Absorbent Pads and Pouches: The "Liquid Management Experts" in Food Packaging and Biological Sample Transport

In the modern fields of food packaging and biological sample transport, there is an unassuming yet critical product—the absorbent pad and absorbent pouch. These products quietly perform the essential tasks of absorbing excess liquid, preventing leaks, extending shelf life, and ensuring transport safety. This article provides a systematic introduction to the principles, types, applications, and industry trends of these products.

1. What is an Absorbent Pad?

An absorbent pad is a material specially designed to manage and control the accumulation of excess moisture and liquid in packaging. In food packaging, it is primarily used to absorb blood, juices, and other liquids exuded by meat, fruits, and vegetables during storage, transportation, or display. These pads are commonly found in supermarkets, meat processing plants, and fresh food distribution channels. In biological sample transport, absorbent pads serve as a critical leak‑prevention barrier, placed between the primary container and the secondary packaging to prevent the leakage of infectious substances during transit.

The core function of absorbent pads is achieved through the synergy between internal absorbent materials and outer liquid‑retention structures. With unique internal water‑absorbing beads and a film layer containing liquid‑locking devices, the pad can absorb substantial amounts of water without releasing it. In use, the pad is simply placed at the bottom of a food tray and sealed with plastic wrap—a quick, convenient, and straightforward process.

2. Structure and Materials

Absorbent pads have a multi‑layer composite structure. The inner layer mainly consists of superabsorbent polymer (SAP) particles, commonly sodium polyacrylate. The outer layer is made of composite materials such as PE film, perforated film, non‑woven fabric, etc.

Based on material composition, absorbent pads can be divided into the following types:

• Cellulose absorbent pads: Made from natural fibres, they offer strong absorbency while being environmentally friendly, widely used in meat and poultry packaging.

• Superabsorbent polymer absorbent pads: Known for ultra‑high absorbency, often used in seafood and fresh food packaging.

• Non‑woven pads: Excellent breathability helps maintain optimal food temperatures, suitable for temperature‑sensitive products such as meat, poultry, and dairy.

All food‑grade absorbent pads are manufactured using virgin food‑grade materials—the use of recycled materials is strictly prohibited—to ensure food safety.

3. Product Types: Absorbent Pads and Absorbent Pouches

3.1 Absorbent Pad

The absorbent pad is the most common form—a flat sheet placed at the bottom of a tray or package. The market offers a wide range of specifications, with common dimensions including 160×70mm, 160×80mm, 180×100mm, etc. Colours are available in white, black, red, and others, while absorption capacities range from 8ml/pad to 45ml/pad, varying by model.

Depending on the application, absorbent pads are further classified into soft pads, hard pads, tea‑bag pads, seafood pads, and more. Among these, the white sample absorbent pad is a popular option for customer sampling and testing.

3.2 Absorbent Pouch

An absorbent pouch is a pouch‑type structure that encapsulates the absorbent material. Compared to flat pads, pouches offer better containment and sealing properties, making them particularly suitable for applications requiring higher liquid‑management performance.

Absorbent pouches typically feature a multi‑bay design—the absorbent material is divided into separate compartments to optimise absorption efficiency and structural stability. Common specifications include:

• 2‑Bay Absorbent Pocket: Suitable for small‑capacity packaging needs

• 4‑Bay Absorbent Pocket: Water absorption capacity approx. 169ml, saline absorption capacity approx. 152ml

• 7‑Bay Absorbent Pocket: Designed for large‑capacity, high‑absorption requirements

The advantage of the multi‑bay design is that even if one compartment is damaged, the others remain functional, significantly enhancing product safety and reliability.

4. 95kPa Absorbent Pad – High‑Standard Safety Assurance

In the transport of biological samples and hazardous substances, the 95kPa absorbent pad is an important technical specification. The term “95kPa” means that the product can withstand a pressure differential of 95 kilopascals without leaking.

95kPa pouches and pads are primarily used in:

• Air transport of biological samples, which must comply with IATA Dangerous Goods Regulations (DGR) packaging requirements

• Transport of UN 3373 Category B biological substances, in accordance with ADR, IMDG, RID, and other international transport regulations

• Cross‑border transport of clinical trial samples and diagnostic specimens

In these scenarios, the 95kPa absorbent pad functions as a liquid‑locking layer placed between the primary container and the secondary packaging, serving as a critical safety barrier to prevent the leakage of infectious substances during transit. Depending on the specific product model, absorption capacities range from tens of millilitres to over 400ml of liquid.

5. Application Scenarios

Food Packaging Sector

Absorbent pads are widely used for:

• Fresh meat (beef, pork, lamb, poultry): absorbing blood and juices to maintain a fresh appearance

• Seafood (fish, shrimp): absorbing seawater or briny liquid to keep the packaging environment dry

• Fruits and vegetables: absorbing excess moisture to prevent decay and mould growth

• Dairy products (e.g., cheese): absorbing whey to preserve quality

Key functions of absorbent pads in these applications include: absorbing liquids released from thawed frozen meat and seafood, reducing the need for repackaging due to liquid contamination, maintaining clean display cases, preventing food spoilage, and reducing odours and bacterial growth.

Medical and Biological Sample Transport Sector

• Storage and transport of diagnostic and clinical samples

• Packaging and transport of infectious and hazardous substances

• Cold‑chain logistics for pharmaceuticals and chemicals

6. OEM Customisation and Factory Direct Supply

As market demand becomes increasingly diversified and personalised, OEM (Original Equipment Manufacturer) services for absorbent pads are gaining increasing favour with customers. Professional absorbent pad factories can provide comprehensive customisation based on specific client requirements:

• Size customisation: options ranging from 80×120mm to 180×320mm, and more

• Absorption capacity customisation: absorption volume can be flexibly designed according to product needs

• Material customisation: different outer layer materials and internal absorbent materials can be selected based on the application

• Colour customisation: available in white, black, red, etc.

• Packaging customisation: such as pieces per bag, bags per carton

The advantages of sourcing directly from an absorbent pad factory include: more competitive pricing, better quality control, shorter lead times, and more direct after‑sales service. Reputable absorbent pad suppliers typically operate fully automatic high‑speed production lines and clean‑room facilities, strictly adhering to international standards throughout production.

7. Market and Industry Trends

The global market for absorbent pads in food packaging is experiencing steady growth. According to statistics, the global food packaging absorbent pad market was valued at approximately US$608 million in 2024**, and is projected to reach **US$941 million by 2031, growing at a compound annual growth rate (CAGR) of 6.4% during the forecast period.

Regional market insights:

• Asia‑Pacific is expected to be the fastest‑growing region, driven by rising urban populations, increasing disposable incomes, and changing consumer preferences for fresh and packaged foods.

• North America holds a major share of the market, supported by stringent food safety regulations and a well‑established food retail system.

• Europe shows particularly strong demand for biodegradable and environmentally friendly absorbent pads.

Industry trends include:

• Sustainability: Growing demand for biodegradable absorbent pads

• Technological innovation: Continuous advancement in superabsorbent polymers and new composite materials

• Application expansion: Extending beyond traditional food packaging into medical, biological, industrial, and other fields