Fire protective
clothing (hereinafter referred to as protective clothing) refers to the
firefighters during fire fighting to protect their jobs and are usually
dressed in clothes.
Performance requirements
Structure
Protective clothing for the imitation safari style, composed by the upload and download.
Protective clothing is divided into conventional-type protective clothing and cold-protective clothing two kinds.
Conventional
flame retardant firefighter clothing should be moisture-resistant
housing and detachable water permeability of the inner components.
Cold-protective
clothing should be flame retardant and moisture resistant jacket
detachable water permeability of the inner layer, warm layer, lining
layer.
Main material properties
Protective clothing should be used with cover and logo has served the function of fabric, should have flame moisture resistance.
Housing
of flame retardant, according to section 5.1 of this standard test
method now, its damage length not greater than 12cm, continued burning
time shall not be greater than 2s, smoldering time not more than 10s,
may not have financial drop phenomenon.
Housings moisture
resistance, according to Section 5.2 of this standard test method
specified in its wet grade not lower than GB4745 in three requirements.
Resistant
housing washing performance, according to the standard method specified
in Section 5.3 the corresponding test, the flame retardant is damaged
not be longer than 15cm, continued burning time shall not be greater
than 5s, smoldering time not more than 20s, may not have financial drop
phenomenon, its moisture resistance rating of not less than GB4745 to
wet the two requirements.
Cover the tear strength, according to
Section 5.4 of this standard test method specified, the warp and weft of
the tear strength of not less than 32N.
Housings dry breaking
strength, according to Section 5.5 of this standard test method
specified in its warp and weft of the breaking strength of not less than
450N.
Cover wear resistance, according to Section 5.6 of this
standard test method specified, worn 100 times, warp and weft dry
breaking strength of not less than 200N.
Cover against radiant
heat permeability, according to the standards specified in Section 5.7
of the test method, upon completion of an irradiation cycle, the
temperature rise of the inner surface of the housing should not exceed
15 ℃.
Use protective clothing impervious water has served the
function of the inner fabric is made of the performance of its water
permeability according to the standards specified in Section 5.8 of the
test method, and its resistance to hydrostatic pressure of not less than
4000Pa.
Cold-warm layer of protective clothing, the use of polyester or acrylic flakes made of artificial fur.
Cover seam breaking strength according to Section 5.5 of this standard test method specified, shall not be less than 360N.
2013年10月25日星期五
Firefighters personal protective equipment and protective clothing standards of ordinary
Clothing protective equipment mainly refers to avoid firefighters subjected to high temperatures, drugs and other harmful environmental damage clothing, helmets, boots, hats, glasses and so on. There are fire-fighting suits, insulated clothing, avoid the fire service, disaster relief and clothing.
First, the battle suit and its supporting apparatus
Fire fighting services are firefighters put out the fire into the general fire fighting to protect themselves while wearing protective clothing, suitable for the fire "normal" state of use. Fire fighting services sub eighty-five style to the 1997 ceremony. Currently fire squadron equipped mostly eighty-five type fire fighting services, the clothing is divided into winter clothing, Xiafu, fireproof and waterproof clothing long fire suits four types, suitable for general fire fighting, does not apply near the fire and rescue operations help. 97 combat clothing is the latest successful research as a fire fighting service, with fire, flame, heat insulation, anti-virus and other functions, suitable for fire fighting and rescue work part.
1, fire on the human body
Burns, radiation, steam burns, frostbite, fatigue
2, fire fighter clothing work status
"Normal" state corresponds eleven firefighters operation in the face of the fire with water, or leaving the fire state a certain distance, the radiation heat flux 1.5kw/m2 below the temperature at below 60 ℃.
"Dangerous" state - the equivalent outside the room in a burning, or burning in a small building outside of the case with its radiant heat flux 1.5kw/m2 ~ 13.6kw/m2, temperature at 60 ℃ ~ 300 ℃ range.
