Extrusion blow moulding of plastic tubular objects

Normal end products: packaging articles, i. e. bottles, canisters or barrels, technical articles, we. e. ventilation ducts, gaiters (e. g. steering gear gaiters and axle boot styles), suitcase hulls, luggage racks or gasoline tanks, huge children¡¯s playthings (e. g. push-powered cars or Bobby-Car?)

Standard materials: PE, PP, PMMA, PC, PA, ABS, PLA, TPU, colour masterbatch

Typical throughputs: 300-1000 kg/h

Process description

In the extrusion blow moulding course, thermoplastic colour and resins masterbatch granules are combined at the consumption of an individual screw extruder. The thermoplastic resins generally emerge from silos while the color masterbatch granules come out of containers on the device pedestal. Flash from blow moulding development is ground directly at the device and the regrind is undoubtedly directed from the grinder over a cyclone and blown into a buffer container. All three pieces (thermoplast, colour masterbatch and and regrind) happen to be extrusion screw dosed respectively through a dosing axle of the GRAVICOLOR (gain-in-weight). Scrap centrally is normally reground, in some cases it afterwards is regranulated. This materials is fed back to the buffer container through a hopper loader and reintroduced into the process.

As a result of high throughputs found in the blow moulding procedure it makes sense to have a central vacuum program when several machines are participating. In a vaccum range system, the air volume of the conveying blower in addition to the vacuum tubing happen to be calculated so that only one hopper loader can convey at the same time. Therefore the proportion of blowers to the number of conveying products in the line must be chosen in order that every level of consumption is supplied with sufficient material at all times. In a central vacuum system several hopper loaders are capable of feeding simultaneously per series or within the complete system. Through the adjustable allocation, output should not be reserved which outcomes in considerable energy savings. The parallel-managed pumps will shut off automatically (pressure controlled) depending on atmosphere requirements. Since total vacuum exists at all time and doesn't have to be built up after a run-on period as in lines, higher throughput rates can be attained.

In the extrusion blow moulding program, a hose is generated through a mould at the final end of the extruder. The hose is cut to fed and length to the ultimate blow moulded product for further processing.

Customer benefits

Adaptable operation through modular designReduction of downtimes at materials changes through intuitive handling (spring catches, etc.)High-grade (digital) load cell technology secures better recipe integrity due to a very short reaction time in recipe and/or throughput changes. In addition, the time-consuming process of sampling and calibrating the machine is without question omittedAcquisition of the usage data ¡ú precise bill of expenses and stockkeeping possibleVery precise control of the entire process (start-up phase, recipe change, fast and continuous adjustment of production capacities), automatic start-up procedure through integration of upstream controlExpertise in process engineering and process-oriented general know-how creates motan-colortronic the ideal partner for you

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