Detailed description

The HV series of new HESTA automatic blow moulding machines is designed for small hollow bodies and small batch sizes as well. Short changeover times are achieved thanks to the quick-change system for the blow mould and the simple replacement of the screw and extrusion head. Due to its small footprint, multiple machines can easily be set up side by side, allowing virgin material feed as well as hollow body and waste removal to be automated conveniently and efficiently.

Economic features:

• High production output
• Precise and reliable operation
• Low acquisition and operating costs
• Low investment costs for blow moulds
• Use of HS moulds, HS crossheads, and HS screws
• Simple operation and maintenance
• Quick changeover of blow moulds
• Clean separation and safe removal of flash
• Material savings through the use of wall thickness control
• Small and large batch production through expansion into production lines
• Trouble-free processing of all thermoplastics, including PVC, powder, or granulate
• Long service life through the use of proven components and high-quality materials

Technical features:

• Compact and service-friendly machine design, narrow front side for installation in production lines, minimal footprint of only about 2 sq m
• Vertical extruder with inline extrusion head makes processing thermally sensitive plastics significantly easier compared to diversion or crosshead dies
• Sophisticated machine design incorporating many years of experience
• Electric crank drives for the complete machine offer:

1. for the mould clamping system: rapid movements, high clamping force, and finely adjustable clamping deceleration;
2. during the blowing process: precise formation of calibrated bottle necks and high calibration force;
3. high economic efficiency and operational reliability

• The unique extruder drive is not only energy-efficient but is driven by four individual motors. This enables the easy replacement of a single motor, and also allows emergency operation or operation at reduced power while a single motor is being repaired.
• Control cabinet with a clear layout and easy access to all parts
• Easy accessibility to the mould clamping system, extrusion head, and calibration unit reduces changeover times
• Shortest distances between the extruder and the blow moulding station, as well as during mould clamping, result in minimal dead times and maximum cycle rates
• A photocell monitors the parison length and feeds deviations into the wall thickness control system. The photocell can also be used without wall thickness control, especially for very long and heavy parisons, ensuring precise parison lengths in a fully automatic work cycle.

The vertical extruder:

The vertical extruder with an in-line extrusion head ensures optimal material flow without deflection, excellent accessibility, and a minimal footprint. The extruder can be easily adjusted across all 3 axes, allowing for a reliable material feed of all blow-molding-grade thermoplastics from the hopper to the extruder via a steep-angled connecting pipe. The raw material, in powder or pellet form with or without regrind admixture, is safely fed into the extruder. This ensures a consistent material intake by the screw, while screw-on mixing or shearing elements for screws to optimize homogeneity and dispersion of specific thermoplastics round out the portfolio. The integration of an automatic screw speed control keeps the cycle constant. Optionally, 20D extruders with a diameter of 36 or 45 mm can be utilized. A photocell determines the parison length. For PE processing, a screw with a mixing section is used. For PVC processing, screws with internal cooling and a cooling fan are employed on the extruder. The unique extruder drive is not only energy-efficient but also powered by four individual motors. This allows for the simple replacement of a single motor, while also enabling emergency operation or reduced-power operation while a single motor is being serviced.

Parison heads:

The parison heads are equipped with double-web mandrel holders for processing thermally sensitive materials (PVC) or highly transparent materials (PETG), and with offset-web mandrel holders for flow-demanding polyolefins. Single, dual, triple, and quadruple parison heads are available, including versions with die adjustment mechanisms. Vario parison heads for view stripes or DeCo2 complete the concept.

Parison cutter:

For cutting the parison, cold and hot cutting systems are available; these are pneumatically driven, but can also be upgraded with our unique Electric High-Speed Knife. Operating at speeds of up to 12 m/s, this knife cuts the parison before it experiences any drag, thereby minimizing parison curling to the greatest possible extent. The portfolio is rounded off by our parison closing and cutting unit with controlled blow-back air.

Blow heads:

Calibration is performed electrically using a maintenance-free crank mechanism with 13 kN of calibration force. The universal blow head is securely guided on both sides; the patented calibration cushion ensures simple 0-point calibration of the blow pin height relative to the pinch-off edge in the mold, as well as a reproducible set calibration force in every cycle. Adjusting the blow pin height and centering the blow pins relative to the mold opening is very straightforward. The blow pins can be water-cooled right up to the tip. It is also possible to provide angular calibration.

