1, different degrees of curl
Cold ironing: ordinary cold ironing focuses on the remodeling of disulfide bonds, but can't do anything about hydrogen bonds. Therefore, the curl effect of wet hair is better, and it is only 30% of the curl of wet hair after drying, which is easy to straighten;
Perm: change the internal structure of hair, it can be permanently set, and it can curl up to 70% after drying;
2, the required temperature is different
Cold perm: at room temperature, the process of perm is completed through chemical reaction;
Blanching: Disulfide bonds and hydrogen bonds are broken by high-temperature heating at 100- 140, thus changing the hair structure and reshaping the hairstyle;
3, the scope of application is different
Cold perm: you can curl your hair from the root, which is suitable for all kinds of curly hair styles;
Perm: due to the limitation of equipment, curly hair can't be close to the scalp and can't be permed from the hair root;
4, the degree of hair damage is different
Cold perm: it has certain damage to hair, but it is relatively low;
Perm: high degree of hair damage, improper operation is easy to burn your hair;
5. Different requirements for hair quality
Cold perm: Hair with high requirements on hair quality is easy to straighten after cold perm, while coarse hair is not easy to curl.
Perm: It can change the nature of hair. Hard hair can also be permed with thermoplastic.
Extended data 1, advantages of cold stamping:
(1) conditions are relatively few. Cold perm does not need large instruments, which is convenient for all kinds of hair salons and even families to operate by themselves.
(2) There are many changes in modeling. Because there is no need for heating, or only simple external heating is needed to speed up the perm process, there are a lot of fancy modeling methods for cold perm, such as tin foil perm, fireworks perm, horn perm, braid perm, positioning perm and so on.
(3) The process is simple, and the technical requirements of perm itself are relatively low. Generally, you only need to choose the right perm water for different hair qualities, control the time of the first dose and pay attention to observation.
2. Compared with cold perm, the hair permed by thermoplastic perm is more durable and elastic, and can keep good curl in dry state, which saves a lot of trouble in styling.
However, due to the limitation of equipment, thermoplastic perm can't be too close to the scalp, so it is not suitable for curling from the root of hair, nor for small curly hair, and the types of styling are relatively lacking.
The hair looks shiny after a thermoplastic perm, but it is actually the effect of strengthening heat. The damage to hair is more serious than ordinary cold perm, and the technical requirements are higher. Improper operation not only leads to poor perm effect, but also produces extreme conditions such as perm.
Thermoplastic perm reshapes hydrogen bonds, thus changing the properties of hair. Straight hair is easy to straighten after ion perm, and it is often necessary to use a thermoplastic perm.
3. Cold perm or hot perm?
First of all, from the principle and effect, the disulfide bond in hair is changed by perming agent, and then the hydrogen bond will temporarily produce memory through modeling, and it will curl more and have better elasticity when wet hair; After drying, the curl will become larger and the texture will be slightly weakened.
The perming agent changes the disulfide bond in hair, but also changes the hydrogen bond, which can keep curly for a long time, and the hair does not come loose, and the texture is very strong.
Secondly, from the point of view of perm hairstyle production and effect management, the cold perm hairstyle production process is more convenient, and personalized curls can also be made, such as tin foil and perm roots. But there must be a correct way to take care of your hair, otherwise it will become rough and shiny. Perm is suitable for dynamic and natural waves, full of elasticity and luster, and the hair will be very stylish without deliberate care.
Cold perm and perm should not be distinguished by good or bad. First of all, it depends on the hairstyle you want to choose and the hair quality of the model, because they directly affect the final effect, and the method of perm should be selected according to the required effect.
References:
Baidu encyclopedia-cold perm
Baidu Encyclopedia-Thermoplastic Hot Hand