In the growing medical device industry, pressure sensitive adhesive tape is widely used. Pressure sensitive adhesive tape is often the main or even key part of the products used in surgery, wound, incontinence care, monitoring, diagnosis and other aspects. The performance and performance of the final product is also closely related to the performance and performance of pressure sensitive tape. Therefore, in the design of medical products, how to select the pressure sensitive tape with appropriate function and excellent performance has become an important topic for the corresponding researchers. This paper briefly summarizes the characteristics of medical pressure-sensitive tape, and introduces the key points of selecting pressure-sensitive tape in the design process from the practical application of disposable surgical towel, ECG electrode and blood glucose test paper.

First, the characteristics of pressure-sensitive adhesive tape. The so-called pressure-sensitive adhesive refers to a kind of adhesive sensitive to pressure. Through the hand or finger, a certain amount of pressure is applied to the bonding surface to form bonding. Pressure sensitive adhesive tape is a kind of adhesive tape which is coated on the strip material (such as film, non-woven fabric and foam) and has pressure sensitivity after drying. Generally, pressure sensitive adhesive tape is composed of substrate, adhesive layer, release paper, unwinder, etc.

Compared with other adhesive methods, pressure sensitive tape has the following advantages:

1. The use of pressure-sensitive adhesive tape is convenient and fast without heating, solvent modulation, mechanical reinforcement and other cumbersome processes.

2. Pressure sensitive adhesive tape is easy to keep, and the adhesive layer will not dry in a long time, so it is also called self-adhesive.

3. In most cases, it can be peeled off from the surface without damage, which is also an important advantage of pressure sensitive adhesive tape. It is because of these unique advantages that pressure sensitive adhesive tape is widely used in medical products, especially in disposable medical products.

Second, simply list some common applications

· disposable surgical towel;

Wound care products, including transparent dressings, functional dressings, infusion stickers, pocket making, etc;

Monitoring products such as ECG electrode, EEG electrode, blood oxygen probe, etc;

In vitro diagnostic products - blood glucose, cholesterol, bilirubin, blood lipid and other test strips;

External paste products.

There are some special requirements for pressure-sensitive adhesive tape used in medical products, which need to be considered and realized in the process of research and development of pressure-sensitive adhesive tape.

Third, different medical tape

(1) Safety for medical products, especially those that directly or indirectly contact with human body, the safety is mainly reflected in environmental protection, biocompatibility, production process stability and traceability. For the key process parameters, the process capability index (CPK) is usually required to be greater than 1.33, and the lot number can be used to trace the raw material batch, operator, equipment parameters and other relevant information of any batch of products, so as to investigate and improve the problems.

(2) The function of functional pressure sensitive adhesive tape, simply speaking, is to stick well.

For medical pressure sensitive tape, there are three main points

1. Whether the adhesion to the material is enough: when the tape needs to stick the material to the skin (for example, when it is used for surgical towel), the tape should be able to stick firmly to the skin surface.

2. Whether the stickiness to the skin is appropriate: as most medical tapes need to stick to the skin, they should have appropriate stickiness, not the stronger the better. 3M clinical research department evaluates the strength and applicability of adhesive tape to skin by testing the peel strength of adhesive tape on skin. (as shown in the figure)

3. Whether it can adapt to the corresponding sterilization methods: different sterilization methods have different effects on the product performance, so it is an important part of product design to select the materials suitable for the sterilization methods.

(3) With the improvement of medical level, comfort of medical products has been paid more and more attention by medical staff and patients. For medical products using pressure-sensitive adhesive tape, whether there is pain when tearing off, whether there is residual adhesive, how the compliance and elasticity are, and whether it is close to the patient's intuitive feelings are the concrete embodiment of the comfort of the tape. How to transform these projects into quantifiable and testable indicators is an important task for medical tape manufacturers.

Fourth, the choice of pressure sensitive adhesive tape for different medical supplies

(1) The first kind of disposable surgical towel is the application of double-sided tape

The front side of the double-sided tape (the open side of the roll) is pasted on the surgical towel material. When it is used in the operating room, the release paper is removed and the back side is pasted on the patient's skin to form a fixation. In addition to fixing the surgical towel, the tape can also prevent the microorganisms in the non sterile area of the skin from moving to the surgical site, so as to avoid the wound infection. The second application is the use of single-sided film tape applied to the surgical site, the doctor directly cut the tape and skin, surgery, commonly known as surgical film, can effectively prevent with the passage of time, the surgical incision around the skin deep microbial migration to the skin surface, and then into the incision, causing infection.

Selection requirements:

Good adhesion to surgical towel material

The skin is sticky, especially wet

Easy to tear off from the skin, no damage and residual glue

Good compliance (skin fit)

It has a certain shear strength

Appropriate unwinding force and release force

(2) For ECG electrodes pasted for a short time, medical adhesive tape with good initial viscosity should be selected instead of paying special attention to air permeability. For the electrode products used in Holter, the adhesion and air permeability of backing tape are more important. On the one hand, it can ensure that the electrode can stick firmly and record information accurately, on the other hand, it can provide better comfort for patients. For departments such as intensive care unit that stick electrodes for a long time, ECG electrodes with lower allergy, better air permeability and milder viscosity are the ideal products they are looking for.

(3) The structure of blood glucose test paper is usually divided into two types: side injection and top injection. However, either way, the double-sided adhesive tape is used to connect the substrate and hydrophilic membrane, and form narrow channels to conduct blood samples. Due to the need of testing, the width and thickness of the product should reach a certain accuracy. According to the different designs of enterprises, the tolerance is usually required to be within ± 0.1 ~ 0.3mm. For double-sided tape, this requires that the substrate has excellent dimensional stability, and the gluing thickness also needs to be very accurate, which does not change due to external influence.

In addition, the cutting process of blood glucose test paper has strict requirements on the performance of double-sided tape. Due to the small size of blood glucose test paper (usually about 3.5cm × 0.5cm), the slight glue overflow and deformation caused by edge stress during cutting are also big defects for the product, which affect the effect of use and detection. Therefore, the double-sided tape used for this kind of products should be designed with thick base material and good rigidity, thin adhesive layer and good cohesion to meet the processing requirements. Conclusion: in the process of product design, the selection of appropriate raw materials is very important, and often becomes the key factor to determine the success or failure of products. Among the above mentioned products, medical tape is not the only raw material component, but it plays a role in determining whether the product is effective or not.