The clamping system:

The open C-frame clamping system with two lower tie bars features a steplessly adjustable clamping force of up to 27 kN and is likewise driven by a maintenance-free crank mechanism, alongside an adjustable mold opening stroke. The tie bars are not subject to bending stress, which ensures precise guidance of the platen; a unique feature is the return of the cooling water through the tie bars themselves. The patented clamping cushion allows you to fully automatically calibrate the mold thickness within ± 5 mm, and the clamping force can also be optimally adjusted to your article in set-up mode. Human setup errors are ruled out with the new HESTA. Should the machine detect even a minimal deviation during production, it immediately performs an automatic set-up and adjusts the clamping force. The blow mold is freely accessible. The lightweight design results in low mass and consequently short cycle times. Two separate cooling circuits are available in each platen, with the integrated cooling circuit connection passing through the platens, which not only makes a major contribution to quick mold changes but also prevents incorrect connections.

Directed transfer:

The blown articles are removed from the blow pin by masks attached directly to the blow mold and transferred to a single plane at the subsequent station, eliminating the need for alignment and setup and drastically reducing changeover times. Double masks can be used to serve an additional subsequent station (e.g., for leak testing). This transport process provides efficient cooling of the hollow bodies and increases output performance. Neck and bottom flash, as well as handle scrap, are removed using pneumatic punching cylinders.

Electric drives and pneumatics:

Energy-efficient servo drives power the extrusion unit, the shifting and clamping movements, as well as the calibration unit. The associated Beckhoff servo drives always represent the latest generation, enabling economical production through optimal adjustment of energy consumption to machine utilization. The pneumatics control the blowing, cooling, transfer, punching, and ejection functions using proven, sophisticated components. The standard pneumatic valves are arranged in a service-friendly manner on a central base plate.

Control cabinet & control system:

The electrical control cabinet is vibration-damped, easily accessible, and mounted on the machine in a service-friendly manner. The programmable logic controller with a front-mounted panel meets the highest standards of reproducibility—simple, secure, and clearly structured. It allows for the individual input of all setpoints for motion sequences, heating, and wall thickness control, as well as the integrated bottle tester. An internal background memory facilitates setpoint optimization. All inputs and error messages are displayed in plain text. The warning and monitoring systems included in the standard equipment monitor the entire machine process. In the basic version, four authorization levels prevent unauthorized inputs, and personalized login can optionally be activated. Inputs and all error messages are logged for process traceability. Two monitor sizes are available depending on the machine type for ease of operation. The colored 12-inch and 21-inch touch panels are directly connected to the Windows-based modular control system. Any number of setpoint datasets can be stored in the internal memory or conveniently transferred to an external storage medium via a USB port. This shortens changeover times—especially for small batch sizes—and increases cost-effectiveness. All common languages can be switched quickly and easily. Preparation for online service is a matter of course for us and can be easily implemented using pre-installed software.

Auxiliary equipment:

Auxiliary equipment completes the HV range:

• Electronic wall thickness control with a maintenance-free crank drive allows the wall thickness to be preprogrammed across the entire parison length using 100 points, with the timing sequence automatically adapting to the cycle time of the extrusion blow molding machine.
• The fully automated production of wide-neck containers is carried out using circular cutters with an optionally electrically or pneumatically actuated, revolving knife to remove the flash outside the mold in the trimming station, with horizontal or vertical cutting possible.
• The fully integrated bottle tester is used for leak testing and neck inspection. This can optionally be expanded with a neck passage inspection. Defective items are thus prevented from being passed on and drop directly onto the flash scrap conveyor. Since 100% tested bottles are discharged from the machine, customer complaints about leaking bottles are a thing of the past.

new HESTA blow moulding solutions GmbH & Co. KG

Address

Werrenwiesenstraße 89
D-73525 Schwäbisch Gmünd

Email

info@hesta.de

support@hesta.de

Telephone & Fax

Tel. +49 (0) 71 71 / 99 790 – 0
Fax +49 (0) 71 71 / 99 790 – 13

Daniel Knabel

Deputy Management, Technical Director, Key Account

Telephone +49 (0) 71 71 / 99 790 – 10
knabel[at]hesta.de