Screw The difference between gradient and mutant

The gradual screw has a gentle temperature rise and a long compression section during plasticization, which is suitable for plastics with poor thermal stability and a wide melting temperature range, such as PVC. The abrupt compression section is shorter and the energy transfer is more violent, which is more suitable for crystalline plastics. Crystalline plastics have a narrow range of melting temperatures.

Screw The difference between gradient and mutation, how did it appear in the love column.

It's injection molded or extruded, but it's about the same, one is suitable for crystalline plastics, and the other is amorphous plastics.

Of course there is a difference.

Gradients change slowly, and mutations change in an instant.

Personal conjecture.

This is just the difference in screw diameter and injection volume, and it has nothing to do with conventional and new, crystalline and amorphous screws, etc., and what kind of screw is needed to communicate with the manufacturer.

The commonly used single screw can be divided into gradual type and mutant type. Zhejiang Jinneng Machinery specializes in the production of screw barrels for plastic machines.

The selection of screw type is mainly determined according to the physical properties of the plastic and the production technical specifications of the extruder.

1) The softening of amorphous polymers is completed in a relatively wide temperature, and equidistant gradient screws are generally used. The temperature range of crystalline polymer melting is relatively narrow, and equidistant mutant screws are generally used.

2) On the small extruder, such as the 45 extruder screw adopts the full thread type of equal distance and unequal depth, the length and diameter of the screw are relatively small, and it is mainly used to extrude the insulation layer and sheath layer of small cross-section, and the extrusion speed is faster.

3) The medium-sized screw adopts the full thread type with equal distance and thread depth gradient, its length-diameter ratio is larger than that of the small screw, and the pitch of the thread is equal, from shallow to deep from the root. The thread at the end of the thread is deeper, and the thread at the root is shallow, so that the plastic extrusion amount is more, and it does not affect the strength of the screw, the extrusion speed is fast, the plastic plasticization is good, and it is the ideal screw for the production of insulation layer and sheath layer by general small and medium-sized extruders.

4) The diameter of large screw is generally more than 150mm, such as 150, 200, and medium-base 250 extruders. There are two types of large screws, one is equal distance and unequal depth, such as 150 and 200 extruders; The second is that the screw is divided into three sections, that is, equal distance and equal depth, equal distance and depth, such as 250 extruder, the compression ratio is between 2 3 and the length and diameter ratio is about 15:1, which is mainly used for the production of large cross-section wire and cable insulation layer and sheath layer.

Huahong screw suggestion.

(1) The ratio of the length l value of the thread used in the injection molding machine to the D value of the screw diameter and the compression ratio of the thread are slightly smaller than the screw used in the extruder.

2) The depth of the thread groove in the metering section of the injection molding machine is slightly larger than that of the screw used in the extruder.

3) The feeding section of the injection molding machine is slightly longer than the feeding section of the extruder screw. The length of the plasticizing section is shorter than that of the extruder screw.

4) Most of the head structures for injection molding machines are pointed conical, and they are also equipped with check valves.

The graded screw of the injection molding machine is mostly used for injection molding of amorphous plastics such as polyvinyl chloride. Mutant screws in injection molding machines are mostly used for injection molding of crystalline plastics such as polyolefins and polyamides.

This is a very general question. There are many ways to divide it. By quantity:

Single screw, twin screw, multi-screw (planetary screw), etc. Twin screws are divided into conical and parallel according to the form, and are divided into the same direction and different direction according to the direction of rotation.

But the screw according to the use: plastic, rubber, injection molding, chemical fiber, etc. According to the structure is ever-changing, various combinations:

Split type, gradient type, pin type, exhaust type, mutant type, equidistant unequal depth, variable pitch and so on.

First, the reference is different.

1. Mutation: It is a change in the gene structure caused by the addition, deletion or change of base pairs in the DNA molecule.

2. Wild-type: refers to the allele that accounts for the majority in nature, and is often used as a standard control gene in biological experiments.

Second, the characteristics are different.

1. Mutation: The occurrence of gene mutation is random in time, in the individual who occurs in this mutation, and in the gene in which the mutation occurs. The myriad mutations found in higher plants illustrate the randomness of genetic mutations.

In bacteria, the situation is far more complicated. Mutations are extremely rare, and wild-type genes are mutated at very low mutation rates.

2. Wild type: It is an important path under signal transduction, that is, it is necessary to transmit the tumor signal downwards through this pathway, and the tumor cells can multiply, differentiate and survive after transmission.

Third, the role is different.

1. Mutation: By inducing a large number of and diverse genetic mutations in organisms, excellent varieties can be selected and bred according to needs, which is a useful aspect of genetic mutations. Prior to the discovery of chemical mutagens, radiation was the main use of radiation as a mutagen in plant breeding.

2. Wild-type: effective people can be screened through special genetic analysis in patients, so as to be able to carry out individualization more effectively.

The reference is different, the characteristics are different, and the role is also different, if you want to know more specific, I will be added in the reply later.

, wild-type: In the current study, individuals obtained from nature, that is, non-artificially mutagenic, are regarded as wild-type.

2. Mutant type: relative to wild type. That is, individuals, cells, or virions whose traits of an organism appear to be artificially mutated.

The forms of the screw of the injection molding machine are as follows:

General, mutated, gradual.

There are six material classifications for injection molding machine screws, which are as follows:

1. The HPT fully hardened powder alloy screw is made of tungsten cobalt powder alloy tool steel, which is hardened and formed by special process, and the internal and external hardness of the screw is the same, reaching about HRC65°. It is suitable for processing all kinds of transparent products, precision products and special high-temperature and high-corrosive plastics such as added fibers, magnetic powders, bakelites, etc.

2. The double alloy screw is made of SACM Crmoala as the base material, and then the top of the tooth or the screw groove ion spray welding tungsten carbide nickel-based alloy, the film density is 98, the density strength: more than 10000psi, the thickness of the alloy layer, and the surface hardness of the screw is about HRC60°.

3. The electroplating screw is based on SACM Crmoala, and the outer surface is plated with a layer of hard chrome, nickel, titanium and other elements after molding. The thickness of the coating is about HRC60°.

4. The stainless steel screw is made of 9Cr18MOV special stainless tool steel, which is treated with integral quenching + integral hardening, and the overall hardness is about HRC55°.

5. The ordinary nitriding screw is formed by special process with SACM Crmoala as the base material, and the nitriding layer depth and overall hardness HV980 1080° are suitable for processing ordinary plastics.

6. The screw is formed by special process, and the product has good toughness and strong torsion resistance.