Custom Plastic Kitchen Storage Box Parts Moulding

In addition, our company has established cooperative relationships with plastic raw material suppliers, printing manufacturers, etc. to ensure the supply of raw materials and printing quality. Through our rich experience and perfect supply chain, our company can provide customers with high-quality customized Custom Plastic Kitchen Storage Box Parts moulding products to meet their specific needs. At the same time, we have 10 years of professional foreign trade service experience, understand the foreign trade process, and better serve our customers. For Custom Plastic Kitchen Storage Box Parts moulding products, we can make corresponding plastic parts, which is mainly done through injection molds.

## Raw Material Control (The first critical step for food-contact products—a common pitfall for many factories)

1. **Certificates and Traceability**

For every batch of raw material, you must obtain: a Technical Data Sheet (TDS), a Certificate of Analysis (COA), and a food-contact compliance certificate. Materials must meet the following standards: (EU) No 10/2011 for the European Union, GB 4806.7 for China, and FDA 21 CFR for the United States.

- Masterbatches and processing aids (antioxidants, lubricants, dispersants) **must also be food-grade** and accompanied by their own migration test reports. The use of standard industrial-grade masterbatches or generic wax-based lubricants is strictly prohibited.

- Minimize the use of additives; a higher number of additives increases the risk of migration.

2. **Rules for Using Regrind (Strictly Regulated)**

✅ Permitted: Clean in-house sprues/runners and material from mold trials—provided they are collected separately, granulated separately, and clearly labeled.

❌ Prohibited: External recycled materials, mixed scrap, floor sweepings, or materials contaminated with oil, grease, or other substances.

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> Regulatory bodies and customer audits generally prefer that **food-contact products be manufactured primarily from virgin (new) material.** If regrind is incorporated, the ratio must be fixed and documented, and migration testing must be conducted accordingly.

3. **Drying Requirements (Material-Specific)**

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> Drying hoppers must be kept clean and dedicated solely to this purpose; do not use them for non-food-grade materials.

- PP, HDPE: Very low moisture absorption; typically do not require drying. If damp, stored for a long period, or mixed with masterbatch, dry at 60–80°C for 2–4 hours.

- Tritan: Must be dried at 80–90°C for 4–6 hours (moisture content <0.02%). Failure to do so will result in silver streaks, bubbles, or hydrolysis.

- PPSU: Dry at 130°C for 4–6 hours.

- TPE (overmolding material): Dry at 60°C for 2 hours.

4. **Raw Material Storage**

Materials must be kept sealed, dust-free, and stored off the floor and away from walls. Do not store them in the same area as chemicals such as inks, cleaning agents, machine oils, or glues, to prevent the absorption of odors. ## II. Mold Considerations (Molds for food-contact parts differ from those for standard cosmetic parts)

1. **Steel Selection**

Prioritize S136 or 420 stainless steel, hardened to HRC 48–52. These materials offer rust and corrosion resistance, are easy to polish, and minimize the risk of metal ion leaching.

For internal structural components (non-cosmetic surfaces), NAK80 may be used; however, all surfaces in contact with the cavity, gates, or runners should ideally be made of stainless steel.

2. **Runner Systems & Hot Runners (Critical Importance)**

- Use **valve-gate hot runner systems** whenever possible to minimize gate remnants and eliminate "dead zones" where material can accumulate. Exercise caution with open-tip hot runner nozzles, as they are prone to material stagnation and carbonization.

- Ensure the inner walls of the runner system are mirror-polished. **Eliminate all dead zones, sharp corners, and recesses.** Material trapped in such areas will carbonize under high temperatures, leading to black specks, unpleasant odors, and the leaching of small-molecule degradation products.

- Hot runner thermocouples and temperature control systems must be highly precise; localized "hot spots" are the primary cause of material degradation.

3. **Venting**

Strictly control the depth of venting channels:

- PP: 0.015–0.02 mm

- Tritan / PPSU: 0.01–0.015 mm

Provide venting at the ends of weld lines, the final fill points of the part, and around inserts and ejector pins. Trapped air can cause scorching; beyond being a cosmetic defect, charred degradation products may migrate into the product, potentially exceeding safety limits.

