Thermoset resins are the material of choice for many engine compartment components. Among their outstanding properties are dimensional stability, chemical resistance (eg, to brake fluid, gear oil and fuel) and temperature stability. In addition, the components can be produced at relatively low cost. Processes and machines for manufacturing brake pistons from thermosets reached market maturity several years ago. They gained swift acceptance and today competition is exerting marked pressure on prices. Baumgarten decided to counter this development by increasing the cavity count to maximize productivity and reduce unit manufacturing costs. KraussMaffei experts developed the SP 3000, a larger plasticizing unit for freeflowing thermosets, and adapted the unit to operate on an all-hydraulic CX injection moulding machine. Baumgarten can now operate with shot weights up to 1400 grams.
Manufacturing high-quality brake pistons from thermosets with a high mineral filler content is a challenge. A 350 tonne KM 350-3000 CX DUR machine is fitted with the newly developed 80 mm diameter screw enabling it to plasticize larger volumes and deliver higher shot weights. In combination with the machine's precision closed loop control system, the special screw design plays a role in keeping shot weights constant and compensates for batch variations inherent in the manufacturing process. The screw's outstanding wear resistance is achieved through a powder metallurgy (PM) process. This type of PM screw has around three times the wear resistance and hardness of conventional steel screws. It ensures that processing conditions remain constant for long periods of time and guarantees extremely stable processes and consistent product quality.
KraussMaffei's CX series machines offer all the features necessary for reliable, cost-competitive thermoset processing. The construction of the two-platen clamp unit with precision guides for the moving platen guarantees 100% platen parallelism and optimal support. The highly reliable, precision-controlled hydraulic system ensures absolutely repeatable processing over long production runs. This is of the greatest importance in the production of components such as brake pistons where highest precision and consistent quality are of the utmost importance.
Easy, unimpeded access to the mould zone of a CX machine cuts set-up and adjustment times, resulting in a noticeable improvement to machine uptime. Precise and responsive mould locking protects against damage to the mould. CX machines can be rapidly converted to other processing techniques, eg, for processing polyester BMC, SMC and TMC by attaching a Polyload AZ 100 automatic stuffer unit. Over and above thermoset processing, CX series machines, with 150 basic versions and over 500 modification options, are the right solution for plastics injection moulding across industry and for production processes from simple to highly complex.
(Company Press Release)