Labor insurance shoes with rubber outsole have a large share in the labor insurance shoe market due to the special characteristics of rubber. In order to ensure that the rubber outsole shoes can adapt to the non-slip, wear-resistant, high temperature and harsh working environment, we must master the formula of the rubber outsole to produce a qualified rubber outsole.
Rubber formula technology is the science and art of selecting and applying materials. The general rubber formula has three purposes: firstly, it makes the rubber products have practical physical properties; secondly, it can cooperate with the existing processing equipment for good processing operations; finally, it can achieve the physical property level that meets the customer's requirements with the lowest possible cost ingredients. In other words, the three most important factors to consider when designing a rubber formulation are the physical properties of the ingredients, the processability and the cost, and the three are given an appropriate balance. This is the most important work of formula design.
Additives commonly used in rubber formulations can be summarized into ten main components:
Rubber or elastomers:
The first and most important step in the design of the rubber formulation is the selection of the rubber substrate or the raw material glue. Rubber is a kind of engineering material, regardless of its composition, with some common basic characteristics. All rubbers are elastic, flexible, tough, impervious to water and air permeable. In addition to these common characteristics, each rubber has its own properties due to its composition.
Vulcanizing agents:
The purpose of adding a vulcanizing agent is to cause a chemical reaction of the ingredients to cause a cross linking between the rubber molecules to change the physical properties of the rubber. The chemical bridging action causes the rubber compound to change from a soft, viscous, thermoplastic body to a tough thermoset, which is less affected by temperature. Sulfur is still the most widely used sulphurizer to date. Other sulfur donors such as TMTD (TUEX) of thiuram disulfide are sometimes used as a formulation for all or part of the replacement of elemental sulfur in a low sulfur or sulfur-free vulcanization system to improve the heat resistance of the article. The second most important job of the formulator is the choice of the vulcanization system, the vulcanizing agent and the accelerator.
Accelerators:
The vulcanization accelerator accelerates the vulcanization rate of the ingredients and shortens the vulcanization time.
Activators and retarders (Retarders):
Activators are used to help enhance the activity and efficacy of the accelerator. The most commonly used activators are zinc oxide powder, stearic acid, lead oxide, magnesium oxide and amines (H).
Antidegradants:
Anti-aging agents can delay the degradation of rubber products due to oxygen, ozone, heat, metal catalysis and buckling motion. Therefore, the addition of the anti-aging agent can enhance the aging resistance of the product and prolong its service life after the ingredients are added.
Processing aids:
Processing aids, as the name suggests, help the ingredients to facilitate processing operations such as mixing, calendering, extrusion, and forming.
Fillers:
Fillers can enhance the physical properties of the ingredients, aid in processability or reduce their cost. Reinforcing fillers can increase the hardness, tensile strength, modulus, tear strength and abrasion resistance of the article. Mineral materials such as soot or fine particles are commonly used.
Plasticizer, softener and tackifier (Tackfier):
Plasticity, softeners and tackifiers are used to help the compound to mix, change its viscosity, enhance the viscosity of the ingredients, improve the flexibility of the product at low temperatures, or replace some of the rubber without too much impact on physical properties. In general, these types of additives can be used as processing aids or extenders.
Color Pigment :
Colorants are used in non-carbon soot formulations to provide a specific color. Generally used color materials can be classified into organic and inorganic materials. Inorganic metals include iron oxide, chromium oxide, titanium dioxide (titanium dioxide), cadmium sulfide, cadmium selenide, barium sulfide, mercury sulfide, lithopone and military blue.
Organic pigments are much more expensive than inorganic pigments. However, its use is better, the hue is bright and the specific gravity is very low. Moreover, the color change of the organic colorant is more than that of the inorganic color material. However, most organic pigments are unstable to steam, light, acid or alkali and sometimes migrate to the surface of the product.
Special purpose materials:
Special-purpose materials are ingredients that are not often used in water, such as foaming agents, flavoring agents, adhesion aids, flame retardants, mildew inhibitors, and ultraviolet absorbers.
Recipe design program:
Almost all new formulations have been modified from existing formulations. At present, few people have tried to design a completely new formula because it is not needed practically. In order for the formula to be effective, the formulator should try to use all kinds of technical data that are intrinsic or extrinsic, then organize and analyze it according to the needs, and use the personal imagination and creativity to design the formula. The following steps can be used as a reference for formulation design.
1. Determine the physical properties and costs of the target.
2. Select the applicable raw material glue.
3. Develop test data for existing similar ingredients.
4. Refer to the technical information on the various types of materials.
5. Set the initial recipe.
6. Try a small sample to test if the physical properties are consistent with the target.
7. Estimate the cost of the materials used as a reference for further evaluation.
8. Evaluate the workability of this ingredient on site.
9. Trial the target with this formula.
10. Test whether the physical properties can meet the specifications.