4. **Cavity Surface & Demolding**

- Polish cavity surfaces to a roughness of Ra ≤ 0.2 μm to facilitate easy demolding, prevent the accumulation of contaminants, and simplify cleaning.

- ❗**Avoid the use of mold release agents whenever possible.** If one is strictly necessary, use only a food-grade, water-based agent. Oil-based release agents are strictly prohibited, as they can migrate into the product and leave residual odors. Rely instead on high-quality polishing and appropriate draft angles to ensure smooth demolding. 5. **Structural Design (Specific to Kitchenware)**

- Ensure smooth internal surfaces with minimal narrow gaps or "dead zones" where food residue could accumulate; use rounded corners for sealing grooves.

- Rib thickness should be ≤0.6 times the wall thickness, with radiused (R-filleted) bases to minimize both sink marks and stress concentrations.

- Position weld lines away from sealing surfaces and areas subject to stress or gripping (as weld lines are inherently weaker and more prone to trapping debris or leaching substances).

- Regarding undercuts: Small undercuts in PP components may be released via "force-ejection" (snap-fit removal); however, for transparent materials like Tritan or PPSU, force-ejection should be avoided to prevent stress-induced whitening or cracking during boiling/sterilization.

We are a Custom Plastic Kitchen Storage Box Parts moulding manufacturer, providing high-quality Custom Plastic Kitchen Storage Box Parts moulding manufacturing. As long as you want to customize/develop Custom Plastic Kitchen Storage Box Parts moulding products, you can find us. We have professional injection mold design and mature manufacturing technology, providing you with one-stop service, from product design-mold making-product production-product packaging-product transportation, we can help you in every link. As long as you come to us, we will provide you with the ultimate service and satisfy you in terms of product quality, production time, information dialogue, etc.

Plastic Injection Mould making

Plastic molding specifications

Mold design:

Transaction process:

Mold testing:

Product packaging

Factory

We are Custom Plastic Mold factory. Our factory is plastic injection mold maker. we has 17 years of experience in professional custom plastic mold and 10 years of foreign trade experience. We are custom Plastic Mold supplier. We can provide custom Plastic Mold service. Our factory can make the Injection molded plastic parts, and the quality of the products will satisfy you.

We have more than 50 high-end machines and hundreds of engineers and designers. We can provide one-stop service, from product design - mold making - product production - product packaging - transportation. We have a complete production chain. We can meet all your requirements.

Services we provide:

Professional custom mold service, Plastic mold design and manufacturing .plastic product production, product design, mold design, blow mold customization, rotational mold customization, die-casting mold customization. 3D printing services, CNC manufacturing services, product packaging, customized packaging, shipping services.

We always adhere to the principles of quality first and time first. While providing customers with the highest quality products, try to maximize the production efficiency and shorten production time. We are proud to tell every customer that our company has not lost any customer since its establishment.If there is a problem with the product, we will seek a solution actively and take responsibility to the end.

FAQ

Q1: Are you trading company or manufacturer ?

A: We are manufacturers.

Q2. When can I get the quotation?

A: We usually quote within 2 days after we get your inquiry.

If you are very urgent, please call us or tell us in your email so that we can quote for you first.

Q3. How long is the lead-time for mold?

A: It all depends on the products' size and complexity. Normally, the lead time is 25 days.

Q4. I have no 3D drawing, how should I start the new project?

A: You can supply us a molding sample, we will help you finish the 3D drawing design.

Q5. Before shipment, how to make sure the products quality?

A: If you don't come to our factory and also don't have the third party for inspection, we will be as your inspection worker.

We will supply you a video for production process detail include process report, products size structure and surface detail, packing detail and so on.

Q6. What is your payment terms?

A: Mold Payment: 40% deposit by T/T in advance, 30% second mold payment before sending out the first trial samples, 30% mold balance after you agree the final samples.

B:Production Payment: 50% deposit in advance, 50% before sending out the final goods.

Q7: How do you make our business long-term and good relationship?

A:1. We keep good quality and competitive price to ensure our customers benefit for best quality products.

2. We respect every customer as our friend and we sincerely do business and make friends with them, no matter where they come from.