5.2 Chemical Waving and Reforming Services

Chemical Waving and Reforming Services

Chemical waving (permanent waving) allows barbers to restructure straight hair into a wavy or curly pattern. This process is divided into two phases: the physical phase (wrapping the hair on rods) and the chemical phase (applying waving solution to break side bonds, and neutralizing to reform them). A barber must understand the chemistry of permanent waving solutions, the distinctions between alkaline and acid-balanced perms, rod mechanics, and the neutralization process.

Chemistry of Permanent Waving

The hair structure is held together by three types of side bonds: hydrogen, salt, and disulfide bonds. Disulfide bonds are strong chemical side bonds formed by the joining of sulfur atoms in neighboring polypeptide chains. Unlike physical hydrogen and salt bonds, which are easily broken by water or heat, disulfide bonds can only be altered through a chemical reaction.

Permanent waving is a chemical process that breaks these disulfide bonds through a chemical reaction known as reduction. The waving solution, acting as a reducing agent, supplies hydrogen atoms to the disulfide bonds. The hydrogen atoms break the disulfide bonds by converting them into cysteine amino acid groups. Once broken, the polypeptide chains can slip into the new curled shape dictated by the size of the perm rod.

The active reducing agent in most permanent waving solutions is a thio compound. The most common is ammonium thioglycolate (ATG), produced by combining thioglycolic acid with ammonia. The ammonia swells the hair cuticle, allowing the thioglycolic acid to penetrate into the cortex where the disulfide bonds reside.

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Alkaline Waves vs. Acid-Balanced Waves

Permanent waving solutions are classified based on their pH and chemical formulation. The two primary categories are alkaline (cold) waves and acid-balanced waves.

• Exothermic Waves: These perms produce their own heat through an internal chemical reaction. When the barber mixes an activator (containing an oxidizing agent) into the waving solution, it generates heat that speeds up processing and swells the hair.
• Endothermic Waves: These perms require an outside heat source, such as placing a plastic cap over the wrapped hair and positioning the client under a preheated hood dryer, to activate the waving solution.

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Wrapping Patterns and Mechanics

The physical phase of permanent waving involves wrapping the hair around perm rods. The size and shape of the rod determine the size of the curl.

• Concave Rods: Have a smaller diameter in the center, producing a tighter curl in the center and looser on the ends.
• Straight Rods: Have a uniform diameter, producing a consistent curl throughout the strand.

Base Control and Placement

Base control refers to the position of the rod in relation to its base section, determined by the angle of wrapping:

1. On-Base Placement: Hair projected at 45 degrees beyond perpendicular. Maximizes volume but puts high tension on the hair follicle.
2. Half-Off Base Placement: Hair projected at 90 degrees (perpendicular) to the scalp. Minimizes follicle stress with moderate volume.
3. Off-Base Placement: Hair projected at 45 degrees below perpendicular. Minimizes volume and tension.

End Paper Techniques

End papers are porous papers used to control the hair ends and prevent fishhooks (crimped ends):

• Bookend Wrap: A single paper folded in half over the ends.
• Single Flat Wrap: A single paper placed over the strand.
• Double Flat Wrap: Two papers, one under and one over the strand, providing the highest level of control.

Wrapping Patterns

• Basic Perm Wrap (Straight Set): Horizontal rows in a grid pattern.
• Bricklay Perm Wrap: Staggered horizontal rows, similar to bricks, preventing visible splits or parts.
• Curvature Perm Wrap: Follows the natural curves and contours of the head.

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Neutralizer Chemistry

After the waving solution has processed, the chemical reaction must be stopped and the hair hardened. This is achieved through the neutralizer.

The active ingredient in most perm neutralizers is a low volume of hydrogen peroxide (H₂O₂) at an pH of 3.0 to 5.0. Neutralization is an oxidation reaction. Oxygen from the neutralizer removes hydrogen added by the waving solution, allowing sulfur atoms to recombine and reform the disulfide bonds in their new curly position.

Barber Exam Trap: The hair must be thoroughly rinsed with warm water for a minimum of 5 minutes and blotted dry with a towel before applying the neutralizer. Leftover water dilutes the neutralizer, resulting in weak curls. Waving solution left in the hair combined with neutralizer can create chemical heat that causes hair breakage and scalp irritation.

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Safety Guidelines for Perming

• Perform a scalp analysis; do not perm if the scalp shows abrasions or lesions.
• Always wear gloves and apply a protective cream and cotton coil around the hairline.
• Check curl development by performing regular test curls during processing.
• Do not shampoo the client's hair for 48 hours after a permanent wave, as disulfide bonds take time to lock into place.