The size of the leather Sleeper is small which takes less space and easy to move. You can have a leather sleeper at your office which is more comfortable for lunch break. And you can use it as a sofa at office time. The leather sleepler sofa is also easy to intall. There are different types of leather sleeper, you can choose the leather sleeper suitable for you. Leather Sleeper,Elegant Sleeper Lounger,Living Room Leather Sofas,Leather Sectional Sofa Loveseats Kaifeng Lanwei Smart Home Co., Ltd , https://www.sofas-world.com
On January 9, 2012, a 20-year-old college student glided out of a snow track at the Ski Resort in Dalian at the “Happy Snow World†ski resort and crashed into the safety net and column next to him. He was seriously injured and died. If you can assume that, assuming that he wore a helmet that day, he might stay in the hospital for a few days and have already returned to campus. Now he is enjoying the beauty of the university.
But death cannot assume that life cannot be repeated! Skiing is not only beautiful, but also high-risk!
Before you ski, you must have a sense of danger: First, you must protect yourself, and then enjoy passion and excitement.
In addition to the snowboard and snowman essentials, there are two lifeguards: ski helmets and ski glasses. Now I will introduce some knowledge about ski helmets (the views are not complete, welcome to express opinions, do not spray).
one. Ski helmet structure
General Ski Helmet consists of: Shell, Liner, Padding, Adjuster, Retention System, Buckle, and Goggle Clip. The helmet used in the event will have a Chin Guard.
Shell: Left and right are not tired. There are two types of housings currently on the market: PC (polycarbonate) and ABS (a type of engineering plastic). This is detailed in the following classification of snow helmets.
Subject: The key part of the helmet, mainly absorbing the energy of the impact. The material is EPS (foamed polyethylene), the same kind of white foam that we normally use for packaging. There are two kinds of EPS, one is white material, domestic production, the other is black material (EPS used in ROCKHARD helmet is black material), more than 90% is produced by American POLYSOURCE, domestic production can not. The price of black material is more than 3 times the price of white material. Some brands use black paint to turn white material into black material. High-grade ski helmets are basically black. (You can see what kind of material is used in your helmet)
Lining: Its role is to increase comfort. The main material is a sponge covered with a variety of fabrics, such as raising cloth, shearing plush. There are also brands that use hot-pressed linings. The benefit of hot-pressing is that they look more refined. The current trend is a detachable liner that can be detached for cleaning (the lining used in the ROCKHARD high-end models is removable).
Regulator: Adjust the size of the size, generally in the helmet of CLASS B, the helmet of CLASS A has no regulator. If a helmet is fitted with a regulator, its adjustment range is at least 4cm.
Fixing device: The second function is to fix the helmet on the head and it is not easy to fall off during exercise. It is generally composed of a webbing (NYLON, ROCKHARD ALL Nylon, width 1.5 cm) and a fan-shaped buckle.
Buckle: The commonly used buckle is a red and black buckle, which is made of POM (polyoxymethylene) injection molding (the buckle used for ROCKHARD helmet is ITW, environmental protection has passed European standard)
Eye buckle: Fixed ski goggles.
Metal chin: In some events, such as DH, SG, the helmet worn by athletes is basically a CLASS A helmet, and a metal iron piece is needed on the helmet. It is mainly to protect the chin. At present, only some brands provide such chins, which are basically wire and dipped. (The ROCKHARD provides the chin 304# stainless steel electrophoresis.)
two. Types of ski helmets
A. Mainly differentiated from the production process: PC integrated helmet and ABS helmet
PC one helmet: The material of the shell is PC. The main production process is as follows:
First use screen printing to print the pattern on the PC slice (sub-automatic and manual, manual reference http://v.ku6.com/show/MPvs7r1BTVI-zEYm.html);
Blister molding is to make a flat PC board into the shape of a helmet;
Cutting and digging holes;
The shell is placed on a foaming machine and the shell and body are brought together.
ABS helmet: shell material is ABS, the main production process is as follows:
Injection cap shell, grinding;
If the pattern is used, the pattern is made into a water patch and applied to the surface of the helmet to spray paint;
The main body foams alone;
The body and the shell are glued together with a hot melt adhesive.
Comparison of PC-integrated helmet and ABS helmet:
1) The PC-body helmet is lighter than the ABS helmet: the average PC helmet has a weight of 350-450 grams, and the ABS helmet has a weight of 500-650 grams.