"Critical" state - equivalent to similar violent burning in the vicinity of the crashed plane, or the occurrence of flashover situation encountered, the radiant heat flux 13.6kw/m2 ~ 200kw/m2, the temperature of 300 ℃ ~ 1100 ℃ range.
3, fire fighting services should have the protection and the associated measurement method
(1) Flame retardant (vertical burning test)
The 12-inch long strips of cloth placed in a propane flame to burn after 12 seconds, remove and measure the flame continued burning time, fire-retardant cloth carbonization time and length.
(2) Thermal Protective Performance (TPP)
① Thermal Protective Performance (TPP) Test: the fabric is placed convection and radiant heat source, the time required for recording two burns.
Time X heat source heat = TPP value
② TPP test method
TPP test is a 6 square inches of fabric placed on the total energy 2cal/cm2.sec thermal convection and radiant heat source, and then recording the time required to achieve the second degree burns, TPP value that is multiplied by the time cal/cm2. sec value. And vertical burning test different, TPP test can tell us simulate human skin through a variety of different fabrics to achieve two burns the amount of energy to be absorbed, ie the higher the value of the TPP fabric for the body exposed to high temperatures and the heat of the flame under the protection of the higher, the unit value of the TPP is the most direct thermal protective performance body connection.
③ hot human instrument thermal protection test (Thermo-man?)
To further simulate the actual extent of the flame burns the body, used to test the actual set of clothes in a simulated fire conditions, the degree of protection offered by the clothes. With this test, we can predict the body burns suffered two and three degrees, the body burns degrees lower, the greater the chance of survival.
Human body model test is to contain 122 temperature testers made from special glass-epoxy six inches high mannequin wearing fireproof suits, and make it the exposure to 12 propane flamethrower set synthetic 2cal / cm2.sec heat, the computer according to the temperature testers from 122 collected data to simulate human skin may be affected by the two and three degree burns and location.
4, protective performance
1) with a permanent protective function;
2) does not melt and does not have the function of combustion;
3) having the function is not broken;
4) resistance to chemical corrosion features;
5) durability;
6) comfort.
First, the battle suit and its supporting apparatus
Fire fighting services are firefighters put out the fire into the general fire fighting to protect themselves while wearing protective clothing, suitable for the fire "normal" state of use. Fire fighting services sub eighty-five style to the 1997 ceremony. Currently fire squadron equipped mostly eighty-five type fire fighting services, the clothing is divided into winter clothing, Xiafu, fireproof and waterproof clothing long fire suits four types, suitable for general fire fighting, does not apply near the fire and rescue operations help. 97 combat clothing is the latest successful research as a fire fighting service, with fire, flame, heat insulation, anti-virus and other functions, suitable for fire fighting and rescue work part.
1, fire on the human body
Burns, radiation, steam burns, frostbite, fatigue
2, fire fighter clothing work status
"Normal" state corresponds eleven firefighters operation in the face of the fire with water, or leaving the fire state a certain distance, the radiation heat flux 1.5kw/m2 below the temperature at below 60 ℃.
"Dangerous" state - the equivalent outside the room in a burning, or burning in a small building outside of the case with its radiant heat flux 1.5kw/m2 ~ 13.6kw/m2, temperature at 60 ℃ ~ 300 ℃ range.
"Critical" state - equivalent to similar violent burning in the vicinity of the crashed plane, or the occurrence of flashover situation encountered, the radiant heat flux 13.6kw/m2 ~ 200kw/m2, the temperature of 300 ℃ ~ 1100 ℃ range.
3, fire fighting services should have the protection and the associated measurement method
(1) Flame retardant (vertical burning test)
The 12-inch long strips of cloth placed in a propane flame to burn after 12 seconds, remove and measure the flame continued burning time, fire-retardant cloth carbonization time and length.
(2) Thermal Protective Performance (TPP)
① Thermal Protective Performance (TPP) Test: the fabric is placed convection and radiant heat source, the time required for recording two burns.
