Collar Type Packing Machine

Collar Type Multi-Heads Granule Weigher Packing Machine

SW-420A / SW-620A / SW-820A

Vertical form-fill-seal machine paired with a 10-head combination weigher for high-accuracy granule packaging — chips, nuts, candy, pet food, seeds, and hardware. Forms 3-side seal bags from roll film at up to 70 bags per minute with ±1 g weighing accuracy.

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ShengWei SW-420A collar type multi-heads granule weigher packing machine — vertical form-fill-seal with 10-head combination weigher for chips, nuts, and granule packaging

Quality

CE Certified

Source

Factory Direct · Guangdong

Customization

OEM · Voltage · Language

After-Sales

2-Year Warranty · Lifetime Remote Support

Product Overview

SW-420A / SW-620A / SW-820A: Multi-Head Weigher VFFS for Granules

The SW-420A, SW-620A, and SW-820A are collar type vertical form-fill-seal (VFFS) machines integrated with a 10-head combination weigher for high-speed, high-accuracy granule packaging. The machine forms each bag in-line from a roll of packaging film — wrapping it around a triangular forming collar into a tube, sealing the back seam vertically, then filling the weighed product and sealing each bag at the bottom.

The 10-head combination weigher achieves ±1 g accuracy for weights up to 100 g and ±1% for weights above 100 g — essential for chips, snack foods, candy, nuts, pet food, seeds, and hardware where product waste from overfilling directly impacts profitability. A Z-type bucket elevator automatically feeds material from ground level to the weigher platform. Three model sizes — SW-420A (bag width up to 200 mm), SW-620A (up to 300 mm), and SW-820A (up to 400 mm) — cover everything from small sachets to large retail and bulk bags. Siemens PLC and touch screen control all parameters from a single interface.

Packing Speed

20–70 bags / min

Fill Range

100–2,500+ g

Max Film Width

820 mm

Parameter	SW-420A	SW-620A	SW-820A
Roll Film Width	≤420 mm	≤620 mm	≤820 mm
Bag Length	80–300 mm	80–320 mm	80–420 mm
Bag Width	80–200 mm	150–300 mm	200–400 mm
Fill Weight Range	100–1,000 g	500–2,500 g	2,500 g+
Packing Speed	30–70 bags/min	20–60 bags/min	20–50 bags/min
Weighing Accuracy	±1 g (≤100 g) · ±1% (>100 g)
Weigher Type	10-head combination weigher (stainless steel)
Bag Format	3-Side Seal / Back Seal / Gusset (from roll film)
Feeding System	Z-type bucket elevator + vibration dispersion feeder
Sealing Type	Vertical back seam + horizontal cross-seal
Control System	Siemens PLC + Siemens HMI touch screen
Servo Motor	Yichuan (film pull servo)
Contact Material	SUS304 Stainless Steel
Total Power	5 kW	6 kW	6.5 kW
Voltage	380V / 220V · 50/60 Hz (customizable)
Air Consumption	0.6–1.2 m³/min
Machine Weight	~1,300 kg	~1,600 kg	~2,000 kg
Dimensions (L×W×H)	4,700 × 2,000 × 3,800 mm	4,700 × 2,234 × 3,900 mm	4,700 × 2,265 × 4,200 mm

SW-420A collar type multi-head weigher packing machine front view — complete system with 10-head combination weigher, Z-type elevator, and VFFS main machine

SW-420A complete packaging system: Z-type bucket elevator, 10-head combination weigher, triangular forming collar, vertical sealing belt, and horizontal sealing jaws.

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Application Scenarios

Recommended Configurations by Product

The SW-420A/620A/820A handles a wide range of granular products. Speed and accuracy depend on product density, piece size, and target fill weight — contact us with your product specification for a tailored estimate.

