Food-grade silicone key chains made in animal shapes

Design stage

Modeling conception

Determine the species of animals: Select animals based on the target audience and usage scenarios. For example, for the children’s market, cute and common animals such as rabbits and bears can be chosen. If it is given as a high-end gift, animals with more artistic sense or symbolic meaning might be chosen, such as cranes and fine horses.

Style positioning: Consider whether the key chain should adopt a realistic style, a cartoon style or a minimalist style. The realistic style pays attention to details and strives to restore the true form of animals. The cartoon style exaggerates and deforms animal images to make them more interesting and approachable. The minimalist style emphasizes simple lines and shapes, highlighting the main features of animals. For example, cartoon-style rabbits can increase the proportion of their eyes to make their ears longer and rounder.

Draw a sketch

Preliminary sketching: Use a pencil to draw a rough sketch of the animal’s shape on paper to determine the general outline and posture of the animal. You can start with simple geometric shapes, such as using a circle to represent the head, an oval to represent the body, and a triangle to represent the ears, etc., and gradually outline the shape of the animal.

Refine features: On the basis of the initial outline, refine the animal’s features, such as eyes, nose, mouth, hair, etc. For food-grade silicone key chains, it is necessary to consider the performance effect of these features after silicone molding to avoid overly complex or small structures that are difficult to produce. For example, the eyes of rabbits can be represented by simple circles, and the whites of the eyes and the eyeballs can be distinguished by different colors.

Adjust the proportion: Check whether the proportions of each part of the animal are harmonious and make adjustments as needed. For instance, if a rabbit’s head is too large and its body is too small, it will look unnatural. In such cases, the head should be appropriately reduced or the body enlarged.

Mold making stage

Mold design

Parting surface design: Based on the complexity of the animal shape and the fluidity of the silicone, design a reasonable parting surface. The parting surface is a plane that divides the mold into two or more halves, and its design should facilitate the filling and demolding of silicone. For simple animal shapes, a single parting surface can be adopted; For complex shapes, multiple parting surfaces may be required. For instance, for an animal shape with multiple protrusions and depressions, it might be necessary to set up parting surfaces from different directions.

Exhaust groove design: Exhaust grooves are designed on the mold to discharge the gases produced by the silicone during the molding process, avoiding bubble defects. The width and depth of the exhaust groove should be determined based on the characteristics of the silicone and the size of the mold. Generally, the width is 0.2-0.5 millimeters and the depth is 0.05-0.1 millimeters.

Mold processing

Material selection: Choose materials suitable for making silicone molds, such as steel or aluminum alloy. Steel molds have high hardness and wear resistance, making them suitable for mass production. Aluminum alloy molds are lighter in weight and have lower processing costs, making them suitable for small-batch production.

Processing technology: CNC milling machines, electrical discharge machining machines and other equipment are used to process the mold materials, precisely replicating the designed animal shapes onto the molds. During the processing, the dimensional accuracy and surface roughness should be strictly controlled to ensure the quality of the mold. For instance, the dimensional tolerance of the mold should be controlled within ±0.05 millimeters, and the surface roughness should be below Ra1.6 microns.

Mold debugging

Mold test: Install the processed mold onto the forming equipment and conduct a mold test. Use silicone raw materials for molding and check the molding effect of the key chain. Observe whether there are defects such as material shortage, bubbles, deformation, etc.

Adjustment and optimization: Based on the results of the mold trial, adjust and optimize the mold. If a shortage of materials is found, it might be due to poor venting of the mold or poor fluidity of the silicone. It is necessary to adjust the venting groove or replace it with silicone raw materials that have better fluidity. If deformation is found, it may be due to uneven cooling of the mold or excessive demolding force. It is necessary to adjust the cooling system or optimize the demolding structure.

Silicone rubber molding stage

Raw material preparation

Silicone selection: Choose silicone raw materials that meet food-grade standards to ensure they are non-toxic, odorless and pollution-free. According to the color requirements of the animal modeling, mix the corresponding colored silicone raw materials. Color masterbatches or color pastes can be used for color mixing. When mixing colors, it is necessary to follow a certain proportion to ensure the uniformity and stability of the color.

Raw material mixing: Mix the silicone raw materials and curing agent in the prescribed proportion and stir evenly. During the mixing process, it is necessary to avoid the formation of bubbles. A vacuum deaerator can be used for deaeration treatment.

Forming operation

Injection of silicone: Inject the mixed silicone raw materials into the mold. When injecting the silicone, it is necessary to control the speed and pressure of the injection well to ensure that the silicone can fully fill the mold. For complex animal shapes, it may be necessary to use multiple injections of glue to avoid the occurrence of bubbles and material shortages.

Curing: Place the mold filled with silicone into the heating equipment for curing. The curing temperature and time should be determined based on the characteristics of the silicone and the size of the mold. Generally, the curing temperature is between 120 and 180℃, and the curing time is 3 to 10 minutes. During the curing process, it is necessary to ensure uniform temperature to avoid local overheating or overcooling.

Demolding and trimming

Demolding: After the curing is completed, remove the mold from the heating equipment and wait for it to cool to room temperature before demolding. When demolding, operate carefully to avoid damaging the key chain. Demolding can be assisted by using mold release agents or compressed air.

Trimming: Trim the edges of the key chain after demolding to remove excess burrs and flash. You can use tools such as scissors and blades to trim the edges. When trimming, be sure to keep the edges of the key chain smooth and neat.

Post-processing stage

Surface treatment

Polishing: If there are rough or uneven areas on the surface of the key chain, sandpaper can be used for polishing. When grinding, start with coarse sandpaper and gradually transition to fine sandpaper until the surface is smooth.

Polishing: For key chains with higher requirements, polishing treatment can be carried out to make their surfaces brighter. Polishing can be carried out using a polishing machine or by hand. When polishing, appropriate polishing paste should be used.

Quality inspection

Visual inspection: Check the appearance of the key chain for any defects, such as scratches, bubbles, color differences, etc. Visual inspection should be carried out in sufficient light to ensure that minor defects can be detected.

Dimensional measurement: Use measuring tools such as calipers to measure whether the dimensions of the key chain meet the design requirements. The dimensional deviation should be within the allowable range; otherwise, it will affect the usage effect of the key chain.

Performance testing: Conduct some performance tests on the key chain, such as tensile tests and bending tests, to check whether its elasticity and flexibility are good. At the same time, food-grade safety tests should be conducted to ensure that the key chains meet relevant standards.

Packaging stage

Packaging design

Select packaging materials: Based on the characteristics of the key chain and the target audience, choose appropriate packaging materials. Common packaging materials include plastic bags, paper boxes, gift boxes, etc. For food-grade silicone key chains, it is necessary to choose non-toxic and environmentally friendly packaging materials.

Design packaging patterns: Print animal-shaped patterns, brand logos, product information, etc. on the packaging. The packaging pattern should be in harmony with the style of the key chain and highlight the features of the product.

Packaging operation

Put the key chain into the packaging: Put the key chain that has passed the inspection into the packaging, and be careful to avoid shaking or damage to the key chain inside the packaging.

Sealed packaging: Seal the packaging to ensure that the key chain is not contaminated during transportation and storage. It can be sealed with a heat sealer or tape.