SK 64/64 SK 64/32 Forward Conveying Elements Pitch 64 Twin Screw Transition Blocks

SK 64/64 & SK 64/32 Forward Conveying Elements | Pitch 64 Twin Screw Transition Blocks

Multi-angle studio shot SK 64/64 continuous uniform conveying segment single flight pitch64 extruder spare part

SK 64/64 and SK 64/32 are standard 64mm medium-small pitch single-flight SK forward conveying elements, specially designed for mid-melting, side feeder transfer and pre-vacuum devolatilization barrel zones of co-rotating twin screw extruders, acting as transition segments between medium pitch SK72 blocks and small pitch SK56/SK44 metering elements.

Both adopt unified standard multi-tooth internal splined bore, fully interchangeable with matching SK series core shafts. Available materials include W6Mo5Cr4V2 high speed steel, 1.2343 hot work die steel and HIP powder metallurgy alloy, processed with integral gas nitriding to reach HRC 58–62 surface hardness for long-term anti-wear compounding production.

The decisive functional difference lies in axial length and spiral loop structure, which completely separates their production positioning:

• SK 64/64: 64mm full axial length = one complete 360° spiral loop, engineered for continuous, uniform melt transportation in standard full-length melting barrel sections.
• SK 64/32: 32mm half axial length = half spiral flight, modular stackable short segment for mild staged pressure build-up and narrow short barrel buffer conveying before vacuum vents.

Unlike large-pitch SK96 series dedicated only to main feed throat, all pitch-64 SK segments focus on downstream molten plastic processing zones.

64mm spiral pitch matched with 64mm full axial length forms an intact single spiral channel. One full rotation delivers a complete cycle of axial material movement. Optimized widened flight surface maintains stable moderate free volume, avoiding the over-high throughput of SK96 feed blocks and flow fluctuation of segmented short elements. Integrated one-piece structure minimizes screw stacking joints inside melting barrels to eliminate material dead zones and carbon deposition.

1. Balanced stable medium melt flow: Bridges high-volume SK72 transition blocks and low-flow small-pitch metering segments, eliminates sudden flow surges during solid-to-melt phase transformation.
2. Long-run clean transport: Smooth continuous spiral flight reduces local melt stagnation, perfect for non-stop mass production of general plastics.
3. Simplified screw layout: Single-piece installation meets standard melting barrel length requirements, reduces assembly steps and screw connection gaps.
4. Stable baseline pressure generation: Moderate channel compression builds consistent low melt pressure to guarantee even mixing before KB kneading blocks.

Core working zones: Standard full-length mid-melting barrel, post-feed main transition section, stable transfer channel before mixing kneading blocks.

Matching materials: Unfilled PP/PE masterbatch, medium-density pellet compounding, non-sensitive general engineering plastics, low-filler modified polymers.

Not applicable: Narrow short barrel gaps, low-density fine powder, vacuum vent front buffer conveying (select SK64/32 instead).

Identical 64mm medium-small spiral pitch as SK64/64, yet only 32mm half axial length with half spiral flight per unit. Split modular design allows customers to stack 2~4 pieces freely to customize total conveying length, adapting to shortened modified barrel sections that cannot fit full-length SK64/64 blocks. Miniaturized body fits narrow intermediate barrel gaps between mixing zones and vacuum vent ports.

1. Multi-stage mild gradient pressure rise: Stacked multiple SK64/32 segments create incremental soft compression, prevents sharp pressure spikes that cause foaming for heat-sensitive filled polymers.
2. Adjustable limited instantaneous flow: Single half-length flight restricts melt throughput, stabilizes flow for lightweight fine powder additives prone to overflow and vent surging.
3. Multi-position cross-zone compatibility: Breaks the single melting zone limitation of SK64/64, works for pre-vacuum vent buffer, side feeder auxiliary transfer channel, post-kneading pressure relief section.
4. Controllable short residence time: Separated short segments adjust local melt staying duration, avoid over-shearing degradable biopolymers like PLA/PBAT.