Chips & Puffed Snacks

30–500 g bag for retail and convenience stores

Model: SW-420A (small packs) / SW-620A (family size)
Weigher: 10-head combination weigher, anti-breakage mode
Accuracy: ±1 g
Speed: ~55 bags/min (100 g format)
Add-ons: Nitrogen flushing for pillow-pack effect

Nuts, Seeds & Dried Fruits

100–1,000 g pouch for retail and bulk

Model: SW-420A (≤1 kg) / SW-620A (family/bulk pack)
Weigher: 10-head combination weigher, standard mode
Accuracy: ±1 g (≤100 g) · ±1% (>100 g)
Speed: ~40 bags/min (500 g format)
Clients: Nut processors, dried fruit exporters, trail mix brands

Candy & Confectionery

100–500 g bag for retail display

Model: SW-420A
Weigher: 10-head combination weigher, gentle-drop mode
Accuracy: ±1 g
Speed: ~50 bags/min (200 g format)
Clients: Candy manufacturers, sugar confectionery brands, seasonal gift packers

Pet Food & Animal Feed

500–2,500 g bag for retail and wholesale

Model: SW-620A (≤2.5 kg) / SW-820A (≥2.5 kg)
Weigher: 10-head combination weigher, high-capacity buckets
Accuracy: ±1%
Speed: ~25 bags/min (2 kg format)
Clients: Pet food brands, animal feed manufacturers, co-packers

The SW-420A/620A/820A is optimized for granular products. For fine powders (spice, flour, milk powder), see the SW-420E/620E auger powder machine. For liquids (sauce, milk, vinegar), see the SW-420F collar type liquid packing machine.

Bag Format

Output Bag Types: 3-Side Seal & Gusset Pouches

The SW-420A/620A/820A forms bags in-line from roll film using a triangular forming collar. The standard output is a three-side-seal bag — a back seam runs along one side, and horizontal cross-seals close the top and bottom. An optional gusseted bag device adds side gussets for increased volume. This is the most cost-effective format for granule portioning: low material cost per bag, excellent seal strength, and compatibility with nitrogen flushing for fragile products like chips.

Lay's potato chips in fin-seal bag — packed by SW-420A collar type multi-head weigher packing machine

Potato Chips — fin-seal bag with nitrogen flush

Gummy candy in 3-side seal pouch — packed by SW-420A collar type granule weigher packing machine

Gummy Candy — 3-side seal pouch, retail display

Coffee beans in gusset pouch — packed by SW-620A collar type weigher machine with gusset device

Coffee Beans — gusset pouch (optional device)

3-side seal pouch structural diagram — standard output of SW-420A collar type granule weigher packing machine

3-Side Seal (Standard Output)

Back seal pouch structural diagram — alternative sealing format for collar type VFFS granule machine

Back Seal (Fin Seal)

Gusset pouch structural diagram — optional with gusseted bag device on SW-420A/620A/820A

Gusset Pouch (Optional Add-On)

Compatible film materials: PE, CPP, PET/PE laminate, aluminum foil composite, nylon laminate, BOPP. Aluminum foil laminates are recommended for moisture-sensitive or light-sensitive granule products. Nitrogen-compatible films are essential for pillow-pack snack applications.

Note: The SW-420A/620A/820A does not support stand-up pouches, zipper bags, or flat-bottom bags. If these formats are required, see the SW-D premade bag granule machine.

Machine Operation

How the SW-420A Weighs, Forms, Fills, and Seals

The SW-420A/620A/820A runs as a continuous-motion system — the multi-head weigher calculates the optimal combination of buckets while the VFFS unit forms, fills, and seals bags without stopping.

Roll Film Loading

A roll of packaging film (PE, aluminum foil laminate, or CPP) mounts on the film frame at the back of the machine. A servo motor pulls the film through dancer rollers that maintain constant tension. An automatic film-end stop halts the machine when the roll is depleted, preventing unsealed bags. Film width accommodates up to 820 mm on the SW-820A model.