2) CLASS A must use ABS helmets;
3) The price of the PC helmet is higher than that of the ABS helmet.
B. Differentiate from the scope of protection: CLASS A and CLASS B.
The European standard CE EN1077 distinguishes ski helmets as CLASS A and CLASS B.
CLASS B: Earmuffs are soft, CLASS A: Earmuffs are hard.
Comparing the two: CLASS A is more protective than CLASS B and has a relatively lighter weight. CLASS B helmets are mainly used in ordinary skiing. CLASS A helmets are mainly used in competitions. (The ROCKHARD helmet can meet the standards of the FIS FIS for use in events such as DH/SG/GS, while providing a metal chin for higher protection)
C. Mainly differentiated by purpose: Apline, Nordic and Freestyle
Alpine skiing trails originate from the Alps, cross-country skiing from Northern Europe, and freestyle skiing from the United States. Alpine skiing speed is faster, generally use CLASS A helmet; cross-country skiing is mainly used ordinary CLASS B helmet; freestyle ski helmet is somewhat similar to a skateboard helmet, pay attention to air and snow movements.
three. Ski helmet style and certification
Ski helmets currently on the market are basically European versions. The head of Europeans is not the same as the head of Asians. Europeans are slender. All the many Chinese people feel skimpy on both sides when wearing ski helmets. Some people will have both sides of the hammer, it is best not to do so, because the protection of the helmet is reduced, at a critical time.
ROCKHARD launched a CLASS A ski helmet WH-A1, according to the Chinese people's head design and development, both sides will never feel the card.
Ski helmet certification mainly includes:
CE EN1077: European certification, most of the helmets sold on the market today are this certification;
ASTM F:2040: United States certification;
FIS 2013/2014 (International Snow Federation): Based on EN 1077/A, the impact speed is increased from 5.38 m/s of EN 1077/A to 6.8 m/s, and the value is not lower than 250 g. Therefore, the FIS 2013/2014 standard is stricter than EN 1077/A. (In this explanation: FIS 2013/2014 must be CLASS A, CLASS B helmets cannot reach this standard)
four. How to choose a suitable helmet
There are all kinds of ski helmets on the market. How to choose a suitable helmet? in my opinion:
1. Must have certification:
Ski helmets sold on the market are all marked with such certification. In fact, relying on our knowledge, it is difficult to determine whether these helmets have been certified. I once took a well-known brand of ski helmets sold in the market to the laboratory for testing, and found that this kind of structural design helmet was just a crash test. So don't trust the brand! I have also seen such a ski helmet on the market. The packaging is marked with CE EN 1078 certification (EN 1078 is a bicycle helmet certification)! In fact, light from the certification is difficult to determine the quality of a helmet, but also to see the work of this helmet.
2. How to judge the work of a ski helmet?
A. ABS helmet:
Enclosure: Whether the surface of the light has particles or scratches; whether the water paste pattern is complete; whether there is a problem with the adhesion of the paint (I have seen helmets like this, the paint on the surface can be buckled down one by one).
Subject: Black or white material, or black material;
Lining: Actually looking at a helmet is mainly about the inner lining. Whether the lining is detachable; whether it is smooth; whether the fabric used is comfortable; whether the color matching is coordinated; whether there is any problem with sewing work; whether there is a complete warning mark and certification mark;
Earmuffs: Whether the earmuffs are detachable; the shape of the earmuffs is not very new; the inside is not V-shaped (the V-shaped earmuffs are well-designed and comfortable to wear)
Buckle: After plugging it in, pull it hard, it will not be disconnected;
Eyes buckle: more buckles, pull back and forth several times, whether the buttons will be pulled down;
B. PC helmet:
Due to process differences, many PC-integrated helmets are not painted. In addition to the ABS helmet work, there are two other concerns:
Where in the vent is the EPS, if there is any frizz, if there is frizz, this model of the helmet has problems;
Whether the EPS on the front and rear edge of the helmet is enveloped by the casing (PC), the wrapped helmet looks more beautiful.
3. The most important: comfort
European version of the ski helmet, how much the Chinese wear up will feel that both sides of the card. Therefore, when buying, be sure to wear different styles and different sizes. It is best to choose a helmet suitable for China's head type (WH-A1)