The elastic adjustment principle of food-grade silicone bracelets

The elastic adjustment of food-grade silicone bracelets mainly involves the principles of raw material ratio, vulcanization process, additive usage, and product design. The following is a detailed introduction for you:

Raw material ratio

The hardness, tensile strength, elongation and other parameters of food-grade silicone raw materials will affect the elasticity of the bracelet. Silicone raw materials produced by different manufacturers have different elastic performances due to differences in formulas. In production, the elasticity can be changed by adjusting the proportion of raw materials. For instance, appropriately increasing the proportion of certain components with elastic enhancement effects can enhance the elasticity of the bracelet. However, the tensile strength and resilience of the raw materials themselves are of different properties. Some materials have good tensile properties but poor resilience. Therefore, it is necessary to precisely mix the raw materials to ensure that the tensile and resilience can be balanced.

Vulcanization process

Vulcanization is a key process for adjusting the elasticity of silicone bracelets. Parameters such as vulcanization time and temperature directly affect the crosslinking degree of silicone rubber, and thereby influence its elasticity.

Vulcanization time: If the vulcanization time is too short, the cross-linking of the silicone will be incomplete, and the bracelet will become soft and undercooked, with insufficient elasticity. If the vulcanization time is too long, it will cause the product to become brittle, hard and have poor elasticity. Therefore, it is necessary to strictly control the vulcanization time to keep it within the normal range, so as to ensure the hardness, softness and uniformity of the saturated product, as well as dimensional control and defect rate control.

Vulcanization temperature: The vulcanization temperature needs to be coordinated with the vulcanization time. The temperature should not be raised or the time reduced at will due to production capacity demands; otherwise, it is easy to cause deformation and softening of the products. The amount of curing agent added should also be determined by the temperature. When the temperature is high, the amount of curing agent should be reduced; otherwise, the mold will become hard and brittle. If too little curing agent is used, the operation time will be prolonged.

Use of additives

Silicone oil: Silicone oil is often used to adjust the hardness of silicone, thereby affecting its elasticity. Generally, adding 1% silicone oil will reduce the hardness of silicone by about 0.9 to 1.1 degrees. Adding 10% silicone oil will reduce the hardness by about 5 degrees. A decrease in hardness can make the bracelet softer, and the elasticity changes accordingly. However, excessive addition of silicone oil will destroy the molecular weight in the silicone, reducing its tear and tensile strength, resulting in a decrease in the number of mold turnover times and a shortened service life. Therefore, the amount of silicone oil added must be strictly controlled. Generally, the ratio of silicone to silicone oil should not exceed 5%, and silicone oil with a higher viscosity should be added as much as possible.

Other additives: If the proportion of silicone oil and silica in the raw materials is not harmonious, it will lead to problems with the quality of the raw materials and affect their elasticity. Reasonable adjustment of the proportion of these additives can optimize the performance of silicone and enhance the elasticity of the bracelet.

Product design

The design factors such as the shape, size and thickness of the bracelet can also affect its elasticity. For example, thinner bracelets are more prone to deformation when subjected to force. However, if designed reasonably, they can also return to their original shape after the external force is removed, showing a certain degree of elasticity. Thicker bracelets are relatively stiffer and have different elasticity performances. In addition, the shape design of the bracelet, such as whether it has a curvature or the degree of bending, will also affect its deformation and rebound when subjected to force.