Technical specifications are the language of packaging machinery buyers. But suppliers sometimes use different definitions for the same term, leading to misunderstandings. This buying guide breaks down every major specification for automatic packaging machines, including hidden nuances that affect real-world performance.
1. Speed Ratings – Theoretical vs Sustained
Most datasheets show “maximum speed” achieved under ideal conditions: smallest bag size, easiest product, perfect film, and skilled operator. The spec you need is sustained operating speed for your specific bag length. A rule of thumb: sustained speed is 70–80% of claimed max. Always ask: “What speed can I expect running a 200mm bag length with standard film?”
2. Fill Accuracy (for weight-based systems)
Expressed as ±X grams or ±X%. For example, ±0.5g on a 100g fill = ±0.5% accuracy. Critical for expensive products (spices, pharmaceuticals). The spec should include standard deviation over 100 consecutive fills. Beware of “accuracy at steady state” – actual accuracy during start/stop cycles is often worse.
3. Seal Types and Their Applications
- Heat seal: Most common, requires coated film. Temperature control ±2°C is good.
- Ultrasonic seal: No heat, ideal for contaminated films (powder on seal area).
- Cold seal: Pressure-sensitive adhesive, for heat-sensitive products like chocolate.
- Vacuum/Modified Atmosphere seal: Includes gas flushing before sealing. Spec includes residual oxygen level (e.g., <1% O2).
Seal strength is measured in N/15mm. For dry products, 20N/15mm is adequate; for liquid or vacuum packs, require 35N/15mm minimum.
4. Bag Length and Width Range
Spec shows “bag length: 50–300mm”. But note: the machine may only achieve max speed at mid-range lengths. Also, the maximum width is often reduced when using gusseted bags. Request a speed vs bag length curve from the supplier.
5. Electrical and Pneumatic Requirements
Check voltage (single-phase 220V vs three-phase 380V/415V), frequency (50/60Hz), and power consumption in kW. For pneumatics: required air pressure (usually 6 bar) and consumption in liters/minute. Under-specifying your compressor leads to pressure drops and faulty seals.
6. Control System and Connectivity
Look for: PLC brand (Siemens, Allen-Bradley, Mitsubishi), HMI screen size and resolution, number of recipe storage slots, and communication protocols (Ethernet/IP, Profibus, OPC UA). For Industry 4.0, ensure the machine can export OEE data via MQTT or REST API.
7. Construction and Materials
Food-grade machines require 304 or 316 stainless steel contact parts. Pharmaceutical grade requires FDA-compliant surfaces with Ra < 0.8µm. For corrosive environments (e.g., salt, fertilizers), ask for electropolished stainless or coating.
8. Noise Level and Safety Features
CE-compliant machines have noise emission under 80 dB(A) at 1 meter. Safety features include light curtains, two-hand controls, and emergency stops. Never compromise safety for price – it can lead to OSHA fines and injuries.
How to Compare Specs from Different Suppliers
Create a standardized test protocol. Send the same product, film, and bag dimensions to three suppliers. Ask each to run for 2 hours and report: average PPM, fill accuracy standard deviation, seal strength, and downtime percentage. Only then will you have comparable data.
Decoding technical specifications is not just about numbers – it’s about understanding what those numbers mean in your production environment. Use this guide to ask the right questions and avoid post-purchase disappointments.