Bag forming collar step — triangular collar folds film into tube for VFFS collar type machine

Bag Forming & Vertical Sealing

The flat film wraps around a precision-machined triangular forming collar, which folds it into a continuous tube. Heated vertical sealing rollers press and seal the overlapping edges to create the back seam. Changing bag width requires only swapping the forming collar — a 15-minute tool-free adjustment. An Omron rotary encoder tracks film position for consistent bag length control.

Multi-Head Weigher Filling

The Z-type bucket elevator lifts product from ground level to the 10-head combination weigher platform. Vibration feeders distribute product evenly across all 10 weighing buckets. The weigher controller calculates which combination of buckets produces the closest match to the target weight — running thousands of calculations per second. The selected buckets release simultaneously into the forming tube. This combination algorithm achieves ±1 g accuracy even with irregularly shaped products.

Sealing and cutting step — horizontal sealing jaws create top and bottom seals, knife cuts finished bag

Horizontal Sealing, Coding & Cutting

After each fill, horizontal sealing jaws clamp across the tube to create the top seal of the filled bag and the bottom seal of the next bag simultaneously. Jaw temperature, dwell time, and pressure are independently adjustable per film type via the HMI. A date printer (standard) codes batch number and expiry date onto each pouch. A cutting knife then severs the finished pouch, which drops onto the output conveyor.

See It in Action

Gallery & Video

SW-420A collar type multi-head weigher packing machine — full factory floor view with two complete packaging lines

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SW-420A on factory floor — two complete granule packaging lines with multi-head weighers and Z-type elevators

SW-420A Z-type elevator and control panel

Production Line

Complete Granule Packaging Line

The SW-420A/620A/820A operates as a complete integrated system: Z-type bucket elevator, 10-head combination weigher, VFFS main machine, and output conveyor. ShengWei supplies all components as a turnkey line and provides a custom layout drawing with every quotation. An optional working platform with staircase gives operators safe access to the weigher for cleaning and maintenance.

SW-420A collar type VFFS main machine — vertical form-fill-seal unit for granule packaging

SW-420A / 620A / 820A Main Machine

Core vertical form-fill-seal unit. Forms bags from roll film, receives weighed product from the multi-head weigher above, seals, codes, and cuts in one continuous cycle.

10-Head Combination Weigher

SUS304 stainless steel combination weigher with 10 independently controlled weighing buckets. Calculates optimal weight combinations at high speed for ±1 g accuracy on granular products.

Z-Type Bucket Elevator

Inclined bucket conveyor lifts product from ground-level hopper to the weigher dispersion plate. Food-grade PU buckets prevent product contamination. Variable speed control matches the packing speed.

Stainless steel working platform with staircase — operator access to multi-head weigher for cleaning

Working Platform & Staircase

Stainless steel elevated platform with safety railings and staircase. Provides operator access to the multi-head weigher for daily cleaning, bucket inspection, and product changeover.

Optional Add-Ons

All options are factory-installed and integrated with the Siemens PLC control system. Request a configuration when you inquire.

Nitrogen flushing device — injects nitrogen before horizontal sealing for pillow-pack effect on chips and fragile snacks
Gusseted bag device — adds side gussets to increase pouch volume without changing bag width
Checkweigher — downstream weight verification with automatic reject gate for 100% weight compliance
Metal detector — downstream inline detection for food safety compliance (HACCP/BRC)
Finished bag conveyor — extended output belt for accumulation and manual case packing
Automatic correction motor — electrically compensates vertical seal offset via HMI without stopping
Hole punch device — creates a hang hole in each bag for retail display hooks

Ask About Line Configuration

Quality Components

Branded Components You Can Verify

Every critical electrical and pneumatic component on the SW-420A/620A/820A is sourced from established industrial brands. Part numbers are listed on the quotation sheet — you can verify pricing and availability before you commit to an order.

