Collar Type with 4 Heads Linear Weigher Packing Machine
SW-320C
Compact vertical form-fill-seal machine with an integrated 4-head linear weigher for small granule sachets — candy, nuts, seeds, sugar, spice, and small hardware. Forms 3-side seal bags from roll film at up to 70 bags per minute with a 10–100 g fill range. Entry-level VFFS solution at a fraction of the cost and footprint of large combination weigher systems.
Quality
CE Certified
Source
Factory Direct · Guangdong
Customization
OEM · Voltage · Language
After-Sales
2-Year Warranty · 24 h Support
SW-320C: Compact 4-Head Linear Weigher VFFS
The SW-320C is a collar type vertical form-fill-seal (VFFS) machine with an integrated 4-head linear weigher designed for small granule sachets in the 10–100 g range. The machine forms each bag 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 4-head linear weigher uses four independent vibration-fed channels, each with its own load cell. The controller reads all four weights and releases the channels whose combined weight is closest to the target — a simplified but effective version of the combination weighing principle. This achieves reliable accuracy for uniform, small-piece granules such as sugar, candy, seeds, and spice blends. With a maximum film width of 320 mm and a machine weight of only 500 kg, the SW-320C occupies a fraction of the floor space required by full-scale 10-head combination weigher systems, making it ideal for startups, contract packers, and small-to-medium production lines that need automated weighing and packing in a single compact unit. Siemens PLC and touch screen control all parameters from a single interface.
Packing Speed
15–70 bags / min
Fill Range
10–100 g
Max Film Width
320 mm
| Parameter | SW-320C |
|---|---|
| Roll Film Width | ≤320 mm |
| Bag Length | 80–200 mm |
| Bag Width | 45–150 mm |
| Fill Weight Range | 10–100 g |
| Packing Speed | 15–70 bags/min |
| Weigher Type | 4-head linear weigher (stainless steel) |
| Bag Format | 3-Side Seal / Back Seal (from roll film) |
| Sealing Type | Vertical back seam + horizontal cross-seal |
| Control System | Siemens PLC + Siemens HMI touch screen |
| Contact Material | SUS304 Stainless Steel |
| Total Power | 3.5 kW |
| Voltage | 220V · 50/60 Hz (customizable) |
| Air Consumption | 0.6–1.2 m³/min |
| Machine Weight | ~500 kg |
| Dimensions (L×W×H) | 1,300 × 1,000 × 2,700 mm |
SW-320C key details: triangular bag forming collar, Siemens HMI touch screen, gusseted bag device, and rear film roll frame.
Recommended Configurations by Product
The SW-320C is optimized for small granule sachets in the 10–100 g range. Speed and accuracy depend on product density, piece size, and target fill weight — contact us with your product specification for a tailored estimate.
Candy & Small Confectionery
10–80 g sachet for retail and vending
- Weigher
- 4-head linear weigher, gentle-feed mode
- Speed
- ~55 bags/min (30 g format)
- Bag Size
- 80 × 45 mm to 150 × 100 mm
- Clients
- Candy manufacturers, confectionery brands, seasonal gift packers
Nuts, Seeds & Dried Fruits
20–100 g sachet for retail and snack bars
- Weigher
- 4-head linear weigher, standard mode
- Speed
- ~45 bags/min (50 g format)
- Bag Size
- 100 × 60 mm to 200 × 150 mm
- Clients
- Nut processors, dried fruit exporters, trail mix brands
Sugar, Salt & Spice Sachets
10–50 g single-serve sachet for food service
- Weigher
- 4-head linear weigher, fine-granule mode
- Speed
- ~65 bags/min (10 g format)
- Bag Size
- 80 × 45 mm to 120 × 80 mm
- Clients
- Sugar mills, spice blenders, food service suppliers, hotels
Small Hardware & Fasteners
20–100 g counted or weighed sachet
- Weigher
- 4-head linear weigher, high-density mode
- Speed
- ~30 bags/min (100 g format)
- Bag Size
- 100 × 60 mm to 200 × 150 mm
- Clients
- Fastener distributors, hardware stores, DIY kit assemblers
The SW-320C is optimized for small granules under 100 g. For larger fill weights (100–2,500 g) or higher accuracy on irregular-shaped products, see the SW-420A/620A/820A multi-head weigher machine. For fine powders (spice, flour, milk powder), see the SW-420E/620E auger powder machine.