Core working zones: Short modified transition barrels, pre-devolatilization vacuum vent front buffer zone, side feeder material transfer channel, post-kneading pressure stabilization section.

Matching materials: Glass fiber filled PA/PC, low-density talc/carbon black powder masterbatch, biodegradable heat-sensitive plastics, recycled fine powder compounding, low-shear high-sensitivity formulations.

Not applicable: Standard full-length main melting zones requiring long-distance continuous melt transport (choose SK64/64).

1. Universal Standard Masterbatch Layout (Unfilled Plastics): SK96/96 (main feed throat) + SK72/72 (mid-transition) + SK64/64 (main melting continuous transport) + KB kneading blocks
2. Compact Modified Short Barrel Layout (Narrow Cylinders): Cancel full-length SK64/64, adopt stacked SK64/32 multi-segment combination for short transition & vent buffer
3. Heat-Sensitive Filled Bioplastic Layout: SK96/48 feed transition + stacked SK72/36 gradient segment + stacked SK64/32 vent buffer, no full-length SK64/64 to avoid over-pressure foaming
4. Devolatilization Compounding Layout: Install 2~3 pcs SK64/32 before vacuum vent ports for stable flow buffering; SK64/64 only deployed far upstream melting zone
5. Complete Gradient Screw Transition Rule: Large pitch SK96 (feed) → Medium pitch SK72 (transition) → Medium-small pitch SK64 (melting/vent) → Small pitch SK56/SK44 (metering)

A1: Both share the same 64mm medium-small spiral pitch for downstream melting & vent zones, the key gap is axial length and spiral loop structure. SK64/64 is a full 64mm single-loop integrated block for long-distance continuous uniform melt transport in standard melting barrels. SK64/32 is half-length 32mm modular short segment, stackable for staged gradual pressure adjustment and narrow barrel vent buffer conveying, cannot fully substitute SK64/64 for long continuous melting sections.

A2: Choose SK64/64 if your extruder is equipped with standard full-length mid-melting barrel sections; you produce non-sensitive general plastic masterbatch requiring stable long-distance melt transportation; you want to reduce screw stacking joints inside the melting zone to avoid dead material.

A3: Pick SK64/32 when you have modified short narrow barrel transition gaps; process heat-sensitive, low-density fine filler materials prone to vent foaming/overflow; need flow buffer conveying before vacuum devolatilization vents; require flexible adjustable total conveying length via modular stacking design.

A4: Two stacked SK64/32 reach total 64mm length matching SK64/64 dimension, but conveying performance differs greatly. Stacked SK64/32 deliver segmented slow gradient flow with mild multi-stage pressure, while single SK64/64 provides one-piece smooth continuous medium melt throughput. They cannot fully substitute each other for strict uniform melting formulations.

A5: SK96 large 96mm pitch blocks are exclusively designed for raw solid material feed throat with maximum high throughput. SK72 medium 72mm pitch segments serve main mid-transition melting zones with balanced medium flow. SK64 medium-small 64mm pitch elements focus on later melting and vacuum vent buffer sections with lower baseline throughput, ideal for precision low-shear compounding.

A6: Both SK64/64 and SK64/32 support custom alloy material upgrade, laser engraving of customer OE/part numbers, modified flight chamfer, and special spline tooth size adjustment. SK64/32 additionally provides free modular screw stacking layout design for segmented barrel configurations. Standard stock items ship within 3–5 working days, custom orders take 15–25 days with volume tiered discounts.

Provide your extruder barrel layout, polymer formulation filler type and target screw assembly scheme for our professional engineering team. We supply free gradient screw stacking design solutions for SK 64/64 continuous melting transport blocks and SK 64/32 modular vent buffer segments, lab test sample support and factory-direct bulk pricing for twin screw extruder spare parts. Contact us via WhatsApp or email to get complete technical dimension drawings and cost quotation.

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