HPMC (hydroxypropyl methylcellulose) is a non-ionic cellulose ether widely used in construction, medicine, food, daily chemical and other industries. According to its dissolution method and application characteristics, HPMC can be divided into two types: instant type and hot melt type. There are significant differences between the two in terms of production process, dissolution conditions and application scenarios.
1. Instant HPMC
Instant HPMC, also called cold water soluble type, can quickly dissolve in cold water to form a transparent colloidal solution. Its main features are as follows:
1.1. Solubility
Instant HPMC exhibits excellent solubility in cold water and is quickly dispersed when exposed to water. It can dissolve in a short time to form a uniform solution, usually without the need for heating. Its aqueous solution has good transparency, stability and viscosity adjustment capabilities.
1.2. Application scenarios
Instant HPMC is mainly used in scenarios that require rapid dissolution and solution formation. Typical application areas include:
Construction field: used as water retaining agent and thickening agent for cement-based materials and gypsum products to help improve construction performance.
Daily chemical products: such as detergents, shampoos, cosmetics, etc., instant HPMC can provide thickening and suspension effects for products, and dissolves quickly, making it suitable for rapid preparation occasions.
Pharmaceutical industry: Used as a film-forming agent, adhesive, etc. for tablets. It can be quickly dissolved in cold water to facilitate the production of preparations.
1.3. Advantages
Dissolves quickly and is suitable for cold processing situations.
Easy to apply and wide range of use.
The solution has high transparency and good stability.
2. Hot melt HPMC
Hot-melt HPMC, also known as hot-water soluble type or delayed-dissolution type, must be fully dissolved in hot water, or it may require a long dissolution time in cold water to gradually form a solution. Its characteristics are as follows:
2.1. Solubility
The dissolution behavior of hot-melt HPMC is significantly different from that of the instant type. In cold water, hot-melt HPMC only disperses but does not dissolve. It will only dissolve and form a solution when heated to a certain temperature (usually around 60°C). If added to cold water and stirred continuously, HPMC will gradually absorb water and begin to dissolve, but the process is relatively slow.
2.2. Application scenarios
Hot-melt HPMC is mainly used in scenarios where dissolution time or specific thermal processing conditions need to be controlled. Typical application areas include:
Building materials: such as construction adhesives, plastering mortars, etc., hot-melt HPMC can delay dissolution, reduce agglomeration during mixing or stirring, and improve construction performance.
Pharmaceutical industry: Such as coating materials for sustained-release tablets, etc., hot-melt HPMC helps regulate the release rate of drugs through its dissolution properties at different temperatures.
Coating industry: used for coating applications under some special high temperature conditions to ensure excellent film formation and stability during the construction process.
2.3. Advantages
It can delay dissolution and is suitable for occasions with special requirements on dissolution speed.
Prevents agglomeration in cold water and has good dispersion performance.
Suitable for thermal processing or applications where control of the dissolution process is required.
3. The main difference between instant type and hot melt type
3.1. Different dissolution methods
Instant HPMC: It can dissolve quickly in cold water to form a transparent solution, which is easy and quick to use.
Hot-melt HPMC: It needs to be dissolved in hot water or needs to be completely dissolved in cold water for a long time, which is suitable for some specific dissolution control requirements.
3.2. Differences in application fields
Due to its rapid dissolution characteristics, instant HPMC is suitable for situations where a solution needs to be formed immediately, such as construction and daily chemical product preparation. Hot-melt HPMC is mostly used in situations where delayed dissolution is required, especially in high-temperature construction environments or areas with strict dissolution time requirements.
3.3. Differences in product process
During the production process, instant HPMC is chemically modified to quickly dissolve in cold water. Hot-melt HPMC maintains its original properties and must be dissolved in hot water. Therefore, in actual production applications, it is necessary to select the appropriate HPMC type according to different process conditions and product requirements.
4. Things to note when choosing HPMC
When choosing to use instant or hot-melt HPMC, you need to make a judgment based on specific application requirements:
For scenarios that require rapid dissolution: such as building materials that need to be used immediately during production, or daily chemical products that are quickly prepared, quick-dissolving HPMC should be preferred.
For scenarios that require delayed dissolution or thermal processing: such as mortars, coatings, or drug sustained-release tablets that need to control the dissolution rate during construction, hot-melt HPMC should be selected.
There are obvious differences in dissolution performance and application fields between instant HPMC and hot-melt HPMC. The instant type is suitable for applications that require rapid dissolution, while the hot melt type is more suitable for scenarios that require delayed dissolution or thermal processing. In specific applications, selecting the appropriate HPMC type can improve production efficiency and optimize product performance. Therefore, in actual production and use, it is necessary to reasonably select the type of HPMC based on specific process conditions and product requirements.
Post time: Sep-25-2024