Output Bag Types: 3-Side Seal Sachets
The SW-320C forms bags in-line from roll film using a triangular forming collar. The standard output is a three-side-seal sachet — a back seam runs along one side, and horizontal cross-seals close the top and bottom. This is the most cost-effective format for small granule portioning: low material cost per bag, excellent seal strength, and high production speed. The compact bag size (up to 200 × 150 mm) makes it ideal for single-serve sachets and small retail pouches.
Sugar, Bouillon, Detergent — 3-side seal sachets
Chocolate, Chips, Crackers — back-seal small packs
3-Side Seal (Standard Output)
Back Seal (Fin Seal)
Compatible film materials: PE, CPP, PET/PE laminate, aluminum foil composite, nylon laminate, BOPP. Aluminum foil laminates are recommended for moisture-sensitive products such as sugar and spice. Laminated paper rollstock film is also compatible.
Note: The SW-320C 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.
How the SW-320C Weighs, Forms, Fills, and Seals
The SW-320C runs as a continuous-motion system — the 4-head linear weigher calculates the optimal channel combination while the VFFS unit forms, fills, and seals bags without stopping. The entire process is automatic from film loading to finished sachet output.
01
Roll Film Loading
A roll of packaging film (PE, aluminum foil laminate, or CPP) mounts on the film frame at the rear 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 runs out, preventing unsealed bags. The SW-320C accommodates film rolls up to 320 mm wide.
02
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 10–15 minute tool-free adjustment. An Omron rotary encoder tracks film position for consistent bag length control across every cycle.
03
4-Head Linear Weigher Filling
Product feeds from the hopper on top of the machine into four independent vibration channels, each with its own load cell. The Siemens PLC reads all four weights simultaneously and selects the combination of channels whose total is closest to the target fill weight. The selected channels open and release product into the forming tube below. This linear weighing method delivers reliable accuracy for uniform, small-piece granules within the 10–100 g range.
04
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 sachet. A cutting knife then severs the finished sachet, which drops onto the output tray or optional conveyor.
Gallery & Video
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SW-320C front view — compact VFFS with 4-head linear weigher mounted on top, forming collar visible at center
Compact Sachet Packaging System
The SW-320C is designed as a self-contained unit: the 4-head linear weigher is integrated directly on top of the VFFS main machine, eliminating the need for a separate weigher platform, Z-type elevator, or bucket conveyor. Simply load product into the top hopper, mount a film roll on the rear frame, and the machine handles everything from weighing to sealing. This all-in-one design minimizes floor space and reduces setup complexity — ideal for small facilities, contract packers, or adding a sachet line alongside existing equipment.
SW-320C Main Machine
Core unit integrating 4-head linear weigher, triangular forming collar, vertical sealing belt, horizontal sealing jaws, date coder, and cutting mechanism in a single compact frame. 220V single-phase power, 3.5 kW total.
Integrated 4-Head Linear Weigher
Four independent vibration-fed channels with individual load cells, mounted directly on top of the VFFS forming tube. No separate weigher stand or elevator needed — product drops directly from channels into the bag tube below.
Optional Add-Ons
All options are factory-installed and integrated with the Siemens PLC control system. Request a configuration when you inquire.
Branded Components You Can Verify
Every critical electrical and pneumatic component on the SW-320C 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 parameters. Stores up to 100 product recipes. 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 Solenoid Valve
Controls the pneumatic sealing jaw and cutting cylinder actuation. High-cycle rated for continuous small granule sachet 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 Guide Cylinder
Anti-rotation guided cylinder for sealing jaw actuation. Consistent jaw alignment maintains seal quality across the full production run.
Schneider Circuit Breaker
CE-compliant thermal-magnetic protection for main electrical cabinet. Overcurrent and short-circuit protection for motor and control circuits.
4-Head Linear Weigher vs 10-Head Combination Weigher: Which Is Right?
Both the SW-320C (4-head linear weigher) and the SW-420A/620A/820A (10-head combination weigher) are collar type VFFS machines for granule products. The right choice depends on your product characteristics, fill weight range, and production volume.
