Hennecke GmbH - machines and plants for polyurethane processing

Hennecke GmbH - machines and plants for polyurethane processing

A head of its time - superior mixhead technology
Whether it's in automotive components, furniture or re-frigerated appliances - wherever polyurethane is pro-cessed, our mixheads are being used. They exert a key influence on the cost-effectiveness and quality of PU parts.

Constant high quality through in-house production
Each mixhead made by Hennecke re-ceives an individual identification or machine number. Based on this number and a specially compiled set of records, we can track all major pro-

duction, application and maintenance data for a given mixhead at any time. Maximum care is exercised right from the incoming goods inspection stage: high-grade tool steels for our mixhead housings are first subjected to a chemical analysis using advanced spectrometry before being released for production.

Only when the housing blank has passed this test, it can proceed to the so-called machining centre. Here it undergoes all relevant machining operations including the generation
of control piston, injector, ejector or transverse piston bores, using pre-

cision tools in a state-of-the-art automatic turning and milling machine. Depending on the mixhead type, this may involve the use of up to 100 different tools, all of which are changed automatically. Machining is perfor-med from five sides so that the housing blanks need to be fixed only once; imprecisions due to repeated clamp-ing and unclamping operations are thus eliminated from the outset. At the next level, a series of finishing steps are performed. Various precision machining me-thods such as honing, cylindrical grinding and eroding are employed to give each bore its specific shape. Sub-sequent surface-finishing provides the necessary wear resistance for the housing's service under tough day-to-day manufacturing conditions.

Made to measure
At a measuring centre designed spe-cifically for quality assurance, the mix-head housings are now meticulously gauged. A computer-controlled three-coordinate gauging device verifies all major dimensions as well as the

shape, position and size of each borehole. The results of these precise measurements are documented in a measuring record. Only when a housing has met all quality criteria, it will be released to enter the assembly line.

A no less stringent process is ap-plied to bushes, cylinders, throttles and transverse pistons. These mixhead add-on parts are likewise manufactured on advanced high-precision machines to stringent quality standards.

Test run
Before the mixhead goes into our warehouse it must pass a rigo-rous individual test under near-field operating conditions. All func-tions and its seal-tightness are ex-tensively tested on a specific test

rig. The results are documented.
After-sales service Although Hennecke mixheads have been known to perform millions of shots without malfunctioning, they are subject to normal wear and tear and will therefore require periodic maintenance and occasional overhaul. To this end, Hennecke provides its customers with extensive support, e.g.

fast assistance by our assembly department in the event of a technical problem

special maintenance staff and operator training programs

regular inspections (check-ups) of mixheads in use

mixhead hire service to bridge downtimes for maintenance or repairs

Hennecke specialists bring maximum care and all their competence to the task of inspecting and re-pairing mixheads returned to the factory. Each mix-head is cleaned, fully dismantled and thoroughly dimension-scanned. A professional check-up or repair of this kind will usually pay off since it can greatly prolong the mixhead's service life, thus hel-ping to avoid a premature replacement. In addition, Hennecke keeps investing significant sums into the enhancement and improvement of its mixhead tech-nologies and the equipment and inspection pro-cesses employed in our mixhead production. Our range comprises proven mixhead designs for any application, from the standard to highly special uses. Variable sizes and injector types, plus an extensive line-up of accessories, allow us to adapt these units to virtually any application.

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