Mastars designed and manufactured virus collection tube molds for Daan Gene, a listed company, and then produced 10ml and 30ml virus collection tubes on a large scale through injection molding. Cooperating with large-scale novel coronavirus nucleic acid testing, it has made positive contributions to the early detection and control of novel coronavirus.

Since the beginning of 2020, the novel coronavirus began to enter the human world. In the same year, it began to break out in the world. So far, the number of novel coronavirus infections in the world has reached more than 500 million, and more than 6 million people have died. This unprecedented super virus is ravaging the world like never before. The trend is tyrannizing the world. Mastars is fortunate to be able to turn its technology and strength into anti-epidemic strength and a social responsibility to fight the epidemic at this time of human crisis, fortunately!

We must be familiar with such a scene and have experienced it many times. Nucleic acid testing is an effective means of precise prevention and control. It is the first line of defense to actively screen asymptomatic infections and positive cases. It can detect the source of infection as early as possible and control the spread of the epidemic from the source, preventing the prevention and control of the epidemic from being brought about by the failure of timely diagnosis and isolation. This is a particularly important part of the fight against the epidemic. The virus collection tube is undoubtedly one of the most important tools for nucleic acid testing.

Process:
Mold: CNC machining, wire cutting machining, electrical discharge machining (EDM), die polished, grinder, fitter
Virus collection tube: injection molding.


Mold manufacturing process:

Material: 

Virus collection tube: PP (polypropylene), cap: PE (polyethylene) 

Mold: High precision injection mold, ASSAB STAVAX ESR high grade stainless die steel

About die steel material:

ASSAB is a famous supplier of die stainless steel in Sweden. The mold is made of STAVAX ESR high-grade stainless die steel, which has the following characteristics:
1. Excellent corrosion resistance 
2. Excellent polishability 
3. Excellent wear resistance 
4. Good machinability 
5. Dimensional stability during heat treatment

Combining the above advantages, this steel has excellent production characteristics. Due to its excellent corrosion resistance, the surface of the cavity remains in its original state after long-term use of the mold. When the mold is stored or used in a humid environment, no special protection is required, and the maintenance cost is low. 
Low production cost: Since the mold cooling water channel is less affected by corrosion (unlike ordinary die steel), the heat conduction characteristics and cooling efficiency remain stable throughout the service cycle of the mold, ensuring a consistent cycle time of the mold. 

The above advantages combined with the high wear resistance of STAVAX ESR provide low maintenance costs and long life of the mold, to achieve the best economic benefits. 

Note: STAVAX ESR is produced by the "Electro-Slag Remelting (ESR)" process, which has a low inclusion content and provides excellent polishability.

Ordered Quantity: 

5 sets of 10ml virus collection tube mold and cap mold 
6 sets of 30ml virus collection tubes mold and cap mold

About the customer
Guangzhou Daan Gene Co., Ltd. is a state-owned biopharmaceutical high-tech enterprise, which is led by molecular diagnostic technology, integrating the research and development, production and sales of clinical test kits and instruments, as well as the clinical test services of national chain medical independent laboratories. 

The company was listed on the Shenzhen Stock Exchange on August 9, 2004. The company has always been the leader in nucleic acid diagnostic reagents in China.

About Products 
Produced high-precision molds that were eventually used to mass-produce novel coronavirus collection tubes and their caps, a product that everyone is very familiar with. We have produced precision molds for both 10ml and 30ml virus collection tubes. Today we focus on introducing the 10ml virus collection tube molds that were put into mass production earlier. The 10ml virus collection tube is the same test tube used by a group of 10 people that we often encounter when we do nucleic acid testing.

About the project 
We all know that virus collection tubes are a new demand under the new crown epidemic. This is a brand-new product. There is no complete experience accumulated. We have rich experience in producing similar assay tubes and cryopreservation tubes, and these valuable experiences have indeed provided great help to our new project. 

