Guides and news from Perotec Systems on plastic processing equipment and technology in Serbia.
Mold temperature has a direct effect on cycle time, surface finish, warpage and dimensional stability. A temperature control unit (TCU) that is undersized, oversized or running the wrong medium will show up as a quality or throughput problem long before anyone thinks to check the TCU itself. A few p...
MORE DETAILSEvery injection molding machine buyer eventually asks the same question: is it worth moving from a hydraulic machine to a full-electric one? The honest answer is that it depends on what the process actually needs — but the differences are consistent enough to lay out clearly, and large enough to be...
MORE DETAILSWhen an automotive supplier or a medical molder specifies an injection molding machine, two requirements appear in every datasheet: process repeatability and production cleanliness. These are exactly the areas where Japan Steel Works (JSW) has been the industry benchmark for years — and the reason a...
MORE DETAILSWhen silver streaks, bubbles or color variation show up on parts, the first instinct is usually to adjust the machine — temperatures, pressures, speeds. Statistically though, the two most common culprits are not on the machine at all: moisture in the granulate and unstable additive dosing. The good...
MORE DETAILSOn Serbian shop floors, the same machine goes by at least three names. Some ask for a "mašina za brizganje", some for a "brizgalica", senior technicians for a "špric mašina", and classified ads offer a "presa za plastiku". Everyone understands each other in person — but online and in documentation t...
MORE DETAILSCooling in a molding plant is invisible — while it works. A mold cooling slower than designed stretches the cycle; water warmer than specified causes warpage and longer cooling times; an oversized chiller burns electricity idling. Here is how cooling is sized properly, and where the biggest savings...
MORE DETAILSOn paper, a color change is trivial: run out the old color, feed the new one. In practice it is one of molding's biggest hidden costs — the machine stands idle, the operator flushes the barrel with production resin, and streaked transition parts go straight to scrap. Multiplied by the number of chan...
MORE DETAILSServo-pump machines are now sold as standard across the market — old-style hydraulics with a pump running flat out regardless of whether the machine is moving have all but disappeared. Buyers increasingly ask a fair question: "Why pay a JSW premium when my servo-hydraulic machine already saves elect...
MORE DETAILSA short shot is a part where the melt failed to completely fill the mold cavity, leaving it visibly incomplete. The most common causes are insufficient injection pressure or speed, low melt or mold temperature, trapped air from poor venting, or a runner system/machine that's undersized for the part....
MORE DETAILSBlack or dark specks on molded parts usually come from one of three sources: carbonized material deposits that sat too long in dead zones of the barrel, nozzle or hot runners; degraded or contaminated regrind; or external dirt introduced through the resin, hopper or surrounding environment. Each has...
MORE DETAILSA high dew point means the dryer isn't delivering air dry enough to pull moisture out of a hygroscopic resin (PET, PA, PC and similar materials), which directly causes hydrolysis, bubbles and streaking in the finished part. The most common causes are a saturated or damaged molecular sieve, an air le...
MORE DETAILSWhen a chiller can't reach its water setpoint, the cause is usually one of four: cooling capacity is insufficient for the plant's actual heat load, the condenser is dirty so the compressor runs at reduced efficiency, refrigerant charge is low due to a leak, or water flow through the system is insuff...
MORE DETAILSUnstable mold temperature — swings cycle to cycle, or uneven temperature between zones of the same mold — usually comes from one of four causes: insufficient flow of the temperature-control fluid (water or oil), a faulty or poorly positioned temperature sensor, poor mold channel design, or a problem...
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