Pencil is a type of pen for writing and drawing sketches. It has a history of more than 400 years. Among them, the pencils of painting sketches are divided into many types.Pen making and hats with a pencil; in addition, its color is red, white, black, white, yellow and black.How to make a pencil?What are the signs of the pen?Lets take a look with Xiaobian below!
Pen pencil logo
The hardness logo of the pencil lead core is generally used "H" to represent the hard pencil, "B" indicates a soft pencil, "HB" represents a soft and hard pencil, and "F" means a pencil between HB and H.
Arrangement method (from soft to hard) 9B, 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, 10H, 10h, etc.Hardness level.The larger the number in front of H, the harder its lead core, the lighter the color.The larger the ahead of B, the softer the lead core, the darker the color.The classification of pencils is divided according to the amount of graphite in the pen.Among them, H type pencil, the hardness of the pen core is relatively high, suitable for objects that are relatively hard or clear in the interface, such as woodworking lines, wild drawing, etc.;For contours; Class B pencil, the pen core is relatively soft, suitable for painting, and can also be used to fill in some machine -recognized cards.For example, we often use 2B pencils to fill in the answer card.In addition, color pencils are common, which are often called color pencils, which are mainly used for painting.
Pencil production
It is divided into two parts: pencil cap and pencils: the appearance of the pencil caps appearance is mainly polyester material. The production process can be divided into molding, rubber printing, assembly and other processes.The appearance of pencils is mainly nitro fiber pencil paint, printed ink, electro -electrized aluminum foil, rubber head and aluminum hoop.The production process can be divided into process processes such as pencil boards, lead cores, pencils, and finished decoration.
Pencil board processing is opened and cut off the logs, and the prescription is sawn into wooden blocks.The board is 184mm long, 73mm wide, and 4.8 to 5.2mm thick.After the heating (60 ~ 120 ° C) drying and high temperature (130 ~ 200 ° C) degeneration treatment, the pencil board can reach the degree of softening and rolling.
The lead core processing graphite lead core is equipped with graphite and clay in a certain proportion. After mixing the training machine and three -roller machine, a certain size size is squeezed by the core (such as HB ~ 3H lead core diameter of 1.80 ~The lead core of 2.10mm) is dried (50-150 ° C) dry and high temperature (800 ~ 1100 ° C) roasting, so that it has a certain mechanical strength and hardness, and is finally made of oil.The color lead core processing is similar to the graphite lead, but no sintering is required.There are two types of processing methods: one is to mix clay, talc powder, adhesive, color, oil and wax, etc., and make it through forming and drying.After mixed with color and adhesive, squeeze into a lead core or put the dried lead core in the oil core container, so that it can fully absorb the oil at a certain temperature, which is called the oil soaking method.
The pencil machining uses a groove machine to cut the pencil board into a thickness of 4.1 to 4.2mm, and there is a groove plate that is compatible with the diameter of the lead core.After drying (50 ～ 120 ℃) ??in a tight state for 1 to 8 hours, it is made into a white rod pencil with a length of 178 to 180mm by processing through the shaving rod machine.
The appearance decoration processing the white rod pencil is painted and printed, as well as processing light, printing trademarks, loading rubber heads, and pens, etc., making it a finished pencil with certain specifications, appearance color and pattern patterns.
Pay attention
1. Is the pencil core toxic?
In fact, the pencil core is not toxic, lead is toxic, and the main raw materials for making pencil cores are graphite and clay, so the pencil core is non -toxic.
The main components of the pencil of pencils are graphite and clay. Graphite is a solid with a metal-shaped luster. Among them, there are carbon-carbon chemical bonds. Fan Dehua Li is between layers and layers.It is very difficult. This is why diamond and graphite are composed of carbon, but the physical properties and prices are very different. There is nothing in the human body that can destroy the carbon-carbon chemical bond, so it is certain that the pencil core is safe (unlessIt is the harmful human health in the inside).
2. Does the pencil have metal poison?
The appearance of the pencil is a parcel model or a pencil paint technology. On the one hand, it can protect the pen and increase the beauty, but the pigment will contain trace heavy metals.Proper.