Siemens SMART 700 HMI

7-inch colour touch screen. Controls bag length, sealing temperature, production count, and weigher communication. Multi-language support on request.

Siemens S7-200 PLC

Programmable logic controller coordinating weigher signal, film pull, sealing jaws, and cutter in real-time. Fault diagnostics display on HMI panel.

AirTAC 4V210 solenoid valve controlling pneumatic sealing and cutting cylinders on SW-420A

AirTAC Solenoid Valve

Controls the pneumatic sealing jaw and cutting cylinder actuation. High-cycle rated for continuous multi-shift granule packaging production.

Omron Rotary Encoder

Precision film position feedback for accurate bag length control. Ensures consistent cut position even as film tension varies during production runs.

SMC guided pneumatic cylinder for horizontal sealing jaw on SW-420A collar type packing machine

SMC Guide Cylinder

Anti-rotation guided cylinder for sealing jaw actuation. Consistent jaw alignment maintains seal quality across the full bag count.

Schneider Easy9 circuit breaker in SW-420A collar type granule weigher packing machine electrical cabinet

Schneider Circuit Breaker

CE-compliant thermal-magnetic protection for main electrical cabinet. Overcurrent and short-circuit protection for motor and control circuits.

Decision Guide

Collar Type VFFS vs Premade Bag: Which Is Right for Your Granule Product?

Both the SW-420A/620A/820A (collar type) and the SW-D series (premade bag) package granules automatically. The right choice depends on your bag format requirements, production volume, and per-bag material cost sensitivity.

Choose SW-420A/620A/820A When:

You weigh irregular or mixed-shape granules — chips, mixed nuts, candy, pet food, trail mix, seeds — where uniform piece weight cannot be assumed
Higher dosing accuracy is required — the 10-head combination weigher achieves ±1 g, compared to ±1% on auger and ±1–2% on volumetric cup systems
Your fill weight is 100–2,500 g+ — too large for compact linear weighers, too irregular for volumetric cups
You run a single high-volume snack or pet food SKU and need nitrogen flushing inline before sealing
If your product is a fine powder, see the SW-420E auger; if a uniform free-flowing granule under 100 g at lowest cost, see the SW-320D cup or SW-320C linear weigher; if a liquid, see the SW-420F

Choose Collar Type SW-420A/620A/820A When:

You need simple 3-side seal or back-seal bags at high daily volume — rollstock film costs meaningfully less than premade pouches
Your product is a dry, free-flowing granule (chips, nuts, seeds, candy, pet kibble, hardware)
Nitrogen flushing is required for chips or fragile products — collar type supports inline nitrogen injection before sealing
High speed matters — 30–70 bags/min compared to 15–50 bags/min on premade bag machines
You run high-volume, single-SKU production with infrequent changeovers

Choose Premade Bag SW-D Series When:

You need stand-up pouches, zipper bags, or flat-bottom bags — formats that collar type cannot produce
High-quality pre-printed graphics are important for retail shelf presentation
You run multiple SKUs and switch bag sizes or formats frequently within a shift
Your product requires a resealable package for consumer retail (e.g. premium nuts, trail mix)

When Neither Is the Right Fit

For powder products (spice, flour, milk powder) that require auger screw dosing instead of weighing, see the SW-420E/620E collar type auger powder machine. For liquid products, see the SW-420F collar type liquid packing machine.

About the Manufacturer

Why Choose ShengWei Machine

Factory Direct from Guangdong

Designed and manufactured in our own 11,000 m² factory in Shantou, Guangdong. No trading companies or middlemen — you communicate directly with the production engineers who build and test your machine before shipment.

Turnkey Granule Packaging Lines

We supply the complete system as a single purchase: VFFS main machine, multi-head weigher, Z-type elevator, working platform, output conveyor, and optional checkweigher / metal detector. One supplier, one warranty, one point of contact.

