Table of Contents
- Why ordinary plastic becomes brittle in a blast-freezer
- Cold-resistant materials: HDPE, PP and temperature limits
- ICD corrugated plastic crates for seafood blast-freezing
- Handling thermal shock when moving crates in and out of the freezer
- Choosing the right crate by seafood processing stage
- Related articles
- Frequently asked questions about cold-storage plastic crates
- Contact ICD Vietnam
Reviewed and updated by ICD - Week 30/2026
Plastic crates and trays used in cold storage and seafood blast-freezing must withstand deep-freeze temperatures without becoming brittle or cracking. Standard PP plastic becomes brittle below -10 C, while seafood blast-freezers run at -18 C to -40 C. Choosing the wrong material causes crates to shatter from impact inside the freezer, dropping loads and creating safety hazards. This guide covers cold-resistant plastics, the brittle-point of each type, how to handle thermal shock when moving crates in and out of the freezer, and ICD corrugated plastic crate specifications for seafood processing and frozen-goods storage.
Why ordinary plastic becomes brittle in a blast-freezer
As temperature drops, plastic loses its ductility and turns brittle. Each plastic type has its own brittle-point threshold. Below that threshold, even a light knock during freezer handling is enough to crack a crate or shatter a corner. This is why standard plastic crates perform well in a chilled store but fail quickly in a blast-freezer.
Cold-resistant materials: HDPE, PP and temperature limits
| Material | Working temperature | Cold-storage suitability |
|---|---|---|
| Virgin HDPE | -40 C to 80 C | Best choice for deep blast-freezing |
| PP copolymer | -20 C to 100 C | Chilled and light-freeze stores; prone to cracking below -10 C under impact |
| Recycled HDPE | Brittle below -5 C | Not suitable for cold storage |
| ABS | -20 C to 85 C | Brittle at deep-freeze temperatures; not suitable for blast-freezers |
Selection rule: seafood blast-freezers running -18 C to -40 C require virgin HDPE. PP is only suitable for chilled and light-freeze applications. Never use recycled plastic or ABS for deep-freeze cold stores.
ICD corrugated plastic crates for seafood blast-freezing
| ICD line | Dimensions (mm) | Freezer application |
|---|---|---|
| Open-mesh HDPE tray | 610 x 420 x 100 | Blast-freezing fish and shrimp; drains melt water |
| Open-mesh HDPE tray (tall) | 610 x 420 x 250 | High-volume seafood holding |
| Solid HDPE crate with lid | To specification | Frozen-goods storage; prevents moisture loss |
Open-mesh trays suit blast-freezing because they drain melt water and let cold air circulate for faster, more even freezing. Solid lidded crates suit already-frozen goods storage to prevent sublimation and moisture loss. Specify virgin HDPE to handle deep-freeze temperatures and allow chemical-sanitiser washing.
Handling thermal shock when moving crates in and out of the freezer
Why thermal shock damages crates
A crate moved abruptly from a -25 C freezer into a 30 C ambient environment faces a large temperature differential that causes uneven expansion and condensation. Repeated cycles fatigue the plastic and shorten service life, especially for materials other than virgin HDPE.
How to reduce thermal shock
Limit the number of freeze-thaw cycles a single crate goes through each day; use a temperature buffer zone between freezer and ambient areas where possible; and specify virgin HDPE because its wide working temperature range handles large differentials better than other materials. Avoid heavy impacts immediately after the crate leaves the freezer while the plastic is still cold and at its most brittle.
Choosing the right crate by seafood processing stage
| Processing stage | Recommended crate type | Reason |
|---|---|---|
| Receiving and primary processing | Open-mesh HDPE tray with ice | Drains water; holds temperature with ice |
| IQF and block blast-freezing | Open-mesh HDPE tray | Cold-air circulation for fast, even freezing |
| Frozen-goods cold storage | Solid HDPE crate with lid | Prevents moisture loss; stackable |
| Frozen-goods transport | Insulated solid crate | Maintains temperature outside the freezer |
Related articles
| ICD industrial plastic crates | How to read plastic crate codes | Plastic crate dimensions: reference table |
Frequently asked questions about cold-storage plastic crates
1. What is the lowest temperature a plastic crate can handle?
It depends on the material. Virgin HDPE handles down to -40 C and is suitable for deep blast-freezing. PP copolymer is rated to -20 C but cracks easily below -10 C under impact. Recycled plastic and ABS become brittle at deep-freeze temperatures and should not be used in cold stores.
2. Which plastic crate should I use in a seafood blast-freezer?
Use virgin HDPE. Open-mesh trays suit blast-freezing because they drain melt water and allow cold-air circulation for faster, more even freezing. Solid lidded crates suit already-frozen goods storage to prevent moisture loss. Avoid PP, recycled plastic, and ABS.
3. Why do standard plastic crates crack in a blast-freezer?
Because plastic loses ductility and becomes brittle below its brittle-point threshold. PP turns brittle below -10 C, so even a light knock during freezer handling is enough to crack or shatter a corner. Virgin HDPE stays ductile down to -40 C and does not have this problem.
4. Which is better for blast-freezing - open-mesh trays or solid crates?
Open-mesh trays are better for the blast-freezing stage because they drain melt water and allow cold-air circulation for fast, even freezing. Solid lidded crates are better for storing already-frozen goods because they prevent sublimation and moisture loss. Each type serves a different stage.
5. How do I prevent crate damage from thermal shock?
Limit the number of freeze-thaw cycles per crate per day, use a temperature buffer zone between the freezer and ambient areas where possible, and specify virgin HDPE because its wide working temperature range handles large differentials better. Avoid heavy impacts immediately after the crate leaves the freezer while the plastic is still cold and at its most brittle.
Contact ICD Vietnam
Hotline: 0983 797 186 / 090 345 9186 / 090 5859 186
Email: sales@icdvietnam.com.vn | Zalo: Chat Zalo