Time X heat source heat = TPP value
② TPP test method
TPP test is a 6 square inches of fabric placed on the total energy 2cal/cm2.sec thermal convection and radiant heat source, and then recording the time required to achieve the second degree burns, TPP value that is multiplied by the time cal/cm2. sec value. And vertical burning test different, TPP test can tell us simulate human skin through a variety of different fabrics to achieve two burns the amount of energy to be absorbed, ie the higher the value of the TPP fabric for the body exposed to high temperatures and the heat of the flame under the protection of the higher, the unit value of the TPP is the most direct thermal protective performance body connection.
③ hot human instrument thermal protection test (Thermo-man?)
To further simulate the actual extent of the flame burns the body, used to test the actual set of clothes in a simulated fire conditions, the degree of protection offered by the clothes. With this test, we can predict the body burns suffered two and three degrees, the body burns degrees lower, the greater the chance of survival.
Human body model test is to contain 122 temperature testers made from special glass-epoxy six inches high mannequin wearing fireproof suits, and make it the exposure to 12 propane flamethrower set synthetic 2cal / cm2.sec heat, the computer according to the temperature testers from 122 collected data to simulate human skin may be affected by the two and three degree burns and location.
4, protective performance
1) with a permanent protective function;
2) does not melt and does not have the function of combustion;
3) having the function is not broken;
4) resistance to chemical corrosion features;
5) durability;
6) comfort.
2013年10月23日星期三
Fire insulation services security issues
Fire insulation services, sometimes referred to (fire protective clothing) is mainly for firefighters or other work in places of high temperature operating personnel compartment (anti-) thermal protection garments. According to Fu Jie fire equipment is understood that it is generally made from flame retardant fabric with vacuum aluminum composite materials are mixed together and made into, fire insulation services features: Asbestos, light weight, high strength, flame retardant , high temperature, thermal radiation, waterproof, abrasion, folding, and harmless to human body and so on, put on the garment can effectively protect the firefighters, hot places workers will not be even close to a heat source heat, flames, steam And burns a protective clothing.
According to the nature of disasters, each equipped with 8 sets of firemen combat uniforms. In addition, each firefighter is also equipped with F1 helmet, protective gloves, safety boots, breathing apparatus and other basic equipment.
Fire insulation services, sometimes referred to (fire protective clothing) is mainly for firefighters or other work in places of high temperature operating personnel compartment (anti-) thermal protection garments. According to Fu Jie fire equipment is understood that it is generally made from flame retardant fabric with vacuum aluminum composite materials are mixed together and made into, fire insulation services features: Asbestos, light weight, high strength, flame retardant , high temperature, thermal radiation, waterproof, abrasion, folding, and harmless to human body and so on, put on the garment can effectively protect the firefighters, hot places workers will not be even close to a heat source heat, flames, steam And burns a protective clothing.
According to the nature of disasters, each equipped with 8 sets of firemen combat uniforms. In addition, each firefighter is also equipped with F1 helmet, protective gloves, safety boots, breathing apparatus and other basic equipment.
A full range of personal protective equipment, but firefighters against dangerous magic. In addition, the detector type of equipment, lifting type of equipment, psychotherapy and disaster monitoring and early warning system for the scene, but also the necessary safety measures.
firefighting clothing is made from a special material, which can effectively cut off slightly firepower. Clothes with eye-catching reflective warning bar. Battle dress has two layers, according to different climate detachable lining is also a certain fire and high temperature capabilities of the material.
Chemical protective clothing for firefighters simple chemical products in the disposal of chemical spills in wearing costumes, but because of simple chemical warfare suits thin convenience features, can not enter the heavily polluted areas, usually in or around the use of chemical products used in decontamination.
Chemical protective clothing firefighters wear heavy heavy chemical warfare suits like astronauts in general, rely on air respirator to breathe. Dressing, it must be both collaborate. Heavy Chemical protective clothing can effectively resist corrosion, prevent inhalation of toxic gases firefighters, so you can enter into chemical poisoning rescue work area. The suit worth 20 million yuan.