Lifetime Remote Support

Free remote video technical support for the life of the machine — not only during the warranty period. Common spare parts typically ship from our Guangdong factory within 3 working days. On-site installation is available on request.

80+ Export Countries

ShengWei granule packing machines are deployed in the UAE, Saudi Arabia, Nigeria, Indonesia, Mexico, Colombia, and 70+ additional markets across snack food, pet food, confectionery, and agricultural processing industries.

Factory Acceptance Test

Tested Before Shipment — How We Prove the SW-420A Series

72-Hour Run Test on Your Recipe

Every SW-420A goes through a structured Factory Acceptance Test before it ships: a 72-hour continuous run with actual packaging film and product material, with speed, seal quality, weight accuracy, and rejection rate all logged. For a collar-type machine that means verifying multi-head weigher dosing accuracy on your actual product, checking the feed-to-bag-forming handover at speed across your bag sizes (80–200 mm bag widths on the SW-420A, 150–300 mm on the SW-620A, 200–400 mm on the SW-820A), and holding output stable across the 30–70 bags/min (SW-420A), 20–60 (SW-620A), and 20–50 (SW-820A) range. Send your product and film and the FAT runs on your recipe, not on a generic substitute.

Approve Before We Crate

Before crating, our QC team sends you the FAT report, a test video of your machine running, and photos for approval. If your order requires it, we coordinate SGS, Bureau Veritas, or TÜV pre-shipment inspection and provide full access to the machine and test records. See how the 4-person QC team works at our Factory & Quality Center.

FAQ

Frequently Asked Questions

What products can the SW-420A/620A/820A handle?

The SW-420A/620A/820A is designed for dry, free-flowing granular products. Typical products include potato chips, corn snacks, puffed rice, roasted nuts, sunflower seeds, dried fruits, candy, gummy bears, brown sugar cubes, pet food kibble, bird seed, coffee beans, pasta, and small hardware parts (screws, bolts). For fine powders that require volumetric auger dosing rather than weighing, see the SW-420E/620E auger powder machine.

How does the 10-head combination weigher achieve ±1 g accuracy?

The combination weigher distributes product across 10 independently weighed buckets. A high-speed microprocessor calculates which combination of buckets produces the closest match to the target weight — evaluating over 1,000 combinations per second. By selecting the optimal subset of buckets (rather than dosing a single stream), the weigher consistently achieves ±1 g accuracy for weights up to 100 g and ±1% for heavier fills. Accuracy depends on individual piece weight — smaller, more uniform pieces yield better results.

What is the difference between the SW-420A, SW-620A, and SW-820A?

The three models differ primarily in bag size capacity and machine footprint. The SW-420A handles bag widths up to 200 mm and fill weights up to 1,000 g — suitable for small to medium retail packs. The SW-620A handles bag widths up to 300 mm and fill weights up to 2,500 g — suitable for family-size and bulk packs. The SW-820A handles bag widths up to 400 mm and fill weights above 2,500 g — designed for large industrial or retail bags. All three share the same Siemens PLC, 10-head weigher, and frame construction.

Can the machine pack chips without breaking them?

Yes. The 10-head combination weigher includes an anti-breakage mode that reduces vibration feeder amplitude and gate opening speed to minimize product damage. The product falls from the weigher buckets through a smooth stainless steel chute into the forming tube — the drop height is minimized by design. For chips and other fragile products, we also recommend the nitrogen flushing option, which inflates each bag with nitrogen before sealing to create a protective cushion around the product.

How does collar type VFFS compare to a premade bag machine for granules?

A collar type VFFS machine forms each bag in-line from a roll of packaging film. The film wraps around a triangular forming collar into a tube, which is then sealed, filled, and cut in a single continuous motion. A premade bag machine loads pre-manufactured pouches from a magazine. The collar type uses lower-cost rollstock film and produces 3-side seal, back-seal, and gusset bags. The premade bag machine supports premium formats (stand-up, zipper, flat-bottom) at a higher per-bag material cost. For high-volume granule production where simple bag formats are acceptable, the collar type with multi-head weigher is typically the more cost-effective solution.

