Bloedsakke raak tydens bloedskenkings al hoe voller.

Here raak means become or get.

So Bloedsakke raak ... voller means Blood bags become/get fuller ...

In Afrikaans, raak is often used when something changes state:

• Ek raak moeg. = I get tired.
• Dit raak donker. = It is getting dark.

So in this sentence, the blood bags are not just full; they are becoming fuller.

Al hoe + comparative adjective is a very common Afrikaans pattern meaning more and more ...

So:

• al hoe voller = fuller and fuller / more and more full

Other examples:

• Dit raak al hoe kouer. = It is getting colder and colder.
• Sy word al hoe sterker. = She is becoming stronger and stronger.

This is one of the most useful patterns to learn, because English often uses more and more or -er and -er, while Afrikaans often uses al hoe + comparative.

Because the phrase al hoe normally goes with a comparative form.

• vol = full
• voller = fuller

So:

• vol would just describe a state
• voller shows an increase

Since the meaning is more and more full, the comparative voller is required.

Tydens means during.

It is a preposition, so it introduces a time phrase:

• tydens bloedskenkings = during blood donations

More examples:

• tydens die winter = during the winter
• tydens die vergadering = during the meeting

So in the sentence, tydens bloedskenkings tells you when the blood bags become fuller.

The plural bloedskenkings suggests blood donations in general or during blood donation events/occasions.

So tydens bloedskenkings means something like:

• during blood donations
• in the course of blood donation sessions

Using the plural can sound general and natural in Afrikaans when talking about a repeated activity or a type of event.

Also, bloedskenking is a compound noun:

• bloed = blood
• skenking = donation
• bloedskenking = blood donation
• bloedskenkings = blood donations

They are both compound nouns, which are very common in Afrikaans.

bloedsakke

• bloed = blood
• sak = bag
• plural of sak is sakke
• so bloedsakke = blood bags

bloedskenkings

• bloed = blood
• skenking = donation
• plural of skenking is skenkings
• so bloedskenkings = blood donations

Afrikaans often writes these as one word, unlike English, which may use two words.

Because the sentence is talking about blood bags in general, not a specific set already identified in the conversation.

So:

• Bloedsakke = Blood bags in a general sense
• Die bloedsakke = The blood bags, meaning specific ones

Afrikaans, like English, often leaves out the article when speaking about plural things in general:

• Honde blaf. = Dogs bark.
• Bloedsakke raak voller. = Blood bags become fuller.

This is normal Afrikaans main-clause word order.

A simple way to see it is:

• Bloedsakke = subject
• raak = finite verb
• tydens bloedskenkings = time phrase
• al hoe voller = complement describing the change

So the structure is roughly:

Subject + verb + time phrase + descriptive complement

Also, Afrikaans is a verb-second language in main clauses, which means the finite verb often comes early in the sentence, typically in second position:

• Bloedsakke raak ...
• Tydens bloedskenkings raak bloedsakke ...

Both of those patterns are possible, but the original sentence starts with the subject.

Sometimes yes, but raak is especially natural when something changes into a new state.

• raak voller = get/become fuller
• word voller can sometimes be understood, but raak often sounds more idiomatic for this kind of gradual change

So in this sentence, raak is a very good choice because it emphasizes the process of becoming fuller over time.

Usually the most natural English equivalent is:

• fuller and fuller
• or more and more full

Both match the Afrikaans well.

So the whole sentence can be understood as something like:

• Blood bags get fuller and fuller during blood donations.

That captures both the meaning of raak and the pattern al hoe voller.