Oil dazzling orange dress clothes, is the body from head to toe suit, can effectively prevent oil-contaminated gloves by a non-slip material, crawling oil contaminated items will not slip.
Insulated clothing clothes, masks, glasses and gloves as one of the silver costume. Able to resist at 800 ℃, 1111 ℃ when the temperature of the object up to the amount of radiation produced to protect the firefighters will not be burned at high temperatures.
According to the nature of disasters, each equipped with 8 sets of firemen combat uniforms. In addition, each firefighter is also equipped with F1 helmet, protective gloves, safety boots, breathing apparatus and other basic equipment.
Fire insulation services, sometimes referred to (fire protective clothing) is mainly for firefighters or other work in places of high temperature operating personnel compartment (anti-) thermal protection garments. According to Fu Jie fire equipment is understood that it is generally made from flame retardant fabric with vacuum aluminum composite materials are mixed together and made into, fire insulation services features: Asbestos, light weight, high strength, flame retardant , high temperature, thermal radiation, waterproof, abrasion, folding, and harmless to human body and so on, put on the garment can effectively protect the firefighters, hot places workers will not be even close to a heat source heat, flames, steam And burns a protective clothing.
According to the nature of disasters, each equipped with 8 sets of firemen combat uniforms. In addition, each firefighter is also equipped with F1 helmet, protective gloves, safety boots, breathing apparatus and other basic equipment.
A full range of personal protective equipment, but firefighters against dangerous magic. In addition, the detector type of equipment, lifting type of equipment, psychotherapy and disaster monitoring and early warning system for the scene, but also the necessary safety measures.
firefighting clothing is made from a special material, which can effectively cut off slightly firepower. Clothes with eye-catching reflective warning bar. Battle dress has two layers, according to different climate detachable lining is also a certain fire and high temperature capabilities of the material.
Chemical protective clothing for firefighters simple chemical products in the disposal of chemical spills in wearing costumes, but because of simple chemical warfare suits thin convenience features, can not enter the heavily polluted areas, usually in or around the use of chemical products used in decontamination.
Chemical protective clothing firefighters wear heavy heavy chemical warfare suits like astronauts in general, rely on air respirator to breathe. Dressing, it must be both collaborate. Heavy Chemical protective clothing can effectively resist corrosion, prevent inhalation of toxic gases firefighters, so you can enter into chemical poisoning rescue work area. The suit worth 20 million yuan.
Oil dazzling orange dress clothes, is the body from head to toe suit, can effectively prevent oil-contaminated gloves by a non-slip material, crawling oil contaminated items will not slip.
Insulated clothing clothes, masks, glasses and gloves as one of the silver costume. Able to resist at 800 ℃, 1111 ℃ when the temperature of the object up to the amount of radiation produced to protect the firefighters will not be burned at high temperatures.
Manual fire fighting services
firefighter suits are firefighters wearing fire fighting protective clothing. For fire operations has prevented nearly wearing the human body against heat, fire fighting operation is the most basic and appropriate personal protective equipment. The clothing is not in the following hazardous environments to provide protection to the wearer.
Through the fire zone or similar hazardous environments
Chemical spills Environment
Contact with large quantities of flammable liquids live in the environment
First, the structure
1, the inner and outer garments using detachable structure, four material combinations. From the surface layer, waterproof breathable layer, insulation layer and comfort layer, and the upper and lower clothing obvious place reflective signs.
2, set of clothing including tops, overalls. The clothing worn body protection just to enter the job site should also wear other personal protective equipment to protect the wearer other parts of the body, such as the feet, hands and head.
Second, the technical characteristics
1, the main performance: a perpetual flame burning compartment, waterproof, breathable, flexible, suitability and other functions in the nearby fire operations can effectively prevent heat conduction.
2, the main technical parameters
Flame retardant: Damaged length ≤ 10cm; continued burning time ≤ 2s; without droplet phenomenon.
