A Guide to Disposable Care Products: What’s the Difference Between Liners and Underpads?​

With the advancement of an aging society and the growing demand for maternal and child care, the market scale of disposable care products continues to expand. However, many consumers often confuse "liners" and "underpads" when purchasing, mistakenly treating them as interchangeable products. This not only affects the care effect but also may lead to resource waste or skin health risks. Recently, the reporter visited a number of medical and health product enterprises and experts in the care field, comparing the two from the perspectives of product positioning, functional design, and application scenarios, to clarify the core differences for consumers.​

Core Positioning: The Fundamental Difference Between "Body-Fitting Protection" and "Environment Protection"​

According to reports, liners, also known as "pad-style absorption towels," are "body-fitting" care products. They usually have a small size (common specifications: 20cm×30cm - 35cm×50cm) and a thin thickness (about 1-3mm). Designed to fit the human skin or underwear, their core function is to absorb a small amount of liquid (such as minor urine leakage in patients with mild urinary incontinence, a small amount of lochia in Postpartum women, and daily sweat in the elderly). This prevents liquid from directly contacting clothing and reduces the frequency of clothing changes. Their material structure mostly adopts "hydrophilic surface layer + thin absorption layer + leak-proof bottom layer," focusing on portability and body-fitting comfort. Some products can also be fixed to underwear, making them suitable for daily activities.

In contrast, Underpads, also known as "disposable care pads," are "environment-oriented" protective products. They generally have a larger size (common specifications: 60cm×60cm - 80cm×180cm) and a thicker thickness (about 5-10mm). Their core function is to "isolate liquids and protect the surface of the environment," such as mattresses, sofas, and wheelchair cushions. Their structure centers on a "high-absorption layer + strong leak-proof bottom layer," with a higher content of superabsorbent polymer (SAP) in the absorption layer. This allows them to quickly lock in a large amount of liquid (such as nighttime urine leakage in infants, urine from patients with severe urinary incontinence, and secretions from post-operative patients), preventing liquid from seeping into bedding or furniture surfaces and avoiding mold, odors, and cleaning difficulties.​

Functional Design: Comprehensive Differences in Size, Absorption Capacity, and Material​

To further clarify the differences between the two, the reporter conducted an experimental comparison of liner and underpad products from two mainstream brands and found significant differences in size, absorption capacity, and material details:​

1、Size and Coverage Area: "Local Body-Fitting" vs. "Large-Area Protection"​

The reporter's actual measurement showed that the size of an adult liner from a certain brand is 32cm×45cm. When unfolded, it can only cover the local area of the human buttocks and thigh roots, and can be easily folded and placed in a pocket or portable bag. In contrast, the underpad of the same brand has a size of 60cm×90cm. When unfolded, it can cover 1/2 to 2/3 of a single mattress, and can even fully cover an infant's crib or wheelchair cushion, making it suitable for large-area protection scenarios.​

"The difference in size is the most intuitive distinguishing feature," Wang Lei emphasized. If a liner is used as a substitute for an underpad on a mattress, the small coverage area will easily cause liquid to spill over the edges, leading to mattress contamination. Conversely, if an underpad is used as a liner next to the skin, its large size will cause inconvenience in movement, and the thick material may cause skin stuffiness and discomfort.​

2、Absorption Capacity: "Small-Amount Emergency" vs. "Large-Amount Storage"​

In the absorption capacity test, the reporter injected equal amounts of normal saline (50ml, 100ml, 200ml) into the two products respectively. The results showed that after injecting 50ml of liquid into the liner, the surface layer remained dry, but slight seepage appeared at the bottom layer. After injecting 100ml, liquid seeped out significantly from the bottom layer. However, after injecting 200ml of liquid into the underpad, there was no seepage, and no rewetting was observed when pressing the surface layer.​

"The absorption capacity of liners is usually 50-150ml, which is suitable for mild and short-term absorption needs. The absorption capacity of underpads can reach 300-800ml, which can meet the needs of long-term and large-volume liquid absorption," Li Min, director of the nursing department of a top-three hospital, explained. For example, elderly people with mild urinary incontinence can use liners to absorb minor urine leakage during daily activities, but must use underpads at night when lying in bed to prevent a large amount of urine from seeping into the mattress.​

3、Material Details: "Portable and Comfortable" vs. "Durable and Leak-Proof"​

In terms of materials, the surface layer of liners mostly uses ultra-thin cotton-soft non-woven fabric, which has a delicate touch. The bottom layer is a thin breathable PE film, focusing on lightness and breathability, making it suitable for close-fitting use. On the other hand, the surface layer of underpads mostly uses thickened hydrophilic non-woven fabric, which has stronger friction resistance. The bottom layer is a thickened leak-proof PE film (some products also add a non-woven composite layer), which can effectively prevent liquid seepage and avoid slipping at the same time. In addition, the absorption layer of underpads has a higher ratio of fluff pulp to superabsorbent polymer (SAP), which can form a stable "gel water-locking layer" and reduce caking and rewetting.

WHOLESOME is dedicated to the R&D, production and sales of absorbent hygiene products, providing customers with safe and convenient one-stop OEM services. If you need to customize Adult Diaper, adult pull ups, underpad, Pet Pad, sanitary napkin and other hygiene products, WHOLESOME is a good choice.We look forward to your contacting us.