Fstsort 8-head linear weigher for small fruits (≤40mm). Fills punnets or clamshells (small plastic boxes up to 1000g). Complete line: inspection belt, multi-head weigher, auto box feeder, checkweigher, labeler. Also known as linear combination weigher. Get quote.
Product Overview – Complete Punnet Packing Line with Linear Weigher
This 8-head linear weigher (also known as a linear combination weigher or multi-head linear weigher) is designed specifically for small fruits that require gentle handling and precise weight filling into punnets or clamshells – small plastic boxes typically used for 1000g or less.
Typical applications:
Cherry tomatoes
Litchi (lychee)
Jujube (winter date)
Longan
Apricot (small)
Walnut (small)
✅ Fruit size limit: Diameter smaller than 40mm (round fruits).
✅ Box capacity: Standard up to 1000g (customizable).
✅ Linear weigher design: Evenly distributes fruit into 8 channels for high-speed, accurate filling.Complete Line Components
The line consists of 8 integrated machines for a fully automated packing process.
No.
Component
Function
1
Inspection belt conveyor
Manual sorting of defective fruit
2
8-head linear weigher
Even distribution + target weight filling into punnets/clamshells
3
Material receiving & box pressing conveyor
Box closing
4
Automatic punnet/clamshell feeder
Feeds empty boxes into line
5
Elevating conveyor
Transfers boxes between sections
6
Checkweigher
Weight verification and rejection
7
Labeling machine
Automatic label application
8
Feed tray
Collects finished boxes
💡 Complete automation: From empty box feeding → filling → weighing → closing → checkweighing → labeling.
What is a Linear Weigher?
A linear weigher (or linear combination weigher) is a type of multi-head weighing system where fruit is distributed linearly into multiple channels. It is ideal for small, uniform products like cherry tomatoes, litchis, and jujubes.
How it works:
Fruit is evenly distributed into 8 linear channels
Each channel weighs a portion independently
The system selects the best combination of channels to achieve target weight
Fruit is released into punnets or clamshells below
Compared to rotary weighers: Linear weighers are more compact and often more accurate for small, delicate fruits.
✅ Also known as: Linear combination weigher, multi-head linear weigher, 8-head linear scale, or simply punnet packing weigher.
Working Process – Step by Step
Step | Process |
|---|---|
1 | Fruits are manually or via conveyor poured onto the inspection belt. Workers stand on both sides to pick out defective fruit. |
2 | Fruits are conveyed to the 8-head linear weigher, which evenly distributes them into 8 channels and completes target weight filling into punnets/clamshells. |
3 | The automatic box feeder drops empty punnets/clamshells onto the receiving conveyor, which moves them under the linear weigher. |
4 | Filled boxes are conveyed to the box pressing mechanism for automatic closing (snaps clamshells shut). |
5 | Closed boxes are lifted via elevating conveyor to the checkweigher for weight re-inspection. Unqualified boxes are rejected. |
6 | Qualified products are conveyed to the labeling machine for automatic labeling. |
7 | Finished boxes are sorted onto the feed tray for collection. |
Key Features
Feature | Benefit |
|---|---|
8-head linear weigher | Even distribution into 8 channels – high speed, accurate filling |
Linear combination weighing | Selects best channel combination for target weight – reduces giveaway |
Target weight filling | Within 1000g – preset weight, consistent pack sizes |
Supports punnets & clamshells | Works with both industry-standard box types |
Stainless steel 304 | Food-grade, hygienic, easy to clean |
WEINVIEW HMI | User-friendly touch screen operation |
50 formula storage | Quick change between different fruits and pack sizes |
Modular control system | Easy and cost-effective maintenance |
Checkweigher + rejection | Ensures only qualified boxes reach labeling |
Automatic labeling | Saves labor, consistent label placement |
Technical Specifications – Main Components
8-Head Linear Weigher
Parameter | Value |
|---|---|
Model reference | FST8H2016 |
Type | Linear combination weigher / multi-head linear weigher |
Single weighing range | ≤ 750g (can be adjusted for up to 1000g) |
Weighing accuracy | Single fruit weight |
Capacity | 20–30 boxes/min (1,200–1,800 boxes/hour) |
Fruit size limit | ≤ 40mm (round fruit) |
Filling weight | Within 1000g (customizable) |
Weighing method | Combined filling – small channel design for accuracy |
Material | Stainless steel 304 |
Power | 1.1kw |
Dimension | 1600*1650*1300 mm |
Key components | KUNLUN touch screen, ZHONGHANG sensors, SIEMENS PLC, OMRON power switch |
Checkweigher
Parameter | Value |
|---|---|
Single weighing range | ≤ 3000g |
Weighing accuracy | ±0.5g ~ ±2g |
Minimum graduation | 0.1g |
Maximum speed | 100 pcs/min |
Material | SUS304 stainless steel |
Labeling Machine
Parameter | Value |
|---|---|
Labeling speed | 30–120 pcs/min |
Labeling accuracy | ±1mm |
Features | Fault alarm, production counting, power saving |
Standard Punnet / Clamshell (Reference)
Parameter | Value |
|---|---|
Capacity | 500–600g (up to 1000g available) |
Dimension | 177*145*75 mm |
Box types | Punnet (general) / Clamshell (hinged lid) |
✅ Custom box sizes – We can adjust the line to your specific punnet or clamshell dimensions, as long as capacity is within 1000g.
Frequently Asked Questions
Key questions customers usually ask before choosing this solution.
What fruits can this line pack?+
It is designed for small round fruits ≤40mm diameter: cherry tomatoes, litchi, jujube, longan, small apricot, and walnut.
What is the box capacity range?+
The standard configuration handles up to 1000g. The reference box is 500–600g (177*145*75mm). Custom sizes within 1000g are available.
How accurate is the linear weigher?+
The 8-head linear weigher uses a combined filling method with small channels for high accuracy. The checkweigher verifies each box with ±0.5–2g accuracy.
What is the packing speed?+
20–30 boxes per minute (1,200–1,800 boxes per hour), depending on fruit size and box volume.