Breaking strength: warp and weft ≥ 650N.
Tear strength: warp and weft ≥ 100N.
Thermal stability: 260 ℃, 5min, shrinkage ≤ 10%, no surface change.
Hydrostatic pressure: ≥ 17Kpa.
Third, the method of dress clothing
Only in jacket and trousers were worn and proper closure to ensure the performance of clothing, dress according to the following methods must be properly dressed.
1, will be set into the fire boots trousers, put together with the pants, pull the zipper, buttoned waistband buckle, adjust the straps.
2, put on the jackets, fasten all enclosed area.
3, if necessary, ruffled collar and buckle clasp around the palate shelter together.
Four, clothing washing method
1, because the clothing is detachable and outside, we recommend that you only have to wash the outer layer, the outer washing, can be washed can be dry cleaning, washing when the water temperature is not greater than 40 ℃, use a neutral detergent.
2, such as the inner layer to be washed, preferably dry, use should be washed with soap wash, and finally use the shower and dry drying, breathable layer to prevent clogged pores, affecting the ventilation effect. NEVER use thump washing method. Inappropriate clothing washing method back to change the appearance and level.
Five, maintenance and repair
1, after wearing the protective clothing should be hung in a ventilated and dry place, not placed in a humid environment.
2, such as clothing hook small area appears timely to mend broken, damaged large areas can play a protective role is not allowed to enter the fire scene.
Six, storage conditions
1, Do not mix with oil during storage or corrosive materials in contact.
2, beware of hooking and prevent mildew.
3, stored in a dry and ventilated room and avoid rain, moisture, exposure.
Through the fire zone or similar hazardous environments
Chemical spills Environment
Contact with large quantities of flammable liquids live in the environment
First, the structure
1, the inner and outer garments using detachable structure, four material combinations. From the surface layer, waterproof breathable layer, insulation layer and comfort layer, and the upper and lower clothing obvious place reflective signs.
2, set of clothing including tops, overalls. The clothing worn body protection just to enter the job site should also wear other personal protective equipment to protect the wearer other parts of the body, such as the feet, hands and head.
Second, the technical characteristics
1, the main performance: a perpetual flame burning compartment, waterproof, breathable, flexible, suitability and other functions in the nearby fire operations can effectively prevent heat conduction.
2, the main technical parameters
Flame retardant: Damaged length ≤ 10cm; continued burning time ≤ 2s; without droplet phenomenon.
Breaking strength: warp and weft ≥ 650N.
Tear strength: warp and weft ≥ 100N.
Thermal stability: 260 ℃, 5min, shrinkage ≤ 10%, no surface change.
Hydrostatic pressure: ≥ 17Kpa.
Third, the method of dress clothing
Only in jacket and trousers were worn and proper closure to ensure the performance of clothing, dress according to the following methods must be properly dressed.
1, will be set into the fire boots trousers, put together with the pants, pull the zipper, buttoned waistband buckle, adjust the straps.
2, put on the jackets, fasten all enclosed area.
3, if necessary, ruffled collar and buckle clasp around the palate shelter together.
Four, clothing washing method
1, because the clothing is detachable and outside, we recommend that you only have to wash the outer layer, the outer washing, can be washed can be dry cleaning, washing when the water temperature is not greater than 40 ℃, use a neutral detergent.
2, such as the inner layer to be washed, preferably dry, use should be washed with soap wash, and finally use the shower and dry drying, breathable layer to prevent clogged pores, affecting the ventilation effect. NEVER use thump washing method. Inappropriate clothing washing method back to change the appearance and level.
Five, maintenance and repair
1, after wearing the protective clothing should be hung in a ventilated and dry place, not placed in a humid environment.
2, such as clothing hook small area appears timely to mend broken, damaged large areas can play a protective role is not allowed to enter the fire scene.
Six, storage conditions
1, Do not mix with oil during storage or corrosive materials in contact.
