, polyurethanes, polyamides (nylon, Pebax),
and PET to form balloons using extruded-polymer tubing materials.
The metal mould is split into symmetrical halves so that mould opening and closing is perpendicular to the long axis of the balloon. A large pneumatic cylinder controls these operations with precision ball-bearing guides. Unlike conventional three-piece moulds, the machine’s mould cavity is fully exposed and can be coated with a layer of Teflon. The formation of the balloon inside the metal mould is driven by high-pressure gas that is introduced inside the stretched and heated section of the balloon tubing. The machine uses a high-speed, high-pressure digital module to control gas pressure and gas flow into the balloon. This approach allows for multiple pressure levels to be used during different parts of the balloon-forming cycle.
An industrial-grade computer controls all the functions of the machine. Real-time data output of all process parameters is available via an RS-232 data port. A touch screen integrates input, control, and display of all parameters. The operator can enter new parameters, manually activate individual machine functions during testing or trial runs, perform machine calibration, set limits, configure new balloon forming sequences, recall complete programs from the machine’s internal memory, and upload or download programs to or from an external PC.
Production management tool goes wireless
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An injection moulding production management system can now interface with WiFi-enabled machine-interface units. The Celltrack system from Moldflow Corp. (Hürth-Efferen, Germany) can be attached to virtually any piece of equipment used for discrete manufacturing without a hard-wired Ethernet or serial network connection. The wireless capability of the machine-interface units increases flexibility and mobility of equipment placement on the factory floor. By reducing the need for hard-wire routing, WiFi-capability can simplify and reduce installation costs. Because the units continue to support serial and Ethernet networking options, a mixture of the three protocols is possible.
Suitable for injection moulding machines and cutting, stamping, welding, and other cyclical operations, the system can provide efficiency, accurate predictions of job completion, and production data analysis. Work orders, job scheduling, mould and machine maintenance tracking, labelling, and statistical quality control and statistical process control functions can be managed with the system.
Machine-interface units are available in two models. The compact MIU 01 includes dedicated input and output units, which provide automatic, real-time data acquisition when connected to cyclical manufacturing equipment. Each unit can monitor up to eight machines in a work cell. The MIU 02 is similar to the MIU 01, but is specifically designed for manual data acquisition. The unit can also be used for statistical quality control operations. Both systems can be connected to third-party devices, such as scales, gauges, and bar code readers, and support English, French, Spanish, Italian, and German.
System monitors screw and barrel wear
Screw and barrel wear can be monitored without interrupting production by means of a SmartBarrel system. Developed by Glycon Corp. (Tecumseh, MI, USA), the system includes digital indicators that can be inserted through ports in the extruder or injection-unit barrel to measure screw-flight dimensions. Plugs seal the ports during normal processing and indicate barrel liner wear.
For installation, monitoring ports are drilled in the barrel where wear is anticipated. Plugs that are machined from material similar to the barrel are installed in the holes. After the barrel liner is honed to its finished dimensions, the plug ends will be perfectly flush with the barrel ID. A plasticating unit is installed on the machine and baseline measurements are taken before production begins. The plugs are removed from the barrel and a digital indicating fixture is mounted over each hole to measure the distance to the flight surface. In addition, all the plugs are placed in a fixture that takes a baseline reading of their dimensions.
Once the critical baseline measurements of the screw and barrel plugs are recorded, production can begin. Measurements can be taken in a matter of minutes with the machine near processing temperature. Subsequent measurements can be made at a frequency appropriate for the amount of expected wear. By correlating wear measurements with process data, the processor can determine when wear of the barrel liner has reached a critical point.
All-electric injection moulding machine provides increased clamping force
A clamping force of 1800 kN is the highest offered by a company’s line of all-electric injection moulding machines. The Elektra evolution 180-2F from Ferromatik Milacron (Malterdingen, Germany) is the latest in a series of all-electric machines that previously offered 300 to 1550 kN of clamping force. The amount of force, combined with 630 × 630 mm of tiebar space for moulds and periphery, makes the machine suitable for high-volume production and the installation of large moulds. Multicircuit cooling technology contributes to short cycle times, especially for fast-running applications with multiple cavities.
The 180-2F has a vertical injection unit that feeds a rotating mould with a servoelectrically driven turntable. Control of the turntable is completely integrated in the machine’s electronics and configurable via the machine’s panel. Reportedly easy to use, the touch screen panel is MOSAIC-based. The electric drive of the rotary plate is incorporated in the machine controls and controlled from the machine’s operator terminal.
Designed to be versatile, the machine can process two colours and use multiple-component moulds with hydraulic functions. A range of options and peripheral equipment can be accommodated. The machine offers a range of injection units from international sizes 55 to 630 and can be equipped with a hydraulic core-pull module.
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