### 1. Definition and application

* A plastic spray head is a nozzle for liquid or gas injection, which is composed of a nozzle, a spray hole and a filter.
* Plastic spray heads have a wide range of applications in various fields, such as cosmetics, medicine, agriculture, industry, etc.
* In the field of cosmetics, plastic spray heads are often used to spray liquid cosmetics such as lipstick, perfume, toner, etc.
* In the pharmaceutical industry, it is used in medical devices such as syringes and nebulizers.
* In the agricultural sector, plastic spray heads are used for irrigation and agricultural product protection.
* In the industrial field, it is used for cleaning, painting and spraying.

### 2. Structure composition

* Plastic spray head is mainly composed of nozzle, valve, extrusion rod, spring and other components.
* The nozzle, as the core component of the nozzle, determines the shape and flow rate of the spray.
* The valve controls the flow of the spray, while the extrusion rod and spring ensure that the valve is open and closed.

### 3. How it works

* Plastic spray heads work by spraying liquid or gas out through pressure.
* When the liquid or gas enters the nozzle, the liquid or gas is sprayed out through the nozzle hole due to the change in pressure.
* Factors such as the size, location and number of the nozzle holes will affect the flow rate and injection effect of the liquid or gas emitted.

### 4. Spray method

* There are two main spray methods for plastic spray heads: spray and linear.
* Spray method refers to the formation of small droplets after the liquid is sprayed, which is suitable for spraying atomizer and other occasions.

### 5. Advantages

* Plastic spray heads are light and easy to install and replace.
* Compared with metal nozzle, plastic nozzle feels more comfortable when using, and is more suitable for children and the elderly.
* Plastic material is relatively cheap, suitable for home decoration and economical and practical choice.

### 6. Weaknesses

* Plastic materials have a relatively low ability to withstand ultra-high temperature and high pressure water, so the service life may be slightly shorter than metal sprinkler heads.
* Environmental performance is relatively not high, vulnerable to ultraviolet radiation and scratches, not easy to clean, easy to breed bacteria, need to be cleaned and replaced regularly.

Application scenario

* Plastic spray heads have important applications in agriculture, household cleaning, health care and industrial production.
* Agriculture: Used to spray pesticides, fertilizers, etc., control the spraying range and quantity, and improve production.
* Household cleaning: Spray the cleaning agent on the surface of the cleaned object to facilitate cleaning and play a bactericidal effect.
: : Health: Spraying disinfectant in hospitals to complete the disinfection of the environment and equipment.
* Industrial production: used to spray lubricants, release agents, paint, etc., to improve production efficiency and reduce waste.

To sum up, the plastic spray head has become an indispensable tool in modern life and production with its wide range of application fields, diverse spray methods and relatively low cost.