Views: 0 Author: Site Editor Publish Time: 2026-06-12 Origin: Site
Many mold buyers and new mold engineers confuse rotary thread mold with 2K overmold (soft rubber overmolding mold) and common fixed injection mold. Actually, plastic thread unscrewing mold is an independent rotary injection mold structure, specially designed for plastic parts with internal & external screw threads, no manual thread stripping, no obvious parting line on thread surface.
Unlike TPE overmold mold (double-color rotary mold for non-slip handle), thread rotary mold focuses on automatic thread demolding via gear rotary system, which is widely used in daily packaging, industrial plastic fittings and consumer plastic products.
This is the standard thread rotary mold we use in injection workshop. Equipped with oil cylinder, gear rack or worm gear driving system, the thread core / thread ring rotates automatically during mold opening. The threaded plastic part will be screwed out synchronously with ejector system, 100% automatic production.
Classification:
Internal thread mold: For bottle cap, cosmetic jar, plastic thread nut, pen tube
External thread mold: For plastic bottle mouth, pipe joint, plastic bolt
Core advantages: Smooth thread surface, no burr, precise thread pitch, high dimensional accuracy, support multi-cavity mold, long mold service life.
No rotary mechanism, no gear parts. Thread cavity adopts two half-slides (Haff mold) structure. Open mold → slide split sideways → finish thread demolding directly.
Disadvantage: Obvious parting line on thread tooth, only fit for coarse thread & low appearance requirement parts, low cost for small batch order.
Most clients mix up these two rotary injection molds, clear comparison below:
Thread rotary mold: Rotary for thread stripping, single plastic material, no TPE soft rubber, make threaded plastic parts
2K Overmold / Double-color mold: 180° plate rotation, hard plastic + TPE/TPU soft rubber, for non-slip handle, remote control, tool grip
We select resin based on thread precision, wear resistance and molding fluidity:
General thread products (bottle caps, packaging): PP, PE, ABS, PS
Precision thread parts (plastic nut, fitting joint): POM (Delrin), PA6, PA66, GF Nylon
Transparent thread cosmetic parts: PC, PET
Tip: POM is the best material for precision plastic thread, low shrinkage, anti-wear, no thread deformation after injection.
Food & cosmetic packaging: Plastic screw cap, cream jar, lotion bottle neck
Daily supplies: Plastic pen barrel, threaded water cup connector
Industrial parts: Plastic thread pipe fitting, injection plastic thread bolt & nut
Home appliance parts: Threaded plastic fixed base, water tank connector
Thread core & thread ring adopt precision CNC lathe + thread grinding processing
Control coaxiality of rotary shaft & thread core within 0.015mm, avoid thread tooth damage
Match rotary speed and ejector speed synchronously to prevent product whitening & scratch
Copper bushing and nitriding treatment for rotary moving parts, improve mold wear resistance
Thread scratch / whitening: Unmatched rotating & ejection speed; optimize motor parameter
Thread tooth incomplete: Improper gate position, increase mold temperature and resin fluidity
Mold rotary stuck: Poor gear fit clearance, add high-temperature lubricating grease
Automatic unscrewing thread mold is a professional rotary injection mold independent from TPE overmold. It is the top choice for mass production of all plastic threaded components. If you need high-precision thread mold, multi-cavity thread tooling or plastic thread part solution, welcome to contact our mold engineering team for customized design and quotation.