2, beware of hooking and prevent mildew.
3, stored in a dry and ventilated room and avoid rain, moisture, exposure.
2013年10月11日星期五
The use of standard safety shoes
Firefighter
boot are shoes and protective safety class class shoes collectively , but also a labor supplies . Protect feet and legs from foreseeable harm footwear.
PPE European standard EN344: 1997 " special security , protection , and work shoes ."
The standard safety shoes models design, the entire shoe uppers, shoe , tongue , insole , outsole and other structures and performance indicators were provided . Each item specified in the standard test methods and other similar standards similar to its principle of the method is also generally applicable to most safety shoes , the main indicators are:
a. Baotou impact resistance steel with a prescribed weight impact test hammer , Baotou Baotou upon impact should be less than the clearance height of the specified value , and Baotou in the axial direction of the test should be no penetrating cracks. It is noteworthy that the national standards of the hammer weight , size , height and impact testing machine structure different from the requirements such as the actual test should be distinguished.
b. puncture resistance test machine is equipped with a plate, nail plate is equipped with a test , the test is a truncated tip of the nail head , nail head should be greater than the hardness of 60HRC. The sole sample is placed on the test machine 's chassis , the position can test for nail piercing through the outsole , the test nails to pierce the speed 10mm/min ± 3mm/min soles until penetrate far, record the maximum required force . Each four points selected on the sole test ( of which at least one point of the heel ) , each point distance of not less than 30mm, and the distance from the inner bottom edge than 10mm. A non-slip bottom block , between the blocks should be pierced. 4 points in the two points should be located away from the implant bottom corner edge line distance of 10-15mm for testing. If the humidity will affect the results , soles should be soaked before testing plus 20 ℃ ± 2 ℃ deionized water 16 ± 1h.
c. conductive anti-static shoes, shoes and shoes like electrical performance through in the dry and wet atmospheric adjustment , will be filled with people clean the ball and put it inside the shoe metal probe device, using a predetermined resistance testing instruments, measuring the first two probe between probe and the third resistor. Under normal circumstances, conductive shoes required resistance should not exceed l00K ohms ; Anti-static shoes should be required 100K ohm resistor to 100M ohms.
d. insulation performance with a shoe as a sample , the inner end of the thermocouple installed at the center of the connection area , and the person filling ball shoes . Adjusting the temperature of the sand bath pot to 150 ℃ disabilities 5 ℃, the shoe placed thereon , so that the sand contacts the shoe outsole , with the temperature of the thermocouple connected to the testing apparatus , measuring the temperature inside the end of the corresponding time , given the increase in the temperature curve . Calculated from the sample placed on a sand bath after 30min from the increase in temperature . General requirements insulated shoes inner bottom surface temperature increase is less than 22 ℃.
e. heel portion of the energy absorption performance test instrument's maximum compression load 6000N, with a record load / deformation characteristics of the device. The shoe will take place with a steel plate , the test punch in the center portion of the inside of the heel against the inner sole . 3mm/min with disabilities speed 10mm/min load is applied . Draw the load / compression curve and calculate the absorbed energy E, expressed in joules .
f. slip outsole for the standard specifies requirements for non-slip soles coefficient test , but the skid block designs, specifications , etc. made ??provisions, such as the thickness of the sole , skid block height , the distance between the edge of the sole , etc. are required .
PPE European standard EN344: 1997 " special security , protection , and work shoes ."
