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Center Seal Bag Making Machine MJ-350A | Dual Servo, 120 Bags/Min – Xuanhai
- Nice Sealing
- Double servos
- Center seal and bottom seal in one step
- Fully Automatic
- Good price
- Fast shipping
Description
MJ-350A · Center Seal Bag Making Machine
Engineering Precision into
Every Sealed Pouch
Dual servo motor technology · Up to 120 bags/min · PET/PE, BOPP/PE, aluminum laminates · Factory direct from Ruian, China
120
Bags per Minute (Max)
350mm
Maximum Bag Width
0.04–0.15
Film Thickness Range (mm)
7.5kW
Total Power Consumption
Production Process
From Roll of Film to Finished Pouch — 5 Precision Stages
Understanding the workflow helps you evaluate exactly how the MJ-350A fits your production line.
1
Unwinding
Laminated film unrolls via magnetic powder brake tension control and dual photocell edge correction.
2
Folding
Film is folded centrally into back-seal, fin-seal, or lap-seal format without mechanical retooling.
3
Longitudinal Sealing
PID-controlled heated blade seals the center seam. Servo maintains print registration at full speed.
4
Bottom Seal & Cut
Dual heat stations (heat + cooling) press and cool the bottom seal before the cross-cut blade separates each pouch.
5
Discharge
Finished pouches exit via conveyor with auto-counting, batch alarm, and low-material auto-stop.
Machine Highlights
What Makes the MJ-350A Different
Dual Servo — Not a Single Motor Compromise
Two 2kW servo motors work in synchrony: one governs film feed, the other controls the sealing cycle. This eliminates the speed-vs-accuracy trade-off common in single-servo machines.
PID Temperature Stability at Full Speed
The MJ-350A's PID loop holds sealing temperature within ±1°C even at 120 bags/min — preventing cold seals, burn-through, and film distortion on sensitive laminates.
Skip-Seal: Bag Length Up to 9× Feed Pitch
Unlike basic machines locked to one-pouch-per-cycle, the skip-seal function enables long-format pouches (e.g. 270mm bag from a 30mm feed pitch) for oversized contents.
Standalone PLC Control Cabinet
Auto-count, batch alarm, auto-stop on material shortage, and variable frequency drive — all housed in an independent control cabinet separate from the machine body.
Machine Demo
Watch the MJ-350A Running at Full Capacity
Real production footage — dual servo feeding, center sealing, bottom seal formation, and finished pouch discharge on laminated film.
Film Compatibility Guide
Which Laminated Films Run Best on This Machine?
The MJ-350A is engineered specifically for heat-sealable laminates. Here's a practical guide to what runs well and why.
Best Performance
PET / PE Laminate
The most popular structure for food packaging. Excellent print surface (PET outer) with strong heat-seal capability (PE inner). Runs reliably at maximum speed.
Best Performance
BOPP / PE Laminate
High clarity with excellent stiffness. Ideal for transparent-window pouches where visual product appeal drives purchase decisions. Consistent print registration.
Excellent
Aluminum Foil Laminate
Maximum barrier against moisture, oxygen, and light. Requires precise PID temperature management — which the MJ-350A's control system delivers even at full speed.
Compatible
NY (Nylon) / PE Laminate
High puncture resistance and oxygen barrier. Preferred for sharp-edged industrial contents and processed food requiring extended shelf life without refrigeration.
Compatible
Kraft Paper / PE Laminate
Eco-positioning with premium shelf appeal. Suitable for specialty coffee, organic goods, and retail brands where sustainability credentials add commercial value.
Compatible
CPP / BOPP
Cost-effective, glossy structure for items with lower barrier requirements. Lightweight and widely sourced — often chosen for promotional, trial-size, or single-serve packs.
Machine Gallery
Key Components Up Close
From the unwinding station to the discharge conveyor — detailed views of the MJ-350A's main mechanical assemblies.
Buyer's Checklist
Questions to Ask Before Purchasing Any Center Seal Machine
- ✓
Single servo or dual servo?
Dual servo is essential for accurate print registration on pre-printed laminates. Single-servo machines drift at high speed, causing misaligned seal patterns.
- ✓
What film thickness range does it genuinely support?
Verify the machine handles your exact laminate structure. The MJ-350A covers 0.04–0.15mm, from thin sachets through thick multi-layer foil composites.
- ✓
Can it switch seal formats without retooling?
Many machines are locked to one seal type at purchase. Confirm back seal, fin seal, and lap seal are all achievable via configuration — not separate hardware.
- ✓
What does post-sale technical support actually cover?
Remote support speed, spare parts lead time, and language availability determine your real downtime exposure. Ask specifically before signing.
Output Formats
Four Bag Structures — One Machine
Each format serves a different end market. Switching between them involves fold-guide adjustment and blade pressure settings — not mechanical retooling.
📦
Back Seal (Fin Seal)
Film edges meet face-to-face and seal flat, creating a fin at the back. Strong and reliable on thick laminates. The standard format for coffee and food pouches globally.
🔁
Lap Seal
Edges overlap before sealing — producing a thinner, flatter longitudinal seam. More aesthetic on transparent films. Preferred in cosmetics, premium retail, and confectionery.
🛍️
Pillow Pouch
Rounded, pillow-shaped bag sealed at both ends, center seam at rear. Widely used for confectionery, grains, single-serve food applications, and sachet formats.
🏷️
OEM Add-Ons
Euro slot, tear notch, zipper closure, and custom die-punch shapes can be integrated. Consult our engineers for your specific artwork dimensions and closure requirements.
Technical Specifications
MJ-350A — Complete Parameter Reference
For non-standard bag sizes or unusual laminate structures, contact our engineering team for a feasibility review before purchase.
| Parameter | MJ-350A Specification |
|---|---|
| Bag Type Output | Back Seal · Fin Seal · Lap Seal · Pillow Pouch 4 formats |
| Drive System | Dual servo motor (2kW × 2) — Zhejiang Julong dual photocell tracking with edge correction |
| Film Compatibility | PET/PE · BOPP/PE · NY/PE · Aluminum laminate · Kraft/PE · CPP/BOPP |
| Film Thickness | 0.04 – 0.15 mm |
| Max Bag Width | 350 mm (330 mm effective seal width) |
| Bag Length Range | 50 – 300 mm · Skip-seal extends to 9× pitch length |
| Production Speed | 80 – 120 bags/min (varies by material and bag dimensions) |
| Sealing Structure | 2× horizontal heat stations + 1× cooling station + 1× longitudinal blade + optional bottom seal |
| Temperature Control | PID intelligent control — stable to ±1°C at full operating speed |
| HMI / Control | Independent PLC microcomputer cabinet + touch-screen HMI (speed, temp, length, batch count) |
| Safety Functions | Auto-stop on material out · Batch alarm · Bottom sealer auto-ascend device |
| Power Supply | 380V / 50Hz / 3-phase · Total: 7.5kW · Main motor: 2.2kW · Variable frequency drive |
| Machine Footprint | 4,200 × 1,300 × 1,800 mm (L × W × H) |
| Net Weight | 1,500 kg |
| Origin & Warranty | Ruian Xuanhai Machine Co., Ltd. — Zhejiang, China · 1 year + spare parts guarantee |
Get Factory-Direct Pricing — No Intermediary Markup
We manufacture every MJ-350A in-house at our Ruian facility. Share your bag dimensions, film structure, and target daily output — we'll respond within 24 hours with a full proposal.
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