How long does it take to change bag size?

Changing bag length is done digitally on the Siemens HMI touch screen — the setting takes effect on the next bag cycle without stopping production. Changing bag width requires replacing the forming collar — a 15-minute manual swap performed at a planned stop, no tools required. Changing the target fill weight is adjusted on the weigher controller, also effective immediately. A full format change (different film roll + new collar + new weight setting) takes approximately 20 minutes for a trained operator.

What film materials are compatible with the SW-420A/620A/820A?

The machine is compatible with standard flexible packaging rollstock: PE, CPP, PET/PE laminate, aluminum foil composite, nylon/PE laminate, BOPP, and metallized films. For nitrogen-flushed chip bags, use a film with adequate gas barrier properties (PET/aluminum/PE or PET/nylon/PE laminate). Sealing temperature and jaw pressure are independently adjustable for each material type via the HMI. Send us a sample of your intended film for a pre-production sealing test confirmation.

Does the system include automatic product feeding?

Yes. The complete system includes a Z-type bucket elevator that automatically lifts product from a ground-level hopper to the multi-head weigher platform. The elevator speed is variable and synchronized with the packing speed. Operators only need to keep the ground-level hopper filled — either manually or via a bulk conveyor from upstream processing equipment. The weigher's vibration feeders distribute product evenly across all 10 weighing buckets automatically.

What is the lead time and payment terms?

Standard lead time is 25–35 working days after deposit confirmation (the multi-head weigher system requires additional assembly and calibration time compared to simpler machines). Payment terms: 30% deposit on order, 70% balance before shipment (T/T). Custom configurations (non-standard voltage, special weigher bucket size, additional accessories) may add 5–10 working days. Contact us with your full specification for a confirmed production schedule.

What warranty and after-sales support is included?

2-year warranty covering manufacturing defects under normal operating conditions. Wear parts (sealing strips, heating elements, weigher bucket springs) are excluded. Common spare parts typically ship from our Guangdong factory within 3 working days. Remote video technical support is provided free of charge for the lifetime of the machine — including weigher calibration guidance, PLC parameter adjustments, and troubleshooting. On-site installation and operator training are available on request, with travel costs quoted separately.

Resources

Expert Guides

Seal Strength vs Seal Integrity

Why a strong-looking seal can still leak, which seal-integrity test finds what, and how the four sealing methods compare.

Read the Sealing Guide →

Multi-Head Weigher vs Auger vs Cup

The accuracy mechanism, give-away cost, cleaning, and failure modes of the three dosing methods compared.

Compare Dosing Methods →

How to Choose the Right Packaging Machine

A step-by-step buyer's path — product type, bag format, dosing, speed, and budget walked through in order.

Read the Choosing Guide →

Other Granule & Collar Type Machines

Same collar type platform or same granule application — different configurations.

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Collar Type Auger Powder Machine

Auger screw filling for fine powder: spice, flour, chemical powder. Same collar type platform with servo-driven auger.

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SW-320C

Collar Type

4-Head Linear Weigher Machine

4-head linear weigher for budget-friendly granule packing. Compact alternative to multi-head weigher systems.

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SW-D200

Premade Bag

Premade Bag Granule Machine

Rotary premade bag machine for granules. Uses pre-formed pouches instead of roll stock film for premium shelf presentation.

View Machine →

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Ready to Discuss the SW-420A/620A/820A?

Send us your product type, target fill weight, speed requirement, and bag dimensions. We will confirm suitability, recommend the correct model, and return a quotation within 24 hours.

info@shengweimachine.com · +86 181 2511 2025

Hellena Ji, International Sales Manager at ShengWei Machinery

Hellena Ji · International Sales Manager
Usually replies within one business day · Helps packaging buyers across 80+ countries

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