The virus collection tube has high requirements, strict standards and short delivery time. In the special period of the novel coronavirus, this is a very important epidemic prevention material. At the same time, due to changes in medical policies, as well as continuous changes and improvements in product requirements and standards, the requirements for molds are constantly being upgraded. 

Based on more than ten years of experience in the medical industry and the rich accumulation of similar products, Mastars adopted the IPD(Integrated Product Development) product development model. For each project in the past, it has detailed project development records. To a large extent, both repeated mistakes are avoided and existing achievements are rationally utilized, which greatly saves development and production cycles. 

In the process from the start of production of 10ml virus tube mold to the production of 30ml mold, it is easy to solve problems that have been encountered before. For new problems, We would first divide the level, and carried out strict control in the process to ensure timely resolution. In this way, the resolution of all problems was brought together into the smooth delivery of the final product.

Challenges and Solutions 
1.Tight delivery cycle. The virus collection tube is an anti-epidemic material that is in short supply and urgently needed in the current society, so the time limit of the customer’s order is tight. For such a large-scale precision mold, the mold transfer cycle is required to be 35 days, including the traditional Chinese Spring Festival holiday. 

Solution: Our engineering designers and production workers worked overtime, sacrificed the beautiful moments of the Spring Festival holiday and family reunion, and at the same time completed the production arrangement efficiently and successfully completed the mold before the delivery date.

2.High precision requirements, mold precision requirements reach 0.005mm. 

Solution: In the manufacture of high-precision molds, we have rich experience and strong technical strength. At the same time, we have German Hermle 5-axis machining center, AGIE spark machine, Sodick spark machine, Okuma, FANUC and other precision mold processing equipment. It ensures the output of high-precision molds.

3.This is a multi-cavity mold with 32 cavities in one mold, and the tubes and caps of each one are required to be interchangeable and fully fit. The more holes there are, the worse the interchangeability is, which put forward very high requirements on the machining accuracy. 

Solution: High-precision CNC equipment and technical strength ensure the machining accuracy of all holes to achieve arbitrary interchangeability. The machining of screws uses a 5-axis machining center. Moreover, the mold material we chose is ASSAB STAVAX ESR high-grade stainless die steel, which we have introduced earlier. It has high hardness to reduce deformation, and excellent wear resistance and corrosion resistance, which can greatly extend the service life of the mold and will not cause mold wear due to injection molding, resulting in dimensional tolerances.

4.High production environment requirements. Since it is a medical consumable, injection molding requires a dust-free workshop.

Solution: All injection molding processes were performed in a dust-free aseptic workshop. The Sumitomo injection molding machine is automatically processed by a manipulator, and the production efficiency is extremely high, which met the requirements of the production environment.

5.Due to the particularity of the product, the requirements are relatively high, and as time goes on, there will also be many changes in demand, and local modifications are required after mold shifting. 

Solution: According to the requirements of customers, we constantly modified the mold and tested it many times to meet all the customer's requirements.


Technical difficulties in mold design and manufacture 
In the design and manufacture of molds, we encountered large and small problems, some problems seem small, but they will obviously affect the quality of the products, and some serious problems will directly affect the delivery of the products. We select representative issues for analysis, but due to technical confidentiality,we cannot make them completely public, please understand.

1. Problems: The water carried by the back mold core of the pipe is not added to the top, and the nozzle is not fixed, which affects the cooling effect. 

Improvement plan: Such as optimized water transport structure in the picture on the right.
Improvement effect: Mold temperature can be controlled within 3 degrees deviation range.

2. Problems: The product sticks to the front die and the back die at T1. When the product is ejected, the front die is pulled and deformed, and the rear die is pushed out and extruded.

Improvement plan: Add a first-stage exhaust to the front and rear molds and cores, and optimize the original exhaust structure.
Improvement effect: The problem of sticking mold has been basically solved.

4. Problem: Partial glue at the top of the product.

Improvement plan: We solve it through a series of improvement schemes, such as inner hole of steel sleeve, glue removal, water transport, exhaust, hot runner plate, bakelite board and so on. 

Improvement effect: The problem of partial glue of the product is improved to the range required by the customer.