Blow Molding Scrap Grinder — Flash, Tails & Reject Recycling

More than most plant owners expect. In extrusion blow molding, flash, pinch-off and tails commonly run 15–35% of shot weight depending on the container shape — handleware and flat bottles sit at the high end. On top of that come start-up parisons during head stabilisation, colour changes, leak-test failures and visual rejects. A line producing 100 kg/hr of good bottles can therefore generate 20–40 kg/hr of clean scrap — which is exactly the number you should use to size your grinder.

Yes — flash is among the cleanest regrind sources in plastics processing: your own polymer, your own colour, trimmed seconds after molding. Reground promptly and kept free of dust and oil, it blends back with virgin granule at a controlled ratio in the same blow molding machine. Two cautions: keep ratios consistent so wall thickness and weight stay stable, and never regrind floor sweepings into production material — contamination shows up as holes and weak pinch lines in blown containers.

It depends on where the regrind needs to go. A plain grinder drops regrind at the machine — fine if you bag it and carry it to a blending area in batches. The blower version conveys regrind pneumatically out of the cutting chamber and pipes it to a collection point you choose, typically near the blender or hopper platform. On a continuously running bottle line, that removes a recurring manual task and keeps the chamber clear at full feed rate. Compare both on the RE Series CB Grinder with Blower page.

Two checks: throat and throughput. The throat must comfortably take your largest reject container whole — RE12 handles bottles up to 1 litre, RE16 up to 10 litre jars, RE20 up to 20 litres. Then match capacity to your scrap rate: blower models run from 20 kg/hr (RE8) through 175 kg/hr (RE20) to 700 kg/hr (RE40). Capacity varies with material density and mesh size, so size with headroom. Send us your container range and shift scrap weight for a free recommendation.

Mechanically, yes — a multilayer HDPE bottle grinds exactly like a mono-layer one. The consideration is where the regrind goes: mixed-layer regrind cannot return to a food-contact or barrier-critical layer, so plants typically run it into middle layers, non-critical products or sell it as mixed regrind. If you run co-ex lines, segregate multilayer scrap from mono-material flash so your best regrind stays pure. Our team can advise on segregation practice during your trial visit.

Every machine is quoted to the job. What moves the number is capacity, throat size, motor rating, MS or SS construction and the automation you add — a blower, a conveyor, a control panel. Our guide to what drives machine cost walks through each of those; send us your material and daily volume and we will size the machine and quote it, usually the same day.

Yes. For export orders we fit motors built for your destination country’s voltage and frequency, and machines are packed for sea freight. Raj Electricals has exported 50+ machines, including to the Gulf and Africa. Share your power specification (voltage/Hz) with your enquiry and we will quote the export configuration.

Yes — bring a sample lot of flash, tails and rejects to our works at Andheri East, Mumbai, and we will grind it in front of you so you can check regrind size, throughput and blower discharge on your actual material. Outstation plants can request a video trial. Contact us to book a slot.