Structure and classification of artificial Christmas trees

　　The structure of an artificial Christmas tree is usually divided into a base,a tree body,and branches.The basic function of the base is to carry the entire tree.The tree body is the trunk that carries all the branches and connects to the base.The branches are a combination of leaves with various specifications and arrangements,and the shape of the tree is mainly determined by the branches and their arrangement.

　　1.Base

　　The design of the base must consider strength and stability,and the base equipped 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 commonly used for bases of trees smaller than 1.5m,while metal stamping and welding are used for bases of trees larger than 2.5m.The main factors affecting the strength of the bases are the weight of the tree and the usage environment.

　　The requirements and testing methods for stability are to install the entire tree on a slanted plane with an angle of 12°to the horizontal,and rotate the base within 360°to prevent the tree from moving or tipping.The factors that affect the stability of the base are the height and diameter of the tree;It should be noted that the material used for the base must be flame retardant or self extinguishing.In addition,for lamp trees or fiber optic tree bases sold separately with electrical appliances,they also need to pass relevant safety tests or certifications specified by the importing country.

　　2.Tree body

　　The tree body is usually composed of iron pipes and nodes installed on iron pipes to connect branches,and the structure of the tree body is relatively simple;In addition to considering its strength and stability,the materials used in the design,like the base,must also be flame retardant or self-extinguishing.In addition,tree bodies with a height greater than 1m are usually designed as segmented for packaging and transportation purposes.

　　3.Branches

　　Combine various specifications,colors,and shapes of leaves in a certain number and position on metal branches to form branches,and assemble all branches to form the shape of the tree;The design of tree branches mainly considers the following aspects.

　　(1)Simulation degree.Choose appropriate leaves and their combinations to make them as close as possible to the branches of various real trees.

　　(2)Economy.Leaves are the most commonly used raw material on trees,and the commonly used materials and methods for manufacturing leaves include calendered PVC film,extruded PE wire,and PE one-time injection molding.The production efficiency of these three types of leaves is arranged in a positive order from high to low,with the order of simulation and cost being opposite.In reality,several types of leaves are often mixed and used.

　　(3)In the design and production of tree branches,attention should be paid to avoiding safety hazards caused by the possible exposure of fine iron wires at the head and tail of the leaves;Leaves made from PVC have self-extinguishing properties,but leaves made from PE must meet flame retardant requirements.