Choose SW-320C When:
- You need a compact 4-head linear weigher integrated with the VFFS in a single small footprint (1.3 × 1.0 m)
- Your fill weight is 10–100 g — small sachets of candy, sugar, seeds, regular small granules
- You need weighed dosing on a low budget — the linear weigher costs significantly less than a 10-head combination system
- Your product is a uniform, regular small-piece granule on a single-product line — the linear weigher works best with homogeneous SKUs
- If your granules are irregular or fills exceed 100 g, step up to the SW-420A 10-head weigher; if uniform free-flowing material at lowest cost, see the SW-320D cup; for powders see the SW-420E auger; for liquids see the SW-420F
Choose SW-320C (4-Head Linear Weigher) When:
- Your fill weight is under 100 g — small sachets for candy, sugar, nuts, seeds, spice, or small hardware
- Your product is uniform, small-piece granules with consistent piece weight — the linear weigher works best with homogeneous products
- Floor space is limited — the SW-320C occupies only 1.3 × 1.0 m and weighs 500 kg, compared to 4.7 × 2.0 m and 1,300+ kg for the SW-420A system
- Budget matters — the compact integrated design costs significantly less than a separate weigher + elevator + platform system
- You are a startup, contract packer, or adding a sachet line alongside existing equipment
Choose SW-420A/620A/820A (10-Head Combination Weigher) When:
- Your fill weight exceeds 100 g — the SW-420A handles 100–1,000 g, the SW-620A up to 2,500 g, and the SW-820A for 2,500 g+
- Your product has irregular pieces (chips, mixed nuts, trail mix) — the 10-head combination algorithm achieves ±1 g accuracy even with non-uniform shapes
- You need nitrogen flushing for pillow-pack snack bags — supported on the multi-head weigher series
- High-volume production is the priority — the multi-head weigher system runs at 30–70 bags/min for larger bags
- Your bags are wider than 150 mm — the SW-420A goes up to 200 mm, the SW-820A up to 400 mm bag width
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. For premade stand-up pouches and zipper bags, see the SW-D premade bag granule machine.
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.
Entry-Level to Full-Scale
Start with the SW-320C compact sachet machine and scale up to the SW-420A/620A/820A multi-head weigher system as your production grows. Same Siemens platform, same spare parts, same support team — your operators only need to learn one control interface.
Lifetime Remote Support
Free remote video technical support for the life of the machine — not only during the warranty period. Spare parts ship from our Guangdong factory within 3 working days. On-site installation is available on request.
80+ Export Countries
ShengWei packing machines are deployed in the UAE, Saudi Arabia, Nigeria, Indonesia, Mexico, Colombia, and 70+ additional markets across food processing, confectionery, spice, and hardware industries.
What Our Clients Say
We purchased the SW-320C for our 25 g and 50 g sugar sachet line. The 4-head linear weigher is surprisingly consistent — we tested 500 bags and the weight stayed within ±2 g of target. Setup took less than two hours from uncrating to the first sealed bag. The compact footprint was the main reason we chose this machine: our production room is only 40 m² and the SW-320C fits alongside our existing filling line. After four months of single-shift operation, we have had zero mechanical issues and the machine runs without any operator intervention beyond refilling the hopper every 30 minutes.
Ahmed K.
Operations Manager — Sugar Packing Company, West Africa
We needed a sachet machine for our mixed nuts trial packs (30 g and 50 g) at trade shows and promotional events. The SW-320C was the right entry point — lower investment than a full combination weigher system, and we can move it between facilities on a pallet jack. The Siemens touch screen was easy for our operators to learn. ShengWei also helped us source the right aluminum foil laminate film and ran a sample test at the factory before shipping. We plan to add the SW-420A for our main production line once the sachet format proves out commercially.
Carlos M.
Marketing Director — Nut & Snack Brand, Central America
Frequently Asked Questions
What products can the SW-320C handle?
How does a 4-head linear weigher work?
What is the difference between the SW-320C and the SW-420A?
How accurate is the 4-head linear weigher?
How long does it take to change bag size?
What film materials are compatible?
Does the SW-320C need a separate elevator or feeding system?
Can I add a date printer and batch code?
What is the lead time and payment terms?
What warranty and after-sales support is included?
Expert Guides
What Is a Collar Type Packing Machine?
How vertical form-fill-seal collar type machines work, what they produce, and how they compare to premade bag alternatives. Complete guide for buyers.
Read Guide →Linear Weigher vs Combination Weigher
How 4-head linear weighers and 10-head combination weighers differ in accuracy, speed, and cost — selection criteria by product type and production scale.
Compare Combination Weigher →Choosing the Right VFFS for Small Sachets
A buyer's guide to compact VFFS machines for 10–100 g sachet packaging — comparing integrated weigher systems, auger fillers, and volumetric cup dosers.
Browse Collar Type →Other Granule Packing Machines
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Ready to Discuss the SW-320C?
Send us your product type, target fill weight, speed requirement, and bag dimensions. We will confirm suitability, recommend the right configuration, and return a quotation within 24 hours.
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