The standard safety shoes models design, the entire shoe uppers, shoe , tongue , insole , outsole and other structures and performance indicators were provided . Each item specified in the standard test methods and other similar standards similar to its principle of the method is also generally applicable to most safety shoes , the main indicators are:
a. Baotou impact resistance steel with a prescribed weight impact test hammer , Baotou Baotou upon impact should be less than the clearance height of the specified value , and Baotou in the axial direction of the test should be no penetrating cracks. It is noteworthy that the national standards of the hammer weight , size , height and impact testing machine structure different from the requirements such as the actual test should be distinguished.
b. puncture resistance test machine is equipped with a plate, nail plate is equipped with a test , the test is a truncated tip of the nail head , nail head should be greater than the hardness of 60HRC. The sole sample is placed on the test machine 's chassis , the position can test for nail piercing through the outsole , the test nails to pierce the speed 10mm/min ± 3mm/min soles until penetrate far, record the maximum required force . Each four points selected on the sole test ( of which at least one point of the heel ) , each point distance of not less than 30mm, and the distance from the inner bottom edge than 10mm. A non-slip bottom block , between the blocks should be pierced. 4 points in the two points should be located away from the implant bottom corner edge line distance of 10-15mm for testing. If the humidity will affect the results , soles should be soaked before testing plus 20 ℃ ± 2 ℃ deionized water 16 ± 1h.
c. conductive anti-static shoes, shoes and shoes like electrical performance through in the dry and wet atmospheric adjustment , will be filled with people clean the ball and put it inside the shoe metal probe device, using a predetermined resistance testing instruments, measuring the first two probe between probe and the third resistor. Under normal circumstances, conductive shoes required resistance should not exceed l00K ohms ; Anti-static shoes should be required 100K ohm resistor to 100M ohms.
d. insulation performance with a shoe as a sample , the inner end of the thermocouple installed at the center of the connection area , and the person filling ball shoes . Adjusting the temperature of the sand bath pot to 150 ℃ disabilities 5 ℃, the shoe placed thereon , so that the sand contacts the shoe outsole , with the temperature of the thermocouple connected to the testing apparatus , measuring the temperature inside the end of the corresponding time , given the increase in the temperature curve . Calculated from the sample placed on a sand bath after 30min from the increase in temperature . General requirements insulated shoes inner bottom surface temperature increase is less than 22 ℃.
e. heel portion of the energy absorption performance test instrument's maximum compression load 6000N, with a record load / deformation characteristics of the device. The shoe will take place with a steel plate , the test punch in the center portion of the inside of the heel against the inner sole . 3mm/min with disabilities speed 10mm/min load is applied . Draw the load / compression curve and calculate the absorbed energy E, expressed in joules .
f. slip outsole for the standard specifies requirements for non-slip soles coefficient test , but the skid block designs, specifications , etc. made ??provisions, such as the thickness of the sole , skid block height , the distance between the edge of the sole , etc. are required .
Helmet is to prevent physical damage to the head impact protection products
Helmet is to prevent physical damage to the head impact protection products . By the cap shell , cap liner , and rear lower cheek with hoop components. Hemispherical cap shell , firm, smooth and have a certain flexibility , impact and puncture combat substance mainly composed of the cap shell to withstand the kinetic energy . Cap shell and leave some space between the cap liner can be buffered , dispersing instantaneous impact, so as to avoid or mitigate the direct damage to the head . Absorption of the impact properties, puncture resistance , lateral stiffness , electrical insulation , flame resistance is a helmet basic technical performance requirements.
Helmet can withstand the pressure is mainly used three principles : 1. Buffer damping effect : cap shell and cap liner between 25 ~ 50mm gap , when the object hit the Fire helmet , the cap shell deformation is not due to a direct impact to the head at the top . 2 . Dispersing stress : cap shell is oval or hemispherical , smooth surface , when the object fall on the cap shell , the object can not stay immediately fall ; And cap shell hit points to withstand the force transmitted to the surroundings through the cap lining cushioning to reduce the force of up to 2 /3 of the rest of the force through the cap liner gives the entire area of ??the skull to pass , so put the focus on the surface becomes a focal point , thus avoiding the impact force to a point on the cap shell stress concentration and reduce the force per unit area . 3 . Biomechanics : GB forth helmet must be able to absorb the 4900N. This is because the biological tests , the force in human cervical maximum limit , exceeding this limit will be harmed cervical spine , the light causing paralysis , severe life-threatening.
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