At a glance
25 kg sacks on pallets are a format for smaller granulate batches, specialty additives, or when customer prefers simpler end-use packaging. Silo trailer transloading is manual and labor-intensive — but standard at SMIALA for many customers.
| Parameter | Value |
|---|---|
| Standard sack | 25 kg (PE/PP/paper) |
| Typical pallet | 1375 kg (55 × 25 kg) |
| Time/sack | 90–120 seconds |
| Time/pallet | 25–35 min |
| Time/20 t silo trailer | 6–8 h |
| Standard | ISO 9001:2015 |
When 25 kg instead of big-bag
Producer chooses 25 kg sacks when:
- Smaller volume — 5–10 ton batch, where big-bags (1000 kg) would be too large for end use
- Specialty additives — color master batches, UV stabilizers, antistatics, antimicrobials — typically in 25 kg
- End customer uses sacks — small-scale production (laboratories, prototypes, for extruders without silo infrastructure)
- Hygroscopic premium grade — paper sacks with aluminum barrier for maximum PA, PET protection
- Legacy logistics contract — some long-term contracts have not changed packaging format
For typical PE/PP importer from Asia — 25 kg sacks are <10% of volume but require separate operational capability.
Procedure — manual pouring
1. Pallet reception
Pallets with sacks delivered in container (mixed pallets in 20’/40’ container) or directly on platform truck. Operator:
- Unloads pallets with forklift (3.5 t standard)
- Visually inspects sack condition (no tears, no moisture)
- Scans pallet labels (lot number, material, quantity)
Damaged sacks — set aside to claim zone, customer contact.
2. Transload station
Receiving silo trailer:
- Working hatches (top hatch) open — preferred for easy pouring
- Or inlet with hopper (if hatch inaccessible)
- Standard compartment cleanliness verification
3. Operator removes sack
From pallet, manually:
- 25 kg is within standard lifting range (ergonomics: single-person lift up to 25 kg)
- Operator carries sack to opening
- Positions above opening
4. Opening and emptying
- Open-mouth sack (typical for PE/PP): operator unfolds top, pours
- Valve sack: operator inserts valve into opening, opens, pours
- Foil sack tightly heat-sealed: cuts with safety knife, pours
Time: 30–60 seconds per sack emptying + 30–60 seconds handling/transport.
5. Empty sack disposal
- PE/PP sacks — segregated foil waste (recycling)
- Paper sacks — segregated paper waste
- Aluminum barrier sacks — separate disposal (mixed recycling or disposal)
- Strings, labels, clips — separate waste
6. Documentation
Standard protocol + for 25 kg:
- Sack count loaded
- Damaged/rejected count (if any)
- Operator work time logs (ergonomics: lifting time limits)
- Photo of first and last pallet
Materials most commonly in 25 kg
Color master batches
Producers: Clariant, Ampacet, Cabot, A.Schulman, PolyOne. Master batches for:
- Film extruders — color concentrates
- Injection molders — optical effects (pearl, metallic)
- Fiber production — UV-resistant colorants
25 kg sacks or smaller (10 kg, 15 kg) on 800–1000 kg pallets.
Functional additives
- UV stabilizers (Ciba, BASF Stabilizers) — 25 kg standard
- Antistatics (Croda, Palsgaard) — 25 kg
- Antimicrobials (Microban, Sanitized) — often 25 kg paper sack with barrier
- Flame retardants — brominated, phosphorus-based, mineral — 25 kg
Premium hygroscopic grades
Some high-quality PA6 / PA66 batches (medical grades) — packed in multi-layer paper sacks with aluminum barrier, 25 kg. Smaller sack = better surface/volume ratio = easier moisture protection between opening and use.
Minerals / lime
In 25 kg paper or kraft sacks. Less common — most minerals handled in big-bag — but some customers prefer for precise dosing in production.
25 kg logistics — operation economics
| Parameter | Big-bag 1000 kg | 25 kg sacks |
|---|---|---|
| Tonnage per 20’ container | 20–24 t | 18–22 t (pallets) |
| Transload time/ton | ~12 min | ~70 min |
| Worker count | 1 | 1–2 (at higher volumes) |
| Packaging waste | Low (1 sack/t) | High (40 sacks/t) |
| Documentation time | Low | Higher (per sack or per pallet) |
| Handling cost/t | Lower | Higher (5–6×) |
For typical PE/PP importer — 25 kg sacks make economic sense for small batches, expensive additives, or when end customer lacks big-bag infrastructure.
OSH — manual pouring safety
25 kg is at ergonomic limit for manual lifting. Standards:
- Maximum 25 kg single lift with partner
- Maximum 15 kg for repetitive lifting (>2/min)
- Operator rotation required every 2-3 hours
- Mandatory annual OSH training
For large sack batches (>5 tons) — additional operator. For very large batches (>20 tons) — discuss with customer whether big-bag would be better format.
Special sacks — moisture barrier
Multi-layer paper sacks with aluminum barrier:
- Used for hygroscopic PA, PET, PBT in smaller volumes
- Opening in zone with RH <40%
- Sack interior exposure time to hall — <5 min
- Humidity documentation during operation
Non-barrier sacks (PE/PP standard) — no special humidity procedure.
Food-grade 25 kg
For food-contact materials delivered in 25 kg:
- Dedicated station (segregation)
- Operator with food hygiene certification
- Tools (knives) replaced between batches
- Silo trailer compartment washed with food-grade detergent before loading
- Documentation: cleanliness certificate + washing report
Contact
PHS Magnum / SMIALA
- Phone: +48 664 135 005
- E-mail: biuro@magnumchorula.pl
- Address: ul. Kościelna 9, 47-316 Chorula, Poland
For 25 kg sack operations — please provide advance notice with pallet/sack count, total volume, material. 48–72h notice for resource planning (operators, stations).
Related: Big-bag to silo trailer · Octabin to silo trailer · Repackaging granulates · Storage · Contact
