Blister packaging is widely used because of its excellent airtightness and portability. However, some pharmaceutical products and skin-care products containing sensitive ingredients often require packaging to provide more protection, which puts higher requirements on the barrier properties of blister packaging materials. How to choose the one with high barrier properties among many blister packaging materials? This article will help you understand the materials commonly used to make blisters, making it easier for you to choose packaging materials for your products.

1. Blister structure

A blister is composed of a formed foil and a lid foil. The formed foil is thermoformed or laminated to form blisters. The lid foil is composed of opaque cardboard, aluminum, or other composite material. Some blisters will cover a layer of aluminum foil over the formed foil or add a coating to the formed foil to improve the seal and barrier properties of the package.

The barrier property of the blister depends on the material of the formed foil. The selection of this part of the material should not only consider the barrier performance but also consider the plasticity and the difficulty of punching.

2. Commonly used materials for forming sheets

• PVC

PVC is a material with a low water vapor transmission rate. It has excellent plasticity and chemical corrosion resistance. These characteristics make PVC a popular choice for blister packaging materials. The cost of PVC is low, but the hydrochloride produced after its combustion will have adverse effects on the environment. Blister packaging usually uses pharmaceutical-grade PVC, which has less impact on the environment.

• PVDC

PVDC is the most common coating in blister packaging, which can reduce the air and moisture permeability of PVC blister packaging by 5-10 times. The heavier the coating weight of PVDC products, the better the barrier effect, and the higher the packaging cost.

• PP

The water vapor transmission rate of an uncoated PP sheet is lower than that of an uncoated PVC sheet, which is almost the same as that of a PVDC/PVC sheet. The advantage of PP is that it is easy to recycle and has good barrier properties, but it also has the disadvantages of high hardness and difficulty in thermoforming.

• OPA/AL/PVC

OPA/AL/PVC is also called a cold-forming foil. Cold-forming foil has an excellent barrier to water vapor and oxygen, and the effect is almost comparable to that of PVDC products with a coating weight of 90 Gramme/Square Meter. However, cold-forming foil is a cold-formed composite material that consumes more material when packaging the same size tablet or capsule compared to thermoformed materials.

To sum up, both PVDC and cold-forming foil have excellent barrier properties, but their packaging costs are also high. When you choose a blister packaging material, you should comprehensively consider the requirements for packaging barrier properties and packaging costs. If you have any needs for pharmaceutical packaging, welcome to browse our products through the official website. We have a variety of pharmaceutical packaging machines including blister packaging machines. If you have other questions, please consult us through the official website. Hoping Machinery sincerely looks forward to your visit!