The structure of artificial Christmas tree is usually divided into base, body and branches.
The basic function of the base is to carry the entire tree, the body of the tree is the trunk that carries all the branches and connects to the base, and the branches are a combination of leaves with various specifications and varieties, and the number of leaves connected to the tree body. determined by the arrangement.
The base design must take into account strength and stability, and the base with electrical appliances must also consider safety performance such as insulation and heat dissipation; from the perspective of strength and cost, plastic injection molding is generally used for the base of a tree less than 1.5m, and a large 2.5m tree is usually used for injection molding. The bases are formed by stamping and welding of metal materials. The main factors affecting the strength of the base are the weight of the tree and the use environment.
The requirements and test methods for stability are to install the whole tree on an inclined plane at an angle of 12° from the horizontal, and turn the base within a range of 360° without the tree moving or toppling. The factors that affect the stability of the base are: The height and diameter of the tree; it is important to note that the material used for the base must be flame retardant or self-extinguishing.
In addition, for the lamp tree or fiber optic tree base with electrical appliances sold separately, it is also required to pass the relevant safety testing or certification stipulated by the importing country.
2. tree body
The tree body is usually composed of an iron pipe and a tree node mounted on the iron pipe to connect the branches. The structure of the tree body is relatively simple; in addition to considering its strength and stability in the design, like the base, the material used must also be flame retardant or Self-extinguishing, in addition, the height of the tree body is greater than lm, for the consideration of packaging and transportation, it is usually designed to be segmented.
The leaves of various specifications, colors and shapes are combined on the metal branches in a certain number and position to form a branch. After all the branches are assembled, the shape of the tree is formed; the branch design mainly considers the following aspects.
(1) Simulation degree. Choose the appropriate leaves and their combinations to make them as close as possible to the branches of various real trees.
(2) Economical. Leaves are the most used raw materials on trees. The common raw materials and methods for making leaves include calendering PVC films, extruding PE filaments and PE injection at one time. The production efficiency of these three types of leaves is from high to low. However, the order of simulation degree and cost is the opposite. In practice, several kinds of leaves are often mixed.
(3) What should be paid attention to in the design and production of branches is to avoid the potential safety hazard caused by the exposed thin iron wires at the head and tail of the leaves; the leaves made of PVC are self-extinguishing, but the leaves made of PE must meet the flame retardant requirements .
The classification of artificial Christmas trees can be mainly divided into the following three categories:
1. According to the height of the tree
The height of most trees is between 1.0 and 2.5m, those less than 1m are called small trees, and those greater than 2.5m are called large trees.
2. According to the structure and the way of use
It is divided into two types: plug-in tree and automatic tree. The feature of plug-in tree is that the finished branches of each level are separated from the tree body and the base and packed in boxes, and the user can install and plug the branches by himself when using it according to the storytelling. The advantage is that the packing box can be reduced. The automatic tree is to connect all the branches and the tree body by hinges. When the user uses it, as long as the tree is erected, the branches at all levels will be automatically scattered and positioned under the action of gravity. The advantage is that it is easy to use. .
3. According to the additional performance of the tree
At present, it can be mainly divided into three categories: pure tree, light tree and optical fiber tree. Pure tree refers to the traditional Christmas tree without additional functions such as light and electricity. The current number is the largest. Light tree is a combination of various holiday lights and trees. , and the optical fiber tree is a combination of light source and plastic optical fiber design on the tree. The lamp tree and the optical fiber tree are products developed in recent years, and the number of them is increasing.