For e-commerce warehouses, the primary requirement is storage equipment. This chapter by Hegris outlines the types of storage equipment, their characteristics, and typical application scenarios.
Storage Equipment
Various types of storage equipment cater to different goods based on shape, weight, volume, and packaging. Common storage solutions for logistics centers (B2B or B2C) include:
1. Pallet racks
2. Drive-in/drive-out racks (traditional aisles, double-depth, narrow aisles, ultra-narrow aisles)
3. Push-back racks
4. Mobile racks
5. Automated storage (AS/RS)
6. Flow racks
7. Lightweight racks
8. Rotating racks (horizontal and vertical)
9. Automatic picking systems
Some less common options include cantilever racks (for long items), portable racks (for fragile or special-shaped goods), and loft racks (for pallets, containers, or single items), which we won't detail here.
E-commerce warehouses generally utilize two main storage methods:
1. Storage area (also called whole storage area or large cargo area)
2. Pick-up area (also known as picking area or single product area)
In the storage area, unit load pallets are primarily used. Pallet storage methods fall into two categories:
1. Ground pile: The simplest method, where pallets are stacked directly on the floor. It's easy to access but has low storage capacity and isn't ideal for irregularly shaped goods.
2. Pallet racks: The most common choice, characterized by:
- Suitable for bulk and boxed storage
- Effective for BC products in ABC classification
- Typically 3 to 5 layers high, below 6 meters
- Adjustable and combinable
- Simple construction at a relatively low cost
- Compatible with standard forklifts
In the zero-picking area, light shelves are predominant, with flow shelves used for first-in-first-out management of some products:
1. Light shelves: Similar to pallet shelves but designed for storage of individual products. Features include:
- Adjustable heights and spacing
- Economical and easy to assemble
- Versatile styles for various small goods
- Limited height, usually below 4 meters
2. Flow racks: Equipped with roller tracks allowing products to slide from the back to the front. Key attributes include:
- Suitable for small quantities of goods
- Prioritizes picking function over storage capacity
- Typically used for first-in-first-out needs
- Each channel stores only one SKU
- Quick installation and easy mobility
These shelving solutions are the most common in e-commerce warehouses, but other types exist, albeit infrequently. The choice of shelves depends on warehouse space, business model, operation type, and storage capacity requirements, with manual and automated warehouses having differing shelf needs.
Finally, to select and design storage equipment for a new warehouse, follow these steps:
1. Analyze and plan the storage system (EIQ analysis, ABC classification)
2. Choose the type of storage equipment (considering product characteristics, storage/access needs, inbound/outbound volume, and warehouse architecture)
3. Basic Design
(1) Number of cargo spaces
(2) Aisle width
(3) Equipment dimensions (length, width, height)
4. Configuration
(1) Logistics flow line
(2) Inbound and outbound locations
5. Evaluation
(1) Operational efficiency
(2) Space efficiency
(3) Product management
(4) Initial and operating costs
6. Implementation
Handling Equipment
Handling equipment primarily consists of vehicles, categorized into two series: stacker vehicles and trolleys. The stacker series safely lifts and moves loads, while the trolley series facilitates the easy transport of selected goods.
1. Stacker Series
(1) Low Lift
Pallet trucks are available in manual and electric types. Manual pallet jacks use hydraulics for horizontal and vertical movement, while electric versions are powered by batteries.
(2) High Lift
Stackers can lift up to 12 meters and include walk-behind, stand-up, and sit-stand types. Walk-behind and stand-up models typically lift between 2.7 and 3.9 meters. Various types are available for specific applications, including counterweight, narrow channel, rotating column, side load, rotating fork, and high lift storage and retrieval machines.
2. Trolley Series
(1) Flatbed Trolley
Flatbed trolleys are customized based on warehouse requirements, considering load weight, size, and material. They can be made of wood or steel and may feature single or multi-layer designs, one-way rollers, universal rollers, and braked casters.
(2) Cage Trolley
Cage trolleys are used for picking and collecting goods, such as moving packages to delivery areas or collection vehicles. They are often customized, with common designs featuring a closed cage and an opening at the front. For picking and sorting, they may have multiple slots based on order volume, functioning as movable sowing walls during the picking process.
Conveying Equipment
The most common warehouse conveyors are unit load conveyors and three-dimensional conveyors. Unit load conveyors include rollers, belts, and chains, primarily used for fixed-path transport of turnover boxes, cartons, or other fixed-size items.
Unit load conveyors can be categorized into gravity and power types. Gravity conveyors rely on the weight of items, sliding down inclined paths. Rolling rotors include rollers, drums, and balls. Power conveyors are motor-driven and can be chain, roller, or belt types, with the latter two being prevalent in e-commerce warehouses.
1. Gravity Type
(1) Roller
(2) Drum
(3) Ball
2. Power Type
(1) Chain Conveyor
a. Sliding
b. Rolling
(2) Roller Conveyor
a. Flat belt drive
b. V-belt drive
c. Chain drive
d. Round belt drive
e. Toothed belt drive
f. Bevel gear drive
g. Electric roller
(3) Belt Conveyor
a. Direct delivery module
b. Turning module
c. Spiral module
(4) Classification Conveyor
a. Push type
b. Guide type
c. Slider type
d. Inclined belt type
e. Tipping type
f. Trolley type
Three-dimensional conveyors are classified into vertical, suspended, and ground rail types based on their spatial orientation.
